From 3.5 billion Reddit comments

273 points

·
8th May 2019

https://www.omnicalculator.com/finance/compound_interest

$100 at a standard 2% savings account yield compounded over 18 years is ... wait for it......

​

$142.82

265 points

·
14th Nov 2021

I think most responders are missing the point of the question.

To quote:

> if the Earth were flat and it was a dark night, a candle's flame could be seen from 30 miles away

OP is asking how high the flame would have to be to see the candle on the surface of the Earth, given that it's ** not flat**.

OP's correct answer is:

At 30 mi, assuming you are both at sea level, and you stand 2m tall, the candle will need to be at least 481 feet high for you to see it.

I'm basing this on the calculator at:

253 points

·
2nd May 2019

>What would happen to your body?

Assuming you could metabolize it... You'd gain 2.86*10^(20) lbs of fat (2.041*10^(19) stones). This would be the weight of around 1/500^(th) the Moon, or about 1/5^(th) the weight of Saturn's moon Tethys.

But... that's a lot of energy in a small space.

So... you'd probably have a tiny hole poked through you. Or you'd die in a massive gamma-ray incident that would wipe out the planet.

I couldn't get weight on a single Reese's, but Skittles and M&Ms are around 1g, so we'll go with that. We're talking 4.184*10^(27) Joules per gram. **That's around the energy put out by the sun over 8-12 seconds**, or around *4 trillion* megaton nuclear devices. All in a tiny forbidden morsel.

The thing you're consuming has to be moving quite fast. Like.. really *really* fast. It's more energy dense than a neutron star. It's more energy dense than *antimatter* (which clocks in at 1.8*10^(14) Joules per gram, leaving... 4.183999999999**82***10^(27) joules; not much of a dent).

So, I figured we could speed things up with newtonian physics. But even going 0.9999999999999c, a gram of mass is going to hit with around 9*10^(13) Joules (then, if it were antimatter, explode with that 1.8*10^(14)). Still a tiny dent.

Ah! But as we approach the speed of light, we gain mass due to relativism, increasing our kinetic energy!

At this point, I broke Wolfram Alpha. It wouldn't calculate with enough digits of c.

So I found this calculator... and sure enough, your Reese's would need to be traveling at around 0.999999999999999999999999999999c to have that much kinetic energy stored up.

**Conclusion**: Do not eat that Reese's Piece, for the sake of all life on Earth.

180 points

·
22nd Nov 2021

NTA Send her a couple bucks, tell her you're square and realize you don't need someone this petty in your life.

I ran the calculator on THIS PAGE with the fairly heavy factors of 30 minute shower, $5 per 1000cu ft, $0.13 kw/h for electrical, and a medium flow rate of 2.1 gpm. Comes out to an estimated cost of $1.21 per shower.

Even if we go with the most expensive showers I've used, truck stops, we're talking a maximum of $20 for a half hour booking.

Using the same water cost and assuming 1.5 gallons per flush, one flush of the toilet costs $0.0075. Flush the toilet 133 times for a buck....

For comparison, my family's monthly water bill, for 2 adults averaging a shower a day each, 2 kids averaging a shower every other day, 4-6 loads of laundry a week, cooking etc, maxes out around $60-75 a month.

170 points

·
10th Jun 2019

Assuming the sister has no problems instantaneously accelerating to that velocity, the velocity required would need to slow her aging by a factor of 2 (causing her to age 32 years while the older brother ages 64 years). According to this calculator, that would be 0.866025 c or 161325.3 miles per second.

103 points

·
17th Jul 2021

This is how I lost 15kgs in3,5 months without micro-managing, or calorie counting or doing anything specific. Just lived, ate, enjoyed life and got connected back with people from all periods of my time again. I hope it helps.

- Removed and stopped buying munchies, snacks and any calorie containing drinks.

- Implemented 2x 30 mins walks and maybe another 1 hour after work.

Llistened to the podcasts, books, video's or called family/friends during these walks. It was not lost time at all.

- Stopped taking warm showers, and wearing a jacket outside. No matter what weather. Some days I could endure 30 mins of -2C, some days couldn't endure an hour of 15C. It didn't matter. Now I enjoy the cold. Everything is too hot.

- Did some fasting in between like not eating a full day and stuff on the days I didn't feel like eating.

- Took breaks from screens after moments of conflict, hate, anger, sadness, happiness during work hours to process.

- Every time I felt hungry, I took a cup of water first and waited 15 mins to see if I was thirsty or really hungry. I ate if I still felt hungry.

Regimen above and adherence to it gave me a caloric deficit of 7000-9000 kcals per week, depending on the fasting days. Gave me a lot of pleasure and I felt better.

- Slept as much as I can and the more I could sleep, the less tired I got and everything got better. It was the real medicine for me. All above were just the means to an end.

P.S.: Just find a caloric [TDEE calculator](https://www.omnicalculator.com/health/tdee) and use Miffin-St. Jeor to calculate your average, if you wanna build a deficit target.

78 points

·
17th Jul 2018

TL;DR: my estimation is 402 feet based on a calculator I found online, but I'm far from certain.

I'm no math genius, so hopefully someone can respond to this and either validate this or explain further, but I used this calculator to plug in the numbers I could find. Acceleration is constant at 9.8 m/s^2 . The velocity seems to be 0 at the time of the fall, though she could've thrown it down slightly making velocity somewhat higher (this would increase the height in the calculation AFAIK). Time of the fall was a bit tricky, it seems to be from 5 seconds to 10 seconds, but some of this time could've been the phone bouncing around after it hit the ground once (it's hard to tell exactly when it hits because the screen is constantly whirring). I put 5 seconds in for time of the fall and ended up with a height of 122.6 meters, or 402 feet. But as I said, this is not my area of expertise. I just used a calculator that (I think) should get the job done.

EDIT: formatting and typos

74 points

·
17th Nov 2020

ill find out if it will.

I am using a projectile motion calculator https://www.omnicalculator.com/physics/trajectory-projectile-motion

Looks like 25 degree angle the bridge that is up.

From The top of the vertical bridge to the road looks about 20feet.

At 50 mph it can travel 162 feet before it drops 20 feet in height to the road.

B. , is there a second draw thing that is up but not in the photo. If so, it can not drop any feet at all, if the draws are at the same height. That would mean it could travel around 125 feet.

**So as long as the gap is either less than 162 in case A or 125 feet in case B. The car will make it.**

54 points

·
1st Jul 2021

I second this. Based on height and current weight, he is considered “overweight” but isn’t that far off from normal. At this point his body may not want him to lose weight very easily. 1500-1800 cals may be too low and is causing him to burn less calories over time. Metabolism does slow as we age but 23 is kinda young for a man to have a lower than average metabolism due to age.

I think he would benefit from at least 150 minutes of steady state cardio a week and weight training (full body, not just the arms) More muscle would mean a higher resting metabolic rate. He may also want to up the calories a bit and try consuming more of those calories from protein as they have higher thermic effect of food (your body will increase the metabolic output when processing more calories from protein). I suggest having a caloric deficit of no more than 500. Slow, steady, and consistency wins the race here.

Here’s a link for determining calories needed based on daily activity, age, current weight, etc. No calculator is perfect and he will probably need to make adjustments but it could be a useful starting point: https://www.omnicalculator.com/health/bmr-harris-benedict-equation

If nothing is working after cutting a lot of calories and upping the cardio, perhaps he should see a doctor to rule out any unusual metabolic issues preventing him from losing weight.

Congrats on losing 8 lbs and him losing 2! Best of luck to you and your boyfriend 👍

53 points

·
4th Aug 2018

Tried to measure the angle of his throw. https://i.imgur.com/TWoheVd.png or maybe this is better https://i.imgur.com/pK5AOWb.png , tried to match it to his belt line

Based on the camera angle, looks to be a 35 degrees throw +- 5.

Timed the throw to take 2.5 seconds.

Knowing these 2 factors, plug in calculator and get that Luck threw in 48 yards in the air.

46 points

·
19th Nov 2021

Not enough information to calculate. Where in the asteroid or comets orbit this impact occurs at and the direction and orbit of both the asteroid and the earth make a huge difference. Is the asteroid going to hit the earth dead center? glancing blow? that makes a big difference too. here is a simple momentum calculator you can use to play around with this. Set the impactor to 7500 m/s and the asteroid to 0 m/s (relative velocity) and your 100 ton impactor can slow down a 750,000 ton asteroid by 1 m/s. for comparison, a 1km dia asteroid weighs around 1.4 billion tons.

46 points

·
30th Sep 2021

Greatest G force handled is 46.2 Gs at a test site, you can definitely survive crazy forces = somewhere around 7700lbs on the human body. Crashing though, at 65mp and 150lbs human would be equivalent to 1076.2 Gs = 161,381lbs on the body.

With a seat belt, that all massively changes to less than 1/5th of what I stated...

46 points

·
29th Jul 2020

That's a wet bulb temperature of 35C, not an ambient temperature. Wet bulb accounts for both temperature and humidity, and it effectively measures the coolest you can reach using only evaporative cooling (so the coolest temperature you could maintain through sweating alone). With an abundant supply of ice water, you might be able to manage a bit warmer, since you'd also be cooling off through the pre-cooled water. At 47C ambient, your wet bulb temp was still below 35C unless you also had above 40% humidity, and nowhere currently on earth experiences that combination of humidity and temperature. You can play around a bit with the calculator here if you want to better understand the relationship.

Above a 35C wet bulb temperature, it's physically impossible to cool something below 35C through evaporation, regardless of how much water you have. This means that regardless of quantity of sweat produced, your body could not keep your skin cooler than 35c, resulting in overheating and likely death.

45 points

·
10th Jun 2021

It's worse than that. This misinformation comes up fairly often. (Pun unintended, but keeping it.) Ignoring air resistance, here is how far 45 km/h ejaculate will travel.

If you we standing up and aiming horizontally (assuming PP at 1 meter height), it would travel 18 feet horizontally.

If you aimed 45 degrees up, it would travel 55 feet horizontally.

If you were on you back, aiming straight up, it would travel 26 feet vertically.

45 points

·
5th Apr 2019

According to this link, 53 average sized balloons would lift an empty Glock 19, and 31 could lift an empty Ruger lcr. This is a far lower quantity of balloons than I had expected.

42 points

·
22nd May 2021

It's worth checking your waist/height ratio as that's a better indicator of risk for obesity related disease

https://www.omnicalculator.com/health/waist-height-ratio

Anything under 0.5 is good - I'm UK 10/12, but my ratio is 0.47, so literally just barely squeaked under the danger level

I tend to focus on my waist measurement more than anything as I'm in my 40's & diabetes is rife in my family, so I have to keep an eye on visceral fat

The healthy zone for women is a waist under 32 inches & I'm currently 32.25, so again - uncomfortably near the danger level

Dress sizes are meaningless these days due to vanity sizing - found a gorgeous Italian dress in storage I bought about 10yrs ago which is L/XL and it fits perfectly on my UK 10/12 body. But it's L/XL. The Italians are harsh 🤣 Explains why the Mediterranean diet is up there with Japan in the healthy league table tho if UK 10/12 is a big girl size.

40 points

·
16th Jul 2021

Did the calculation on omni calculator just to double check. The size of 1200 pb comes **only** from the data that Google, Amazon, Microsoft and Facebook collectively stored 2 years ago. How is the entire internet only 47.85 pb in size (according to your calculations)?

39 points

·
21st Jul 2017

According to this it would get you a little less than 150 miles but that's not including the cost of leveling land which in my opinion would be the majority of the cost. I doubt 1.6 billion would be enough for even 50 miles in real life, and that's assuming we aren't talking about the part of the border that's on a mountain range.

Not too mention a wall does fuck all.

35 points

·
21st Apr 2021

So I'm curious and I used this free fall calculator to do the hard math for me.

Using the stopwatch on my phone I'm getting 2.5-2.8 seconds of free fall. That gives a range of 100-126'. Two seconds = 64 feet. And 1.5 seconds = 36 feet.

I don't know whether your forward momentum matters. Or maybe wind resistance. And I'm just eyeballing it on my phone but it *seems* like 40' might be a super lowball estimate. Like I don't know how tall that spruce tree on the ground is but you're waaaaaaaaaay above that. Even if it's just a 10' tree you're looking higher than 3-4x that.

TL;DR: don't shortchange yourself, you probably jumped off a 100'+ cliff and until a physics nerd corrects me let's go with that.

34 points

·
14th Nov 2021

Doing the math because I'm bored: According to this calculator an hour of 1080P 60FPS video encoded in H.264 (pretty much the standard compression method) is 93.2GB. That's around 640 hours or 26.5 days. Uncompressed 1080p video is 1343GB per hour so it would "only" end up at 44 hours... Which is still a lot, but far from 6.6 years

31 points

·
29th Mar 2019

Per this site, 0.02 mg would be the equivalent of 1797510 megajoules. And according to this site, that is the equivalent of 429.62 lbs of TNT. Not anything near a nuke, but still a fuckton of energy.

28 points

·
16th Oct 2020

I loaded the video into Avidemux and did the math.

Launch initiated at around 3.90 seconds, launch complete at around 4.07 seconds. 170 ms for the launch. Impact at 6.57, airtime 2.5 seconds, horizontal distance roughly 1.8x the height.

With a launch end height of 2 meters, he reached a height of 8.7 meters, and had to have had an initial speed around 13 meters per second (using a 61.3 degree launch angle derived from horizontal distance = 1.8x max height). Given that he achieved the speed in 0.17 seconds, the average acceleration during that time was 76.5 m/s2 or 7.8 g.

Reasonably good confidence on the altitude and launch speed (probably got that within 15%), the acceleration is going to be inaccurate due to the short time frame being hard to measure (but given that it probably wasn't linear in practice, peak acceleration was likely higher).

The guy experienced an acceleration comparable to a fighter pilot (albeit for a shorter time), with very sudden onset. He also suddenly found himself flying through the air at around 47 km/h, while simultaneously being weightless (free fall).

Sounds fun, and definitely must feel like low orbit. Space shuttle launches are limited to 3 g (but sustained, so not really comparable).

Tools used: youtube-dl to get the video, Avidemux to seek through it frame by frame, https://www.omnicalculator.com/physics/projectile-motion for the flight.

28 points

·
31st Mar 2019

According to this online calculator the Shwarzchild Radius (the radius of the spherical volume a given mass must be compressed into for it to become a black hole) of 1,234,016,267kg is 2 attometers. That's 0.000000000000002 millimeters, or 2 quintillionths of a meter, or one 500th of the radius of a proton.

Yeah; making a black hole is not easy.

27 points

·
26th Nov 2021

Here. It’s a digital coin flipper. Not sure if he used this particular website, but the OP did state that they took the predictions from NFL.com/ESPN etc prior to the season and dumped them on a online coin flipper.

27 points

·
20th Nov 2020

This time dilation calculator says it would be about the same, 40,000 years.

To get the time dilation effect you need to be traveling at the speed of light or close to it. Voyager is going at 17 km per second, so not even close to the speed of light, which is about 300,000 km per second.

26 points

·
30th Nov 2021

I think a good explanation is to use the length/time contraction formula and and energy consumption.

So when we observe objects(with mass and dimensions) travelling close to the speed of light the length of objects start to get compressed or get shorter or closer and closer to zero, their clocks start to tick slower and the amount of energy needed to get closer and closer to the speed of light gets more and more tending to infinity.

Since we are made of matter we would need an infinite amount of energy when at C.

There are a few online calculators that you can play with that show this like https://www.omnicalculator.com/physics/length-contraction

24 points

·
31st May 2021

21 in Scotland and I've already been asked to put my name on the register for an appointment. Just waiting for the text now.

24 points

·
12th May 2021

This is cool, but the "Hot Streak" feature felt broken. So naturally I did the math.

Default average PC to-hit chance is ~65% that they hit. That means they'd need to roll 7 on the die to hit most monsters, which is really convenient for this gimmick.

By default, Critical Hits are 5% likely to hit.

Statistically, there's a 11% chance they roll 7 or better 6 times in a row if you make the auto-crit trigger on 7+ only. However, since you're adding +1 to hit every time, the trend will statistically be nearly 90% likely to trigger the auto-crit every 3 turns.

If you get rid of the +1 attack/damage rolls, and increase the streak to require 8, it's about 5-6% chance of making it. I know this ruins the whole 7's thing, but greatsword crits aren't screwing around. If you do go for the 7 charges, I'd put this on a longsword or Greataxe instead to mitigate some of the damage.

23 points

·
27th Nov 2021

One board foot is a piece of wood 12 inches long, 12 inches wide and 1 inch thick. It’s a measure of volume, so you can shape it anyway you want, 6 inches wide, 24 inches long, 1 inch thick is still one board foot.

23 points

·
17th Apr 2020

If the dog is 10 lbs, you'd need 371 11" balloons to lift it. Plus, you can tell by the irregular/halting/unsmooth speed of lift. https://www.omnicalculator.com/everyday-life/helium-balloons

23 points

·
28th Jun 2018

The tackle was mostly vertical, so the vast majority of the force of impact would have been the result of gravity, of which Io apparently only has 0.183G, slightly more than our moon at 0.16G.

Bobby falls for 4.6 seconds in that clip, on Io falling for 4.6 seconds would cover a distance of 19 meters. At the moment you hit the surface you would be traveling at 8.26m/s (using https://www.omnicalculator.com/physics/free-fall).

Being hit with a car at 20mph (8.94 m/s) yields a 90% survival rate for someone not wearing any sort of protection. Bobby's 8.26m/s translates to 18.47mph.

Bobby given the data we are shown would almost always survive that fall.

Basically the fall in the show is stylized to look more exciting and dangerous than it really would have been, the footage makes it look like far more than a 19 metre drop is taking place and that she is hitting at way more than 18.47mph.

I make no claims about Diogo surviving or not, but the clip from the show is not really proof that the armour can allow people to suffer huge fall damage, when a regular person without armour would stand a good chance of surviving the same fall conditions.

22 points

·
30th Apr 2021

Using atomic weight here wouldn't make a ton of sense, since the atomic weight would be pretty much the weight of the protons and neutrons added together...in other words very, very small.

But apparently the typical size of a testicle is around 4cm x 3cm x 2cm, which means it has a total volume of 12.566 cm^3. The density of steel is 8.05 g/cm^3, so his nutsack would weigh approximately 202.31g (0.44 lbs) with a solid steel set of nuts.

21 points

·
8th Aug 2021

This doesn't seem far off.

https://www.omnicalculator.com/sports/stairs-calorie says 1 minute of "slow" stair-climbing leads to 1 calories burned per every 31.5lbs of bodyweight.

Other sources offer non-weight-adjusted estimates of 0.75 calories per step, or 0.6 calories per step.

20 points

·
18th Nov 2021

I didn't clarify, but that article actually IS talking about slowing down at the other end too :)

>If you wanted to travel at a constant 1G acceleration and then deceleration to the very edge of the observable Universe. That’s a distance of 13.8 billion light-years away; you would only experience a total of 45 years.

You can mess around with these kinds of calculation here: https://www.omnicalculator.com/physics/space-travel (choosing the option Aim: Arrive at destination and stop)

20 points

·
19th Aug 2021

1.82m Starship ring-height, roll diameter looks about 3/4 of that = 1.365m, with hole about half of that = 2.0 m^3 = about 16.000 kg = $20,800,- ($1300/ton for 304 rolls on alibaba)

19 points

·
22nd Nov 2021

> From the Chief Medical Officers of Health, the likelihood that you have a medical exemption from a vaccination is one to five in 100,000. The Conservative Caucus is 119 people

Taking the 5 in 100,000 (0.005%) chance, there's a 0.6% chance that one conservative MP would have one, or a 0.002% chance that 2 do, 0.000003% that there's 3 of them (thanks binomial calculator)

I'd doubt them if there's even 1, if there's 2 they're almost certainly lying, 3 is just ridiculous. Unless maybe there's significantly increased risk for old people

19 points

·
6th Sep 2021

Fat tissue is not really doing much and doesn't need a lot of oxygen to hang around. It is just energy storage.

I think if you have a buff person and a fat person of the same weight the buff person would have more blood volume.

19 points

·
12th Aug 2021

The issue isn't that it couldn't happen to someone Summer's age, it's the time required for death to occur.

From the last time she was seen by someone other than the family, H, to when the 911 call was placed was about 3-4 hours. Also, the video of her sleeping was taken after the time H claimed he was dropped off. So let's assume they got home and left her in the car around 3:30pm.

The way kids die in hot vehicles is the interior temperature increases to dangerous levels which in turn increases body temperature. The lower the outside temperature the longer it takes. The high that day was 80F. Here is a calculator to estimate how long it takes for the heat to reach dangerous levels. Assuming the worst, 0% cloud cover, windows up, and dark car, it's estimated to take 65 min for body temp to reach 104F and the life-threatening level, and 105 min to reach the medical emergency level. This is based off a 2 year old child. After 25 min she would be sweating profusely and very uncomfortable. Again this is based off of worse case scenario. The property is surrounded by trees so the truck could have been parked in the shade, which would increase the time it took for the temperature to become dangerous. Also if the windows were open or cracked.

Back to assuming the worst. She would most likely need at least an hour to hour and half unattended in the car for her to expire, possibly longer. Even it's just an hour, that gives Candus 2 hours to dispose of a body outside the search area, that has still not been found almost 2 months later, get back and call authorities. That's assuming she doesn't freak out and panic first. She doesn't come across as the type to be able to think on her feet in a situation like that.

19 points

·
12th Jul 2021

The distance traveled per second goes up enormously fast: a 172 foot fall only takes 3.27 seconds and you’re going over 100 ft per second on impact

19 points

·
25th Jun 2018

I used the Navy method body fat calculator. It is supposedly accurate to within ±2%, and from my own comparison to a DEXA scan, I would say that sounds about right.

EDIT the one above only uses inches and feet. This one also allows metric

18 points

·
4th May 2021

>Das wird jetzt schon schnell gehen, dann sind auch wir dran. Mit etwas Glück schon vor Juni, im schlechtesten Fall Ende Juni. Durchhalten Brudi!

Was bist denn du für ein Optimist? Also bei mir spuckt der Rechner Anfang Juni - Ende August raus. Mit AZ (12 Wochen zw. Impfungen) kommt dann der zweite Pieks möglicherweise erst im November.

> Aber ja ist kacke. Und ich glaube auch, dass hier einige unterschätzen, wie sehr das auf Jahre das Vertrauen in's Grundgesetz und den Staat bei einer ganzen Generation erschüttern wird.

Ich hoffe mal lieber, dass das glorreich verspielte Vertrauen mal Auswirkungen auf die dafür verantwortlichen hat bei der nächsten Wahl...

18 points

·
12th Jan 2021

17 points

·
19th Nov 2021

This is just... not true? Just because there is compounding doesn't mean the daily values are negligibly different. Play with this apy calculator, set the compounding + Term to 1 day, and see what different APY will get you after one day. https://www.omnicalculator.com/finance/apy

40% APY is about 0.092% per day, and 80% APY is about 0.161% per day. 80% APY might not give twice as much as 40% APY daily, but it's almost twice as much. You'd definitely be able to tell using OP's methodology.

17 points

·
7th Jan 2020

Using this calculator --> https://www.omnicalculator.com/other/earthquake

> A magnitude of 5.8 is ~5 times stronger than a magnitude of 5.1 (in amplitudes) > and ~11 times stronger (in terms of energy released).

17 points

·
10th Aug 2018

it does appear to look like a short rim. you could maybe guess the height if you count the bricks - https://www.omnicalculator.com/construction/brick

if they are normal size bricks, 44 bricks tall would be 10ft

16 points

·
20th Jan 2019

This calculator shows it only takes ~3e15 MJ to get a 1000 lb object going 99.99% C. That's about 3000 kg of matter (3e15 MJ / c^(2)), nowhere near a full planet.

15 points

·
3rd Nov 2021

That is my hope is that there was at least no suffering from either who passed in the end of it all- I haven't seen any sort of articles confirming if she survived impact or not either and hope that you're right and that she did not. Her car certainly looked in bad shape

Based on this calculator I found it is looking like she too should have hopefully passed away fast due to the impact force created if not directly on impact

15 points

·
24th Jan 2021

Chiming in for the womens here to confirm this may be especially true for us.

Last time i stopped (for 7years!) i was a binge drinker. Of course when i started again i moved on to daily because of the progression of this disease.

I didn’t think it through when i stopped cold turkey - and was very lucky but had a few rough days. More than expected. So yes, please check in with something like the alcoholic calculator and if it says severe then get thee to a dr.

15 points

·
8th May 2019

https://www.omnicalculator.com/finance/compound_interest

$100 at a standard 2% savings account yield compounded over 18 years is ... wait for it......

$142.82

14 points

·
4th Dec 2021

But a semi circle has way more curve than the Australia.

When you have two points on a circle, the distance along the circumference is called an arc and the straight line that cuts inside the circle is called a chord. Using 6371 km for the radius and 4000 km for the arc length in this calculator https://www.omnicalculator.com/math/arc-length the chord is 3935 km. I'm surprised it's such little difference tbh so reddit do your thing and correct me.

14 points

·
9th Nov 2021

That is indeed hard. But you can calculate Elo here. If Hikaru plays 9 games against 2500 Elo rated opponents then he can lose 1 and draw another one and still gain 6,8 Elo points.

Let's say he loses 3 and wins 6. Then he will drop 23,2 Elo points. Which is quite a lot, but still better than losing your rank. And this is basically a worst case scenario where he does pretty badly.

14 points

·
28th Sep 2021

>same diagonal give you the same area for different ratio.

This isn't true. The same size diagonal will give a bigger area the closer the ratio is to square.

Try it out here: https://www.omnicalculator.com/math/diagonal-of-rectangle

14 points

·
16th Aug 2021

> And IMHO 2027 sounds totally unrealistic.

I agree with you there.

>Also I may confuse something here, but in my estimations their proposed angular speed (1.25 revolutions per minute) given their size (200m overall diameter) does not turn into anything remotely close to the "moon-like artificial gravity" they are claiming.

A 200m diameter station spinning at 1.25 rpm would result in 0.17G. That's about lunar gravity. (calculator here).

I have no idea if this particular project will ever happen. My point was that structurally, all you need are livable pods designed to be suspended by cables, and the cables to connect them. Nothing structuraly challenging about that. The biggest obstacle is that it would require a lot of mass in orbit, and that's expensive.

14 points

·
21st Jun 2021

Hmm, I'm not sure about that one. Wouldn't any ship traveling to a distant star use the same amount of acceleration while approaching light speed and deacceleration while slowing down to stop? That typically being 1g, so everyone can walk around during the trip? And you don't need to be immortal, because as you approach light speed time slows down for you. A 90ly trip (where you accelerate to near light speed then slow back down) would only seem like ~9 years to those on board (while 92 years would have passed on Earth), at least based on this calculator. How could other ships pass you unless they decide to endure multiple g's the whole trip? Unless of course we're talking about drifting along in a multi-generational ship that's not constantly accelerating/deaccelerating.

14 points

·
30th Jul 2020

what theyre referring to is a wet bulb temperature which is 35+ celsius with 100% humidity. human body is unable to cool itself in such circumstances and thus spending time outside/without a/c means death. currently there arent many places on earth this inhospitable, but thanks to climate change we're slowly (or not) getting there in a lot of highly-populated areas like the persian gulf and south-east Asia (including the entirety of bangladesh).

​

heres a neat little calculator that shows you what constitutes a wet bulb temperature and also includes a description far better than mine

13 points

·
2nd Dec 2021

4.9 Gs

I’m no physicist and these calculation are extremely rough

Assume he is 135lbs, doing 60rpm, he is revolving around a circle about 4ft wide, I used this calculator https://www.omnicalculator.com/physics/centrifugal-force Says it’s about 667.5 lbf 667.5/136 = 4.9 Gs If his head weighs about 11lbs, there would be a force of 54 lbs pushing against his head alone.

These calculations may be incorrect.

13 points

·
1st Dec 2021

Bigger isn't better. Look at the room you have and seating distance. Once the screen fills about a 35-45 degree arc centered on you, you have your maximum screen size. You can go bigger and gain peripheral screen space for some added feel and imersion, but you lose the ability to focus on what's on the screen and will miss out on much of the movie. While your eye is drawn to the top left, you will miss the detail of whats going on in the center because your eye can only focus on a few degrees at best and your brain fills in the rest.

The only reason to go larger is to accomodate larger crowds. You must also consider that the larger your screen, the bigger the pixels on digital projectors and you lose image quality.

A 25' screen exceeds what I would want in any home theatre for 10 ppl or less. You would need to sit 30ft back or so, plus space behind you for speakers or a second row of guests. This calculator will help you work out the details.

13 points

·
4th Jul 2019

"Free fall" isn't some strange concept nobody can understand. It's 9.8 meters per second squared. Here's a free-fall calculator. It's not that hard.

The south tower was 1,362′ high.

The north tower was 1,368' high.

Building 7 was 741' high.

That and videos at the correct frame rate and record rate are all you need to do the work yourself to determine if the buildings were in freefall. No tricks.

12 points

·
8th Aug 2021

Nope! Velocities don't add the way you think they do. At low speeds (and really also at what we consider high speeds, like say 40 000 mph) they appear to add like w = u + v, but to get exact results you need to use special relativity. When the speeds start approaching something like 20% of the speed of light, the errors you get by simple additions are getting large.

Play around with this calculator a bit. I recommend having the units set to c, i.e. fractions of the speed of light.

For example: if you travel at 0.5 c and shine a flashlight, that light moves at 0.5 c + 1 c = 1 c.

If you travel at 0.8 c and fire a projectile forward at 0.5 c, it travels at 0.8 c + 0.5 c = 0.9286 c relative to you.

Very weird, very unintuitive, but very proven to be correct.

12 points

·
22nd May 2021

If something can accelerate at 700g's indefinitely without any form of traditional propulsion, in it's own local frame of reference the trip from Alpha Centauri would take 8 days.

You can calculate that (and similar journeys) here.

Food for thought.

12 points

·
14th Jan 2021

500k a day would be amazing. If you try and input 3,500,000 a week into the vaccine queue calculator that’s been doing the rounds (link), it warns you 500k a day is unlikely 😂

11 points

·
1st Dec 2021

- Calculate profit/loss for each bet (actual profit - expected profit)
- Calculate std. deviation of those values (use =STDEV(range) in excel)
- Calculate confidence interval

If your profit falls outside 95% confidence interval you can consider your strategy statistically significant.

This does assume most of your 168 bets are about the same size. If not you may need to normalize...perhaps by expressing profit as a percentage profit instead of absolute value.

11 points

·
27th Oct 2021

I scrolled farther than I should have.

I think it looks kind of like the Caprice they have in Jacksonville... 60-0 is 125ft.

So using https://www.omnicalculator.com/physics/stopping-distance and plugging in 60, with 0 reaction added, and 25% grade, we've got about an equal calculation for the speed.

He needed to reduce his speed by 21mph, so plug that in to find distance needed. It's telling me it's 15ft.

I'm counting 7 sidewalk tiles the car crosses before being equal with the sign. The ones in front of my house are about 4.5ft long between contraction joints. While I'm not a resident of the county, I AM a resident of the state, so I presume the standards will be similar.

That's 31ish feet to reduce speed. He needed 15, I think there's plenty of room for error to say the person recording is entirely sensationalizing this, just as some cops try to peg people with higher tickets themselves.

Don't stoop to their level.

11 points

·
21st Oct 2021

You would get up to to a significant fraction of light speed after a couple of years causing the trip to seem much shorter to the crew. A 100 light year trip at 1 g would only take 9.02 years for the ship's perspective.

https://www.omnicalculator.com/physics/space-travel

Of course the down side is such a fast trip is ** absurdly** energy intensive, requiring 11070 tons of mass to be perfectly converted into energy to move 1 ton of ship.

11 points

·
19th Oct 2021

The force of gravity on an object is directly proportional to the mass of that object. A butterfly has a very small mass, so it experiences a very small gravitational force. Therefore, it only needs to exert a small force in order to overcome gravity and fly around.

As for the Earth's rotation, we can calculate the centrifugal forces caused by it using this calculator, which shows that any object on Earth experiences 0.03 m/s^(2) of outward acceleration, easily overcome by the 9.8 m/s^(2) downward acceleration due to gravity. The centrifugal acceleration from the Earth's orbit around the Sun is balanced by its gravitational acceleration toward the Sun, which keeps the orbit stable.

11 points

·
16th Oct 2021

It's actually thought that black holes open and close around us all the time. It's just that their mass is so tiny that they immediately give off enough hawking radiation to evaporate.

Black holes are only dangerous if they've got enough mass to stay alive long enough to keep eating things nearby.

A coin sized black hole (let's say the coin is 0.5 inches in diameter, so it's shwarzchild radius is 0.25 inches) would have a mass of 9,426,011,967,771,582,728,736,422 lbs, roughly.

Which is why it would be able to delete earth as seen in OP.

The black holes the are thought to form spontaneously would be like ~40 orders of magnitude less massive than a coin sized black hole.

Edit: here's a neat calculator that lets you calculate the size or mass of a black hole, so you don't gotta actually do the math.

11 points

·
20th May 2021

Most of my office are over 40and have it. Hopefully my turn soon.

Try this out, it was fairly accurate for the people who I've asked that already have appointments

11 points

·
5th May 2021

A right triangle is a triangle with one angle equal to 90°. Two heights are easy to find, as the legs are perpendicular: if the shorter leg is a base, then the longer leg is the altitude (and the other way round). The third altitude of a triangle may be calculated from the formula:

hᶜ = area * 2 / c = a * b / c

10 points

·
21st Nov 2021

Google says the Saturn V was 220 decibels, and starship has about twice as much thrust, but let’s just take that 220 figure to be generous and roll with it.

Throwing 220 decibels and 100 miles into this online calculator gives us a sound of 68 decibels at 100 miles away. That’s louder than someone talking right next to you is (60 dB). So you would literally have to raise your voice, almost shout, to talk to someone right next to you if a starship was launching 100 miles away.

If a starship only launched every now and then then people would probably be okay with it, but if you have dozens of flights a day like Elon wants, people will not be okay with it.

10 points

·
12th Nov 2021

Using https://www.omnicalculator.com/physics/stopping-distance you need 450 metres plus your reaction distance which is at least another 50m. Nobody is looking that far behind them in their mirrors.

You need a minimum of 0.5km clear vision ahead of you at 300kph. Thats 0.5km of zero chance of a vehicle pulling out in front of you at 80km/h

That's a lot more than the just over 100m you need at 160km/h closing on 80km/h vehicles.

10 points

·
5th Oct 2021

I usually draw and cut a paper pattern out with the dimensions found in this calculator , then I just slice down the paper pattern to make another seam until you can fit all the pieces onto your fabric. I REALLY suggest making it out of paper first especially if you're working with limited fabric since it allows you to maneuver the pattern to get the most out of your fabric.

Pro-tip, if you have to add seams to make the pattern work with your fabric, try your best to keep one edge of each pattern piece on the straight grain. Seam one straight to one bias for stability and your skirt won't stretch out as much as if you did bias to bias.

10 points

·
16th Jun 2021

Compound Annual Growth Rate. I don't feel like working out the numbers, but you can do a quick search and see that it's not just Michael Saylor. He talks about it a lot, but there are other voices in bitcoin referencing the past performance of Bitcoin being 200% CAGR per year.

Here's the formula:

CAGR = (FV / PV)^1/t - 1

And here's an online calculator. Without checking the exact number 365 days ago, let's estimate that Bitcoin was about $10,000 on this date last year, and let's just call it $35,000, to account for recent fluctuations and be extra conservative with nice round numbers. CAGR = 250%, and that is underselling it because we are currently sitting above $40k

10 points

·
12th Jun 2021

According to this Schwarzschild radius calculator you would only need to be about 42 light seconds away from the 4.3 million solar mass singularity of Sag A*, which just about fits its exclusion zone in Elite (I don't exactly recall the exclusion zone, but I remember it was around 50 Ls)

10 points

·
21st Jan 2021

https://www.omnicalculator.com/health/impfterminrechner

Wie viele Impfungen pro Woche sind realistisch?

>Bei einer Impfrate von 2.000.000 pro Woche und einer Impf-Bereitschaft von 80%, können Sie erwarten, Ihre erste Impfdosis von 2.5.2021 bis 7.8.2021 zu erhalten.

10 points

·
16th Oct 2020

Everybody has a plan until they get launched ~~5~~ 8.7 meters into the air.

Actually, let's do the math. Launch initiated at around 3.90 seconds (Avidemux timestamps), launch complete at around 4.07 seconds. 170 ms for the launch. Impact at 6.57, airtime 2.5 seconds, horizontal distance roughly 1.8x the height.

With a launch end height of 2 meters, he reached a height of 8.7 meters, and had to have had an initial speed around 13 meters per second (using a 61.3 degree launch angle derived from horizontal distance = 1.8x max height). Given that he achieved the speed in 0.17 seconds, the average acceleration during that time was 76.5 m/s^2 or **7.8 g**.

The guy experienced an acceleration comparable to a fighter pilot (albeit for a shorter time), with very sudden onset. He also suddenly found himself flying through the air at around 47 km/h, while simultaneously being weightless (free fall).

I suspect that if this was your first time, you wouldn't have done a flip or posed. You'd be flailing wildly.

Edit to add - Tools used: youtube-dl to get the video, Avidemux to seek through it frame by frame, https://www.omnicalculator.com/physics/projectile-motion for the flight.

10 points

·
15th Apr 2020

They have real life physics modeled in the game (Not 1:1 but a close approximation in ratio).

So they use the normal calculations with flying objects as one would with the real world.

In game it goes something like this:

- User throws grenade
- Grenade object is created in front of the player model
- Grenade is given a specific velocity and direction of travel based on the users direction/angle etc
- Those values are put into a quadratic equation (this website explains how they do it: https://www.omnicalculator.com/physics/projectile-motion )
- Grenade travels on the predetermined path UNTIL IT HITS AN OBJECT
- subsequent bounces go through the same calculations with reduced velocity based on preset values
- Grenade either explodes or comes to a stop and does it's thing
- Grenade object removed from existence

10 points

·
13th Jun 2019

I'm no so sure that's right, so I'm going to try to do some math too.

Antimatter annihilates to mass-energy as you state. So to calculate it we use the E=MC^2 formula.

So 4,800 metric tons would annihilate to 431,402,485,793,672,467 MegaJoules according to this calculator.

To keep the comparisons simple I'm going to round that big number down to 431,000,000,000,000,000 Mj, or 4.31x10^23 joules.

For comparison, the total energy released by a 1 megaton nuclear weapon is 4.18 x 10^15 joules. So our swimming pool is 100,000,000 times more powerful. We could say it is a 100 *Teraton* nuclear weapon equivalent.

So how much energy is 4.31x10^23 joules? For that we will have to consult one of my favorite Wikipedia pages. Orders of magnitude in comparative energies as joules.

https://en.wikipedia.org/wiki/Orders_of_magnitude_(energy)

So lets scroll down to 10^23 ...

>Approximate energy released in the formation of the Chicxulub Crater in the Yucatán Peninsula[187]

Well there ya go. You were 100% right on the money.

So no quite world destroying, but enough to cause a massive extinction event and possibly the end of mankind and society as we know it.

Good math. That was fun.

One final note, and this is something I think of every time I hear about nations getting rid of their biggest nuclear weapons. Damage yield does not scale linearly with size of blast. In short, two 1,000Kt bombs will do more damage than one 2,000Kt bomb. So the more smaller bombs a nation has, the more damage they can inflict.

To put it simply, 100,000,000 megaton swimming pools are better than one 4.31x10^23 swimming pool if your goal was destroying the world.

10 points

·
2nd Nov 2018

According to this study, a falling human in perfect position will have a drag coefficient of about 0.2 - 0.3, so lets say 0.25. Average male is around 95kg. surface area of a human foot is 300cm2, so we kan use the formula k=1/2*C*A*rho. Rho is air density, C is the drag coefficient and A is the surface area. We find k=0.0031kg/m. Plugging that and the data above into this calculator for laziness gives us that the velocity of this guy is 34m/s at impact, which is If hits the water he will have to decelarate before he hits the bottom of the pool. Generously saying that this neighbourhood pool is 2.5m deep, he will have to decelerate his 34 m/s in about 0.15s. Which is 25G, about three times as much as fighter pilots will dare to risk.

This guy would not make it to the pool, and if he would, he would break most of the bones in his legs on impact with the water and the rest of them hitting the pool bottom.

9 points

·
2nd Dec 2021

11.15 seconds according to https://www.omnicalculator.com/physics/free-fall

Edit: actually, realised that was without wind resistance, found another calculator and for a 70kg person it would be about 15.2 seconds, so nice estimate

9 points

·
30th Oct 2021

According to this post by Cornell University, Earth's orbital speed varies from 67,779.17 mph to 65,542.233 mph, neither of which has a 666 in it.

The curvature approximation of 8 in/mi^(2) is only accurate out to about 100 miles. A formula without such a distance limit is given at this site, with an explanation of the derivation. Even if we did decide to use the 8 in/mi^(2) approximation, this is not 0.666 ft/mi. Instead, 8 inches is 2/3 of a foot, meaning that you must express it either as a fraction, as 0.666666666666... (with the 6's repeating infinitely), or, if you wish to express it as a finite decimal, the last digit rounds to 7, not 6. Eg: 0.667. Again, we have a complete lack of a 666.

Finally, although Earth's axial tilt is currently about 23.4 degrees, this varies from 22.1 to 24.5 degrees, over a several thousand year cycle. Again, no 666 here.

9 points

·
4th Sep 2021

Another game another draw! This game was defined by the big exchange starting at move 16, leaving the players in an endgame with both rooks and knight vs. bishop. Levy got into some pretty serious time trouble and was running extremely low (had around 3 minutes while his opponent had 25). IMO he did a good job getting out of it (with a line that would have forced the second set of rooks off the board) and making the draw.

Levy is now 1.5/3, and needs 5/6 remaining to make a GM norm. The norm looks unlikely, but he has gained 10 rating points just from these draws via this elo calculator. Good stuff from Levy!

9 points

·
23rd Aug 2021

https://www.omnicalculator.com/physics/relativistic-ke

You can play around with this calculator to get an idea of the insane energies involved with a moon-sized object impacting at relativistic speeds. For an example, I plugged in the mass of our moon - moving at 0.95c and got around 3.5e+23 **megatons.**

For reference, the Tsar Bomba (the biggest nuclear device ever detonated) was a puny 50 megatons. So almost 10 sextillion times more force (and for additional reference, the sun is **only** about 300k times more massive than the earth). And that's just **one** moon sized object, not two.

Additionally - the thing about stars is they're in a state of equilibrium, with the outward force of hydrogen fusion battling against the pull of gravity (it's actually a lot more complicated, but that's the simple version). So you don't necessarily need enough energy to tear the star apart, but **just** enough energy to tip the balance so that the outward force wins, then the star will disperse.

Relativistic impactors are easily the among the most deadly weapons in Sci-Fi - all the more scary because any civilization that has accessible light-speed travel (like the Bobiverse) means that anyone who controls a single ship, controls a doomsday weapon far more powerful than anything humanity has access to today

​

tl;dr - not only would it work, it was frankly overkill

9 points

·
21st Jan 2021

Get rid of the pills and the shakes.

Try to figure how many calories you need a day (its an estimation but its a place to get started) using something like this formula . Let say for the sake of the argument you daily calorie intake currently is at 3000 calories what you should do next is cut 300 calories from your diet (meaning you only eat 2700) and keep the cardio sessions that you’re doing at the moment.

Weigh yourself everyday and at the end of each week calculate the average of the past 7 days, from that point compare each week to the previous one at the beginning you will lose a lot of water weight weeks later you’ll see a slow in weight loss and a stop eventually then and only then either reduce calorie intake by another 300 calories or increase your cardio workouts (a combination of the two is better) and so on and so forth.

Set a realistic goal within a realistic timeline meaning do not expect to lose the 30 kg in two months (even though you can by severe calorie deficit you will bounce back to where you started and possibly more). So lose it slowly to keep it off when you reach your goal.

Eat anything you want within you daily calorie limit (preferably low calorie dense foods and not sweets, chips and whatnot to keep you full).

Cardio is what burns fat so find a cardio workout that you enjoy may it be walking or biking or whatever, weight lifting builds muscle but doesn’t burn as many calories as cardio does.

Consistency is key to losing weight.

9 points

·
16th Sep 2020

Thanks. Saved me from posting this, so I'll add a couple useful links.

> A sustained wet-bulb temperature exceeding 35 °C (95 °F) is likely to be fatal even to fit and healthy people, unclothed in the shade next to a fan

9 points

·
12th Mar 2020

Linking one disease doesn't prove anything you say.

>Really hope you don't think infections are seasonal because of temperature.

The air is more dense during the cold months allowing for the easier transfer of the respitory droplets from one person to the next. In addition the flu, and many other respitory diseases, can't survive on surfaces in the warmer weather.

https://www.omnicalculator.com/physics/air-density

https://time.com/5790880/coronavirus-warm-weather-summer/

http://sitn.hms.harvard.edu/flash/2014/the-reason-for-the-season-why-flu-strikes-in-winter/

Just because our moron of a president casually said it was nothing doesn't mean he has no basis for the thought. Covid 19 is new. No one knows how it will react, but many expert models predict it following a similar pattern to other respitory diseases.

8 points

·
3rd Dec 2021

Is your concern the carbon footprint/environmental impact, or do you just not like the idea of cutting down a living tree? If your concern is the environmental impact, a real, locally-sourced tree has a much lower carbon footprint than a fake tree (even if made with recycled materials). I can’t recall the exact numbers off the top of my head, but organizations like The Carbon Trust researched this and found that a plastic tree would have to be used for about 10 years to even out its carbon cost. Unfortunately, not many people do that.

For anyone who’s curious and wants to do the comparison themselves, there are handy calculators (like this one: https://www.omnicalculator.com/ecology/zero-waste-christmas-tree) that will let you compare real vs plastic trees. It’s fun to play around with the inputs and see how it changes things.

8 points

·
7th Sep 2021

The size of the rotating object does matter, as well as the tangential velocity. The centrifugal force formula is F = mv^(2)/r, where m is the mass of the object on the edge of the spinning object, v is the tangential velocity, and r is the radius of the spinning object. Thus, higher tangential velocity does increase centrifugal force, but larger radius decreases that force. If we plug these values into a centrifugal force calculator, we find that an object on Earth is accelerated outward by centrifugal force at a mere 0.034 m/s^(2).

8 points

·
8th Jul 2021

My guess is it will be this:

132.853 - (0.0769 × Weight) - (0.3877 × Age) + (6.315 × Gender) - (3.2649 × Time) - (0.1565 × Heart rate)

Google "Rockport fitness walking test formula." Here is a VO2 max calculator based on a 1-mile walk test: https://www.omnicalculator.com/sports/vo2-max

8 points

·
1st Jun 2021

Hello! This calculator will help:

https://www.omnicalculator.com/finance/apy

Keep in mind this is APY not APR. The difference being that APY factors in compounding. So 10 eth @ 4.5% APY should be .45 eth at the end of 1 year.

If you decide to get your interest paid in another coin, please keep in mind that block Fi takes 1% of your total interest as a fee + block Fi prices tend to have a higher spread with buy/ sell prices (I'm told around 1% higher for buys, and 1% lower for sell orders.)

8 points

·
17th Dec 2020

This would be why. You can fire twice with a heavy pistol, but you only have a 37.5% chance of getting through SP11 light armorjack. With four, you have a 76% chance.

The odds of rolling at least two 6's increases between three (7.4%) and four (13.1%) dice.

This is what I used to grab the probabilities: https://www.omnicalculator.com/statistics/dice

8 points

·
20th Sep 2020

Its actually worse than that cause they actually throw the sack instead of letting it go so the initial velocity is not zero.

As for comparing to a car crash, I found this calculator while writing this, so i havent used it yet.

8 points

·
11th Jun 2020

According to this calculator, shifting almost all of my beef consumption to chicken and fish saves over 2 tons of CO2 emissions every year. I thought it was going to be only 800 pounds.

Cut down on beef y'all.

8 points

·
10th Jun 2019

Same mass, sure, but the size of a black hole with the mass of the sun would be about 2 miles across. A black hole the *size* of the sun would destroy this solar system; it would have about 236,000 times the mass of the sun.

8 points

·
24th Nov 2018

The galaxy is apparently about 5e20 metres across, so 3.37e47 kg. So about 100 millionths of the total mass of the universe, or 100,000 times the mass of the Milky Way. That seems surprisingly small to me, but it's the answer returned by this site and confirmed by Wolfram Alpha.

8 points

·
27th May 2018

Did I screw it up? The Dell S2716DG monitor has a screen size of 23.5" wide by 13.22" high, with a diagonal measurement of 27".

23.5 * 13.22 = 310.67 square inches.

1920 * 1080 = 2073600 pixels on the screen.

2073600 / 310.67 = 6674 pixels per square inch (I had 6685 before due to rounding).

edit: I found out why it sounded wrong to you. PPI is measured by the number of pixels in a 1-pixel line that's an inch long. A typical 27" monitor has a PPI of 81.59. But square that to get the pixels per SQUARE inch of 6656.

7 points

·
5th Dec 2021

First calculate the bond price. Then divide annual coupon rate by the price.

Bond Price = ∑i=1n C/(1+r)n + F/(1+r)n Or use any online calc or Excel

https://www.omnicalculator.com/finance/bond-price

Price = 130.15

Current yield = 9.5/130.15 = 7.3%

7 points

·
4th Dec 2021

> But a semi circle has way more curve than the Australia.

Yeah, fair point.

> Using 6371 km for the radius and 4000 km for the arc length in this calculator https://www.omnicalculator.com/math/arc-length the chord is 3935 km. I'm surprised it's such little difference tbh so reddit do your thing and correct me.

u/Handzister concurs: see sibling comment.

7 points

·
9th Nov 2021

Idk how to deal with sadness well so you get a technical answer instead of a hear pour:

The brakes on that train are terrible. To prove it here’s some math. If we assume the train is about half a kilometer out when it starts to brake and the initial speed is 80kph or about 50mph then by using an online speed calculator I found (Credit where credit is due) we can say the train had 22 seconds between starting to break and running over the girl. Ok well that can’t be right the man was clearly on screen for more than 22 seconds so let’s assume a slightly better time of 35 seconds. That means with 80 kph the train would have had to been a little over 3/4 of a km away. Ok so let’s do a bit more math and say that the speed at which the girl go ran over was about 10 kph. Calculating the deceleration that comes out to ~0.8 M/S^2 which is just… god and that’s the aggressive estimate ok let’s do the conservative and say it takes 35 seconds. Thats comes out to 0.54 M/S^2

Go load up a shopping cart full of heavy crap at your store of choice and push it as hard as you can and I can say with relative certainty that the cart (without any additional force) would likely slow down faster than this train. Like fr, India fix your trains.

Edit: or better yet get a car and go to large empty road and go to 50 mph and then just release the gas (no brake) and it will probably slow down faster than this train. Assuming you don’t have a fancy super friction reducing car wheels

7 points

·
5th Nov 2021

Far more than that. It looks like they accelerated from 25 meters per second to 9.5 km per second in let's say about a tenth of a second. That means OP pulled 9,662 Gs, according to this calculator. I got bored, so I checked.

The CMDR in question is dead. The ship is also dead.

7 points

·
27th Oct 2021

UH-60 Blackhawk main rotor D spins at 258 rpm

- 4.3 per second
- let’s estimate their head is 0.75 metres from the Center. So one rotation means the head travels 2 * 0.75 * pi = 4.71 metres
- 4.3 * 4.71 metres = 20.25 m/s = ~73km/h

Using this:

https://www.omnicalculator.com/physics/centrifugal-force

And a 5 kg head:

2,734 newtons

1 G = 9.8 newtons per kg

2734/9.8/5 = 55.8Gs on their head

…which sounds high? I must be making an error somewhere