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Based on following what would be the weight of an average person at the equator if the equatorial velocity was slowed to 0.8 m/s?

Earth's radius at the equator: 6,371,000 m
Earth's velocity at the equator: 464 m/s
Average weight of a person: 84,000 g
formula: centripetal_force = mass * velocity^2 / radius

Please provide the answer in grams and show your work!

0.8/464 X 84,000 = ____

Did I do that right?

Full Disclosure: I was the first one finishing the test and got a perfect 800 on the math section of the SAT back in 1978, but have probably forgotten more than half of what I've learnt back in the day. I taught myself calculus because it wasn't offered in my high school.

I purchased a Timex Sinclair 1000 from Radio Shack (circa 1983), read the manual and learnt how to program a clock via Basic. Upon the first read-through, I quickly realized that I could program a clock to run backwards. Without referencing the program further, I implemented the program and it worked as I envisioned it. I then realized how boring this computer programming bullshit was, so I abandoned all future efforts. And you guys thought I was an idiot.  ::)

https://upload.wikimedia.org/wikipedia/commons/d/da/Zx81-timex-manipulated.jpg

Ironically, during the same basic timeframe on some other part of the world, some dude named Andreas Antonopoulos immersed himself with basically the same device. I wonder what ever happened to him.  :'(

I'm considering adding a reward, is 0.01 BTC enough?

144.82758612 gms

.8/464 = 0.00172413793

0.00172413793 X 84,000 = 144.82758612

The merry-go-round is slowed to a fraction of its regular speed, the centripetal force countering gravity is also reduced and the average person weighs less according to your answer?

I'm sorry but the average person is going to weigh more not less as the centripetal force is reduced.

Consider two magnets stuck together with one of them tied to a string. If you twirl the magnets fast enough the one held on will fly off once the centripetal force exceeds the magnetic force holding them together.

I do however appreciate your attempt at answering the question all-be-it a less than serious attempt.

How about a 0.1 BTC reward, would that be enough to get a serious attempt at answering this question? That's almost $28 USD.

I think 0.02BTC would do.
Just a small rewards for attach people :D

I've added a 0.01 BTC reward for the first correct answer.

Let me try

( 464-0.8 )^2 / 464^2 * 84,000 = 83,710.5945303210463 gram

sent to here
1E1j2uMTLfXMDM6YZrWSnXPneRsVbht8k3
If my answer satisfy you  ;D

0.64/ 6,371,000 =4077440
4077440x84,000= 342504960000gs?

The centripetal force that counters the gravitational force has been reduced to a fraction of what it normally is. How can they (the average person) possibly weigh 0.3 kg less?


You got a nice big number so you're going in the right direction but, where did you get '0.64' from?

Tip: the SI unit for force (in this case centripetal force) is the Newton. 1 newton = 101.971621 grams.

342504960000gs/101.xxx=

3358826275.7929483145119366102849gs
0.8^2?= 0.64?

Using the information you've provided I've formatted your response to make it readable...


(velocity^2 / radius) * mass = 342,504,960,000 grams
342,504,960,000 / 101.971621 = 3,358,826,275.7929483145119366102849 newtons

So based on your response your answer is about 3,358,826,276 newtons or 342,504,960 kg, is that correct?

We're getting close but I don't think we've arrived at a BTC reward yet...

Problems I can see:

a) your giving results from your force formula in grams not newtons.
b) your mass is still incorporating a velocity of 464 m/s to get 84 kg.
c) many other issues.

Tip: The SI unit of mass is the kilogram. Mass is not the same as weight.

lol ok i will break out pen and paper now i been trying do it in my head all day

ok so mass=x   84,000=x(464^2)/6,371,000 ---- 
                          x/101= 25,202
0.64 / 6371000 = 4077440
4077440 *25,202  = 102759642880g's or 102,759,642.880Kg

^^^ I think *** am i getting closer?

So what are you looking for ?
The mass shift or looking for the exact mass ?

How about

0.8^2 / 464^2 * 84,000 = 0.2497026 gram

this is going to be games and rounds section sir.
i dont like math sigh ....

pie squared - 2

let me know when you need my addy for reward.

                      Centripetal_force 1      =  centripetal_force 2
84,000 g * (464 m/2)^2 / 6,371,000 m = mass * (463.2 m/s)^2 / 6,371,000 m

mass = 84,290.4 g

So you're saying that the force on an average person from being whipped around at 464 meters per second is 290.4 grams?  :D There's a ride at PlayLand called the Gravitron, you should ride it sometime!

Also, the only velocities that should be used here are 464 m/s and 0.8 m/s. Where on Earth did you get 463.2 m/s from?

Let this spin for a bit...  ;)

"...the weight..."


You're short a few kg.

here's another attempt

r = 6,371,000 m
v = 464 m/s
m = 84,000 gr

cf = m* v^2 / r
   = 84,000 gr * (464 m/s)^2 / 6,371,000 m
   =2,838.62251 gr.m/s^2

if v = 0.8 m/s then
cf = m * v^2 / r

m = cf * r / v^2
   = 2,838.62251 gr.m/s^2  * 6,371,000 m  / (0.8 m/s)^2
   = 28,257,600,000 gr

While I've provided the average weight of a person in grams and requested the answer in grams the SI unit for mass is the kilogram.

Also keep in mind the fact that mass is not the same as weight.

84000 * 0.8^2/6,371,000 = 0.00843823575 grams.

Er.. wait.. something is wrong?

Edit: Re-attempt. I assume that weight and mass in both cases are equally proportional.
Honestly, I know nothing Physics. ;D


OH okay, so this centripedal force acts against gravity?
I see.

This is fucked up on so many levels! Does this now mean that I wasn't even close with my answer? If so, that really makes me out to look like a fool.  :'(

At the Equator.


84,000 * 9.79/0.00843823575 = 97456390.6916 grams. ;D

we'll apply the calculation used to answer this skill testing question to the north pole as a test of its validity later...

a) The SI unit for mass is the kilogram.
b) Where do you get '9.79' from?
c) Again, where do you get '0.00843823575' from?
d) How is the result of your calculation in grams and not newtons?
e) Many other issues.

I've increased the reward to 0.08 BTC.

given:  if the equatorial velocity was slowed to 0.8 m/s?
Earth's radius at the equator: 6,371,000 m
Earth's velocity at the equator: 464 m/s
Average weight of a person: 84,000 g

formula: centripetal_force = mass * velocity^2 / radius

84,000 * (464-0.8/464)^2 / 6,371,000 = 2838.60141269 newtons
2838.60141269 *101.97 =  289452.186052 grams

this is my try :)
i think im missing something

a) The SI unit for mass is the kilogram.
b) You've only attempted to calculate part of the problem.
c) Other issues with the part you've attempted.

Reduction in weight = Change in centripetal force = m(V^2)/r - m(v^2)/r =  84(464^2 - 0.8^2)/6,371,000 = 2.83861407

However, since centripetal force is in Newtons, this is in Newtons.
Converting it to mass equivalent with the number you gave (1 newton = 101.971621 grams)

2.83861407 Newtons * 101.971621 Grams per newton = 289.458078111 Grams heavier

Wait what really? So less?

Let's look at the equation of centripetal force again.
Let's calculate the total centripetal force for any person

Mass in kg * (velocity)^2 / Radius
84 KG * 464 * 464  / 6,371,000
The thing you notice is that the radius is so large it makes the speed look extremely tiny.


Yes it is so low!
The author of that response made a mistake (464^2 - 0.8^2) =/= (463.2^2) , but was correct for the rest.

I'm not sure if you're playing a prank on the forums, but that's what happens when something is inversely proportional to the radius of something, and that radius is HUGE.

The fact that someone noted that this was consistent with NASA calculations regarding weight at the poles hints that your idea is wrong.

Leaving margin for error, I can say with certainty that the weight of the average person will be approximately 826.59 Newtons. (YES, Google it. The SI unit of weight is Newton, not mass)
Or, to use your extremely weird scale of stating weights in mass equivalent, 84,289.46 grams. Can't vouch for accuracy, may vary between 84,280 and 84,300 grams.

And here's my address: 1FRkoJDy8CwZ84RSeMs2tCEKBdVfHu32Ra

Best attempt yet... but, I need some time to go over it and some sleep. If I can't poke any holes in it I'll send the 0.08 BTC.

EDIT:

Reviewing the other posts it looks like 'lili song' (19jD5PfF5TqeF5xJWa5US2rM7GHVr5hdX) may have beaten you to it especially with your margin of error...


Oh, my precious Bitcoins, this isn't looking good for me. 'lili song' did however post while the reward was 0.01 BTC.

I'm still going over the numbers...

its too hard  :D

84000*464^2/6,371,000

2838.622 G

It's 4567,85 g

Lilisong answer answer is correct?

'lili song' is the winner! (19jD5PfF5TqeF5xJWa5US2rM7GHVr5hdX) <-- 0.07 BTC

'jambola2' is the runner up. (1FRkoJDy8CwZ84RSeMs2tCEKBdVfHu32Ra) <-- 0.01 BTC

I decided not to be a cheap ass and reward the entire 0.08 BTC but, lili song's works sucks so jamola2 gets 0.01 BTC of her reward. Technically lili song posted while the reward was 0.01 BTC so consider yourself lucky.

Yes.

Don't think this proves that the Earth is a spinning globe, it doesn't. It does however prove that I'm somewhat of a massive fool for just assuming the centripetal force would be a large value.  :'(

NASA and the rest of the establishment are a den of vipers. Their eggheads have however defiantly crunched all the numbers. I won't make the same mistake twice. Math is the only science you can be 100% sure of the results and I'm going to find a hole in their global conspiracy.

The Earth is flat!

I was wonder why YouTube was suggesting me the likes of Saudi Cleric Was Right: USA Faked Moon Landing - Coriolis Effect Fraud (https://www.youtube.com/watch?v=oCSvx5ONIB8) lately. It's because I commented on this thread. Bad, notbatman!  ;)

Woah  ::) I can't believe it that I'm the winner
Thanks notbatman  ;D and thanks for jambola2 for clarification (since english is not my mother tongue, I can't argument just like you did. )

Yup, you owe me one for proving you right ;)

And notbatman, shoot me a PM the next time you're hosting this sort of stuff.
This was fun, and the free BTC for a few minutes of work was more fun :P

i want to reclamation

From your question, you are looking for weight in grams.
in physics weight are united with Newton, not in grams. but in real world sometimes people call mass as weight.

   Quote from: lili song on July 24, 2015, 08:00:46 AM
                      Centripetal_force 1      =  centripetal_force 2
   84,000 g * (464 m/2)^2 / 6,371,000 m = mass * (463.2 m/s)^2 / 6,371,000 m

   mass = 84,290.4 g

and u claimed this answer as the winner. So the answer you are looking is mass not weight.

from this https://en.wikipedia.org/wiki/Weight is the description of weight physics
and this https://en.wikipedia.org/wiki/Mass is the description of mass in physics

if you are reading it carefully, in paragraph 2 of description of mass you will read  "An object on the Moon would weigh less than it would on Earth because of the lower gravity, but it would still have the same mass".
so whenever you are, whatever the velocity or radius of the planet
your mass will still same, but your weight will change.

and I want to straighten our concept about centripetal force.

from lili song answer centripetal force 1 = centripetal force 2.
This is completely wrong! As far as i know centripetal force change as the related variable change.
Sorry, lili, i did not mean to blame you.
this for the reference of the centripetal force description http://www.regentsprep.org/regents/physics/phys06/bcentrif/default.htm

So, the answer should still same mass(weight) 84,000 grams

btw, that is already accounted for here:


To clarify, (I know some basic Physics)
Mass is universal. Same everywhere. SI unit is kg - kilogram.
Weight varies. SI unit is Newton.



This one is a little weird answer:


I just corrected that here: ;D



The question clearly states:


There is no problem is weight is stated in grams just because SI unit happens to be Newtons.



That said, I still think the answer is 28,257,600,000 grams..
jambola2 is right.


and this should be: ;D

As ndnhc pointed out, and as I already said in my answer, I gave it in mass equivalent.
What do I mean by mass equivalent?

The weight is 826.59 N, but it is the same weight of an object with mass of 84,289.46 grams on the surface of the earth.
OP asked for it in grams, so I gave it in mass equivalent.

Read my answer, it is different from lili's answer, but straightens out a lot of things he said, better explaining them.
He has a valid reason for being unable to explain it too, as English is not his first language either.