I wondered if the force of 6.4 billion people all running in place for a lengthy period of time would begin to affect the counterclockwise rotation and eventually reverse the direction.
2006-11-22 06:16:34 · 29 answers · asked by rj80909 1 in Science & Mathematics ➔ Physics
I think you meant to say that the people were running forward, not in place. If they were running in place, nothing changes.
Otherwise, assuming that an average person has a mass of 70kg. That means that all the people have a combined mass of about 70*6.4*10^9 = 448*10^9 kg. The earths mass is approximately 6*10^24 kg. That means that all of the peoples mass is only 0.00000000000007466667 of the earths mass. Using the conservation of angular momentum with:
m = moment of inertia of people
M= moment of inertia of earth
w_1 = angular velocity of earth with people standing still
w_p = angular velocity of FORWARD running people
w_e = angular velocity of earth while people are running
w_1*(m+M) = w_e*M + w_p*m
so by the conservation of angular momentum you can see that you would effect the rotation of earth. However m compared to M is essentially zero, as mentioned before (mass is in a way related to ineria) so setting m = 0, you get:
w_1*(m+M) = w_e*M + w_p*m
w_1M = w_e*M
w_1 = w_e
The effect that this would have is practically none so no you will not change the direction but, yes you do slow the earth down a tiny, tiny, minuscule amount.
2006-11-22 11:05:12 · answer #1 · answered by Andy M 3 · 0⤊ 0⤋
Answer is no. Why? what good would it do to run in place? By running in place there would be no outward force to give play to the reversing of the direction it would be the same concept as to just standing there. Now if we all ran in the same direction without standing in place the force from our feet pushing the ground then that would be the force needed to break the rotation. But, with such a strong gravitational pull it would be impossible to break because the way the moon affect the tides and the oceans we would also have to take into consideration that we would have to reverse the jet streams in the ocean and the direction of the flow of water which plays a major role in the direction also.
2006-11-22 06:31:51 · answer #2 · answered by Robby 1 · 1⤊ 0⤋
What you are assuming is that a force is actually being exerted on the planet by doing this, and it isnt. When you run in place you're really just lifing your feet and putting them back down. The force is a downward force that is absorbed by the planet. There is no lateral force at all. When you run, you are imparting a lateral vector to the earth, but it is miniscule. Even if we had 100 TRILLION people all running in the same direction, it wouldnt be enough to overcome the inertia that has this ball rotating the way it is now
2006-11-22 06:37:13 · answer #3 · answered by shinobisoulxxx 2 · 0⤊ 0⤋
That's a cool question. But keep in mind that over 70% of the earth is covered by water, so even if you got all the humans to run in place... it would only affect 30% (at it's highest probability) of Earth.
2006-11-22 07:17:47 · answer #4 · answered by Mel 2 · 0⤊ 1⤋
when all of us start running to east , we are applying force to earth, the earth will decelerate.
But any way we have to stop running, and by that time we are giving the earth an opposite force, and the earth start acccelerating. Hence back to square one.
2006-11-22 15:08:57 · answer #5 · answered by Harry 3 · 0⤊ 0⤋
no because you have to figure that a lot of them are handicapped. Plus, if you were looking from the south pole, the earth does rotate counter-clockwise. from the north pole, it's clockwise. Which one are you at right now?
2006-11-22 06:18:33 · answer #6 · answered by Cold Fart 6 · 2⤊ 0⤋
hmm, I'm kinda of in the middle with this. I don't think 6 billion people can move this Earth. And that might have dangerous consequences. If we all reverse the direction we could probably turned back time or destroy the moon's orbit.
2006-11-22 06:19:05 · answer #7 · answered by Anonymous · 1⤊ 3⤋
No. running in place would do nothing. Running forward would have some effect but you would have to ask a physicist to do the calculations for you
2006-11-22 06:27:33 · answer #8 · answered by birdman 2 · 0⤊ 0⤋
No, because the earth is rotating independently of the people on it - i.e. you need an external influence to change the rotation of the earth. People are not an external influence.
2006-11-22 06:19:12 · answer #9 · answered by Big Super 6 · 1⤊ 2⤋
no, the people would just run regularly. i've wondered before if everyone were to be on one part of the earth and do pushups, if it would throw the earth of it's axis, but neither is possible because there would be nothing for the people to push against.
does that make sense?
2006-11-22 06:19:53 · answer #10 · answered by obxfisher1444 2 · 0⤊ 2⤋