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If scientist are not lying and weight does not matter in spa

## If scientist are not lying and weight does not matter in spa

[From: Physics] [author: ] [Date: 03-26] [Hit: ]
If scientist are not lying and weight does not matter in space. Then why cant you push earth around by pressing on the ground?......

If scientist are not lying and weight does not matter in space. Then why cant you push earth around by pressing on the ground?

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answers:
Jeffrey K say: The earth doesn't have weight, but it has a lot of mass. So you still need a lot of force to move it. F = ma

Second, what would you be standing on when you push the earth?
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oldprof say: While weight, the force of gravity, does not matter, mass, the resistance to change in momentum, does.

To change the speed and/or direction (i.e., momentum) of the Earth with a push we need a net force F = dP/dT where dP is the change in Earth's momentum and dT is the interval of time for making that change.

And note this, dP = M dV + dM V where M is Earth's mass, not its weight. And V is its speed as it whirls through space. Also note, if we assume Earth's mass is constant then we have F = M dV/dT = MA and A = F/M is the acceleration of the Earth given the force F.

And there you are. If you can push Earth with a force F you can accelerate (or decelerate) it depending on which direction you're pushing. But here, do the math:

Suppose you want to decelerate Earth at 1 meter/sec^2, what kind of force F would you need to do that? The mass of the Earth M = 5.97E24 kg. So F = MA = 5.97E24*1 = 5.97E24 Newtons of force. That's 1.3421093903052717e+24 lbs of force which is roughly 1.34 million billion billion lbs of force.

That's more than our world-wide technology today can produce.
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D g say: WEIGHT is FORCE

MASS is used in the calculation of force but that is the determining factor not weight

Weight = mass x acceleration

it is mass that determines if you see the object move

the earth has a BIT MORE MASS THAN YOU thats why you fall toward s it and not it falling toward you it does a bit but more you to it
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BigBird say: Squat. When you stand up, you are pushing the earth away from you; but the center of mass for you, the earth, and the moon continues on a smooth elliptical path around the sun.
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regerugged say: You can. But it is impossible to measure the effect.
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runningman022003 say: You can. But the acceleration experienced by earth ...a=F/m = ~ your weight/mass of earth = 100 kg*g/(6*10^24 kg) ~ 10^-23 m/s2 ...pretty close to 0 and is drowned out by all the other forces acting on earth
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billrussell42 say: you are confused between weight and mass.

Mass is the important factor, that resists a push. Weight is just how much gravity pulls on a mass.
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Quentin say: You can't press hard enough against something.
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Ardeshir say: You can, but the earth pushes you back in the same degree, so neither you nor the earth get anywhere as a result.
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Anony Mouse say: Lol. Say what?
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Philomel say: Try this. stand behind your car and push it forward a few feet. Now get into the drivers seat and push the steering wheel to move the car a few feet. Now ponder why it didn't work.
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Chad say: Because gravity, mate. Weight still "exists" in space, in the sense that everything still carries a mass. (Weight is just the amount of gravitational pull that is exerted upon an object, and so it s subject to where that is -- in space, no gravitational pull is enough to reach you, so you re "weightless," but you haven t lost anything fundamental because you re still made of matter and thus have mass.) You can t push on the earth in any meaningful way because the gravitational pull of the sun on the Earth is millions of times greater than any force you could exert on the Earth. You would have to exert more force than the pull of the sun in order to see the Earth move, and that s basically impossible.
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CarolOklaNola say: Because your mass is so infinitesimally small compared to Earth's mass is why. YOU have gravity too.

When you get over the humiliation, insatiable curiosity or a life time of fear and ignorance is YOUR choice. Become a scientist Or not.
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say: why can't you put down that bong ?
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Dev say: The earth has way more mass than you do so maybe you can push it a very very small distance, but it won't make much of an effect.
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don_sv_az say: mass matters
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