Weight of the Earth on the moon?

In summary, the problem presented is to determine the weight of the Earth if it were on the moon, using the masses and radii of both objects. The suggested formula is (GmM)/(R+r)^2, but the connection to torques and moments of force is unclear. The group eventually confirms that this is the same as the weight of the moon on the Earth, and the question is resolved. One member also mentions the potential impact of the varying gravitational pull on different parts of the Earth.
  • #1
cosmic_tears
49
0
Hi everyone!
Ok, so here's the problem:
What would be the weight of the Earth if it were on the moon (just try and imagian that :). The masses of the moon and the earth, and their radiuses, are given.
I cannot see what's the trick here.
There are four possible options.
The one that seemed the most logical is :

(GmM)/(R+r)^2
where m - moon mass, M - Earth mass, R - Earth radius, r - moon radius.

But the material it's supposed to be related to is torques and moments of force... I don't see how it's related :-\

I'd be really thankful for help on how to approach this problem.

Thanks!
Tomer.
 
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  • #2
Is it the same as the weight of the Moon on the Earth?
 
  • #3
Weight = gravitational force between two object.

P.S. I wonder if the Earth is sitting on me, or I am sitting on the earth?
 
  • #4
Your idea and equation are correct cosmic_tears.
 
  • #5
Thank you all!
I simply thought I'm missing something! I thought maybe I should somehow consider the fact that the far side of the Earth is much further away from the moon than the close side, (as opposed to now, when there's hardly any difference).
It made me think about the fact that if you walked into a black hole your legs will probably get torn cause of the different gravity on your body :).
Thanks again!
 

FAQ: Weight of the Earth on the moon?

What is the weight of the Earth on the moon?

The weight of the Earth on the moon is approximately 1.62 x 10^20 kilograms. This is significantly smaller than the Earth's weight on Earth, which is approximately 5.97 x 10^24 kilograms.

How is the weight of the Earth on the moon calculated?

The weight of the Earth on the moon is calculated using Newton's law of universal gravitation. This formula takes into account the masses of both objects (Earth and moon) and the distance between them. It can be represented as W = G * m1 * m2 / d^2, where W is the weight, G is the gravitational constant, m1 and m2 are the masses, and d is the distance.

Does the weight of the Earth on the moon change?

Yes, the weight of the Earth on the moon changes slightly depending on the moon's position in its orbit. This is due to variations in the distance between the two objects. However, the change is very small and difficult to measure.

How does the weight of the Earth on the moon affect the moon's orbit?

The weight of the Earth on the moon has a significant impact on the moon's orbit. The Earth's gravity pulls on the moon, keeping it in orbit around the Earth. Without the Earth's gravitational pull, the moon would continue in a straight line and eventually leave the Earth's orbit.

Can humans feel the weight of the Earth on the moon?

No, humans cannot feel the weight of the Earth on the moon. Weight is a measure of the force of gravity on an object, and on the moon, the force of gravity is significantly lower than on Earth. This means that objects and humans would feel lighter on the moon compared to Earth.

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