# Gravitational field line

nilic1
Where on an imaginary gravitational field line between Earth and moon, a mass would have no weight neither due Earth nor due to moon?

## Answers and Replies

Homework Helper
If you mean when the gravitational force is zero, then you just need to equate

FEarth and FMoon for a mass m and solve for the distance.

nilic1
If you mean when the gravitational force is zero, then you just need to equate

FEarth and FMoon for a mass m and solve for the distance.

Thanks for your reply. This was meant to be a straight forward answer without any calculation.
Since the gravity of the moon is 1/6 that of Earth , does it follow that the distance where there is no gravity on the object is 1/6 the distance between moon and Earth, starting off from the moon?

Last edited:
Staff Emeritus
Homework Helper
No, that 1/6 figure is only true about the surface gravity of the Earth vs. the surface gravity of the moon. It is not applicable everywhere in space.

I think you really do need to set up an equation using the equation for gravitational force. At least, I can't imagine solving it any other way.

nilic1
No, that 1/6 figure is only true about the surface gravity of the Earth vs. the surface gravity of the moon. It is not applicable everywhere in space.

I think you really do need to set up an equation using the equation for gravitational force. At least, I can't imagine solving it any other way.

Thanks for you answer. I did as you both suggested. The final answer is 1/10 the total distance starting from the centre of the moon.

Regards