Question

Gravity on the moon is about 1/6 th the gravity felt on the earth. This is because A) the moon is so far away from the earth. B) the moon is much less massive than the earth. C) the earth has a molten core and the moon doesn't. D) the moon is so much further from the sun than the earth.

Answer 1

Answer:

Option (B)

Explanation:

The acceleration due to gravity depends on the mass of planet and the radius of planet .

As the value of acceleration due to gravity on moon is one sixth of the acceleration due to gravity on earth.

g = GM / R^2

Where, G is the universal gravitational constant, M be the mass of planet, R be the radius of planet.

As the mass of moon is much lesser than the mass of earth so the value of acceleration due to gravity on moon is one sixth of the acceleration due to gravity on earth.

Answer 2

So we want to know why is there a difference between the force of gravity on the Moon and the force of gravity of the Earth. So the gravitational force between two objects depends on the masses of both objects. That can be seen from Newtons universal law of gravity. F=G*m1*m2*(1/r^2). So lets say we are holding an object of mass m=1kg on a height r=1m on the Moon and we are holding the same object on the Earth also on the same height of r=1m. The Gravitational force on the Earth will be Fg=G*M*m*(r^2) where M is the mass of the Earth. The force between the moon and that object will be Fg=G*n*m*(r^2), where n is the mass of the moon. Since mass of the Moon is much smaller than mass of the Earth, The gravitational force between the Moon and that body will be almost 6 times smaller than the gravitational force between the Earth and that body. So the correct answer is B.