Question

1)A friend says that since the Earth's gravity is so much stronger than the moon's gravity, rocks on the moon could be dropped to the Earth. Is that true??????why or why not??
2) Is the force of gravity stronger on a piece of iron than on a piece of wood if both have the same mass????? why or why not???

Answer 1

1. The correct statement is that "earth's gravity on earth's surface" is much stronger than "moon's gravity on moon's surface". but "earth's gravity on moon's surface" is not stronger than "moon's gravity on moon's surface". So "gravitational force due to earth" on a rock which is on moon's surface is less than the "gravitational force due to moon" on the rock. So the rock can't be dropped to earth from moon.

2. Gravitational force is given as mg. It is clear that it depends on mass. If two objects have same mass, the force of gravity on them will be the same.