The strength of the gravitational forces between two objects
depends on two things about the objects:
==> It depends on the product of their masses.
Notice, it doesn't depend on whether they're both big, or one is big
and one is tiny, but only on the product of the masses, whether they're
equal or wildly different.
==> It depends on the distance between the centers of the two objects.
It doesn't depend on anything else. For example ... it makes no difference
what's in between the two objects, or whether or not they're moving.
And even though you didn't ask, here's another unbelievable factoid:
There are two gravitational forces between two objects ... one force in
each direction. One gravitational force pulls Object-A toward Object-B,
and the other one pulls Objest-B toward Object-A. Strange as it may seem,
the two forces are equal ... it doesn't matter whether the objects have the
same mass or not.
Your weight on Earth is the same as the Earth's weight on you !
