Back to the old question - you take a feather and a brick - drop them in a vacuum at the same time and both objects hit the ground at the same time - but do they really?
Isn’t the gravitational force a factor of both masses (brick + planet opposes to feather + planet)?
To put another way what if we took the time it took the feather to strike the ground from 20 feet - I would assume it was longer then the time a neutron star would take.
If I remember correctly, the masses of the objects only make a difference if they are very large. The mass of the earth is large, but the masses of the feather and brick are small enough to be practically negligible. Now, I’m no expert at physics, so I’m sure someone will be around shortly to explain it better, with equations, special effects, and an award-winning soundtrack.
F = gm[sub]1[/sub]m[sub]2[/sub]/d[sup]2[/sup], m[sub]1[/sub] is the mass of the falling object, m[sub]2[/sub] is the mass of the earth, d is the distance between the earth and the object, and g is the universal gravitational constant. Also, F is the force of gravity acting on both objects.
But the force acting on an object is given by F = ma, where m is the mass of the object, and a is the acceleration. So for the falling object, we have m[sub]1[/sub]a = gm[sub]1[/sub]m[sub]2[/sub]/d[sup]2[/sup]. Since m[sub]1[/sub] appears as a factor on both sides of the equation, it’s irrelevant.
Therefore, the acceleration of an object due to gravity is due entirely to the mass of the object it’s falling towards, and the distance between those two objects.
No special effects or soundtracks, but it’s as good as I can do.
Oooo, I get all tingley when you guys talk physics - with formluae and everything…
(caution - really big MPEG file at that link above…)