Quote:
Originally Posted by Fazor
The thing Fazor seems to be looking at is more:
(impact is energy from 1 m fall)
mass weight acceleration impact
Actually, disregarding impact. Obviously two objects moving at the same velocity with two seperate masses, the object of larger mass has more KE, and more momentum.
What I was looking at is this: If you have a 10-ton safe, and a barstool, both at rest on the gymnasium floor (why a gym, safe, and stool? I dunno I'm random like that): it takes more force to accelerate the 10-ton safe at the same rate as it would to accelerate the bar stool (unless it's one of those rare 10-ton bar stools). But with gravity, the force is the same, yet the resulting acceleration is also the same. That's what I was asking about, but examining the answers, I think I'm just considering gravity in the wrong manner.
The question would be, in the absense of any other gravitational fields, would a 1kg object be attracted to a 10kg object at the same rate that a 10kg object is attracted to a 100kg object? would the 1kg object be attracted to the 100kg object at the same rate as the 10/100? (I know the answer is yes, but the question is why).
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Technically, my impact energy is the KE after a 1m fall.
There are two parts to the why. First is the assumption that you are in the frame of the larger mass, and therefore its movement is zero. This isnt actually necessary, but it makes the math alot easier.
When you use the first assumption, The equations of motion become very simple
ma=GmM/r^2
The cancellation of the m, in this case the smaller mass, makes the acceleration independent of the smaller mass. That really is all there is to it. the rest of the quantities, like p, KE, v are all dependent to some degree or another on a, so they all scale in one way or another.