- #1
CGandC
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Homework Statement
Suppose I have particles with masses m1 and m2 , both are in freefall:
Then , looking at the center of mass coordinates , I know that the sum of momentums of masses m1 and m2 in the center of mass coordinates is equal to zero : P1c + P2c = 0
so now I know that the total force acting on the masses in the center of mass frame is :
Fcmf = d(P1c + P2c )/dt = 0
From here I get : Fcmf = 0
But , If I sum the forces ( only weights ) of the two bodies, I don't get zero : Fcmf= -M2g -M1g ≠ 0
(I get contradiction , because I know as a fact that Fcmf must be equal to zero , Fcmf = 0 )
Why do I get a contradiction?
Homework Equations
F = ma
The Attempt at a Solution
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