Posted by Daisy on Friday, July 16, 2010 at 1:09am.
A 26.0 g object moving to the right at 17.0 cm/s overtakes and collides elastically with a 10.0 g object moving in the same direction at 15.0 cm/s. Find the velocity of each object after the collision.
a) 26.0 g object
b) 10.0 g object

Physics  drwls, Friday, July 16, 2010 at 7:09am
The center of mass of the two objects moves to the right at a velocity
(26*17 + 10*15)/(26 + 10) = 16.44 m/s
Consider what happens in a coordinate system travelling the the CM.
a) The heavier object comes from the right at velocity 1716.44 = 0.56 cm/s and leaves at 0.56 cm/s.
b) The lighter object approaches from the left at velocity 15  16.44 = 1.44 cm/s and leaves with velocity +1.44 m/s.
Transfering back to lab coordinate sytem (by adding +16.44 to both velocities) , the final velocity of the heavier object is 0.56 + 16.44 = 15.88 cm/s, and the lighter object is +1.44 + 16.44 =
17.88 cm/s.
The above is a shortcut compared to solving both the momentum and energy cnservation equations for two unknowns. It should give the same reult if I did the math right.