Question

A 9.7 kg block moving at 3 m/s makes a head-on elastic collision with a stationary block of mass 7.6 kg.
Find the velocity of the 7.6 kg block.
Answer in units of m/s.

Answer 1

9.7*3 + 7.6*0 = 9.7 Va + 7.6 Vb
so
Va = (29.1 -7.6Vb)/9.7

then

.5(9.7)(9)= .5(9.7)Va^2+.5(7.6)Vb^2