Two balls have masses 44 kg and 86 kg. The 44 kg ball has an initial velocity of 80 m/s (to the right) along a line joining the two balls and the 86 kg ball is at rest. The 86 kg ball has initial velocity of −24 m/s. The two balls make a head-on elastic collision with each other.

(1)What is the final velocity of the 44 kg ball?
(2)The final velocity of the 86Kg ball?
Answer in units of m/s

2 answers

you will have to use conservation of momentum; and energy. See this one as an example..

http://www.jiskha.com/display.cgi?id=1312940695
Two balls have masses 44 kg and 86 kg. The 44 kg ball has an initial velocity of 80 m/s (to the right) along a line joining the two balls and the 86 kg ball is at rest. The 86 kg ball has initial velocity of −24 m/s. The two balls make a head-on elastic collision with each other.
(1)What is the final velocity of the 44 kg ball?
(2)The final velocity of the 86Kg ball?
Answer in units of m/s