A 4.0-kg metal ball with an initial momentum of 20 kg m/s, collides with a 1.0-kg metal ball initially at rest. After collision, the final momenta of the 4.0-kg and 1.0-kg metal balls are 16 kg m/s and 4.0 kg m/s, respectively. What is the change in energy of the system? Is the collision elastic or inelastic?

Answer 1

initial energy=1/2 *4*5^2=50joules
final energy= 1/2 *4*4^2+1/2*1*4^2=1/2(5*16)=40Joules
inelastic