Two masses traveling in the same direction (m1=10kg u1=9ms^-1) (m2=8kg u2=4ms^-1). They both collide and move off together.
What is their resultant velocity after collision.
The loss of kinetic energy.
m1*vi1 + m2*vi2 = (m1+m2)* vf
initial Ke = .5 m1 vi1^2 + .5 m2 vi2^2
final Ke = .5 (m1+m2) vf^2