Question

In a closed system, glider A with a mass of 0.40 kg and a speed of 2.00 m/s collides with glider B at rest with a mass of 1.20 kg. The two interlock and move off. What speed are they moving at?

Answer 1

Conservation of momentum.
m1*u1 + m2*u2 =m1*v1 + m2*v2
here u2=0 body at rest, v1=v2=v both interlock and move together
0..4*2+1.2*0 = 0.4*v+1.2*v
v= 0.8/1.6 = 0.5 m/sec