A lead ball of mass 60kg hangs from a string. A piece of putty mass of 15kg hits the ball with velocity of 12m/s. If the putty sticks to the ball, what will be their velocity immediately after the impact?

1 answer

M1*V1 + M2*V2 = M1*V3 + M2*V3
V3 = V4.

60*0 + 15*12 = 60*V3 + 15*V3
180 = 75V3
V3 = 2.4 m/s = Velocity after impact.