A 2 kg chunk of putty with mass of 2 kg is moving with a velocity of 1 m/s to the east. it collides and sticks to a bowling ball with mass of 5 kg initially at rest. the bowling ball and putty then move with a total momentum of

We apply the conservation of momentum:

m1v1 + m2v2 = m1v1' + m2v2'

Since it is specified that the two objects stick together, this is an inelastic collision wherein the two objects would move together in one direction and with the same velocity. The equation would then be simplified into

m1v1 + m2v2 = (m1 + m2) v'

where v' is the velocity after collision. Substituting the values,

(2) (+1) + (5) (0) = (2+5) (v')

v' = + 0.29 m/s (to the east)