A 0.200 kg clay model slides on ice at 0.750 m/s and collides with a stationary 0.350 kg clay model, and the two stick together. What is their final velocity?

1. Since the two clay models stick together, this is a perfectly inelastic collision, so they share one common final velocity. 2. Momentum is conserved: (0.200 kg)(0.750 m/s) + (0.350 kg)(0 m/s) equals (0.200 kg + 0.350 kg) times the final velocity. 3. The left side gives 0.150 kg m/s, and the combined mass on the right is 0.550 kg. 4. Dividing gives a final velocity of about 0.273 m/s. 5. 0.750 m/s would ignore that the mass being pushed increases, and 0.429 m/s and 0.136 m/s come from dividing by the wrong mass entirely. _Source: OpenStax College Physics (CC BY 4.0), Ch 8 "Linear Momentum and Collisions", section 8.3 Conservation of Momentum_