A 1000-kg car is traveling north at 20.0 m/s. A 1500-kg car is traveling north at 36.0 m/s. The 1500-kg collides with the rear of the 1000-kg car and they lock together. Ignoring external forces acting during the collision, what is the velocity of the cars immediately after the collision?

Question

Quizplus · Accepted Answer

Momentum is conserved in the collision, so the total momentum before the collision is equal to the total momentum after the collision. The total momentum before the collision is:$$(1000	ext{ kg})(20.0	ext{ m/s}) + (1500	ext{ kg})(36.0	ext{ m/s}) = 82000	ext{ kg m/s}$$The total mass after the collision is:$$1000	ext{ kg} + 1500	ext{ kg} = 2500	ext{ kg}$$So the velocity of the cars immediately after the collision is:$$82000	ext{ kg m/s} / 2500	ext{ kg} = 29.6	ext{ m/s north}$$

A 1000-Kg Car Is Traveling North at 20