A 2 900-kg truck moving at 11.0 m/s strikes a car waiting at a traffic light,hooking bumpers.The two continue to move together at 7.00 m/s.What was the mass of the struck car?

Question

Quizplus · Accepted Answer

We can use conservation of momentum to solve this problem.

Initial momentum of the system (truck + car) = (2900 kg) x (11.0 m/s) = 31900 kg*m/s

Final momentum of the system = (2900 kg + mass of car) x (7.00 m/s)

Using conservation of momentum:
31900 kg*m/s = (2900 kg + mass of car) x (7.00 m/s)

Solving for the mass of the car:
mass of car = (31900 kg*m/s)/(7.00 m/s) - 2900 kg = 1660 kg

Therefore, the mass of the struck car was 1660 kg, which corresponds to answer choice D.

A 2 900-Kg Truck Moving at 11