Question

Is momentum conserved in a car crash?

Answer 1

Hint:According to Newton’s second law of motion, the rate of change of momentum is directly proportional to the applied force on an object. Hence if there is no external force, the momentum will be conserved. The law of conservation of linear momentum has to be concluded to answer the question. Two types of collision generally occur – elastic collision and non-elastic collision. In the elastic collision, the momentum is conserved as there no external force affects the collision.


 Complete step by step solution:
The law of conservation of linear momentum states that, if there is no external force applied to an object the linear momentum does not change even after the interaction happens. This law can be explained from Newton’s law of motion mathematically and vice versa.
The elastic collision happens in an isolated system in which no external force is applied. In this case, the linear momentum is conserved. During the car crash, if their external force does not exist the total initial momentum of these two cars is equal to the total momentum of these two cars.
Hence, the momentum conserved in a car crash.

Note:In the absence of external force, the total linear momentum is conserved in any collision. But, generally, the total kinetic energy is not conserved. Most of the time, some parts of the kinetic energy are converted into thermal energy as well as sound energy. Therefore, total kinetic energy decreases. This collision is known as an Inelastic collision. In reality, most of the collisions are inelastic.