Question

Akhtar, Kiran and Rahul were riding in a motorcar that was moving with a high velocity on an expressway when an insect hit the windshield and got stuck on the windscreen.

Akhtar and Kiran started pondering over the situation. Kiran suggested that the insect suffered a greater change in momentum as compared to the change in momentum of the motorcar (because the change in the velocity of the insect was much more than that of the motorcar).

Akhtar said that since the motorcar was moving with a larger velocity, it exerted a larger force on the insect. And as a result the insect died.

Rahul while putting an entirely new explanation said that both the motorcar and the insect experienced the same force and a change in their momentum. Comment on these suggestions.

Answer 1

I agree with Rahul. This is because due to the law of conservation of momentum, during a collision, momentum of the system is conserved. Both the bodies suffer the same momentum change.

However, the insect having smaller mass will suffer greater change in velocity. The motor car having much larger mass does not suffer any noticeable change in velocity.