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 wind screen. 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

Hint:Here the Newton’s third law will be applicable.An equal and opposite reaction occurs for any action. The statement implies that there is a pair of forces acting on the two interacting objects of any encounter. The force size of the first object is identical to the force size of the second object.

Complete answer:
Statement by Kiran:
By conserving momentum, the shift in momentum of the bug and the motorcar is equal. The velocity of the bug varies dramatically because, relative to the motorcar, its mass is very small. Similarly, since its density is so high relative to the insect, the speed of the motorcar is very insignificant. Kiran's argument is also inaccurate.

Akhtar's statement:
By the third law of motion of Newton, movement and reaction force are identical and opposite and function on various bodies. Therefore, both the motorcar and the insect sense the same energy. Relative to the motorcar, because the mass of the insect is very small, there is a significant difference in velocity compared to the engine. Insects suffer because of this. Akhtar's assertion however is inaccurate.

Rahul's Statement:
Both the motorcar and the insect feel the same power and shift of velocity, as discussed before. Hence the assertion by Rahul is right.

Additional information:
In the first law, once a force acts on it an entity cannot alter its motion. The force on an object is proportional to its mass times the acceleration in the second equation.

Note:Here we have to observe each statement one by one to get the answer. Here we may be confused between Kiran and Rahul’s statement because there is a shift in momentum but the speed of the motorcar is very insignificant in Kiran’s case.