7. 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.
Answers
Answer:
kiran- due to great change in momentum of insect as compared car,and insect died
Akhtar - Since motorcar was moving with a larger velocity, it exerted a larger force on the insect. And the insect died. Rahul - Both motorcar and insect experienced the same force and change in their momentum
Kiran's statement:
Change in momentum of the insect and the motorcar is equal by conservation of momentum. The velocity of insect changes significantly because its mass is very small compared to the motorcar. Similarly, the velocity of motorcar is very insignificant because its mass is very large compared to the insect. Hence, Kiran's statement is false.
Akhtar's statement:
By newton's third law of motion, action and reaction force are equal and opposite and they act on different bodies. Hence, the motorcar and insect both experience the same force. Since the mass of the insect is very small compared to the motorcar, it suffers a huge change of velocity as compared to the car. Due to this, insect dies. Hence, Akhtar's statement is false.
Rahul's Statement:
As discussed before, both the motorcar and the insect experience the same force and change in momentum. Hence, Rahul's statement is correct