Physics Two Dimensional Motion Question 308

Question: If a particle covers half the circle of radius R with constant speed then

[RPMT 2000]

Options:

A) Momentum change is mvr

B) Change in K.E. is 1/2 mv2

C) Change in K.E. is mv2

D) Change in K.E. is zero

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Answer:

Correct Answer: D

Solution:

As momentum is vector quantity \ change in momentum $ \Delta P $ = $ 2mv\sin (\theta /2) $ =$ 2mv\sin (90)=2mv $ But kinetic energy remains always constant so change in kinetic energy is zero.