Question

A particle of mass M is moving in a horizontal circle of radius R with uniform speed v. When it moves from one point to a diametrically opposite point, its ___________

(a) Kinetic energy changes by (Mv)^2/4

(b) Momentum does not change

(c) Momentum changes by 2Mv

(d) Kinetic energy changes by (Mv)^2

I had been asked this question in quiz.

I would like to ask this question from Moment of Inertia in section System of Particles and Rotational Motion of Engineering Physics I

Answer 1

The correct choice is (c) Momentum changes by 2Mv

The explanation is: At any two diametrically opposite points, velocities of the particle have the same magnitude but opposite directions. Therefore change in momentum = Mv-(-MV)=2Mv.