Question

If mass (m) is doubled and velocity (v) is halved then _____

(a) Kinetic energy decreases by half

(b) Potential decreases by half

(c) Momentum decreases by half

(d) Potential and kinetic energy remains unchanged

The question was posed to me in an interview.

My doubt stems from Kinetic Energy in chapter Work, Energy and Power of Physics – Class 11

Answer 1

Right choice is (a) Kinetic energy decreases by half

To explain I would say: Momentum doesn’t change i.e. (2m)*(v/2). K.E decreases by half while P.E becomes twice the original value.