Question

When the momentum of a body is doubled, its kinetic energy ___________

(a) Remains the same

(b) Drops to zero

(c) Becomes four times its initial kinetic energy

(d) Becomes ten times its kinetic energy

This question was addressed to me by my school principal while I was bunking the class.

My question is based upon Conservation of Energy in division Laws of Motion of Engineering Physics I

Answer 1

The correct choice is (a) Remains the same

The explanation: K = 1/2 mv^2 = (mv)^2/2 m = p^2/2 m

K α p^2

When the momentum of a body is doubled, its kinetic energy becomes four times the initial kinetic energy.