Question

  A baseball has 20 times the mass of a ping pong ball although the ping pong ball is moving.  twice as fast as the baseball. Compared to the kinetic energy of the ping pong ball, the baseball has.

Answer 1

Let the kinetic energy of the ping pong ball be

$E_{ping-pong}=\frac{mv^2}{2}$

Then, the kinetic energy of the baseball equals

$E_{baseball}=\frac{20m\times(\frac{1}{2}v)^2}{2}=5\frac{mv^2}{2}$ , or 5 times greater than the kinetic energy of a ping-pong ball.

Answer: $E_{baseball}=5E_{ping-pong}$