Question

A rocket is moving up with velocity v. If the velocity of the rocket is tripled, what will be the ratio of kinetic energies? [2 MARKS]

Answer 1

Each point: 1 Mark

1. We know, kinetic energy = $\frac{1}{2}m{v}^2$

2. If the velocity is tripled, Kinetic energy = $\frac{1}{2}m{\left(3v\right)}^2$

= $\frac{9}{2}m{v}^2$

Kinetic energy increases by 9 times.

Thus the ratio of the kinetic energies is 1:9.