Question

Question 10
A rocket is moving up with a velocity v. If the velocity of this rocket is suddenly tripled, what will be the ratio of two kinetic energies?

Answer 1

Let the initial velocity $=v$
Let the new velocity be $v^{\prime }=3v$
Initial kinetic energy = $\frac{1}{2}m{v}^2$
Final kinetic energy (K.E) =$\frac{1}{2}m{v}^{\prime 2}=\frac{1}{2}m(3v{)}^2=9\left(\frac{1}{2}m{v}^2\right)$
$\therefore$$(K.E{)}_{initial}:(K.E{)}_{final}$ $=1:9$