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?

Initial velocity = v, then final velocity, v’ = 3v

Initial kinetic energy = {{1\over 2}mv^2}

Final kinetic energy (KE) = {1\over2} mv^’2 = {1\over2}m(3v)² = 9 ({{1\over2}𝑚𝑣^2})

(KE) initial: (KE) final = 1 : 9.