A car is moving on a levelled road and gets its velocity doubled

A car is moving on a levelled road and gets its velocity doubled. In this process,
(i) how would the potential energy of the car change?
(ii) how would the kinetic energy of the car change?
(iii) how will its momentum change? Give reasons for your answer.

(i) The potential energy of the car remains same, since PE (= mgh) is independent of velocity.
(ii) The kinetic energy of the car becomes four times, since KE(=1/2 m ${{v}^{2}}$) j is proportional to square of velocity.
(iii) The momentum of the car will also get doubled, since momentum (p = mv) is proportional to velocity.