Car A is three times lighter than car B. Car A moves three times faster than car B. The ratio of the kinetic energy of car A to the kinetic energy of car B is

Question

Quizplus · Accepted Answer

Kinetic energy is proportional to mass and the square of velocity. Car A is three times lighter than car B, so its mass is 1/3 that of car B. Car A moves three times faster than car B, so its velocity is 3 times that of car B. Therefore, the ratio of the kinetic energy of car A to the kinetic energy of car B is (1/3) * (3^2) = 3.

Car a Is Three Times Lighter Than Car B