Car J moves twice as fast as car K, and car J has half the mass of car K. The kinetic energy of car J, compared to car K is A) 1 to 2. B) 2 to 1. C) the same. D) 4 to 1. E) 4² to 1.

Question

Quizplus · Accepted Answer

Kinetic energy is proportional to mass and the square of velocity. Since car J has half the mass of car K and moves twice as fast, its kinetic energy is 2 * (1/2)^2 = 1/2 that of car K.

Car J Moves Twice as Fast as Car K, and Car