Which has the greater kinetic energy?

Question

Quizplus · Accepted Answer

Kinetic energy is given by 1/2 mv^2 where m is the mass of the object and v is its velocity. Therefore, the kinetic energy of a car is directly proportional to the square of its velocity and mass. In option B, the car is half the mass, but it is traveling at twice the speed of the car in option A. Thus, its kinetic energy would be (1/2)(1/2)m(2v)^2 = 2mv^2 which is greater than the kinetic energy of the car in option A. Therefore, the correct answer is B.

Which Has the Greater Kinetic Energy