Two trailers, X with mass 500 kg and Y with mass 2000 kg, are being pulled at the same speed.The ratio of the kinetic energy of Y to that of X is:

Question

Quizplus · Accepted Answer

Kinetic energy is directly proportional to the mass of the object and to the square of its velocity. Since the two trailers are being pulled at the same speed, the ratio of their kinetic energies is simply the ratio of their masses:

$KE_Y/KE_X = m_Y/m_X = 2000/500 = 4/1$

Therefore, the ratio of the kinetic energy of Y to that of X is 4:1.

Two Trailers, X with Mass 500 Kg and Y with Mass