Two masses, M_A and M_B, with M_B = 2M_A, are released at the same time and allowed to fall straight down. Neglect air resistance. When we compare their kinetic energies after they have fallen equal distances, we find that A) K_B = K_A. B) K_B = 2K_A. C) K_B = 4K_A. D) K_A = 2K_B. E) K_A = 4K_B.

Question

Quizplus · Accepted Answer

The kinetic energy (K) of an object is given by K = 0.5 * m * v^2. Since both masses fall the same distance, they have the same velocity. Therefore, K_B = 0.5 * M_B * v^2 = 0.5 * (2M_A) * v^2 = 2 * (0.5 * M_A * v^2) = 2K_A.

Two Masses, MA and MB, with MB = 2MA, Are

Two Masses, M_A and M_B, with M_B = 2M_A, Are