試題詳解

53. As shown in the figure below, particle 1 of mass m₁ is sliding to the right along the x-axis on a frictionless floor with velocity v₁. When it reaches x = 0, it undergoes a one-dimensional elastic collision with stationary particle 2 of mass m₂. When particle 2 reaches the wall at , (＞0), it bounces off the wall  without losing velocity. What is the condition that (0 Xw particle 2 collides only twice with particle 1? 

(A) m₂ ＜m₁
(B) 1/3 ＜ m₁/m₂ ≤ 1
(C) 1/3 ≤ m₁/m₂ ≤1
(D) 1/3 ≤ m₁/m₂ ＜ 1
(E) None of the above.