試題詳解

1.Cart A, of mass m, starts from rest and travels in a straight line with acceleration a. It traverses a ance x in time t. Cart B, of mass 4m, starts from rest and travels in a straight Iine with acceleration a/2. At time t it has traversed the distance
(A) x/4
(B) x/2
(C) x
(D) 2x
(E) 4x