試題詳解

2. A small ball of mass m is suspended in an elevator by a string of length L. The string does not stretch and its mass can be ignored. If the elevator located at the surface of the Earth and moves upward with an acceleration a, what is the frequency of the ball's oscillatory motion?
(A) m(g - a)/(2πL),
(B) m(g +a)/(2πL),
(C)
(D)
(E)Here g is the gravitational acceleration on Earth's surface.