单摆周期式的推导.pdf

F x x F = −kx k m x a t k F = ma = −kx a = − x m a x x x d 2 x k a a F 2 dt m 2 d 2 x 2 = − x dt 2 x x = A sin(t + ) k 2 = = m T m T = 2 k l T A T B G1 P O G2 G G O G 1 1 T O G T O