x ( t ) = A sin ( ω t + φ )
v x ( t ) = A ω cos ( ω t + φ )
a x ( t ) = − A ω 2 sin ( ω t + φ )
F x ( t ) = − m A ω 2 sin ( ω t + φ )
T = 2 π l g
T = 2 π m k