A weight attached to a spring is pulled down 4 inches below

A weight attached to a spring is pulled down 4 inches below the equilibrium positin.

Assuming that the frequency of the system is 8/pi cycles per second, determine a trignometric model that gives the position of the weight at time t seconds.

Solution

y = A cos ( Bt -C ) + D

A : Amplitude = -4 ......................since the weigth is pulled down by 4 inches below the equilibrium

B : Stretch on x -axis

B = 16

y = - 4 cos 16 t