An object attached to a coiled spring is pulled down a dista

An object attached to a coiled spring is pulled down a distance a from its rest position and then released. Assuming that the motion is simple harmonic with period T, write an equation that relates the displacement d of the object from its rest position after t seconds. Also assume that the positive direction of the motion is up. a = 8; T = 3 seconds a. d = -3 cos(1 /4 pie t) b. d = -8 cos (2 /3 pie t) c. d = -8 sin(2 /3pie t) d.d = -8 cos (1 /3pie t)

Solution

Comparing with y = acos(bx)

T = 3 seconds

==> 2/b = 3

==> b = 2/3

Initially it is 8 units below from the rest position

so a = -8

so equation is y = -8cos[(2/3)t]