A weight hanging from the end of a spring is pulled 8 inches below its rest position. When released, the weight then exhibits simple harmonic motion, with period 1/2 second. Find an equation describing its motion

Answer 1

the amplitude is 8, so

y = 8cos(kx) or 8sin(kx)

It starts with y(0) = -8, so

y = -8cos(kx)

The period is 1/2, so 2π/k = 1/2

y = -8cos(4πx)