A 1 lb weight is suspended from a spring. Let y give the deflection (in inches) of the weight from its static deflection position, where “up” is the positive direction for y. If the static deflection is 24 in, ﬁnd a differential equation for y. Solve, and determine the period and frequency of the simple harmonic motion (SHM) of the weight if it is set in motion.
I'm having a hard time coming up with a solvable differential equation to the problem. I'm fairly certain that the motion can be modeled with $my'' + ky = 0$, but I don't really know where that gets me. Any ideas?