# Oscillations & spring problem.

1. Aug 5, 2008

### teenholiday

A massless sping of spring constant k=74 N/m is hanging from the ceiling. A 490g mass is hooked onto the unstretched spring and allowed to drop. Find the amplitude and the period of the resulting motion.

Attempt:
F= -kx

x= A cos (wt)
w = sqrt(k/m) t

I'm trying to solve for A, but how do I get rid of the t variable?

Thanks

2. Aug 5, 2008

### rock.freak667

Find $\omega$ and you could use the fact that at max displacement from the equilibrium posistion, velocty=0.