# Spring/incline problem

1. Oct 18, 2009

### sfram35

1. The problem statement, all variables and given/known data
A spring (80 { N/m} has an equilibrium length of 1.00 { m}. The spring is compressed to a length of 0.50 {m} and a mass of 2.1 { kg} is placed at its free end on a frictionless slope which makes an angle of 41 degrees with respect to the horizontal. The spring is then released.
If the mass is not attached to the spring, how far up the slope will the mass move before coming to rest? If the mass is attached to the spring, how far up the slope will the mass move before coming to rest? Now the incline has a coefficient of kinetic friction uk. If the block, attached to the spring, is observed to stop just as it reaches the spring's equilibrium position, what is the coefficient of friction uk?

2. Relevant equations

PE(spring)=1/2kx^2
PE(gravitational)=mgh
KE=1/2mv^2

3. The attempt at a solution

I think you have to use conservation of energy where the equation would be:

mgh=1/2mv^2+1/2kx^2