Spring launching object up a 30° frictionless incline

[shorti2406]

I just can't seem to derive the correct formula for this one.

A spring with k=40.0 N/m is at the base of a frictionless 30 degree inclined plane. A 0.50 kg object is pressed against the spring, compressing in 0.3m from its equilibrium position. The object is then released. If the object is not attached to the spring, how far up the incline does it travel before coming to res and then sliding back down?

 

[shorti2406]

I keep getting d=.43, and I am almost positive that is not correct!

 

[whozum]

How are you solving this problem?