Calculating Height of a Pebbled Launched by a Catapult

[Jtappan]

Homework Statement

You shoot a 57 g pebble straight up with a catapult whose spring constant is 310 N/m. The catapult is initially stretched by 0.30 m. How high above the starting point does the pebble fly? Ignore air resistance.
_____ m

Homework Equations

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The Attempt at a Solution

I am totally lost...this incorporates gravity and the spring...and ah...my head hurts...any one help?

 

[Anadyne]

There's more than one way to solve this problem. Do you want to use the force of the spring to figure out its acceleration?

Or to use conservation of energy?

Can you think of any equations that might help you?