Kinetic Energy of a wood on a spring?

[Bottomsouth]

Homework Statement

When a piece of wood is pressed against a spring and compresses the spring by 4.00cm , the wood gains a maximum kinetic energy K when it is released.

How much kinetic energy (in terms of K) would the piece of wood gain if the spring were compressed 20.0 cm instead? K_2 = ___K

Homework Equations

K=1/2mv^2

The Attempt at a Solution

How do I begin this problem?

 

[tiny-tim]

Hi Bottomsouth!

Homework Equations

K=1/2mv^2

No, the relevant equation is the equation for the energy of a spring, which is … ?