# Work done by spring

1. Feb 16, 2009

### magma_saber

1. The problem statement, all variables and given/known data
A mass of 0.103 kg hangs from a spring. you pull the mass down and has a speed 3.60 m/s. The mass moves down .10 m.
What was the work done by the earth?
When the mass moved downward, it slowed down to 2.66 m/s. What was the work done by the spring.

2. Relevant equations
Work done by earth = m*g*d
Work done by spring = 1/2 m*$$\Delta$$v2?

3. The attempt at a solution
I got the work done by the earth to be 0.10094 J.
I can't seem to get the work done by the spring. Is that the right formula? Am i suppose to take the rest energy of the spring and add that to the work done by the Earth?

2. Feb 16, 2009

### cse63146

Use conservation of energy problem $$E_i = E_f$$ to determine work done by the spring.