# Homework Help: Collision of a block with a spring

1. Nov 26, 2008

### mjolnir80

1. The problem statement, all variables and given/known data
a 100g block on a frictionless table is firmly attached to one end of a spring with k = 20 N/m. the other end of the spring is anchored to the wall. a 20g ball is thrown horizontally toward the block with a speed of 5.0 m/s.
assuming that the collision is perfectly inelastic what is the speed of the ball immediately after the collision and what is the maximum compression of the spring?
2. Relevant equations

3. The attempt at a solution
so for a perfectly inelastic collision the ball and the block fuse? this one is kind of confusing me. can someone help me out with this

2. Nov 26, 2008

### nasu

Yes. They move together after collision.

3. Nov 26, 2008

### jumpman11372

Start off by writing a conservation of momentum equation. Have the initial momentum of both objects added together equal to the momentum of both masses stuck together.

m1v1 + m2v2 = (m1+m2)V ; find V and use energy equations to solve for X