The Ol' Spring and Bullet Combo

[physicsbro]

Homework Statement

A 4.66 g bullet moving with an initial speed of vi = 410 m/s is fired into and passes through a 1.18 kg block.The block, initially at rest on a frictionless horizontal surface, is connected to a spring with a spring constant of 844 N/m.
a) If the block moves x = 4.01 cm to the right after impact, calculate the speed at which the bullet emerges from the block.
b) Calculate the energy lost in the collision.

Homework Equations

Not entirely sure, maybe some hooke's law, maybe a little bit of momentum and KE equations.

The Attempt at a Solution

I'm not sure where to start and any hints would be much appreciated.

 

[ideasrule]

What was the block's velocity after the bullet passed through? You can use that and the conservation of momentum equation to calculate the bullet's exit speed.

 

[physicsbro]

Thanks.