(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A bullet of mass 4 g moving with an initial speed of 300 m/s is fired into and passes through ta block of mass 5kg. The block, initially at rest on a frictionless horizontal surface, is connected to a spring of force constant 600 N/m. If the block moves a distance of 1.6 cm to the right after bullet passed through it, find the speed v at which the bullet emerges from the block.

2. Relevant equations

KE = 1/2 m v^2

PEspring = 1/2 k x^2

KEinitial + PEinitial = KEfinal + PEfinal

p = mv

m1v1 +m2v2 = m'1v'1 + m'2v'2

3. The attempt at a solution

I tried KEbulletinitial = PEspring = KEbulletfinal by .5mv1^2 = .5kx^2 + .5mv2^2. I guess its not a conservation of energy problem. I was thinking conservation of momentum but wasn't sure how to find the momentum of the spring. I know the fspring = kx. Any hints?

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Bullet Question

**Physics Forums | Science Articles, Homework Help, Discussion**