Inelastic or elastic collision?

1. Oct 9, 2006

bearhug

A 4.0 kg firework is tossed onto a hockey rink. As it slides, it explodes into exactly two 2 kg pieces. There is an x-y coordinate system painted under the ice. One part of the exploded firework has velocity 3.0 m/s along the y direction. The other part has a velocity of 5.0 m/s at an angle of +30 degrees relative to the x-axis.
(a) What is the original speed of the firework on the ice (before the explosion)

My biggest question is that in order to solve this problem should I treat it as an inelastic collision or any collision for that matter? Since technically there is no collision, just an explosion.

2. Oct 9, 2006

Staff: Mentor

You need to decide what's conserved and what's not. What do you think?

3. Oct 9, 2006

bearhug

I was thinking it was elastic.

4. Oct 9, 2006

bearhug

seriously any help on this problem is appreciated.

5. Oct 10, 2006

Staff: Mentor

Answer my question: What's conserved and what's not conserved?