I am having quite a bit of trouble with this problem. I would greatly appreciate any and all help and advice. Here's the problem:(adsbygoogle = window.adsbygoogle || []).push({});

A fire cracker is thrown with velocity 12.0 m/s [W]. While moving in this direction, it explodes into two pieces. One piece has a mass of 2.1 g and moves with velocity 10.0 m/s [W 70 S] What is the velocity of the other piece which has a mass of 1.1 g?

Ok. So far I understand that the fire cracker's momentum is

Pfc=12m/s(3.3 g)= 39.6 gm/s

The first pieces momentum is

P1= 2.1 g(10m/s)= 21 gm/s

i am having trouble deciding how to approach finding the velocity of the other peice.

Do i use P total (before)= P total (after)???

And once I find the velocity how do i figure out which direction the piece is moving???

Thanks for any help you smart people can provide.

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# Homework Help: 3D Momentum Problem

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