- #1

-PhysicsMajor-

- 2

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## Homework Statement

Consider an inelastic collision between two blocks on a horizontal plane. Block M1 is moving with velocity V

_{o}and collides with block M2 which is at rest. During the collision a fraction Q of the original kinetic energy is lost. It is observed that M1 is deflected by an angle theta (above the x axis), and M2 is deflected at an angle phi (below the x axis). After the collision M1 is moving to the right.

Find the angle phi, and the final velocities of the blocks.

M1=2kg

M2=4kg

V

_{o}=10m/sec

Theta=30

^{o}

Q=.2

## Homework Equations

Inital Momentum = Final Momentum (M1

_{i}V

_{o}+M2

_{i}V

_{o}=M1

_{f}V

_{f}+M2

_{f}V

_{f})

KE

_{f}= (1-Q)KE

_{i}

*I'm sure there are more but this is what I have from class.

## The Attempt at a Solution

Finding the final KE was easy enough using the above equation: KE inital =100 KE final =80

Then I tried to split them up in the x and y components. They both start with zero in the y direction and only M1 has initial momentum in the x direction. In the Y direction after the impact I got some sin and cos directions

So M1

_{i}V

_{o}= M1V1

_{f}Cos(theta)+M2V2

_{f}cos(phi)+M1V1

_{f}-M2V2

_{f}sin(phi) (negative because it is below the x axis)

If that is right (big if) I have no clue where to go from here. I really don't know how to turn the final kinetic energy into two different objects and I REALLY don't know how to find that phi angle. I'm at a complete loss.

This is my first post here so hopefully formatted the question correctly. This stuff is really stressing me out. Every time I think that I've stumbled upon something useful online, it just seems way to simple, which is pretty much a guarantee that it can't help me. Our homework consists of just a few problems over the course of a week, and when he shows examples in class my professor fills several chalkboards full of calculations. So anything that is a quick answer must be wrong.

I don't want the answer, I just need a nudge in the right direction of how to even set up the problem. I have not found a single thing online that can help with these intermediate inelastic collisions with two objects of a different mass.

This forum is my last hope.

*Way too many words, not nearly enough physics. Sorry