# Rotational Motion - Disk-Disk Collision problem

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1. Feb 16, 2015

### CaptCoonoor

Hey Guys, Can you tell me how to solve this one, Need not give me direct answers but just take a look at this :

Consider two disks A and B of equal radius, let m1 be the mass of disk A and m2 be the mass of disk B, Both are moving towards each other with Velocity v1 and v2 respectively, If they collide and if they were moving on a ground with μ as the coefficient of friction, Can I calculate angular momentum/speed.. I want to dervie expression for this..

I know how to it without friction

2. Feb 16, 2015

### DEvens

You say you know how to do it without friction.

What difference will friction make to the actual collision? Presumably at this level of approximation you are treating the collision as though it took place in zero time. So the actual collision will be very much the same with or without friction.

The only difference the friction will make is in what the two disks do on their way to the collision. Or the miss if the friction were to make them miss. Hint: Could the friction make them miss? How?

3. Feb 16, 2015

### proton007007

You need to show your working on which we can build up