1. The problem statement, all variables and given/known data A ball of clay of mass m travels with velocity v in a path tangent to a disk of radius R and mass M. The clay collides with the disk tangentially to its outer rim (a totally inelastic collision) and the clay and disk begin to spin about the axis. What is the final angular speed of the clay and disk? 2. Relevant equations I don't know any? 3. The attempt at a solution I found some random equations which I tried using. m*v+M*v2*cos (theta) = (m+M) * vf*cos (theta)f. And M*v2*sin (theta)= (m+M)*vf*sin (theta)f. I just plugged in the values but I got weird answers. I got mv/(m+M)*vf*cos(theta)f. I also got 0=vf * sin (theta)f. Then I took the arcsin for the second equation and got (theta)f=0. So I ended up with mv/(m+M)=vf I would just like somebody to show me a step by step solution and the correct equations to use. Any help appreciated though!!