1. The problem statement, all variables and given/known data Disk P (inertia 0.41 kg ) moves at an unknown velocity across a low-friction horizontal surface and collides with disk Q (inertia 0.75 kg ), which is initially at rest. After the collision, the two (now slightly dented) disks move apart without spinning. Velocity information is provided in the initial and final top-view diagrams in the (Figure 1) . What was the initial velocity of disk P? What fraction of the initial kinetic energy is converted during the collision? 2. Relevant equations v1im1 + v2im2 = v1fm1 + v2fm2 3. The attempt at a solution So I know you use conservation of momentum, but I'm not entirely sure how to set up the equations to include theta.