1. The problem statement, all variables and given/known data A wheel with rotational inertia I = 0.5MR^2 about its central axle is set spinning with initial angular speed w and is then lowered onto the ground so that it touches the ground with no horizontal speed. Initially it slips, but then begins to move forward and eventually rolls without slipping. What is the wheel's final translational speed? 2. Relevant equations I know that the torque where the wheel touches the ground is MgR*mu and that the angular momentum is initially Iw. Thus the angular momentum at time t is I*(w-2*g*mu*w*t/R) 3. The attempt at a solution I am missing something conceptual here. What does it mean physically so that the angular momentum decreases in such a way that it translates into linear momentum?