Applications of Newton’s Second Law When a round or spherical object rolls without slipping, the track it makes is similar to a tangent, so it advances at its tangential velocity. The same is true for a rope, chain or belt that moves around a wheel or pulley without slipping. VT=Rω aT=Rα

9-5 Rotaional Kinetic Energy Get a copy of Sample problem 8E Conservation of mechanical energy. Work through the solution and then work Practice 8E number 1, show all work, and answer the question. The original energy is all potential energy gravitational, or mgh. The kinetic energy is divided among ½ mv2 for linear KE and ½ Iω2, for rotational KE. Note how the units are converted so the KEs can be combined. Solve for velocity final and compare the results.

Rolling With Slipping When a ball has enough frictional force, the ball will roll without slipping. When a ball or other round object meets the nonslip condition vcm= Rω

Power P=dW/dt = (τ dθ)/dt=τω