Question

A customer service person in a department store is wrapping packages for customers. The ribbon spool she uses has 13.7 m of ribbon wound on it. The radius of the spool is 12.0 cm and its moment of inertia is 0.37 kg = m^2. As the spool turns, friction forces cause a torque of C.17 N middot m to act on it. The spool is initially at rest. The service person pulls on the spool with a constant tension of 14.5 N. Determine the time it takes to unwind 4.0 m of the ribbon, assuming there is no slippage and the mass of the ribbon is negligible.

Answer 1