1. The problem statement, all variables and given/known data A spool of thin wire (with inner radius r = 0.40 m, outer radius R = 0.55 m, and moment of inertia I_cm = 0.7139 kg*m^2) pivots on a shaft. The wire is pulled down by a mass M = 1.350 kg. After falling a distance D = 0.550 m, starting from rest, the mass has a speed of v = 65.4 cm/s. Calculate the energy lost to friction during that time. im not really sure how to do this. i would like any ideas.