Two blocks with masses m1 = 2 kg and m2 = 9 kg are attached over a pulley with mass M = 3 kg, hanging straight down as in Atwood's machine (Fig. 8.28b). The pulley is a solid cylinder with a radius 0.05 m, and there is some friction in the axle. The system is released from rest, and the string moves without slipping over the pulley. If the larger mass is traveling at a speed of 2.5 m/s when it has dropped 1.0 m, how much mechanical energy is lost due to the friction of the pulley?