Q. Two blocks with masses m1 = 2.40 kg and m2 = 9.80 kg are attached over a pulley with mass M = 2.50 kg hanging straight down as in Atwood's machine. The pulley is a solid cylinder with radius 0.0510 m, and there is some friction on 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 2.25 m/s when it has dropped 1.00 m, how much mechanical energy was lost due to friction in the pulley's axle?
Q. A person stands between two speakers driven by the same source. Each speaker produces a tone with a frequency of 200 Hz on a day when the speed of sound is 330 m/s. The person is 1.65 m from one speaker and 4.95 m from the other. What type of interference does the person sense?