College Physics with MasteringPhysics 7th Edition by Jerry Wilson,Anthony Buffa,Bo Lou

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Two masses are suspended from a pulley as shown in Fig 1. (the Atwood machine revisited; see Chapter 4, Exercise). The pulley itself has a mass of 0.20 kg, a radius of 0.15 m, and a constant torque of 0.35 m · N due to the friction between the rotating pulley and its axle. What is the magnitude of the acceleration of the suspended masses if m 1 = 0.40 kg and m 2 = 0.80 kg (Neglect the mass of the string.)

FIGURE 1 The Atwood machine revisited See Exercise.
Exercise
The Atwood machine consists of two masses suspended from a fixed pulley, as shown in Fig. 2. It is named after the British scientist George Atwood (1746-1807), who used it to study motion and to measure the value of g. If m 1 = 0.55 kg and m 2 = 0.80 kg, (a) what is the acceleration of the system, and (b) what is the magnitude of the tension in the string

FIGURE 2 Atwood machine See Exercise.