1. A washing machine drum has a radius of 25 cm. The drum is rotated from rest by an electrical motor until it is rotating 11 times per second. The drum takes 0.50 seconds to be sped up by the motor. What constant torque must the electrical motor apply if the washing machine contains wet clothes weighing 4.0 kg and we assume that the clothes distribute themselves uniformly around the rim of the washing machine drum? The moment of inertia of a thin cylindrical shell is I = MR^2.
1. A washing machine drum has a radius of 25 cm. The drum is rotated from rest by an electrical motor until it is rotating 11 times per second. The drum takes 0.50 seconds to be sped up by the motor. What constant torque must the electrical motor apply if the washing machine contains wet clothes weighing 4.0 kg and we assume that the clothes distribute themselves uniformly around the rim of the washing machine drum? The moment of inertia of a thin cylindrical shell is I = MR^2.
2. Assuming the electrical motors apply a constant torque, through what angle does the washing machine drum rotate in the 0.50 seconds it takes to be sped up by the motor?
3. If the washing machine contains instead 8 kg of wet clothes, explain what would happen differently to the case with 4 kg of wet clothes and why. Would it take longer or shorter to spin up the drum? Would the electrical motor use more or less energy? Assume that the electrical motor will apply the same torque and the drum is sped up to the same rate of rotation.
4. During the rapid rotation of the washing machine, water is removed from the clothes through small holes in the walls of the drum. Explain in terms of Newton's laws of motion and conservation laws why water can be removed in this way.
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