Learning Goal: To determine the maximum possible power transmission for a circular shaft and the minimum diameter required to avoid exceeding shear stress limits. A rotating shaft can be used to transmit mechanical power from one place to another. For example, a shaft can be connected to a motor at one end and a pulley at the other. The shaft can then transmit power from the motor to the pulley. When the machine is operating, the shaft will rotate at some angular velocity w and will be subject to a torque T. The power transmitted by the shaft is P=Tw. The shaft's rotation can also be expressed as a frequency, f, which represents the number of revolutions of the shaft per unit time. The frequency and angular velocity are related by w = 2πf. so the power can also be calculated using P=2fT. When designing a shaft, one consideration is limits on shear stress. The torsion formula Te Tallow= J relates the allowable shear stress in a circular shaft with outer radius c to the torque T. The polar moment of inertia is J = c for a solid shaft. In the SI system, the units of torque are newton-meters (N- m), and the units of power are watts ( 1 W = 1 N-m/s). In the FPS system, the basic units of torque are foot-pounds (ft-lb), and the units of power are foot-pounds per second (ft-lb/s). However, power is often expressed in horsepower, where 1 hp = 550 ft-lb/s. Part A - Transmitted power A solid circular rod is used to transmit power from a motor to a machine. The diameter of the rod is D = 1.75 in and the machine operates at w=200 rpm. If the allowable shear stress in the shaft is 10.6 ksi, what is the maximum power transmissible to the machine? Express your answer with appropriate units to three significant figures. ▸ View Available Hint(s) for Part A for Party do for Part redo for Part A recerror Part A. keyboard shortcuts for Part A help for Part A Value Units Submit Previous Answers Request Answer Part B - Minimum diameter A solid circular shaft is required to transmit P = 49 kW from a motor to a machine. The maximum allowable stress in the shaft is allow = 74 MPa. If the machine runs at w = 18 rad/s, what is the minimum diameter for the shaft? Express your answer in cm to three significant figures. ▸ View Available Hint(s) D= for Part B for Part B for Part B for Part B do for Part redo for Part B resor Part B keyboard shortcuts for Part B help for Part B Submit Request Answer cm