A motor drives a shaft at 12 Hz and delivers 20 kW of power as shown in Fig.4. (a) If the shaft has a diameter of 30 mm, what is the maximum shear stress τmax in the shaft? (b) If the maximum allowable shear stress is 40 MPa, what is the minimum permissible diameter dmin of the shaft? A solid circular bar of diameter d = 50 mm is twisted in a testing machine until the applied torque reaches the value T = 500 Nm as shown in Fig.4. At this value of torque, a strain gage oriented at 45 ° to the axis of the bar gives a reading ε =339 ×10-6 . What is the shear modulus G of the material?

A motor drives a shaft at 12 Hz and delivers 20 kW of power as shown in Fig.4. (a) If the shaft has a diameter of 30 mm, what is the maximum shear stress τ_max in the shaft? (b) If the maximum allowable shear stress is 40 MPa, what is the minimum permissible diameter d_min of the shaft?

A solid circular bar of diameter d = 50 mm is twisted in a testing machine until the applied torque reaches the value T = 500 Nm as shown in Fig.4. At this value of torque, a strain gage oriented at 45 ° to the axis of the bar gives a reading ε =339 ×10^-6 . What is the shear modulus G of the material?