A 1.50-in.-diameter solid bronze [G = 6,500 ksi] shaft is used to transmit 15 hp. The length of the shaft is 42 in. If the allowable shear stress is 6,000 psi and the allowable angle of twist is 2.5 ,...

A 1.50-in.-diameter solid bronze [G = 6,500 ksi] shaft is used to transmit 15 hp. The length of the shaft is 42 in. If the allowable shear stress is 6,000 psi and the allowable angle of twist is 2.5, calculate the slowest permissible speed of rotation in Hz.