The diameter of a solid shaft made of mild steel rotating at 200 RPM is 40 mm. The shaft is designed to transmit 40 kW. What will be the factor of safety if the ultimate shear stress at yield is 417 N/mm2?

The diameter of a solid shaft made of mild steel rotating at 200 RPM i

1.	The diameter of a solid shaft made of mild steel rotating at 200 RPM is 40 mm. The shaft is designed to transmit 40 kW. What will be the factor of safety if the ultimate shear stress at yield is 417 N/mm2?
A.	4.5
B.	3.5
C.	2.7
D.	3.8
Answer» D. 3.8