A cylindrical rod has length L, radius r and shear modulus n. One end of the rod is clamped. Show that a torque C applied to the other end will twist ii through an angle Ф where
Φ = 2LC/πnr1
An engine is transmitting a power of 75 kW at 1100 r.p.m. through a cylindrical drive shaft of radius 0.025 m and length 2.0 m. If the shear modulus of the material of the drive shaft is 80 GPa, calculate the angle through which it is twisted.