Answer:
(a) Maximum torque is 19.63 KN.m for a diameter of 100 mm.
(b) Maximum torque is 13.42 KN.m for a hollow rod of outer diameter 100 mm and inner diameter 75 mm.
Explanation:
The maximum torque is given by the formula:
Tmax = τmax J/c
(a)
J = (π/2)r^4 = (π/2)(0.05 m)^4
J = 9.8174 x 
T = (100
Pa)(9.8174 x
)/0.05 m
<u>T = 19.63 KN.m</u>
(b)
J = (π/2)(r1^4 - r2^4) = (π/2)[(0.05 m)^4 - (0.0375 m)^4
J = 6.711 x 
for maximum torque, we will take c = external radius = 0.05 m
T = (100
Pa)(6.711 x
)/0.05 m
<u>T = 13.42 KN.m</u>
The shear stress distribution along a radial line in each case is given in the attachement.