AC has an outside diameter of 250mm and CD has an outside diameter of 150mm. Both pipes have a wall thickness of 8mm. Find the torque T if the allowable rotation between A and D is 2.5°. Gsteel= 77.2GPa, Gcopper = 44GPa. Hint: Use statics to find the torque in each segment.

B) Between two private individuals

A Carnot heat engine receives heat from a reservoir at 900$^\circ{}$C at a rate of 800 kJ/min and rejects the waste heat to the ambient air at 27$^\circ{}$C. The entire work output of the heat engine is used to drive a refrigerator that removes heat from the refrigerated space at -5$^\circ{}$C and transfers it to the same ambient air at 27$^\circ{}$C. Determine (a) the maximum rate of heat removal from the refrigerated space and (b) the total rate of heat rejection to the ambient air. Answers: (a) 4982 kJ/min, (b) 5782 kJ/min