1.Estimate the energy required to raise the temperature of 2 kg (4.42 lbm) of the following materials from 20°C to 100°C (68°F to 212°F): aluminum, steel, soda–lime glass, and high-density polyethylene.
2.Design a hollow steel shaft with an inside diameter 1/3 that of the outside diameter. The shaft transmits 200 kW at a speed of 20 Hz. The allowable shearing stress is 55 MPa, and the allowable angle of twist is 1 degree per meter of length.