A steel rod, which is free to move, has a length of 200 mm and a diameter of 20 mm at a temperature of 15oC.  If the rod is heated uniformly to 115oC, determine the length and diameter of this rod to the nearest micron at the new temperature if the linear coefficient of thermal expansion of steel is                   12.5 x 10-6 m/m/C.  Is there a stress on the rod at 115oC?

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A plastic material has creep behaviour at 20 oC which can be given by: with J0 = 0.24 GPa-1, J1 = 0.22 GPa-1s-0.4 and n = 0.4 A pipe of this material has a diameter of 7.3 cm, and a wall thickness of 5 mm. The pipe is filled with water and the pressure is increased at a constant rate of 2 kPa.s-1 starting at t = 0 until it reaches 607 kPa. The pressure is then held at 607 kPa. What would the maximum strain in the pipe be 2 hours after the pressure started to increase (when t = 2 hours)? The temperature is 20 oC throughout. Give your answer as a number, with no units to 4 dp (ie don't use standard notation). You have an error margin of 2%.

3-52 A 4-m-high and 6-m-wide wall consists of a long 18-cm X 30-cm cross section of horizontal bricks (k = 0.72 W/m . °C) separated by 3-cm-thick plaster layers (k = 0.22 W/m . °C). There are also 2-cm-thick plaster layers on each side of the wall, and a 2-cm-thick rigid foam (k = 0.026 W/m - °C) on the inner side of the wall. The indoor and the outdoor temperatures are 22°C and −4°C, and the convec- tion heat transfer coefficients on the inner and the outer sides are h₁ = 10 W/m² . °℃ and h₂ = 20 W/m². °C, respectively. Assuming one-dimensional heat transfer and disregarding radi- ation, determine the rate of heat transfer through the wall. Foam Plaster Brick 1+₂+18 2 FIGURE P3-52 18 cm N 1.5 cm 30 cm 1.5 cm

An airplane has a half-wingspan of 40 m. Determine the change in length of the aluminum alloy [a = 22.0 × 10-6/°C] wing spar if the plane leaves the ground at a temperature of 20°C and climbs to an altitude where the temperature is -47°C. Answer: 5 - i mm