Question

Calculate the rate of energy loss due to thermal radiation from an unclothed person if the average skin temperature is 37 °C and the room temperature is 20 °C. You may sume a total surface area of 1.5 m and a skin emissivity value of 0.9. How much energy (from food) must be consumed per day to compensate for this loss? If the person is surrounded by a layer of insulation of thickness 1.0 cm with a thermal conductivity of 0.05 W.m K, calculate the rate of heat transfer due to conduction. (3 marks) Argon is stored in a container of volume 2 litres at a pressure of 3 atmospheres. The amount of gas present is 0.2 mole. Find (i) the absolute temperature of the gas, (i) the number of atoms of gas in the container,iii) the total mass of the gas, and (iv) the total internal energy of the gas. You may assume that argon behaves as an ideal gas. The atomic mass of argon is 40 g.mol1. One atmosphere -1.01x10 Pa. (5 marks)

Answer 1

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ue to Con auctish hich thicknes a Jinsulation layLL o.om