HEAT TRANSFER SHOW SOLUTION 5. The roof of an electrically heated home is 6 m long, 8 m wide, and 0.25 m thick, and is made of a flat layer of concrete whose thermal conductivity is k 0.8 W/m · °C .The temperatures of the inner and the outer surfaces of the roof one night are measured to be 15°C and 4°C, respectively, for a period of 10 hours. Determine (a) the rate of heat loss through the roof that night b. heat flux though the roof     a. 35.21 W/m2, 1690 W b. 1690 W, 35.21 W/m2 c. 1960 W, 53.21 W/m2

In a physics lab, students are conducting an experiment to learn about the heat capacity of different materials. The first group is instructed to add a number of 1.50 g pellets made of lead, at a temperature of 92.0°C, to 305 g of water at 16.0°C. A second group is given the same number of 1.50 g pellets as the first group, but these are now aluminum pellets. Assume that no heat is lost to or gained from the surroundings for either group. (a) If the final equilibrium temperature of the lead pellets and water is 25.0°C, how many whole pellets did the first group use in the experiment? The specific heat of lead is 0.0305 kcal/(kg · °C). pellets (b) Will the final equilibrium temperature for the second group be higher, lower, or the same as for the first group? The specific heat of aluminum is 0.215 kcal/(kg · °C). O higher O lower O the same (c) What is the equilibrium temperature of the aluminum and water mixture for the second group? °C

Suppose a walrus transfers energy by conduction through its blubber at the rate of 125 W when immersed in -1.25°C water. The walrus’s internal core temperature is 37.0°C, and it has a surface area of 1.85 m2. Chart attached. What is the average thickness of its blubber, in centimeters, which has the conductivity of fatty tissue?

1.