A metal rod of length 30 cm and radius 1 cm is cov- ered with an insulating material. One end of the rod is maintained at 100°C and the other end is immersed in ice at 0°C. It is found that 31.4 g of ice melts in 5 minutes. Calculate the thermal conductivity of metal. Latent heat of fusion of ice = 80 cal g.

A ceramic heater element is 30.5 cm by 10.2 cm by 5 cm. It is rated at 1500 W and emissivity of .68. The surrounding area is at 20 0C. What is the temperature of the element?

A high-pressure gas cylinder contains 50 L of toxic gas at a pressure of 1.5.107 N/m² and a temperature of 23 °C. Its valve leaks after the cylinder is dropped. The cylinder is cooled to dry ice temperature -78.5 °C to reduce the leak rate and pressure so that it can be safely repaired. (a) What is the final pressure in the tank, assuming a negligible amount of gas leaks while being cooled and that there is no phase change? P: 9837079 Pa (b) What is the final pressure if one-tenth of the gas escapes? P 8853371 Pa (c) To what temperature must the tank be cooled to reduce the pressure to 1.00 atm (assuming the gas does not change phase and that there is no leakage during cooling)? T: 200.331 K (d) Does cooling the tank appear to be a practical solution to bring the pressure down and reduce the leak? Assume N, N2. Take into account the values calculatesd in parts (a) through (c). No ! No, that's only partially correct

(a) How much heat transfer (in kcal) is required to raise the temperature of a 0.650 kg aluminum pot containing 3.00 kg of water from 10.0°C to the boiling point and then boil away 0.600 kg of water? X kcal Enter a number. (b) How long (in s) does this take if the rate of heat transfer is 600 W (1 watt = 1 joule/second (1 W = 1 J/s))?

A homeowner is unhappy with her heating costs. One wall of her house is 4 meters tall and 8 meters wide and has no windows, and it is made of brick and mortar with a thermal conductivity of 1.0 W m K . It is 40 cm thick. The house is heated to a temperature of 20 ◦C inside. (a) What is the rate of heat loss through the wall on a day when it is 0◦C outside? (b) A layer of rock mineral wool, which has a thermal conductivity of 0.032 W m K is to be installed on the interior surface of the brick wall. How thick should the layer be to lower the rate of heat transfer through this wall to half its original value? (c) If the rock mineral wool is instead installed on the outer surface, is the thickness required the same?

(a) Calculate the rate of heat conduction (in W) through house walls that are 11.5 cm thick and that have an average thermal conductivity twice that of glass wool. Assume there are no windows or doors. The surface area of the walls is 150 m2 and their inside surface is at 20.0°C, while their outside surface is at 5.00°C. 1565.21 (b) How many 1 kW room heaters would be needed to balance the heat transfer due to conduction? (Round your answer to the next whole integer.) 2 1 kW room heaters

A rod has a length of 4.6m and is made of an element which has a coefficient of linear expansion of 2.40 x 10^-5 ( C)^-1. It is initally at a temperature of 38.7C and the temperature drops to -2C. Find the change in the length of the rod in the units of mm.

A 1.82 m wide by 1.11 m high metal plate must be insulated to prevent contact burn injuries.  If the heat transfer rate is 136 W and the temperature across the insulation must be reduced from 87.3°C to 40.3°C, what is the minimum thickness (in cm) of insulation required [round your final answer to two decimal places]? {kins = 0.031 W/m∙K}