A concrete slab is 10.0 cm thick and has an area of 6.00 m2. Electric heating coils are installed under the slab to melt the ice on the surface in the winter months. What minimum power must be supplied to the coils to maintain a temperature difference of 21.0°C between the bottom of the slab and its surface? Assume all the energy transferred is through the slab, and the thermal conductivity of the concrete is 1.3 J/s · m · °C.

A copper bar of thermal conductivity 401 W/(m·K) has one end at 114°C and the other end at 24.0°C. The length of the bar is 0.180 m, and the cross-sectional area is 1.00 × 10−6 m2. If two such bars were placed in series (end to end) between the same constant-temperature baths, what would the rate of heat conduction

A family comes home from a long vacation with laundry to do and showers to take. The water heater has been turned off during vacation. If the water heater has a capacity of 51.3 gallons and a 4940 W heating element, how much time is required to raise the temperature of the water from 19.4°C to 63.3°C? Assume that the heater is well insulated and no water is withdrawn from the tank during this time.

While swimming, conduction can play a big role in heat loss from the body. The body of one swimmer has a total surface area of 1.80 m2 and an average thickness of 1.60 mm. The skin's thermal conductivity is 0.370 W/m-K. If the water's temperature is 20.0°C, and the blood reaching the inner surface of the skin is at 37.0°C, what is the rate of energy loss for that person through conduction?

A closed box is filled with dry ice at a temperature of -88.3 oC, while the outside temperature is 18.8 oC. The box is cubical, measuring 0.309 m on a side, and the thickness of the walls is 3.80 × 10-2 m. In one day, 3.62 × 106 J of heat is conducted through the six walls. Find the thermal conductivity of the material from which the box is made.

The figure shows the cross section of a wall made of three layers. The thicknesses of the layers are L1, L2 =0.650 L1, and L3 = 0.350 L1. The thermal conductivities are k1, k2 = 0.900 k1, and kg = 0.600 k1. The temperatures at the left and right sides of the wall are TH = 30 °C and Tc= -20 °C, respectively. Thermal conduction is steady. (a) What is the temperature difference AT2 across layer 2 (between the left and right sides of the layer)? If k2 were, instead, equal to 1.180 kg, (b) would the rate at which energy is conducted through the wall be greater than, less than, or the same as previously, and (c) what would be the value of AT2? k1 ko k3 TH TC L1 L2 L3 (a) AT2 = i (b) (c) AT2 = i

You drop an ice cube into an insulated container full of water and wait for the ice cube to completely melt. The ice cube initially has a mass of 60.0 g and a temperature of 0°C. The water (before the ice cube is added) has a mass of 850 g and an initial temperature of 30.0°C. What is the final temperature (in °C) of the mixture? (Assume no energy is lost to the walls of the container, or to the environment.)

A large steam pipe is covered with a 4.80 cm thick insulating material with a thermal conductivity of 0.17 W/(m°C). How much energy is lost every second when the temperature of the steam inside the pipe is at 265 °C and the temperature outside of the pipe is 13.0 °C? The pipe has a diameter of 3.70 m and a length of 185 m. Neglect losses through the ends of the pipe. 3863.3 J

@ 2 O: F2 W S 8. An electric immersion heater has a power rating of 1900 W. If the heater is placed in a 1.8 kg of water at 30 °C, how many minutes will it take to bring the water to a boiling temperature? (Assume that there is no heat loss except to the water itself. Cwater=4186 J/kg.°C) min # 3 X 80 F3 E D $ 4 C F4 R TI F or do % 5 V F5 T G > 6 MacBook Air B F6 < H 887 & ◄◄ F7 U N * 8 J DII F8 M ( 9 K F9 O ) C L F10 (4) P F11 31 + 11 F12 18 BEL ?

Ice of mass 12.8 kg at 0°C is placed in an ice chest. The ice chest has 2.7 cm thick walls of thermal conductivity 0.07 W/m·K and a surface area of 1.29 m2. Express your answers with appropriate mks units. (a) How much heat must be absorbed by the ice during the melting process? (b) If the outer surface of the ice chest is at 39° C, how long will it take for the ice to melt?