1. The upper surface of a 50-cm-thick solid brass plate (k-109 W/m K) is being cooled by water with temperature of 10°C. The upper and lower surfaces of the solid plate maintained at constant temperatures of 60°C and 190°C, respectively. Determine the water convection heat transfer coefficient and the water temperature gradient at the upper plate surface. Water T₁,2

Consider a 1.5-m-high and 2.4-m-wide double-pane window consisting of two 3-mm-thick layers of glass (k=0.78 W/m-K) separated by a 12-mm-wide vacuum. Determine the steady rate of heat transfer through this double-pane window and the temperature of its inner surface for a day during which the room is maintained at 23°C while the temperature of the outdoors is -5°C. Take the convection heat transfer coefficients on the inner and outer surfaces of the window to be h=10 W/m2K and h2=25 W/m2.K, respectively, and disregard any heat transfer by radiation. Glass mm Frame The steady rate of heat transfer is The inner surface temperature of the window is W. °C.

A person is found dead at 5PM in a room whose temperature is 20°C. Thetemperature of the body is measured to be 25°C when found, Modeling thebody as a 30-cm-diameter, 1.70-m-long cylinder and the heat transfer coefficient estimated to be 8 W/m2·K. and using the lumped system analysis as a rough approximation, estimate the time of death of the person.

A 0.2-m-long and 25-mm-thick vertical plate (k = 15 W/m-K) separates the hot water from the cold water. The plate surface exposed to the hot water has a temperature of 100°C, and the temperature of the cold water is 7°C. Determine the temperature of the plate surface exposed to the cold water (Ts c). Start the iteration process with an initial guess of 53.5°C for the Tsc- Plate Cold water 7°C Hot water 100°C Given: The properties of water at Tfr = 30.25°C. k = 0.6033 W/m-K, p = 995.5 kg/m3, u = 0.0007935 kg/m s, B = 0.0003072 K-1 The thermal conductivity of the plate is given as kplate = 15 W/m-K.

Consider a 0.6-m * 0.6-m thin square plate in a room at 30°C. One side of the plate is maintained at a temperature of 90°C, while the other side is insulated. Determine the rate of heat transfer from the plate by natural convection if the plate is (a) vertical, (b) horizontal with hot surface facing up, and (c) horizontal with hot surface facing down.

A 0.2-m-long and 25-mm-thick vertical plate (k= 15 W/m∙K) separates the hot water from the cold water. The plate surface exposed to the hot water has a temperature of 100°C, and the temperature of the cold water is 7°C. Determine the temperature of the plate surface exposed to the cold water (Ts,c). Hint: The Ts,c has to be found iteratively. Start the iteration process with an initial guess of 53.5°C for the Ts,c .

A 40-cm-long, 800-W electric resistance heating element with diameter 0.5 cm and surface temperature 120°C is immersed in 75 kg of water initially at 20°C. Determine how long it will take for this heater to raise the water temperature to 80°C. Also, determine the convection heat transfer coefficients at the beginning and at the end of the heating process.

During a picnic on a hot summer day, the only available drinks were those at the ambient temperature of 90°F. In an effort to cool a 12-fluid-oz drink in a can, which is 5 in high and has a diameter of 2.5 in, a person grabs the can and starts shaking it in the iced water of the chest at 32°F. The temperature of the drink can be assumed to be uniform at all times, and the heat transfer coefficient between the iced water and the aluminum can is 30 Btu/h·ft2·°F. Using the properties of water for the drink, estimate how long it will take for the canned drink to cool to 40°F.

A 5.1-m internal diameter spherical tank made of 1.6-cm-thick stainless steel (k = 15 w/m- c) is used to store iced water at 0 C. the wall of the room are also at 31 C. The convection heat transfer coefficient at the inner and the outer surface of the tank are 80 w/m - c, respectively. Determine (a) the rate of heat transfer of the iced water and (b)  the amount of iced at 0 C that melts during a 24 h period. the heat of fusion of water at atmospheric pressure is 333.7 kj/kg.

A solid plate, with a thickness of 15 cm and a thermal conductivity of 80 W/m-K, is being cooled at the upper surface by air. The air temperature is 10°C, while the temperatures at the upper and lower surfaces of the plate are 50 and 60°C, respectively. Determine the convection heat transfer coefficient of air at the upper surface and discuss whether the value is reasonable or not for force convection of air. Air, T. = 10°C T1 = 50°C T2 = 60°C L = 15 cm