Education ide onoxide ght McGraw Rele Ar CH 0.2870 กาก CO. Tablo points) Consider a flat-plate solar collector placed horizontally on the flat roof of a house. The collector is 5 ft wide and 15 ft long, and the average temperature of the exposed surface of the collector is 100 °F. a) Determine the rate of heat loss from the collector by convection. Assume it is a calm day when the ambient air temperature is 70 °F and the convection heat transfer coefficient on the exposed surface is 2.5 Btu/h-ft2.°F. and b) Determine the rate of heat loss from the collector by radiation. Assume the effective sky temperature for radiation exchange is 50 °F and the emissivity of the exposed surface of the collector is 0.9. c) Given these two types of losses, determine how much energy is being collected when the incoming solar radiation is 23,885 Btu/hr. Toky 70°F = 50°F Solar collector

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Thermal question. A system has two thermal layers. The first layer has a Rth 0.5 K/W, and Cth 0.8 J/K, and the second layer has a Rth 0.2 K/W, and Cth  0.4 J/K. The ambient air temperature is 50 °C. The power dissipation in the system is 100 W. What is the temperature of the second layer 5 s after a system is switched off? Please do not include any units in your answer.

A piece of silver wire has a resistance of 1 ohm. Determine the resistance of alead wire one-third the length and one-third the diameter if the resistivity of lead wire is 30 times that of silver. NOTE: Please explain where did you get the variables so I can understand them. Thank you