The amount of heat transferred per hour through a glass window varies jointly with the surface area of the window and the difference in temperature between the areas separated by the glass. A window with a surface areaof 7.5 square feet loses 135 Btu per hour when the temperature difference is 40°F. How much heat is lost per hour for a similar window with a surface are of 12 square feet when the temperature difference is 35°F?

Heat is being transferred from the bottom of a saucepan of soup, to the top. Once convection begins, the temperature of the soup increases by 10 degrees Celsius. If it takes 3 minutes for the soup to increase temperature, and the mass of the soup is 2 kilograms, calculate the heat transferred per second in the process of increasing the soup's temperature. (The average specific heat capacity of the soup is 4000 J / kg C.) 44.4 Joules per second. 4444.4 Joules per second. 26667 Joules per second. 180 Joules per second. 444.4 Joules per second.

A hot steel plate with a surface area of 2.47 m2 and a constant surface temperature of 161°C is exposed to ambient air at 23°C.  If the convection heat transfer coefficient is 18.2 W/m2· K, what is the rate of heat transfer (in W) from the plate to the air [round your final answer to zero decimal places]?

Newton's Law of Cooling  The temperature of a cup of coffee t min after it is poured is given by the following equation where T is measured in degrees Fahrenheit. T = 65 + 90e−0.068t   (a) What was the temperature (in degrees Fahrenheit) of the coffee when it was poured? ____ °F (b) When (in minutes) will the coffee be cool enough to drink (say, 120°F)? (Round your answer to one decimal place.)  ______min