A sheet of glass 1/4 in. thick, 3 ft wide, and 4 ft tall is at an initial temperature of 50°F. It is heated to 75°F by two air streams, one on either side of the glass. Th e air temperature is 90°F,...

A sheet of glass 1/4 in. thick, 3 ft wide, and 4 ft tall is at an initial temperature of 50°F. It is heated to 75°F by two air streams, one on either side of the glass. Th e air temperature is 90°F, and the convection coeffi cient between the air and the glass is 2 BTU/(hr · ft2 · °R). Determine the time required for the process to occur. Graph the instantaneous heat transferred as a function of time.