A short brass cylinder of diameter D 10 cm and height H 12 cm is initially
at a uniform temperature Ti 120
C. The cylinder is now placed in atmospheric
air at 25
C, where heat transfer takes place by convection, with a heat
transfer coefficient of h 60 W/m2 ·
C. Calculate the temperature at (a) the
center of the cylinder and (b) the center of the top surface of the cylinder
15 min after the start of the cooling.