A 2-in. copper cylinder, 6 in. in length, at a uniform temperature of 200°F, is plunged vertically into a large tank of water at 50°F.
a. How long will it take for the outside surface of the cylinder to reach 100°F?
b. How long will it take for the center of the cylinder to reach 100°F?
c. What is the surface temperature when the center temperature is 100°F? Heat transfer from ends of the cylinder may be neglected.