Aten-centimeter radius thorium sphere with a thermal conductivity of 55 w/mk experiences a uniform heat generation rate of 1x106 w/m. the sphere is surrounded by air at 20°c with a film coefficient of 500 w/m-k. determine the total heat transfer from the sphere to the air and the temperatures at the following locations: (1) the sphere center; (2) at a radius of 5 cm; and (3) at the sphere surface.

Asolid cylinder is concentric with a straight pipe. the cylinder is 0.5 m long and has an outside diameter of 8 cm. the pipe has an inside diameter of 8.5 cm. the annulus between the cylinder ad the pipe contains stationary oil. the oil has a specific gravity of 0.92 and a kinematic viscosity of 5.57 x 10-4 m2/s. most nearly, what is the force needed to move the cylinder along the pipe at a constant velocity of 1 m/s?