1. (15) Below is a cross section of a modern pool ball made of phenolic resin. Did you know that the white core ran all the way through the ball? Long ago, pool balls were made of ivory, but we all know that was not a good idea due to the decimation of elephants for their tusks that sadly continues even today. Molecular cross linking of sections resists to 5 tons of pressure. Center core runs all the way through the ball 3 CNC engraved number Coloured throughout the mass The phenolic resin has a thermal conductivity of 0.16 W/m-C, a density of 1346 kg/m, and a specific heat of 1350 J/kg-C. American pool balls have a diameter of 57 mm. During manufacturing the balls are heated to form them and then allowed to cool slowly in air. The process is actually quite complicated, but we will just model a part of it. Assume they cool from an initial temperature of 175 C with h = 15 W/m-C and at an ambient temperature of 20 C. Plot the ball centerline temperature and the ball surface temperature from time = 0 (when they start cooling) for 2 hours.