An Object's Cooling Constant, K, Is Often Taken to Be

An object's cooling constant, k, is often taken to be proportional to the its surface area. An iron ball cools from 200^oC to 100^oC in 50 seconds in a fast flowing stream of 30^oC water. Use Newton's Law of Cooling to estimate how cool a similar volume of hot iron would become in 50 seconds if it were in the shape of a rod with surface area 4 times larger than the ball's.

A) 32.0^oC
B) 145.3^oC
C) 30.0^oC
D) 34.9^oC