Question

A steel sphere with a diameter is to be hardened by heating and quenching in water. Given data: surface heat transfer coefficient, thermal conductivity of steel, specific heat of steel, and density of steel. Calculate:

(a) Time elapsed in cooling the surface to
(b) Time elapsed in cooling the center to

Answer 1

To calculate the time elapsed in cooling the surface and center of the steel sphere, use the formula for heat transfer through conduction and rearrange the equation to solve for time.

Step-by-step explanation:

The time elapsed in cooling the surface and center of a steel sphere can be calculated using the equations for heat transfer through conduction. To calculate the time elapsed in cooling the surface and center of the steel sphere, use the formula for heat transfer through conduction and rearrange the equation to solve for time.

The rate of heat transfer can be determined using the formula Q/t = kA(T2-T1)/d, where Q/t is the rate of heat transfer, k is the thermal conductivity of steel, A is the surface area, T2 and T1 are the final and initial temperatures respectively, and d is the thickness of the sphere. The time elapsed can then be found by rearranging the equation to solve for t.