Chapter 1, Problem 1.26P

Quenching is the process of immersing a hot metal object in a bath for a specified time to improve properties such as hardness. A copper sphere 25 mm in diameter, initially at 300°C, is immersed in a bath at 0°C. Measurements of the sphere’s temperature versus time are shown here. Plot the data and find a functional description of the data.

$\begin{array}{llllllll}\text{Times}\left(\text{s}\right)\hfill & 0\hfill & 0.1\hfill & 0.2\hfill & 0.3\hfill & 0.4\hfill & 0.5\hfill & 0.6\hfill \\ \text{Temperature }\left(\text{°C}\right)\hfill & 300\hfill & 150\hfill & 75\hfill & 35\hfill & 12\hfill & 5\hfill & 0\hfill \end{array}$