Suppose That During the First Hour and 15 Minutes of a Physics

Multiple Choice

Suppose that during the first hour and 15 minutes of a physics experiment, the surface temperature of a small iron block is modeled by the exponential function f(t) = 15e ^t , where f(t) is the Celsius temperature t hours after the experiment begins. Compute the average rate of change of temperature over the second half hour of the experiment (i.e., over the interval $0.5 \leq t \leq 1$ ) . Round the answer to one decimal place.

A) $32.1 ^ { \circ } \mathrm { C } \text { hour }$
B) $31.8 ^ { \circ } \mathrm { C } / \text { hour }$
C) $41 ^ { \circ } \mathrm { C } / \text { hour }$
D) $32.2 ^ { \circ } \mathrm { C } / \text { hour }$
E) $33.1 ^ { \circ } \mathrm { C } / \text { hour }$