### Home > CALC > Chapter 7 > Lesson 7.4.4 > Problem7-213

7-213.

Regina's position along a straight wooden bridge is given by $x =\operatorname{log} t$ , where $x$ is measured in feet and $t$ is measured in seconds. At $t = 1$ she passed her friend Angela who was going the other way, and at $t = 10$ she stopped to gaze at the water below.

1. Find her average velocity in the interval $1 ≤ t ≤ 10$.

$\text{average velocity}=\frac{\text{displacement}}{\text{time}}$

2. At what time in this interval was she traveling at her average velocity?

This is an application of the Mean Value Theorem, which guarantees that, on a closed interval, IROC $=$ AROC somewhere if the function is continuous and differentable.