Example 2.8 from College Physics, 2.5 Motion Equations for Constant Acceleration in One Dimension

Calculating Displacement: How Far does the Jogger Run?

A jogger runs down a straight stretch of road with an average velocity of 4.00 m/s for 2.00 min. What is his final position, taking his initial position to be zero?

Work it out on paper first. Then open the solution one step at a time, and stop as soon as you can finish on your own.

Strategy
Draw a sketch.

Figure 2.26
The final position $x$ is given by the equation

$x = x_{0} + \bar{v} t .$
2.31

To find $x$ , we identify the values of $x_{0}$ , $\bar{v}$ , and $t$ from the statement of the problem and substitute them into the equation.
Solution
1. Identify the knowns. $\bar{v} = 4 . 00 m/s$ , $Δ t = 2 . 00 min$ , and $x_{0} = 0 m$ .
2. Enter the known values into the equation.

$x = x_{0} + \bar{v} t = 0 + (4 . 00 m/s) (120 s) = 480 m$
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Discussion
Velocity and final displacement are both positive, which means they are in the same direction.

0 of 3 steps open

How did it go?

Strategy

Solution

Discussion

Strategy

Solution

Discussion