Chapter 3.2, Problem 21PP

To determine

To Calculate:The displacement of each person during the $4\text{s}$ interval shown on the graph.

Explanation of Solution

Given:

  

Formula used:

From the velocity-time graph, displacement can be calculated from area under the graph.

Calculation:

For person C:

Displacement can be given as area of rectangle OABC

  $\begin{array}{l}{s}_C=\text{OC × OA}\\ s_C=4\times 2\\ s_C=8\text{m}\end{array}$

For person D:

Displacement can be give as area of triangle OBC

  $\begin{array}{l}{s}_D=\frac{1}{2}\times \text{OC }\times \text{ BC}\\ s_D=\frac{1}{2}\times \text{4 }\times \text{2}\\ s_D=\text{4}\text{m}\end{array}$

Conclusion:

Displacement of C is $s_c=\text{8}\text{m}$ .

Displacement of D is $s_D=\text{4}\text{m}$ .