Chapter 2, Problem 63A

(a)

To determine

To Describe: The position of runner A relative to runner B at the y-intercept.

Explanation of Solution

Introduction:

The position-time graph is given. The slope of position-time graph gives the velocity. The y-intercept gives position of the two runners at the beginning.

At the y-intercept, the position of runner A is ahead of runner B.

(b)

To determine

To Find: The runner who is faster.

Explanation of Solution

Introduction:

The position-time graph is given. The slope of position-time graph gives the velocity. The y-intercept gives position of the two runners at the beginning.

The slope determines the velocity. The slope of runner B is steeper than that of runner A. Thus, by examining the slope of runner A and B, one can conclude that runner B is faster.

(c)

To determine

To Describe: The significance of point P.

Explanation of Solution

Introduction:

The position-time graph is given. The slope of position-time graph gives the velocity. The y-intercept gives position of the two runners at the beginning.

At the intersection point P, runner B who was initially behind runner A, overtakes. Beyond point P, runner B remains ahead of runner A.