Chapter 2.4, Problem 39SSC

To determine

The difference of the average velocities between the objects A and B, objects C and D.

Answer to Problem 39SSC

The average velocity of the object A is decreasing and object A is increasing.The average velocity of the object C is decreasing and object D is increasing.

Explanation of Solution

Introduction:

The slope of the position- time graph describes the average velocity of the objects. The motion of the object may be uniform or non-uniform according to the slope of the graph.

The slope of the line of object A in the position-time graph is negative and the slope of the object B is positive, so the average velocity of the object A is decreasing and the object B is increasing. The motion of the object A is decelerated motion while the motion of the object B is accelerated motion. The average velocity of the object A and B become same at the point of intersection of the line A and line B.

The slope of the line of object C in the position-time graph is negative and the slope of the object D is positive, so the average velocity of the object C is decreasing and the object D is increasing. The motion of the object C is decelerated motion while the motion of the object D is accelerated motion. The average velocity of the object C and D become same at the point of intersection of the line A and line B.

Conclusion:

Hence, the average velocity of the object A is decreasing and object A is increasing; and the average velocity of the object C is decreasing and object D is increasing.