Chapter 2, Problem 12STP

To determine

To identify: whether all of the swimmer swim at a constant speed or not.

To explain:reason for the above occurrence.

Answer to Problem 12STP

Only B and C swim at a constant speed.

Explanation of Solution

Given:

The distance vs. time graph.

Formula used:

The average speed is

  $s=\frac{d}{t}$  ...... (1)

Here, $d$ and $t$ are distance and time taken to travel.

Calculation:

The slope of the distance-time graph is the speed of the runner. From the graph, it is found that the slope of swimmer C is greater than other swimmers. To specific a constant speed of the swimmer, the slope along the graph lines needs to be constant throughout the time interval of 30 min.

It is evident from the above graph, swimmer B and C have constant speed but not A . This is because swimmer A stopped his work at 400 m between time interval 10 min to 20 min, so his speed between this time intervals is zero.

Conclusion:

Hence,except swimmer A , rest two swimmer have the same constant speed.