Chapter 4, Problem 58A

By any method you choose, determine your average speed of walking. How do your results compare with those of your classmates?

To determine

Average speed of walking.

To compare: The average speed of a person with his friend.

Answer to Problem 58A

Average speed of walking of a person is $v=6\frac{\text{km}}{\text{h}}$

Average speed of walking of his friend is $v=6\frac{\text{km}}{\text{h}}$

Explanation of Solution

Given:

Suppose, a person travelled 6000 m distance in 60 minutes. His friend travelled 5000 m in 1 hour.

Formula used:

Average speed is given as,

  $v=\frac{d}{t}$

Calculation:

The distance travelled and time of a person is

  $d=6000$ m

  $t=60$ minutes

So, average speed of walking is

  $\begin{array}{c}v=\frac{6000\mathrm{m}}{60\min }\\ =\frac{6000\text{m}}{60\min }\times \frac{60\min }{1\text{h}}\times \frac{1\text{km}}{1000\text{m}}\\ =6\frac{\text{km}}{\text{h}}\end{array}$

Now, consider his friend case. Distance travelled and time taken by friend is

  $d=5000$ m

  $t=1\text{h}$

So, average walking speed is,

  $\begin{array}{c}{v}_F=\frac{5000\text{m}}{1\text{h}}\\ =\frac{5000\text{m}}{1\text{h}}\times \frac{1\text{km}}{1000\text{m}}\\ =5\frac{\text{km}}{\text{h}}\end{array}$

Hence, from the above calculations it is observed that average speed will increase if the distance travelled by a person is more for the same time.