Chapter 2.4, Problem 30PP

(a)

To determine

The average speed of the bicycle.

Answer to Problem 30PP

The average speed of the bicycle is $40\text{km}/\text{h}$ .

Explanation of Solution

Given info:

Distance covered by the bicycle, $x=20\text{km}$

Time taken by the bicycle to cover the distance, $t=30\text{min}$

Formula Used:

The expression for the average speed of the bicycle is,

  $s=\frac{x}{t}$

Calculation:

Substitute the values in the above expression.

  $\begin{array}{c}s=\frac{20\text{km}}{\left(30\text{min}\times \frac{1\text{h}}{60\text{min}}\right)}\\ =40\text{km}/\text{h}\end{array}$

Thus, the average speed of the bicycle is $40\text{km}/\text{h}$ .

(b)

To determine

The average velocity of the bicycle.

Answer to Problem 30PP

The average velocity of the bicycle is $40\text{km}/\text{h}$ .

Explanation of Solution

Given info:

Displacement of the bicycle, $d=20\text{km}$

Time taken by the bicycle to cover the displacement, $t=30\text{min}$

Formula Used:

The expression for the average velocity of the bicycle is,

  $v=\frac{d}{t}$

Calculation:

Substitute the values in the above expression.

  $\begin{array}{c}v=\frac{20\text{km}}{\left(30\text{min}\times \frac{1\text{h}}{60\text{min}}\right)}\\ =40\text{km}/\text{h}\end{array}$

Thus, the average velocity of the bicycle is $40\text{km}/\text{h}$ .