Question

A bicyclist travels $21$miles in $1$hours and $45$minutes. What is her average velocity during the entire $1\frac{3}{4}$ hour time interval?

Answer 1

Find the average velocity.

The formula of average velocity is defined as follows:

$\Delta v=\frac{\Delta d}{\Delta t}$

Where, $\Delta v,\Delta d,$ and $\Delta t$ are velocity, distance, and time.

Substitute $\Delta d=21,\Delta t=1\frac{3}{4}=\frac{7}{4}$ in the above formula:

$\begin{array}{rcl}\Delta v& =& \frac{21}{\frac{7}{4}}\\ & =& 21·\frac{4}{7}\\ & =& 12\raisebox{1ex}{$\mathrm{miles}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{hours}$}\right.\end{array}$

Therefore, the average velocity is $\mathbf{12}\mathbf{}\raisebox{1ex}{$\mathbf{miles}$}\!\left/ \!\raisebox{-1ex}{$\mathbf{hours}$}\right.$.