Question

A bird can fly at 25 km/h. How long does it take to fly 3.5 km?

Short answer

The bird takes 0.14 h to fly 3.5 km.

Step-by-step solution

Step 1. Relation between distance, time, and speed

The speed of an object is defined as the rate of change of position of an object in unit time. The speed of an object can be calculated as the distance traveled divided by the time taken.

Given data.

The average flying speed of the bird is $v=25\frac{\mathrm{km}}{\mathrm{h}}$.

The traveled distance of the bird is $\Delta x=3.5\mathrm{km}$.

The expression for the time taken by an object is

$\Delta t=\frac{\Delta x}{v}$.

Here, $\Delta t$is the time taken for the change in position, $\Delta x$is the distance traveled, and V is the speed of the object.

Step 2. Calculation of the time

Substituting the known values in the above expression,

$\begin{array}{c}\Delta t=\frac{3.5\mathrm{km}}{25\frac{\mathrm{km}}{\mathrm{h}}}\\ =0.14\mathrm{h}\end{array}$

Therefore, the bird takes 0.14 h to fly 3.5 km.