Question

How many times a wheel of radius $28cm$ must rotate to go $352m$? (Take $\pi =\frac{22}{7}$)

Answer 1

Step 1: Find the circumference of the wheel

The circumference of the wheel is given as

$C=2\mathrm{\pi r}$

$$\begin{gathered} C=2\times \frac{22}{7}\times 28\left[\because \pi =\frac{22}{7}\right] \\ C=176cm \end{gathered}$$

Step 2 : Find the number of rotations

$\mathrm{The}\mathrm{number}\mathrm{of}\mathrm{rotations}\mathrm{of}\mathrm{wheel}=\frac{\mathrm{Total}\mathrm{distance}\mathrm{covered}}{\mathrm{Circumference}\mathrm{of}\mathrm{the}\mathrm{wheel}}$

. $$\begin{gathered} =\frac{352\times 100}{176} \\ =200 \end{gathered}$$ $\mathbf{[}\mathbf{\because }\mathbf{1}\mathbf{}\mathbf{m}\mathbf{=}\mathbf{100}\mathbf{}\mathbf{cm}\mathbf{]}$

Hence, the given wheel completes $200$ rotations to travel $352m$.