Question

The diameter of a wheel of a bus is 90 cm which makes 315 revolutions per minute.Determine its speed in kilometers per hour. $(Use\pi =\frac{22}{7})$

Answer 1

Diameter of the wheel (d)=90 cm.

$\therefore Circumference=\pi d=\frac{22}{7}\times 90=\frac{1980}{7}cm$

Distance travelled in one minute=$\frac{1980}{7}\times 315cm=1980\times 45cm=\frac{1980\times 45}{100}m=891m$

$\therefore Distancetravelledinonehouri.e.60minutes=891\times 60=53460m=\frac{53460}{1000}=53.46km$

$\therefore Speed=53.46\frac{km}{hr}$