Question

The diameter of a cycle wheel is $21cm$. How many revolutions will it make to travel $1.98km$?

Answer 1

Diameter of wheel $=21cm$

Radius $=\frac{21}{2}=10.5cm$

So circumference $=2\times \pi \times r$

$=2\times \frac{22}{7}\times 10.5$

$=66cm$

As we know that

Total no. of revolutions

$=\frac{Distancetobetravelled}{Circumferenceofwheel}$

$=\frac{(1.98\times 1000\times 100)}{66}$

$=\frac{198000}{66}$

$=3000$