Question

the radius of a wheel is 42 cm how many revolutions will it take to cover 33 km

Answer 1

hi mate! here's your answer

33km= 3300000cm

circumference of the wheel=2πr

=2×22/7×42

=2×22×6

=2×132

=264

revolution taken by the wheel to cover 33km

=3300000/264

=12500 revolution

hope that it will be help you

Answer 2

$\underline{\bold{Given}}$

Radius of a wheel = 42cm.

To find ,

Number of revolution it will take to cover 33km

Let find the circumference of the wheel.

We know that ,

$\boxed{\bold{Circumference = 2\pi r}}$

According to the question,

$\implies\bold{circumference =2\pi r}$

$\implies\bold{2\times \dfrac{22}{7}\times 42cm}$

$\implies\bold{2\times \dfrac{22}{\cancel{7}}\times {\cancel{6}}}$

$\implies\bold{2\times 22\times 6cm}$

$\implies\bold{264cm}$

$\therefore{\bold{Circumference = 264cm}}$

Let find the number of revolutions it will take to cover 33km.

$\implies\bold{Number\:Of\:revolution=\dfrac{33km}{264cm}}$

First of all, let make the units same.

$\implies\bold{\dfrac{3300000}{264}}$

$\implies\bold{\dfrac{\cancel{3300000}}{\cancel{264}}}$

$\implies\bold{12500}$

To cover 33km it will take 12500 revolutions.