Question

The diameters of front and rear wheels of a tractor are 80 cm and 2m respectively. Find the number of revolutions that rear wheel will make in covering a distance in which the front wheel makes 1400 revolutions.

Answer 1

Given diameter of front, $d_1=80cm$

And diameter of rear wheels, $d_2=2m=200cm$

$\therefore$ Radius of front wheel $\left(r_1\right)=\frac{80}{2}=40cm$

And radius of rear wheel $\left(r_2\right)=\frac{200}{2}=100cm$

$\therefore$ Circumference of the front wheel
$=2\pi r_1=\frac{2\times 22}{7}\times 40=\frac{1760}{7}$

$\therefore$ Total distance covered by front wheel
$=1400\times \frac{1760}{7}=200\times 1760$

$=352000cm$

Number of revolutions by rear wheel $=\frac{Distancecovered}{Circumference}$

$=\frac{352000}{2\times \frac{22}{7}\times 100}=\frac{7\times 3520}{2\times 22}=\frac{24640}{44}=560$