Question

A wheel with diameter $80$cm, makes 50 revolutions per minute. How long will it take to cover a distance of $37.68$cm. ($\pi =3.14$)

Answer 1

Distance covered by wheel in 1 minute $=$ circumference of wheel $\times 50$

Here circumference of wheel$=2\pi r$

$=(2\times 3.14\times \frac{80}{2})cm$

$=251.2cm$

Hence distance covered by wheel in 1 minute$=251.2\times 50$

$=12560cm$

Hence time taken to cover 1 cm $=\left(\frac{1}{12560}\right)minutes$

Therefore time taken to cover $37.68cm=(\frac{1}{12560}\times 37.68)minutes$

$=0.003minutes$