Question

A wheel completes $2000$ revolutions to cover the $9.5km$ distance, then the diameter of the wheel is _____m

Answer 1

Answer: 1.5

Distance covered in n revolutions is $n.2\pi r=n.\pi D$
$\Rightarrow$ $2000\pi D=9500$
as n = 2000, distance = 9500 m
so, $D=\frac{9500}{2000\times \pi }=1.5m$