Question

A bicycle wheel makes 5,000 revolutions in moving 11 km. Find the diameter of the wheel. (take $\pi$ =22/7)

Answer 1

The bicycle wheel makes $5000$ revolutions in moving $11$ kms. Then in $1$ revolution the bicycle moves $\frac{11}{5000}km=\frac{11\times 1000}{5000}m$

$=2.2$m

$\therefore$ perimeter of the bicycle wheel$=2.2$m

$\Rightarrow 2\pi r=2.2$

$\Rightarrow r=2.2\times \frac{1}{2\pi }$

$\Rightarrow r=2.2\times \frac{1}{2}\times \frac{7}{22}$

$\Rightarrow r=0.35$m

Hence diameter of the wheel$=2r=0.7$m.