Distance covered by point on the rim

Question

Given a circular wheel that is rotating at the rate of 25 revolutions per minute. If the radius of the wheel is 50 cms, what could be the distance covered by a point on the rim in one second (Given the π = 3.1416)

Any takes? Thanks.

Answer 1

The number of revolutions per second is $$\def\textstyle{} 25{\textstyle {\text{ rev} \over \text{ min}}}\cdot\textstyle{1\over 60}\textstyle{\text{min}\over \text{sec} } ={25\over 60}{\text{rev}\over\text{sec}} ={5\over12}{\text{rev}\over\text{sec}}.$$ The point travels $\pi\cdot2\cdot50=100\pi {\text{ cm}\over\text{rev}}$ . So, in one second, the distance would be $$\underbrace{100\pi \textstyle {\text{ cm}\over\text{rev}}}_{\text{ dist per rev}}\cdot\underbrace{\textstyle {5\over12}\textstyle{\text{rev}\over\text{sec}}\cdot 1\text{sec}}_{ \text{number of revs.}}={125\pi\over3} \text{ cm}.$$

See TonyK's comment. The above is for a wheel whose center remains stationary.