Question

The wagons wheel revolves at 45 revolution per minute. the radius of the wheel is 30cm. what its linear velocity?

Answer 1

I got `1.4m/s`

Explanation:

You know the radius so you can evaluate the circumference (the length of the rim) of your wheel as:

`C=2pir=2*3.14*30=188.4cm=1.884m`

this corresponds also to the linear distance described by the wheel during one revolution.
We have `45` revolutions (each one of length `C`) each minute (each minute formed by `60` seconds) so we can write:

`v_"linear"=45*1.884/60=1.4m/s`