SEARCH HOME
 Math Central Quandaries & Queries
 Question from Kenzi, a student: A wheel of radius 14 inches is rotating 45°/sec. What is the linear speed in in/sec and the angular speed in RPM? (Round your answers to three decimal places) I already found the linear speed. I got 10.996 in/sec. I don't know how to find the angular speed.

Hi Kenzi,

$\large\frac{360}{45} = 8$ so the wheel rotates one eights of a revolution per second.

$\frac18 \frac{\mbox{revolutions}}{\mbox{second}} \times \frac{60}{1} \frac{\mbox{seconds}}{\mbox{minute}} = \frac{60}{8} \mbox{RPM.}$

Penny

Math Central is supported by the University of Regina and the Imperial Oil Foundation.