SEARCH HOME
Math CentralQuandaries & Queries

search

Question from Al, a parent:

how many rpm does a 3.5 in. diameter wheel turn at 7 miles per hour

Hi Al,

The wheel has diameter 3.5 inches. What is its circumference in inches?

A point on the circumference of the wheel moves at 7 miles per hour. There are 5280 feet in a mile and 12 inches in a foot so 7 miles is $7 \times 5280 \times 12$ inches. Divide that by the circumference of the wheel to determine the number of revolutions there are in an hour. How many minutes are in an hour? How many revolutions are there in a minute?

Penny

 

About Math Central
 

 


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.
Quandaries & Queries page Home page University of Regina PIMS