You are here:

Advanced Math/Number of Revolutions- Solution/Explanation


Number of Revolutions
Number of Revolutions  
I have attached a problem about number of revolutions with solution.  Please explain the solution.  Thanks.

The solution shows only the end result, after converting unit. It doesn't show the previous steps in which conversion factors are applied and units canceled out. I think would be clearer if the conversion factors were shown.

"In 1 min, the wheel travels π28n inches"
The missing details:
1 min n rev/min 28π in/rev = 28πn inches

"In 60 min, the wheel travels π28n60 inches"
60 min n rev/min 28π in/rev = 6028πn inches

"i.e. πx28n60/(528012) = 10"
(6028πn inches)/(60 minutes) = 10 mi/hour 5280 ft/mi 12 in/ft 1 hour/(60 minutes) = (10528012 in)/(60 min)
(6028πn) in = 10528012 in
Then they solve for n.  

Advanced Math

All Answers

Answers by Expert:

Ask Experts


Janet Yang


I can answer questions in Algebra, Basic Math, Calculus, Differential Equations, Geometry, Number Theory, and Word Problems. I would not feel comfortable answering questions in Probability and Statistics or Topology because I have not studied these in depth.


I tutor students (fifth through twelfth grades) and am a Top Contributor on Yahoo!Answers with over 24,000 math solutions.

Co-author of An Outline of Scientific Writing: For Researchers With English as a Foreign Language

I have a Bachelor's degree in Applied Mathematics from the University of California at Berkeley.

Past/Present Clients
George White Elementary School. Homework Help program at the Ridgewood Public Library, Ridgewood, NJ. Individual students.

©2017 All rights reserved.