Efficiency Problems!  Let me at them!!!

Basic Formula: E = (Fr x dr ) / (Fe x de) x 100

 or

E =Workout  / Workin x 100

E = Efficiency dr = resistance distance Fr = resistance force
  de =  effort distance Fe = effort force
Units: Work will always be a distance unit times a force unit. It is usually a newton*meter (Nm) - also known as a Joule (J)
Distance unit:  m (meters) 
Force units: usually in N (newtons) <Yes, in honor of Sir Isaac>

 

These problems are not really very hard to solve as long as you match the given numbers (usually using their units) with the formula above.  The hardest part of these problems is figuring out what the resistance and effort forces are. Look below for some quick references, then  if you would like to check out some sample problems, click on this link:  <efficiency sample problems>

 

Determining the resistances and efforts:
Resistance Force: This will be the force which comes out of the work being done.  If you had to lift a 300N box, then the resistance force would be the 300N.  It is how much resistance the box had to moving.
Resistance Distance: This would be the total distance you actually had to move that box, if you needed to ultimately lift it 2 meters, (no matter how you got it there, the ultimate distance it had to go was 2.0 meters up).  This would be your resistance distance.
Effort Force This is how much effort you, the person (or machine) doing work had to put into the movement in order to do work on the object.  If it took you 500N to move to that box, that would the amount of effort you had to put in.
Effort Distance This is how far you had to apply that effort force.  It could have been longer or shorter than the resistance distance depending on the machine you are using.  Either way, it is how far you have apply the needed force.

 

 

Last Updated: April 8, 2005.  All Rights Reserved.  If you have any questions or comments, please contact the IPCWebmaster. test