Ideal Mechanical Advantage Problems!  Wow!

Basic Formula: IMA = E / R * This is going to sound confusing since each simple machine has their own formula, but they all boil down to:  Effort / Resistance
IMA = Ideal Mechanical Advantage E = effort R = Resistance
 
Units: IMA is a multiplier.  Meaning it represents how much the machine will multiply the force which is put into it.  It, therefore, has no unit and would be written like:  3.  This means that whatever amount of work is put into the machine, you will get 3 times the work out.
Effort will usually be a distance: cm, m
Resistance will also usually be a distance although it needs to be the same unit as the effort so we compare apples to apples. :)

 

These problems are a bit different than any of the others we have done before.  (Many students think these are easier since there are not any units involved.) There are 6 types of simple machines, four of them have distinct formulas to calculate IMA.  They are all based on the idea of E/R, but you have to figure out what the Effort is and what the Resistance is.  This page has all the formulas for the different machines.  Once you look at the formulas, if you would like to check out some sample problems, click on this link:  <IMA sample problems>
Formulas:
IMA of a lever: IMA= length of the effort arm / length of the resistance arm
IMA of a Wheel and axle: IMA= radius of the wheel (larger) / radius of the axle (smaller wheel)
IMA of a inclined plane: IMA= length of the slope/height of the slope
IMA of a pulley: The IMA is not a formula but a counting of the number of Ropes that support the weight. (see page 191 in your book for illustrations of this)

 

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