Finding the Right Place for the Fulcrum
24) Where would you place the fulcrum for a 33-foot lever, if
at one end there is 100 pounds and 60 pounds on the other?
100 * x = 60(33-x)
100x = 1980 -60x
160x = 1980
x = 12.375
The fulcrum would be placed 12.375 feet away from the 100 pound
weight -- or 12 feet and 4 and 1/2 inches. NOTE: 0.375 (feet)
* 12 (inches) = 4.5 (inches)
When we plug the 12.375 into the term for the 60 pound weight
(33-x), we have 33-12.375 = 20.625 -- or 20 feet and 7 and 1/2
inches. It, therefore, will be that far away from the fulcrum.
Let's now double-check:
100 * 12.375 = 60 * 20.625
1,237.5 = 1,237.5