Finding the Right Weight for the Lever

    21)  If 50 pounds were placed on a lever, 3 feet to the left 
of the fulcrum, how much weight would have to be placed at 5 feet
to the right of the fulcrum to have an even balance?

    Using the lever formula makes figuring problems of this nature
very simple.

    When we think of a lever, we might think of a teeter-totter on
which if weight were placed just right, by scooting up or  scooting
back, there could be an even balance -- regardless  of how different
the two people were in weight..

    Here's the formula:

        weight * distance = distance * weight

    e.g.  100 * 6 =  10 * 60  This means that  on our lever we 
have 100 pounds that is 6 feet from the fulcrum; and, on the other
side, there is 60 pounds that is 10 feet from the fulcrum, for
an even balance.  The equation is true (600 = 600).

    With that in mind, let us answer the above question:

        50 * 3 = 5 * x
        150 = 5x
        30 = x

    Therefore, to make the lever balance with 50 pounds on one 
side (3 feet from the fulcrum), we would have to place 30 pounds 5
feet from the fulcrum on the other side.