posted by Stacey .
An 18 kg mass is placed st one end of a steel bar that is 1 m long. A 35 kg mass is placed at the other end. Where should the fulcrum be placed to balance the bar?
mass x distance on one side = mass x distance on the other side
let the distance be x m from the heavier mass
35x = 18(1-x)
35x = 18 - 18x
53x = 18
x = 18/53 = .3396
the fulcrum should be appr 34 cm from the heavier load.
34(35) = 1190
66(18) = 1188 , close enough for 2 digit accuracy.