Wed July 18, 2012 By: Tarangini Boedoloi

A 4m long rod of negligible weight is to be balanced about a point 126cm from one end. A load of 18kgf is suspended at a point 60cm from the support on shorter arm. (a) A weight W is placed 250cm from the support on the longer arm. Find W. (b) If W=5kgf, where must it be kept to balance the rod?

Expert Reply
Wed July 18, 2012
The situation is expressed in the diagram shown below:
(a)  Here x = 250 cm
       Using balance of moments due to weights about the point of balance:
       18 x 60 = W x 250
       W = 4.32 kgf
(b)  Here W= 5 kgf
       thus again
       18 x 60 = 5 x
       x = 216 cm
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