Question

Figure 4 shows a uniform rod AB of length 1m and weight 8N pivoted at 20 cm from one end. It is balanced by supporting it with a string attached to a fixed support.

The tension in the string is 4N. Determine the position of the string from end A.

Answer 1

Sum of clockwise moments = sum of anticlockwise moments
 4 x X = 8 x 30
4X= 240
X=60
position of string = 60 + 20 = 80cm=0.8m