Verification of Principle of Moments:
Suspend a metre scale horizontally its mid point O’, by means of a thread with its other end connected to a fixed support.
Now suspend some weights on both sides of the mid-point and adjust their distances in such a way that scale again becomes horizontal.
Let W1, W2 and W3, W4 be the weights suspended and l1, l2 and l3, l4 are respective lengths.
The weights W1 and W2 tend to turn the scale clockwise while the weights W3 and W4 tend to turn the scale anti-clockwise.
Total clockwise moments = W1 × l1 + W2 × l2
Total anti-clockwise moments = W3 × l3 + W4 × l4
In equilibrium, when the scale is horizontal, it is found that:
Total clockwise moments = Total anti-clockwise moments
W1 l1 + W2 l2 = W3 l3 + W4 l4
This verifies the principle of moments.
