A non uniform meter rule pivoted at the 30cm mark .It is balanced horizontally by a force W placed at the 20cm mark and 0.4N force placed at the 70cm mark . Determine the weight W

1 answer

To determine the weight W, we can use the principle of moments. The total clockwise moments about the pivot point must be equal to the total anticlockwise moments.

Clockwise moments = Anticlockwise moments
(W x 10cm) + (0.4N x 30cm) = (W x 10cm) + (0.4N x 40cm)

10W + 12 = 4W + 16
10W - 4W = 16 - 12
6W = 4
W = 4/6
W = 0.67N

Therefore, the weight W is 0.67N.