Question

a uniform metre scale of weight 50 gf .is balanced at 40 cm mark when weight of 100 gf is suspended at 5cm mark .where must weight of 80 gram must be suspended to balance the scale?

Answer 1

A weight of 80 gram must be suspended at 76.25 cm to balance the scale

Explanation:

X is the point where a weight of 80g is suspended.

So the anti-clockwise moment = 50g * 40 + 100g * 5

= 2500 gcm

Clockwise moment = 80g* (x - 45) = 80xgcm - 3600gcm

According to the law of moments, we know that the clockwise and anti-clockwise moment will be equal.

So 80xgcm - 3600gcm = 2500 gcm

80xgcm = 6100gcm

 x = 6100/80

  x  = 76.25 cm.