Question

A uniform meter scale is in equilibrium as shown in the diagram : 

(i) Calculate the weight of the meter scale.
(ii) Which of the following options is correct to keep the ruler in equilibrium when 40 gf wt is shifted to 0 cm mark ?
F is shifted towards 0 cm
or
F is shifted towards 100 cm

Answer 1

(i) Mass of the meter scale wiil be concentrated at its centre
∴ At 50 cm, Mass of meter scale = M gf
`therefore F_1d_1= F_2 d_2`
`(25) = F_2(20)`

50 gf = F₂

0.49N = F₂ 

∴ F₂ = m (9.8) 

`=(0.49)/(9.8)= m`

∴ m = 0.05kg

1m = 500m

(ii) F is shifted towards 0 cm.