Question

Find the weight of a meter scale balanced at 30 cm such that two weights one of 80 gf and 10 gf are suspended at 5 cm mark and 40 cm mark respectively
10 gf
105 gf
25 gf
32.5 gf

Answer 1

The metre scale is balanced at 30 cm such that two weights one of 80 gf and 10 gf are suspended at 5 cm mark and 40 cm mark.

• Always remember that weight of the scale will act at the centre of mass (i.e. at the middle) at 50 cm mark.

• Also, the distance of force acting on the scale will be calculated from the 30 cm mark.

Now, since the scale is at rotational equilibrium, you can say:

$\sum( \tau) = 0$

$\implies \{80 \times (30 - 5) \} = \{10 \times (40 - 30) \} + \{w \times (50 - 30) \}$

$\implies \{80 \times 25 \} = \{10 \times 10\} + \{w \times 20 \}$

$\implies 2000 =20w + 100$

$\implies 20w = 1900$

$\implies w = 95 \: gf$

So, weight of scale is 95 gf.

Answer 2

Answer:

32.5gf is give n as the ans