Answer:
Unknown mass, [tex] m = 14 \textrm{ g}[/tex]
Explanation:
From the figure below,
OE is a meter scale with markings in centimeter.
A is the position of unknown mass m, B is the position of 90 g mass, C is the fulcrum, D is the position of mass 73 g.
Length AC = 40 cm, BC = 10 cm, CD = 20 cm
For equilibrium of the meter scale,
Sum of anti-clockwise moments = Sum of clockwise moments
[tex]F_{A}\times AC+F_{B}\times BC=F_{D}\times CD\\m\times 40+90\times10=73\times20\\40m+900=1460\\40m=1460-900\\40m=560\\m=\frac{560}{40}=14\textrm{ g}[/tex]
Therefore,unknown mass is 14 g.
