Answer:
[tex]m = \sqrt{M_1 M_2}[/tex]
Explanation:
Two casess are mentioned in the given figure
first case
two mass m and M_1
m is l_1 distance from center and M_1 is l_2 distance from center
second case
two mass m and M_2
m is l_2 distance from center and M_2 is l_1 distance from center
The balance in the 1st case requires [tex]m l_1 = M_1 l_2.[/tex]
And the balance in second case
[tex]M_2 l_1 = m l_2.[/tex]
Cancel[tex] l_1 and l_2 [/tex]
from the above equations.
So[tex] m^2 = M_1 M_2[/tex], i.e.
[tex]m = \sqrt{M_1 M_2}[/tex]