Question

The common balance works on the principle of equality of

Answer 1

Balance is the equal distribution of weight. In design the weight is visual.
The common balance works on the principle of equality of the moment of weight. Equilibrium is attained when the weights are balanced. 

Answer 2

Answer:

HAve two arms suspended and one known weight

Explanation:

the common balance is a balance that we all have seen in examples of Justice, it was well known in the old times, but nowadays its more common seeing it as a jsutice symbol, it works in the principle of having two weights accross a balance and letting gravity work on them, while you have an object on one side of the balance of which you know the mass and you add mass to the object in the othar side of the balance to equalize the weights.