Question

A physical balance has its arms of length $60cm$ and $40cm$. What weight kept on a pan of the longer arm will balance an object of weight $100gf$ kept on another pan:

Answer 1

For the plan to come in equilibrium Anti-clockwise moment in one force must be equal to clockwise moment of other force.

Anti-clockwise$:-100\times 40=400$

At equilibrium$:-$ Anti-clockwise moment$=$clockwise moment

$60x=4000\Rightarrow x=66.67gf$