A meter stick sits on a pivot. You place 4 nuts 10 cm away from the pivot. Where would you place a single nut to make the meter stick balance?

x = 40 cm

Explanation:

We have to place 4 nuts 10 cm away from the pivot.

Lets take mass of nut = m

Lets take single nut is place distance x from the pivot.

So the moment due to single nut = m g x

The moment due to 4 nuts = 4 m g (10)

For balancing the system these two moment should be equal

40 m g = m g x

So x = 40 cm

So we have to place a single nut at a distance of 40 cm from the pivot but on the other side.