Question

uniform meterstick is balanced at its midpoint with a single support. A 65 N weight is suspended at the 39 cm mark. At
what point must a 40 N weight be hung to balance the system?

Answer 1

Using the law of the lever [https://en.wikipedia.org/wiki/Lever#Law_of_the_lever]

$$\frac{F_b}{F_a}=\frac{a}{b},$$

we get

$$\frac{40}{65}=\frac{39}{b},$$

from where

$$b = 63.375.$$

Answer: 63.375 cm.