Question

A meter stick balances horizontally on a knife-edge at the 50.0cm mark. With two 5.0g coins stacked over the 12.0cm mark l, the stick is found to balace at the 45.5cm mark. What is the mass of the meter stick?

Answer 1

Answer:

mass of the scale is 7.44 g

Explanation:

As we know that the meter scale is balanced at 45.5 cm mark when two coins are placed at 12 cm mark

now we can say that the torque due to weight of the coin is balanced by the weight of scale above the knife edge because the scale remains horizontal

so we will have

$mg(50 - 45.5) = (5g + 5g)(45.5 - 12)$

$m (4.5) = 10(33.5$

$m = \frac{335}{4.5}$

$m = 7.44 g$