Question

A meter stick is balanced on a knife edge at its center. When two coins, each of mass 5g we put one on top of the other at the 12cm mark, the stick is found to be balance at 45cm. What is the mass of the meter stick?​

Answer 1

Given:

• A meter stick is balanced on a knife edge at its center
• Two coins, each of mass 5g we put one on top of the other at the 12cm mark
• The stick is found to be balance at 45cm

ToFind:

• Mass of the meter stick

Solution:

• Total mass of the coins (m) = 10g
• Mass of the stick = M

The moment of masses about C to balance the stick is:

⇒ m × AC = M × CG

⇒ 10 × 33 = M × 5

⇒ 330 = M × 5

⇒ M = 330/5

⇒ M = 66g

∴ The mass of the meter stick is 66g