Turning Effect of a Force (Moment of a Force)

🔹 Definition:

The turning effect of a force is known as the moment of a force.
It occurs when a force causes an object to rotate about a pivot (or fulcrum).

🧮 Moment = Force × Perpendicular Distance

$$\text{Moment} = F \times d$$

• F = Force (in newtons, N)

• d = Perpendicular distance from the pivot to the line of action of the force (in meters, m)

🔄 Types of Moments

1. Clockwise moment – turns an object in the clockwise direction

2. Anticlockwise moment – turns an object in the anticlockwise direction

⚖️ Principle of Moments:

If a body is in equilibrium (not turning), the total clockwise moment equals the total anticlockwise moment.

$$\text{Clockwise Moment} = \text{Anticlockwise Moment}$$

📏 Applications:

• See-saws

• Levers

• Spanners

• Wheelbarrows

• Door handles

🛠️ Levers:

A lever is a rigid bar that rotates about a fixed point called a pivot or fulcrum.

Classes of Levers:

🧠 Key Concepts:

• The larger the distance from the pivot, the greater the moment.

• Using longer tools (like spanners) increases turning effect.

• Balancing beams and levers uses the principle of moments.

  Turning Effect of a Force (Moment of a Force)

  🔹 Definition:

  The turning effect of a force is known as the moment of a force.
  It occurs when a force causes an object to rotate about a pivot (or fulcrum).

  ---

  🧮 Moment = Force × Perpendicular Distance

  $$\text{Moment} = F \times d$$

  • F = Force (in newtons, N)

  • d = Perpendicular distance from the pivot to the line of action of the force (in meters, m)

  ---

  🔄 Types of Moments

  1. Clockwise moment – turns an object in the clockwise direction

  2. Anticlockwise moment – turns an object in the anticlockwise direction

  ---

  ⚖️ Principle of Moments:

  If a body is in equilibrium (not turning), the total clockwise moment equals the total anticlockwise moment.

  $$\text{Clockwise Moment} = \text{Anticlockwise Moment}$$

  ---

  📏 Applications:

  • See-saws

  • Levers

  • Spanners

  • Wheelbarrows

  • Door handles

  ---

  🛠️ Levers:

  A lever is a rigid bar that rotates about a fixed point called a pivot or fulcrum.

  Classes of Levers:

  Class	Order of Parts (from one end to the other)	Example
  1st	Load – Fulcrum – Effort	Seesaw, scissors
  2nd	Fulcrum – Load – Effort	Wheelbarrow
  3rd	Fulcrum – Effort – Load	Tongs, human arm

  ---

  🧠 Key Concepts:

  • The larger the distance from the pivot, the greater the moment.

  • Using longer tools (like spanners) increases turning effect.

  • Balancing beams and levers uses the principle of moments.