Keshu

TURNING EFFECT OF A FORCE

🔹 Definition

The turning effect of a force is the ability of a force to rotate an object about a fixed point called the pivot. This turning effect is known as the moment of a force.

🔹 Examples

• Opening or closing a door• Using a spanner or wrench• Seesaw• Bicycle pedals• Steering wheel

🔹 Pivot (Fulcrum)

The pivot is the fixed point about which an object rotates. Examples:• Door → hinges• Seesaw → middle support

🔹 Moment of a Force

Moment of a force depends on:

1. The magnitude of force

2. The perpendicular distance from the pivot

📐 Formula

Moment = Force × Perpendicular distance

M=F × d

🔹 SI Unit

Newton metre (Nm)

🔹 Factors Affecting Turning Effect

1️⃣ Force applied→ More force = more turning effect

2️⃣ Distance from pivot→ Greater distance = greater turning effect

(This is why door handles are far from hinges.)

🔹 Direction of Turning

• Clockwise moment• Anticlockwise moment

🔹 Levers

A lever is a rigid bar that turns about a pivot. Examples:• Seesaw• Scissors• Wheelbarrow• Tweezers

All levers work on the turning effect of a force.