FORM 2-PHYSICS-TOPIC 4-FORCES IN EQUILIBRIUM

Moment of a Force

Centre of Gravity

Types of Equilibrium

The Condition for Equilibrium

Explain the condition for equilibrium

Equilibrium:A body is said to be balanced if its center of gravity is directly above the point of support.

Stable, Unstable and Neutral Equilibrium

Explain Stable, Unstable and Neutral equilibrium

There are three types of equilibrium, namely:

1. Stable equilibrium
2. Unstable equilibrium
3. Neutral equilibrium

Stable equilibrium:A body is said to be in stable equilibrium if is given with small displacement the center of gravity will be raised and the body returns to its original position after displacement.

Unstable equilibrium:A body is said to be in unstable equilibrium if when given a small displacement the center of gravity will be lowered and the body doesn’t returns to its original position after displacement.

Neutral equilibrium:A body is said to be in neutral equilibrium when a small displacement doesn’t alter the position of the center of gravity; the body is at rest in whichever position it is placed, eg, rolling a sphere or a barrel.

Conditions of Stable, Unstable and Neutral Equilibrium in Daily Life

Apply conditions of stable, unstable and neutral equilibrium in daily life

Application of turning effect in daily life

• Is applied by a hand to unscrew a stopper on the bottle.
• Is applied by a spanner to unscrew a nut on a bottle.
• Turning a steering wheel of a car.

Exercise 1

.The moment of a force about a point is 1120 Nm.If the magnitude of the force is 5600N,find the perpendicular distance between the point and the line of action of the force