Physics SSS1 Third Term

WEEK 4

Equilibrium of Forces

Performance Objectives

Students should be able to:

1. Explain Resultant and Equilibrant forces
2. Describe Parallel forces and Moment of a force

Content

An object is in equilibrium when it is not accelerated, that is, there is no net force acting on it in any direction. For such a body in equilibrium, the forces acting on it are so related in magnitude and direction that no acceleration results. Thus the body may either be at rest or maybe moving with constant velocity. Such bodies at rest are said to be in static equilibrium. When the body is moving with a constant velocity in a straight line, or when it is rotating with a constant angular velocity about a fixed axis through its centre of mass, the equilibrium is said to be kinetic or dynamic equilibrium. This means that the forces that set the body in motion balance the forces that resist the motion..... View More