Physics Definitions Matric

Term 2 Definitions - Test

Projectile

An object which has been given an initial velocity and then it moves under the influence of the gravitational force only

Free fall

Motion during which the only force acting on an object is the gravitational force

Momentum

The product of an object's mass and its velocity

Linear momentum

A vector quantity with the same direction as the velocity of the object

Newton's second law of motion in terms of momentum

The net (or resultant) force acting on an object is equal to the rate of change of momentum of the object in the direction of the net force

Impulse

The product of the resultant/net force acting on an object and the time the net force acts on the object

System

A defined collection of objects in Physics

Isolated system

A system on which the net external force is zero

Principle of conservation of linear momentum

The total linear momentum of an isolated system remains constant (is conserved)

Work

The work done on an object by a constant force $F$ as $F \Delta x \cos \theta$, where $F$ is the magnitude of the force, $\Delta x$ the magnitude of the displacement, and $\theta$ the angle between the force and the displacement

Work-energy theorem

The work done on an object by a net force is equal to the change in the object's kinetic energy

Conservative force

A force for which the work done in moving an object between two points is independent of the path taken

Non-conservative force

A force for which the work done in moving an object between two points depends on the path taken

Principle of conservation of mechanical energy

The total mechanical energy (sum of gravitational potential energy and kinetic energy) in an isolated system remains constant

Power

The rate at which work is done or energy is expended

Doppler effect

The change in frequency (or pitch) of the sound detected by a listener, because the sound source and the listener have different velocities relative to the medium of sound propagation