Relfltive velocity The velocity of a body A relative to a body B is obtained by combining the velocity of A with the velocity of B reversed.

Relfltive velocity
The velocity of a body A relative to a body B is obtained by combining the velocity of
A with the velocity of B reversed.

First Law
Every body continues in a state of rest or uniform motion in a straight line unless
compelled by some external force to act otherwise.
Momentum
The momentum of a body is defined as the product of irs mass and its velocity.
Change of momentum
The rate of change of momentum of a body is proportional to the applied force and takes
place in the direction in which the force acts.
Newton
The SI unit of force is called the Newton and is the force which produces an aceelratiol
of 1 ms-2 when its acts on a mass of 1 kilogramme.
Third law
To every action there is an equal and opposite reaction
Conservation If Momentunn
When two or more bodies act upon one another their total momentum remains constant,
providing no external forces are acting.
Work
Work is said to be done when the point of application of a force moves and is measured
by the product of the force and the distance, moved in the direction of the force.
Energy
rnergy is the capacity to perform work
The SI unit of work is called the . Joule and is the wok done when the point of app
lication of a force 1 newton moves through 1 metre in the direction of the force.
Mechanical energy
Kinetic energy is the energy which a body possesses by reason of its motion
Potential energy is the energy which a body has by reason of its position or state.
Heat
Heat is defined as energy which flows from one place to another owing to a temperature
difference between them.
Power
Powere is defined as the rate of doing work.
The SI unit of power is called the watt and is the rate of working of 1 joule per
secound.