**Displacement** – is distance in a given direction.

**Speed** – is the rate of change of distance with respect to time.

**Velocity** – is the rate of change of Displacement with respect to time.

**Acceleration** – is the rate of change of Velocity with respect to time.

**Scalar Quantity** – is one which has magnitude only.

**Vector Quantity** – is one which has both magnitude and direction.

**Force** – is that which can cause an acceleration.

**Newton** – is that force which gives a mass of one kg an acceleration of 1 ms-2.

**Friction** – is a force which opposes the relative motion between two objects.

**Weight** – of an object is the force of the Earth’s gravity acting on it.

**Momentum** – is the product of Mass times Velocity.

**Newton’s First Law of Motion** – states that every object will remain in a state of rest or travelling with a constant velocity unless an unbalanced external force acts on it.

**Newton’s Second Law of Motion** – states that the rate of change of an object’s momentum is directly proportional to the force which caused it.

**Newton’s Third Law of Motion** – states that if an object A exerts a force on an object B, then B will exert an equal but opposite force on A.

**Principle of Conservation of Momentum** – states that in any collision between two objects, the total momentum before impact equals total momentum after impact provided no external forces act on the system.

**Density** – of a substance is a measure of its mass per unit volume.

**Pressure** – is defined as Force per unit Area.

**Archimedes Principle** – states that when an object is immersed in a fluid, the upthrust it experiences is equal to the weight of the displaced fluid.

**Law of Flotation** – states that the weight of a floating object is equal to the weight of the fluid it displaces.

**Boyle’s Law** – states that at constant temperature, the volume of a fixed mass of gas is inversely proportional to its pressure.

**Newton’s Law of Gravitation** – states that any two objects in the universe are attracted to each other with a force that is directly proportional to the product of their masses, and inversely proportional to the square of the distance between them.

**Conditions for Equilibrium of an object under Coplanar Forces** – The vector sum of the forces in any direction is zero AND The sum of the moments about any point is zero

**Moment of a Force** – is equal to the force multiplied by the perpendicular distance between the force and the fulcrum.

**Work** – is defined as the product of Displacement by Force (in the direction of the displacement).

**Energy** – is the ability to do work.

**Principle of Conservation of Energy** – states that Energy cannot be created or destroyed but can only be converted from one form to another.

**Power** – is the rate at which work is done.

**Angular Velocity** – is the rate of change of angle with respect to time.

**Centripetal Force** – The force -acting in towards the centre – required to keep an object moving in a circle is called.

**Hooke’s Law** – states that when an object is stretched the restoring force F is directly proportional to the displacement – provided the elastic limit is not exceeded.