Definitions

• Vector

  A physically quantity that has both magnitude and direction.
• Scalar

  A physical quantity that has magnitude only.
• Resultant vector

  The single vector which has the same effect as the original vectors acting together.
• Distance

  The length of path travelled.
• Displacement

  A change in position.
• Speed

  The rate of change of distance.
• Velocity

  The rate of change of displacement.
• Acceleration

  The rate of change of velocity.
• Weight (Fg)

  The gravitational force the Earth exerts on any object on or near its surface.
• Normal force (FN)

  The perpendicular force exerted by a surface on an object in contact with it.
• Frictional force (Ffr)

  The force that opposes the motion of an object.
• Newton's First Law

  An object continues in a state of rest or uniform (moving with constant) velocity unless it is acted upon by a net or resultant force.
• Inertia

  The property of an object that causes it to resist a change in its state of rest or uniform motion.
• Newton's Second Law

  When a net force, Fnet, is applied to an object of mass, m, it accelerates in the direction of the net force. The acceleration, a, is directly proportional to the net force and inversely proportional to the mass.
• Newton's Third Law

  When object A exerts a force on object B, object B simultaneously exerts an oppositely directed force of equal magnitude on object A.
• Linear momentum

  The product of the mass and velocity of the object.
• Newton's Second Law in terms of momentum

  The net force acting on an object is equal to the rate of change of momentum.
• The Law of Conservation of Linear Momentum

  The total linear momentum of an isolated system remains constant (is conserved).
• Elastic collision

  A collision in which both momentum and kinetic energy are conserved.
• Inelastic collision

  A collision in which only momentum is conserved.
• Impulse (J)

  The product of the net force and the contact time.
• Work done on an object by a force

  The product of the displacement and the component of the force parallel to the displacement.
• Gravitational potential energy

  The energy an object possesses due to its position relative to a reference point.
• Kinetic energy

  The energy an object has as a result of the object's motion.
• Mechanical energy

  The sum of gravitational potential and kinetic energy at a point.
• The Law of Conservation of Energy

  The total energy in a system cannot be created nor destroyed, only transformed from one form to another.
• The Principle of Conservation of Mechanical Energy

  In the absence of air resistance or any external forces, the mechanical energy of an object is constant.
• Work-Energy theorem

  The work done by a net force on an object is equal to the change in the kinetic energy of the object.
• Power

  The rate at which work is done.
• Efficiency

  The ratio of output power to input power.
• Newton's Law of Universal Gravitation

  Every particle with mass in the universe attracts every other particle with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centres.
• Weight (Fg)

  The gravitational force the Earth exerts on any object on or near its surface.
• Gravitational field

  A region in space where a mass will experience a force.
• Coulomb's Law

  Two point charges exert forces on each other. The force is directly proportional to the product of the charges and inversely proportional to the square of the distance between the charges.
• Electric field at a point

  The force per unit positive charge.
• Potential difference

  The work done per unit positive charge.
• Current

  The rate of flow of charge.
• EMF

  The total energy supplied per coulomb of charge by the cell.
• Magnetic flux linkage

  The product of the number of turns on the coil and the flux through the coil.
• Faraday's Law of electromagnetic induction

  The EMF induced is directly proportional to the rate of change of magnetic flux (flux linkage).