Physics Paper 1 Definitions

• Normal force: The force or the component of a force which the surface exerts on an object with which it is in contact, and which is perpendicular to the surface.
• Frictional force: The force that opposes the motion of an object and which acts parallel to the surface.
• Static frictional force


  The force that opposes the loading of motion of a stationary object relative to the surface
• Kinetic friction force


  The force that opposes the motion of a moving object relative to the surface
• Weight


  The gravitational force exerted by the earth on the object
• Mass


  The amount of matter in a body
• Resultant


  The vector sum of two or more vectors
• Resultant force


  A single vector having the same effect as two or more vectors
• Newton's first law of motion

  A body will remain in its state of rest or motion at constant velocity unless a nonzero resultant or net force acts on it
• Newton's second law of motion

  When a net force acts on an object, the object will accelerate in the direction of the net force with an acceleration directly proportional to the force and inversely proportional to the mass.
• Newton's third law of motion

  When object A exerts a force on object B, object B simultaneously exerts an oppositely directed force of equal magnitude on object A
• Newton's Law of Universal Gravitation

  Each body in the universe attracts every other body with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them
• Weightlessness


  The sensation experienced when all contact forces are removed
• Coulomb's Law


  The magnitude of the electrostatic force exerted by one point charge on another point charge is directly proportional to the product of the magnitudes of the charges and inversely proportional to the square of the distance between them
• Principle of conservation of charge: The net charge in an isolated system remains constant during any physical process
• Electric field


  A region of space in which an electric charge experiences a force. The direction a positive test charge would move in the electric field at a point is the direction that a force acts on a positive charge placed at that point.
• Electric field of a point charge

  The electrostatic force experienced per unit positive charge placed at that point
• Ohm's Law


  The potential difference across a conductor is directly proportional to the current in the conductor at constant temperature
• Current


  The rate of flow of charge
• Potential difference


  The work done or energy transferred per unit of charge
• EMF


  The maximum energy provided by a battery or cell per unit charge passing through it
• Power


  The rate at which work is done or energy is transferred
• Vector


  • A physical quantity that has magnitude and direction
• Force


  A push or pull action that can act on an object to change its speed, direction, or shape
• Non-contact forces


  • Forces which act on an object without physically touching the object
• Contact forces


  • Forces that act only when physical contact between two objects occurs
• Tension

  Stretching or straining action
• Equilibrium


  When all the forces acting on an object are balanced and the resultant force is equal to zero
• Equilibrant


  The force that balances the resultant and acts in a direction opposite to the resultant
• Inertia


  The resistance of an object to any change in its state of motion
• Acceleration


  Rate of change of velocity
• Electrostatics


  The study of electric charges at rest
• Closed circuit


  A closed pathway that allows current to flow
• Open circuit


  Incomplete pathway that does not allow current to flow
• Short circuit: A direct connection between two points in a circuit that aren't supposed to be silently connected.