Studied by 0 people
This is falsh cards for physical science grade 12 exams. This is meant for SACAI as this will help with navigating their strict marking guides.
Scalar
A physical quantity that has magnitude only.
Vector
A physical quantity that has magnitude and direction.
Resultant
A vector sum of two or more vectors. OR A single vector having the same effect as two or more vectors together.
Equilibrium
is when the forces are balanced and the resultant is zero
Normal force, (FN)
the force or the component of a force which a surface exerts on an object with which it is in contact, and which is perpendicular to the surface.
Frictional force ,(Ff)
the force that opposes the motion of an object and which acts parallel to the surface.
Static frictional force, (ƒS)
the force that opposes the tendency of motion of a stationary object relative to a surface.
Kinetic frictional force, (ƒK)
as the force that opposes the motion of a moving object relative to a surface.
Newton's first law of motion
A body will remain in its state of rest or motion at constant velocity unless a non-zero resultant/net force acts on it.
Newton's second law of motion
When a resultant/net force acts on an object, the object will accelerate in the direction of the force at acceleration directly proportional to the force and inversely proportional to the mass of the object.
Newton's third law of motion
When one body exerts a force on a second body, the second body exerts a force of equal magnitude in the opposite direction on the first body.
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 their centres.
Momentum
the product of an object's mass and its velocity
Newton's second law of motion in terms of momentum
The resultant/net force acting on an object is equal to the rate of change of momentum of the object in the direction of the resultant/net force.
Impulse
the product of the resultant/net force acting on an object and the time the resultant/net force acts on the object.
Closed/an isolated system (in Physics)
a system on which the resultant/net external force is zero. A closed/an isolated system excludes external forces that originate outside the colliding bodies, e.g. friction. Only internal forces.
The principle of conservation of linear momentum
The total linear momentum of a closed system remains constant (is conserved)
A projectile
an object upon which the only force acting is the force of gravity
Free fall
motion during which the only force acting on an object is the gravitational force.
Work Done
is the energy transferred to or from an object through the application of force along a displacement
Work-energy theorem
The net/total work done on an object is equal to the change in the object's kinetic energy OR the work done on an object by a resultant/net force is equal to the change in the object's kinetic energy.
A conservative force
a force for which the work done in moving an object between two points is independent of the path taken
A 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.
The 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
Coulomb's law
The magnitude of the electrostatic force exerted by one point charge (Q1) on another point charge (Q2) is directly proportional to the product of the magnitudes of the charges and inversely proportional to the square of the distance (r) between them
Electric field
a region of space in which an electric charge experiences a force. The direction of the electric field at a point is the direction that a positive test charge would move if placed at that point.
Electric field at a point
The electric field at a point is 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
Emf
the maximum energy provided by a battery per unit charge passing through it.
Rms for an alternating voltage or an alternating current
The rms value of AC is the DC potential difference/current which dissipates the same amount of energy as AC.
The photoelectric effect
the process whereby electrons are ejected from a metal surface when light of suitable frequency is incident on that surface.
Threshold frequency, (ƒo)
the minimum frequency of light needed to emit electrons from a certain metal surface
Work function, (Wo)
the minimum energy that an electron in the metal needs to be emitted from the metal surface
Note 
Flashcard (49)