PHYSICS SAGS DEFINITIONS
Kiara Burra
Kinematics
Vector: A physical 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 and know that distance is a scalar quantity
Displacement: A change in position
Speed: The rate of change of distance
Velocity: The rate of change of position or the rate of displacement or the rate of change of
displacement
Acceleration: The rate of change of velocity
Freefall: An object is in freefall when the only force acting on it is the force of gravity
Newton’s Laws and the Application of Newton’s Laws
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 due to a surface, Ff: The force that opposes the motion of an object and acts
parallel to the surface with which the object is in contact
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
Momentum, Impulse, Work, Energy and Power
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. (Note: there are two acceptable statements of Newton's Second
Law)
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
Kiara Burra
Kinematics
Vector: A physical 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 and know that distance is a scalar quantity
Displacement: A change in position
Speed: The rate of change of distance
Velocity: The rate of change of position or the rate of displacement or the rate of change of
displacement
Acceleration: The rate of change of velocity
Freefall: An object is in freefall when the only force acting on it is the force of gravity
Newton’s Laws and the Application of Newton’s Laws
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 due to a surface, Ff: The force that opposes the motion of an object and acts
parallel to the surface with which the object is in contact
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
Momentum, Impulse, Work, Energy and Power
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. (Note: there are two acceptable statements of Newton's Second
Law)
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
