SAGS Flashcards
(45 cards)
Vector
A physical quantity that has both magnitude and direction.
Scalar quantity
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 (scalar quantity).
Displacement
A change in position (vector quantity).
Speed
The rate of change of distance (scalar quantity).
Velocity
The rate of change of position / The rate of change of displacement / The rate of
displacement (vector quantity).
Acceleration
The rate of change of velocity (vector quantity).
Weight
The gravitational force the Earth exerts on any object on or near its surface.
Normal force
The perpendicular force exerted by a surface on an object in contact with it.
Frictional force
The force that opposes the motion of an object.
Gravitational field
Description: A region in space where a mass will experience a force.
Def: A force acting per unit mass
Newton’s 1st 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.
Newton’s 2nd 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 is directly proportional to the net
force and inversely proportional to the mass.
Newton’s 3rd law
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
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.
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.
Principle of
conservation of
mechanical energy
In the absence of air resistance or any external forces, the mechanical energy of
an object is constant.
Power
The rate at which work is done OR the rate at which energy is transferred.
Efficiency
The ratio of output power to input power.
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.
