Physics IEB definitions
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 the path travelled.
Displacement: Change in position.
Speed: The rate of change of distance.
Velocity: The rate of change of displacement.
Acceleration: The rate of change of velocity.
Newton’s Laws
Weight: The gravitational force that the Earth exerts on any object near its surface.
Normal force: The perpendicular exerted by a surface on an object in contact with it.
Frictional force: 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 the state of rest or uniform velocity unless it is
acted upon by a net force.
Inertia: The property 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 is applied to an object of mass (m), m accelerates
in the same direction of the net force. The acceleration is directly proportional to the net
force and inversely proportional to the mass.
Newton’s Third Law: When an object A exerts a force on object B, object B will
simultaneously exert an oppositely directed force of equal magnitude of object A.
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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 the path travelled.
Displacement: Change in position.
Speed: The rate of change of distance.
Velocity: The rate of change of displacement.
Acceleration: The rate of change of velocity.
Newton’s Laws
Weight: The gravitational force that the Earth exerts on any object near its surface.
Normal force: The perpendicular exerted by a surface on an object in contact with it.
Frictional force: 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 the state of rest or uniform velocity unless it is
acted upon by a net force.
Inertia: The property 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 is applied to an object of mass (m), m accelerates
in the same direction of the net force. The acceleration is directly proportional to the net
force and inversely proportional to the mass.
Newton’s Third Law: When an object A exerts a force on object B, object B will
simultaneously exert an oppositely directed force of equal magnitude of object A.
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