Grade 12 IEB Physical Science: Physics (Paper 1) SAG De nitions:
Section A: Kinematics:
• Vector: Physical quantity that has both magnitude and direction
• Scalar: Physical quantity that has magnitude only
• Resultant vector: Single vector which has the same e ect as the original vectors acting together
• Distance: The length of path travelled
• Displacement: Change in position
• Speed: Rate of change of distance
• Velocity: Rate of change of position OR Rate of displacement OR Rate of change of displacement
• Acceleration: Rate of change of velocity
Section B: 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: The force that opposes the motion of an object and acts
parallel to the surface with which the object is in contact
• Newton's rst law: An object continues in a state of rest or uniform 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 is applied to an object of mass, 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 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.
fi
Section A: Kinematics:
• Vector: Physical quantity that has both magnitude and direction
• Scalar: Physical quantity that has magnitude only
• Resultant vector: Single vector which has the same e ect as the original vectors acting together
• Distance: The length of path travelled
• Displacement: Change in position
• Speed: Rate of change of distance
• Velocity: Rate of change of position OR Rate of displacement OR Rate of change of displacement
• Acceleration: Rate of change of velocity
Section B: 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: The force that opposes the motion of an object and acts
parallel to the surface with which the object is in contact
• Newton's rst law: An object continues in a state of rest or uniform 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 is applied to an object of mass, 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 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.
fi
