AQA AS Level Physics - Unit 2, AQA AS
Level Physics - Waves, Physics Electricity
AQA AS, Photoelectric
Scalar>>>A physical quantity with magnitude only.
Speed>>>Change of distance per unit time.
Acceleration>>>Change in velocity per unit time.
Vector>>>A physical quantity with magnitude and direction.
Displacement>>>The distance in a given direction.
Velocity>>>Speed in a given direction or the change in displacement over time
Resultant>>>The force which results from two or more forces acting on the same particle.
Moment>>>Moment of a force about a point defined as force × perpendicular distance from the
point to the line of
Principle of moments>>>The sum of the clockwise moments is equal to the sum of the
anticlockwise moments.
Centre of mass>>>The point on a object through which a single force on the body has no turning
effect.
Uniform>>>A body is uniform if it's mass is evenly distributed along its length.
Couple>>>A couple is a pair of equal and opposite forces acting on a body, but not along the
same line.
Terminal velocity>>>The maximum speed reached by an object at which the drag force is equal
and opposite to the forcce causing the motion of the object.
Thinking distance>>>The distance travelled by a car in the time it takes the driver to react.
Braking distance>>>The distance travelled by the car in the time it takes to come to a stop
safely.
Stopping distance>>>The distance travelled in both the thinking and braking distances.
Vehicle Bumpers>>>They give way in a collision, which increases the impact time of a collision
and thus reduces the resultant force on a passenger.
Crumple zones>>>The engine compartment crumples under a front end impact to increase the
impact time and thus reduce the resultant force.
Seat belts>>>Restrain the wearer from crashing into the vehicle frame during a sudden change in
momentum and brings them to halt more slowly, increasing the impact time and thus reducing
the reulstant force.
Collapsible steering wheel>>>Increases the impact time by collapsing when contacted by the
drive, reducing the resultant force on the driver in the impact.
Air bags>>>Increases the impact time and the area over which the resultant force acts,
decreasing the pressure and force on the passanger.
Principle of the conservation of energy>>>Energy cannot be created or destroyed.
Work done>>>Force multiplied by the distance moved in the direction of the force.
Kinetic Energy>>>The energy of an object due to its motion.
Power>>>The rate of transfer of energy.
Efficiency>>>The work done over the total energy supplied.
Density>>>The mass per unit volume of a substance.
, Hooke's Law>>>States that the force needed to stretch a spring is directly proportional to the
extension of the spring from its naturual length up to the limit of proportionality.
Elastic Limit>>>The point beyond which the a wire is permanently stretched/deformed
Elasticity>>>The property of a solid that enables it to regain its shape after it has been deformed
or distorted.
Tensile>>>Deformation that stretches an object.
Compressive>>>Deformation that compresses an object.
Tensile stress>>>The tension over the cross sectional area of the wire. It's unit is the Pascal.
Tensile Strain>>>The increase in length of the wire over the original length. It has no unit
because it is a ratio.
Limit of Proportionality>>>The limit beyond which, when a wire or spring is stretched, its
extension is no longer proportional to the force that stretches it.
Young's Modulus>>>Tensile stress over tensile strain.
Ultimate Tensile Stress>>>Also known as the breaking stress, the ultimate tensile stress is the
stress needed to break a solid or material.
Brittle>>>A brittle material snaps without any noticeable yield.
Ductile>>>A ductile material can be drawn into a wire.
Electromagnetic Waves>>>Vibrating electric and magnetic fields that progress through space
without the need for a substance. They all travel at the speed of light.
Longitudal Waves>>>Waves in which the direction of vibration of the particles is parallel to the
direction in which the wave travels.
Transverse Waves>>>Waves in which the direction of vibration of of the particles is
perpendicular to the direction in which the wave travels.
Stationary Waves>>>A wave pattern with nodes and antinodes formed when two or more
progressive waves of the same frequency and amplitude pass through each other.
Progressive Waves>>>Waves which travel through a substance or space if electromagnetic.
Plane-polarised>>>Transverse waves in which the vibrations are limited to one plane only.
Displacement>>>Is the distance and direction of a vibrating particle from its equilibrium
position.
Amplitude>>>The maximum displacement of a vibrating particle. In a transverse wave this is
the height of the wave crest.
Wavelength>>>The least distance between two adjacent vibrating particles with the same
displacement and velocity at the same time.
Period>>>The time for one complete wave to pass a fixed point.
Frequency>>>The number of cycles of vibration of a particle per second, or the number of
complete waves passing through a point a second.
Phase Difference>>>The fraction of the cycle between the vibrations of two particles, measured
in radians.
Wave properties>>>Waves can be reflected, refracted and diffracted.
Refraction>>>The change in direction of a wave when it crosses a boundary due to changes in
speed as it crosses the boundary.
Diffraction>>>When waves spread out after passing through a gap or around an obstacle.
Principle of superposition>>>States that when two waves meet, the total displacement at a point
is equal to the sum of the individual displacements at that point.
Supercrest>>>When a crest meets a crest and the waves reinforce each other.
Supertrough>>>When a trough meets a trough and the waves reinforce each other.
Level Physics - Waves, Physics Electricity
AQA AS, Photoelectric
Scalar>>>A physical quantity with magnitude only.
Speed>>>Change of distance per unit time.
Acceleration>>>Change in velocity per unit time.
Vector>>>A physical quantity with magnitude and direction.
Displacement>>>The distance in a given direction.
Velocity>>>Speed in a given direction or the change in displacement over time
Resultant>>>The force which results from two or more forces acting on the same particle.
Moment>>>Moment of a force about a point defined as force × perpendicular distance from the
point to the line of
Principle of moments>>>The sum of the clockwise moments is equal to the sum of the
anticlockwise moments.
Centre of mass>>>The point on a object through which a single force on the body has no turning
effect.
Uniform>>>A body is uniform if it's mass is evenly distributed along its length.
Couple>>>A couple is a pair of equal and opposite forces acting on a body, but not along the
same line.
Terminal velocity>>>The maximum speed reached by an object at which the drag force is equal
and opposite to the forcce causing the motion of the object.
Thinking distance>>>The distance travelled by a car in the time it takes the driver to react.
Braking distance>>>The distance travelled by the car in the time it takes to come to a stop
safely.
Stopping distance>>>The distance travelled in both the thinking and braking distances.
Vehicle Bumpers>>>They give way in a collision, which increases the impact time of a collision
and thus reduces the resultant force on a passenger.
Crumple zones>>>The engine compartment crumples under a front end impact to increase the
impact time and thus reduce the resultant force.
Seat belts>>>Restrain the wearer from crashing into the vehicle frame during a sudden change in
momentum and brings them to halt more slowly, increasing the impact time and thus reducing
the reulstant force.
Collapsible steering wheel>>>Increases the impact time by collapsing when contacted by the
drive, reducing the resultant force on the driver in the impact.
Air bags>>>Increases the impact time and the area over which the resultant force acts,
decreasing the pressure and force on the passanger.
Principle of the conservation of energy>>>Energy cannot be created or destroyed.
Work done>>>Force multiplied by the distance moved in the direction of the force.
Kinetic Energy>>>The energy of an object due to its motion.
Power>>>The rate of transfer of energy.
Efficiency>>>The work done over the total energy supplied.
Density>>>The mass per unit volume of a substance.
, Hooke's Law>>>States that the force needed to stretch a spring is directly proportional to the
extension of the spring from its naturual length up to the limit of proportionality.
Elastic Limit>>>The point beyond which the a wire is permanently stretched/deformed
Elasticity>>>The property of a solid that enables it to regain its shape after it has been deformed
or distorted.
Tensile>>>Deformation that stretches an object.
Compressive>>>Deformation that compresses an object.
Tensile stress>>>The tension over the cross sectional area of the wire. It's unit is the Pascal.
Tensile Strain>>>The increase in length of the wire over the original length. It has no unit
because it is a ratio.
Limit of Proportionality>>>The limit beyond which, when a wire or spring is stretched, its
extension is no longer proportional to the force that stretches it.
Young's Modulus>>>Tensile stress over tensile strain.
Ultimate Tensile Stress>>>Also known as the breaking stress, the ultimate tensile stress is the
stress needed to break a solid or material.
Brittle>>>A brittle material snaps without any noticeable yield.
Ductile>>>A ductile material can be drawn into a wire.
Electromagnetic Waves>>>Vibrating electric and magnetic fields that progress through space
without the need for a substance. They all travel at the speed of light.
Longitudal Waves>>>Waves in which the direction of vibration of the particles is parallel to the
direction in which the wave travels.
Transverse Waves>>>Waves in which the direction of vibration of of the particles is
perpendicular to the direction in which the wave travels.
Stationary Waves>>>A wave pattern with nodes and antinodes formed when two or more
progressive waves of the same frequency and amplitude pass through each other.
Progressive Waves>>>Waves which travel through a substance or space if electromagnetic.
Plane-polarised>>>Transverse waves in which the vibrations are limited to one plane only.
Displacement>>>Is the distance and direction of a vibrating particle from its equilibrium
position.
Amplitude>>>The maximum displacement of a vibrating particle. In a transverse wave this is
the height of the wave crest.
Wavelength>>>The least distance between two adjacent vibrating particles with the same
displacement and velocity at the same time.
Period>>>The time for one complete wave to pass a fixed point.
Frequency>>>The number of cycles of vibration of a particle per second, or the number of
complete waves passing through a point a second.
Phase Difference>>>The fraction of the cycle between the vibrations of two particles, measured
in radians.
Wave properties>>>Waves can be reflected, refracted and diffracted.
Refraction>>>The change in direction of a wave when it crosses a boundary due to changes in
speed as it crosses the boundary.
Diffraction>>>When waves spread out after passing through a gap or around an obstacle.
Principle of superposition>>>States that when two waves meet, the total displacement at a point
is equal to the sum of the individual displacements at that point.
Supercrest>>>When a crest meets a crest and the waves reinforce each other.
Supertrough>>>When a trough meets a trough and the waves reinforce each other.
