# Shared Flashcard Set

## Details

G481 flashcards OCR
flashcards for the AS physics module G481 for all definitions required by the specification.
35
Physics
02/24/2014

Term
 scalar
Definition
 A physical property with magnitude (size) but not direction; for example, speed, distance, pressure, potential difference, etc.
Term
 velocity (v)
Definition
 The displacement per unit time, measured in metres per second (m s–1), e.g. 330 m s–1; a vector quantity.
Term
 displacement (s or x)
Definition
 The distance travelled in a particular direction, measured in metres (m), e.g. 3 m; a vector quantity.
Term
 average speed
Definition
 A measure of the total distance travelled in a certain time.
Term
 speed (s)
Definition
 The distance travelled per unit time, measured in metres per second (m s–1), e.g. 12 m s–1; a scalar quantity.
Term
 velocity (v)
Definition
 The displacement per unit time, measured in metres per second (m s–1), e.g. 330 m s–1; a vector quantity.
Term
 acceleration (a)
Definition
 The rate of change of velocity, measured in metres per second squared (m s–2); a vector quantity.
Term
 instantaneous speed
Definition
 The speed of an object at a given moment in time.
Term
 newton
Definition
 Unit of force (N), e.g. 4000 N. 1 N is the force which gives a mass of 1 kg an acceleration of 1 m s–2.
Term
 weight (w)
Definition
 The gravitational force on a body, measured in newtons.
Term
 drag
Definition
 The resistive force that acts on a body when it moves through a fluid.
Term
 terminal velocity
Definition
 The velocity at which an object’s drag equals its accelerating force. Therefore there is no resultant force and zero acceleration.
Term
 centre of gravity
Definition
 The point at which the entire weight of an object can be considered to act.
Term
 couple
Definition
 Two forces that are equal and opposite to each other but not in the same straight line.
Term
 torque
Definition
 The turning effect due to a couple, measured in newton metres (N m).
Term
 moment of a force
Definition
 The turning effect due to a single force, measured in newton metres (N m), e.g. 4 N m; a vector quantity.
Term
 thinking distance
Definition
 The distance travelled from seeing the need to stop to applying the brakes.
Term
 braking distance
Definition
 The distance a vehicle travels while decelerating to a stop.
Term
 stopping distance
Definition
 The sum of the thinking distance and the braking distance (i.e. the total distance required to stop a vehicle from seeing the need to stop to vehicle becoming stationary).
Term
 work (W)
Definition
 The product of force and the distance moved in the direction of the force, it can also be considered as the energy converted from one form into another, measured in joules (J); a scalar quantity.
Term
 joule
Definition
 Unit of energy (J), e.g. 1200 J. 1 J is the work done when a force of 1 N moves its point of application 1 m in the direction of the force.
Term
 conservation of energy
Definition
 Physical law stating energy cannot be created or destroyed, just transformed from one form into another or transferred from one place to another.
Term
 power (P)
Definition
 The rate of doing work, measured in watts (W); a scalar quantity.
Term
 watt
Definition
 Unit of power (W), e.g. 60 W. 1 W = 1 J s–1.
Term
 elastic limit
Definition
 The point at which elastic deformation becomes plastic deformation.
Term
 elastic deformation
Definition
 The object will return to its original shape when the deforming force is removed.
Term
 plastic deformation
Definition
 The object will not return to its original shape when the deforming force is removed, it becomes permanently distorted.
Term
 Hooke’s law
Definition
 The extension of an elastic body is proportional to the force that causes it.
Term
 stress
Definition
 The force per unit cross-sectional area, measured in pascals (Pa).
Term
 strain
Definition
 The extension per unit length.
Term
 Young modulus (Y)
Definition
 The ratio of tensile stress to tensile strain, measured in pascals (Pa).
Term
 ultimate tensile strength
Definition
 The maximum tensile force that can be applied to an object before it breaks.
Term
 ductile
Definition
 Materials that have a large plastic region (therefore they can be drawn into a wire); for example, copper.
Term
 brittle
Definition
 A material that distorts very little even when subject to a large stress and does not exhibit any plastic deformation; for example, concrete.
Term
 polymeric material
Definition
 A material made of many smaller molecules bonded together, often making tangled long chains. These materials often exhibit very large strains (e.g. 300%), for example rubber.
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