# Shared Flashcard Set

## Details

Definitions; Mechanics, Materials and Waves
AS level physics
30
Physics
06/07/2014

Term
 Amplitude
Definition
 The maximum displacement of a particle on a wave. For a transverse wave, it is the distance from the peak to the equilibrium.
Term
 Centre of mass
Definition
 The centre of mass of a body is the point at which all of it's mass is assumed to act. At this point, a single force on the body has no turning effect.
Term
 Coherant light source (2)
Definition
 Constant phase difference and the same frequency/wavelength
Term
 Couple
Definition
 A pair of equal and opposite forces that do not act upon the same line. The moment of a couple can be defined as torque.
Term
 Critical angle
Definition
 The angle at which the incident angle must exceed for TIR to occur
Term
 Elasticity
Definition
 The property of a solid that allows it to regain it's shape after deformation
Term
 Frequency
Definition
 Number of wave cycles that pass a point per second, measured in Hz
Term
 Fundamental mode of vibration
Definition
 The pattern of a stationary wave on a string when it vibrates at it's lowest possible frequency
Term
 Hooke's law
Definition
 Force is directly proportional to extension up to the limit of proportionality
Term
 Interferance
Definition
 Formation of points of cancellation and reinforcement when two coherant waves pass through one another (IN OPPOSITE DIRECTIONS)
Term
 Limit of proportionality
Definition
 The limit beyond which, when a wire or spring is stretched, its extension is no longer proportional to the force applied to it
Term
 Longditudinal wave
Definition
 A wave where the oscillation of the waves particles are parallel to the propagation of the wave
Term
 Moment
Definition
 The moment of a force about a point is defined as the force times the perpendicular distance from the line of action of the force to the point
Term
 Multipath dispersion
Definition
 The lengthening of a light pulse in a optical fibre as it repeatedly undergoes TIR, causing light to arrive at different times due different distances travelled
Term
 Node
Definition
 A point on a stationary wave where displacement/amplitude is always 0
Term
 Period
Definition
 The time taken for one complete wave cycle to pass
Term
 Path difference
Definition
 The difference in distances from two coherant sources to an interferance fringe
Term
 Plane-polarised waves
Definition
 Transverse waves that only vibrate in 1 plane
Term
 Plastic deformation
Definition
 Deformation of a solid beyond it's elastic limit
Term
 Principle of moments
Definition
 For an object to remain stationary (or in equilibrium), the sum of all forces (upward and downward) must be zero, and clockwise moments must equal anticlockwise moments
Term
 Refraction
Definition
 A change in the speed of a wave when it strikes a boundary at an angle, and changes medium
Term
 Examples of scalar quantities
Definition
 Mass Length Time (s)
Term
 Stationary wave
Definition
 A wave formed when two coherent waves travelling in opposing directions interfere to produce a stationary wave, which transmits no energy and contains varied amplitudes
Term
 TIR
Definition
 A light ray that travels from a more optically dense (refractive) index to a less optically dense (refractive index), and must have an angle of incidence greater than the critical angle
Term
 Ultimate tensile stress
Definition
 Energy required to break a solid
Term
 Examples of vectors
Definition
 Momentum Velocity Accellaration Displacement Force
Term
 Wavelength
Definition
 The least distance between two adjacent vibrating paricles of the same amplitude and velocity (Ie distance between 2 peaks)
Term
 Young's fringes
Definition
 Parallel bright and dark fringes observed when light goes through a double slit arrangement
Term
 Double slit arrangement
Definition
 A single slit followed by two slits, causing interferance and Bright-dark fringes that remain constant
Term
 Single slit arrangement
Definition
 Light and dark fringes observed when light passes through one slit, decreasing in intensity as you increase distance from the central maximum
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