Motion which repeats itself at regular intervals about a mean position
Oscillatory Motion
Complete execution of a motion
Cycle
The position of the oscillating body when no unbalanced forces are acting upon it
Equilibrium/Mean Position
The distance measured from the equilibrium position in a particular position
Displacement (oscillation)
The magnitude of the maximum displacement
Amplitude (oscillation)
Time taken for one complete cycle
Period
The number of cycles per second
Frequency (oscillation)
Position of an oscillating body in its cycle
Phase
Difference in phase between two oscillations
Phase difference
Oscillatory motion in which the acceleration is proportional to the displacement and is directed towards the mean position
Simple Harmonic Motion
When SHM occurs while there is a resistance force which is opposite to the direction of the motion of the oscillating body, the amplitude decrease with time
Damped SHM
When the body returns to its mean position in the smallest time possible
Critical Damping
When the damping force increases, and the body is returned to its mean position but in a longer time
Over-damping
A force in which the work it does depends on the path taken
Dissipative Force
The frequency of oscillation when a body which is free to oscillate is displaced from its mean position and released
Natural frequency of oscillation
When a body is forced to oscillate at the frequency of a series of periodic impulses that are forced upon it
Forced oscillations
When a body which is capable of oscillating, oscillates with a larger amplitude due to a series of periodic impulses of the same frequency of the natural oscillation of the body
Resonance
A single disturbance which travels along, each position moving up, then down, just once from its mean position
Wave Pulse
A series of pulses, each position moving up and down, either side of the mean position
Continuous Travelling (Progressive) Wave
A wave in which graphs of displacement versus position, and displacement versus time are sinusoidal
Harmonic Wave
A disturbance which travels from one place to another with transfer of matter
A Wave
A wave in which the direction of the motion of the particles of the medium is at right angles to the direction of the transfer of energy
Transverse Waves
A wave in which the direction of the motion of the particles of the medium is parallel to the direction of transfer of energy
Longitudinal Waves
The distance of any point from the mean position in any given direction
Displacement (waves)
Maximum value of the displacement of a point on the wave
Amplitude
Number of oscillations of a point of the wave per second
Frequency (waves)
The time for one complete wave to pass a point
Period (waves)
The shortest distance between two points on the wave that are in the same phase
Wavelength
the disturbance per unit time
Wave Speed
The energy of the wave which crosses a unit area per second perpendicular to the wave
Intensity
Waves that move in a straight line in 2 dimensional space
Plane Waves
Waves that move radially out from a source in 2 dimensional space
Circular Waves
Lines joining all adjacent points on the wave which are in the same phase
Wavefronts
Lines showing the direction of travel of the wave energy
Rays
i = r
Law of Reflection
Reflection from very flat surfaces that results in image formation
Specular Reflection
Reflection from uneven surfaces, seeing things that don’t radiate their own visible light
Diffuse Reflection
Bending or changing of direction of a wave due to the change in its speed as it passes from one medium to another
Refraction
Spreading of a wave as it passes a barrier or through an aperture
Diffraction
At the point where two or more waves meet, the resultant displacement is the vector sum of the individual displacements
Principle of Superposition
When two waves of the same phase meet, they add to form a wave of large amplitude
Constructive Interference
When two waves of opposite phase meet, they negate each other to form a wave of small or zero amplitude
Destructive Interference
Positions of destructive interference
Nodes
Positions of constructive interference
Antinodes
