3.1 General wave properties Wave: A disturbance that repeats regularly in space and time and that is transmitted progressively from one place to the next with no actual transport of matter. A disturbance, oscillation, or vibration propagated (moving through) a medium or space.
Examples: Sound waves, Water waves, Light waves • Demonstrate understanding that waves transfer energy without transferring matter • Describe what is meant by wave motion as illustrated by vibration in ropes and springs and by experiments using water waves

WAVE ON A STRING SIMULATION from Phet
Simple harmonic motion: The back-and-forth vibratory motion of a swinging pendulum. • Give the meaning of speed, frequency, wavelength and amplitude • Distinguish between transverse and longitudinal waves and give suitable examples

Transverse wave:
Oscillation is perpendicular to direction energytravels.
A wave with vibration at right angles to the direction the wave is traveling.

Longitudinal wave:
Oscillation is parallel to direction energy travels.
A wave in which the vibration is in the same direction as that in which the wave is traveling, rather than at right angles to it.

Crest / Peak: One of the places in a wave where the wave is the highest or the disturbance is the greatest.

Trough: One of the places in a wave where the wave is the lowestor the disturbance is greatest in the opposite direction from a crest.

Compressions: The most dense part of a longitudinal wave.

Rarefactions: The least dense part of a longitudinal wave.

Wavelength:Distance along the wave to the next particle making the same oscillation.
The distance from the crest of a wave to the following crest, or equivalently, the distance between successive identical parts of the wave.

Amplitude: Maximum displacement of a particle.
The distance from the midpoint to the maximum (crest of a wave), or equivalently, from the midpoint to the minimum (trough).

Displacement: Distance of a particle in the wave from its rest position.

Period:Timetaken for one oscillation. The time required to complete a single cycle.

Frequency: Number of oscillations in onesecond .

Hertz: The SI unit of frequency . One hertz (Hz) is one cycle per second.

Wave speed: The speed with which the energy of the wave travels.

Wavefronts: A line of surface which joins the peaks of a transverse wave or the compressions of a longitudinal wave.

Oscillation: Regular variation in magnitude or position around a central point.
Vibration: The back-and-forth vibratory motion of a swinging pendulum. An oscillation, or repeating back-and-forth motion, about an equilibrium position.
Oscilloscope: Apparatus which represents oscillations by a trace on a screen
Periodic motion: Repetitive motion in regular interval.
Sine curve: A curve whose shape represents the crests and troughs of a wave, as traced out by a swinging pendulum that drops a trail of sand over a moving conveyor belt.
Medium: The intervening substance through which energy is conveyed
Propagate: Move through
Pitch and loudness: Properties of a sound wave which are determined by frequency and amplitude.
Phase: The angle with the respect to the X axis.
A curve whose shape represents the crests and troughs of a wave, as traced out by a swinging pendulum that drops a trail of sand over a moving conveyor belt.

In Phase:
Term applied to two or more waves whose crests (and troughs) arrive at a place at the same time, so that their effects reinforce each other.

Out of Phase:
Term applied to two waves for which the crest of one wave arrives at a point at the same time that a trough of the second wave arrives. Their effects cancel each other.

Test yourself : State one similarity and one difference between transverse waves and longitudinal waves. Give one real life example of each.

• Use the term wavefront
WAVEFRONT: A line of surface which joins all points which have the same displacement at the same moment (they are all in phase).
RAY: A line at right angles to the wavefronts which shows the direction of energy travel of the wave.

• Describe the use of water waves to show: – reflection at a plane surface – refraction due to a change of speed – diffraction produced by wide and narrow gaps

• Describe the use of water waves to demonstrate reflection, refraction and diffraction Supplement • Describe how wavelength and gap size affects diffraction through a gap • Describe how wavelength affects diffraction at an edge

Worksheets; 02 link v, f & L-1.doc 06 water waves.doc Diffraction: Waves spread out after an object of opening with a size similar to the wavelength of the wave.

Supplement • Recall and use the equation v = f λ • Interpret reflection, refraction and diffraction using wave theory 04 wave equation.doc TOP TIPS FOR PHYSICS CALCULATIONS.

( 1.) Using letters for short write down all the information given in the question. ( 2.) Change all the numbers into the basic SI units. ( 3.) Pick an equation that might be useful. ( 4.) If you need to re-arrange it using the formula triangle. ( 5.) Put in the numbers from part ( 1.) ( 6.) Calculator. ( 7.) Show the final units. ( 8.) Check the answer is sensible. ( 9.) Remember, you always get marks for showing your working out !

Speed of light: All EM waves travel at 300 million m/s in a vacuum Example 1) What is the speed of a sound wave if it has a frequency of 110 Hz and a wavelength of 3m ?

Frequency f = Wavelength λ = Speed v = ?

Example 2) If the speed of sound in air is 330 m /s and a tuning fork produces a wave with a frequency of 165 Hz what is it’s wavelength ?

Frequency f = Speed v = Wavelength λ = ?

Example 3) If a water wave moves at 25 cm / s and it’s crests are 50 cm apart what is it’s frequency ?

Speed v = Wavelength λ = Frequency f =

Example 4)
A sound wave has a frequency of 384Hz and a wavelength of 0.86m. Calculate its speed in m/s.

Example 5)
Another sound wave has a frequeny of 38400 Hz. Would you be able to hear this sound wave? Explain your answer.

Wave:A disturbance that repeats regularly in space and time and that is transmitted progressively from one place to the next with no actual transport of matter. A disturbance, oscillation, or vibration propagated (moving through) a medium or space.Examples: Sound waves, Water waves, Light waves

• Demonstrate understanding that waves transfer energy without transferring matter

• Describe what is meant by wave motion as illustrated by vibration in ropes and springs and by experiments using water waves

WAVE ON A STRING SIMULATION from Phet

Simple harmonic motion: The back-and-forth vibratory motion of a swinging pendulum.

• Give the meaning of speed, frequency, wavelength and amplitude

• Distinguish between transverse and longitudinal waves and give suitable examples

## Definitions

Transverse wave:Oscillation is

perpendicularto directionenergytravels.A wave with vibration at right angles to the direction the wave is traveling.

Longitudinal wave:Oscillation is

parallelto directionenergytravels.A wave in which the vibration is in the same direction as that in which the wave is traveling, rather than at right angles to it.

Crest / Peak:One of the places in a wave where the wave is thehighestor the disturbance is the greatest.Trough:One of the places in a wave where the wave is thelowestor the disturbance is greatest in the opposite direction from a crest.Compressions:The most dense part of a longitudinal wave.Rarefactions: The least dense part of a longitudinal wave.Wavelength:Distancealong the wave to the next particle making the same oscillation.The distance from the crest of a wave to the following crest, or equivalently, the distance between successive identical parts of the wave.

Amplitude:Maximumdisplacementof a particle.The distance from the midpoint to the maximum (crest of a wave), or equivalently, from the midpoint to the minimum (trough).

Displacement:Distance of a particle in the wave from its rest position.Period:Timetaken for one oscillation. The time required to complete a single cycle.Frequency:Number ofoscillationsinonesecond.Hertz:The SI unit offrequency. One hertz (Hz) is one cycle per second.Wave speed:The speed with which theenergyof the wave travels.Wavefronts:A line of surface which joins the peaks of a transverse wave or the compressions of a longitudinal wave.Oscillation: Regular variation in magnitude or position around a central point.

Vibration: The back-and-forth vibratory motion of a swinging pendulum. An oscillation, or repeating back-and-forth motion, about an equilibrium position.

Oscilloscope: Apparatus which represents oscillations by a trace on a screen

Periodic motion: Repetitive motion in regular interval.

Sine curve: A curve whose shape represents the crests and troughs of a wave, as traced out by a swinging pendulum that drops a trail of sand over a moving conveyor belt.

Medium: The intervening substance through which energy is conveyed

Propagate: Move through

Pitch and loudness: Properties of a sound wave which are determined by

frequencyandamplitude.Phase: The

anglewith the respect to the X axis.A curve whose shape represents the crests and troughs of a wave, as traced out by a swinging pendulum that drops a trail of sand over a moving conveyor belt.

In Phase:Term applied to two or more waves whose crests (and troughs) arrive at a place at the same time, so that their effects reinforce each other.

Out of Phase:Term applied to two waves for which the crest of one wave arrives at a point at the same time that a trough of the second wave arrives. Their effects cancel each other.

Test yourself :

State one similarity and one difference between transverse waves and longitudinal waves. Give one real life example of each.02 wave notes.doc

FLASHCARDS:LINK TO FLASHCARDS WITH IGCSE WAVES DEFINITIONS• Use the term wavefront

WAVEFRONT: A line of surface which joins all points which have the same displacement at the same moment (they are all in phase).

RAY: A line at right angles to the wavefronts which shows the direction of energy travel of the wave.

• Describe the use of water waves to show:

– reflection at a plane surface

– refraction due to a change of speed

– diffraction produced by wide and narrow gaps

• Describe the use of water waves to demonstrate reflection, refraction and diffraction

Supplement

• Describe how wavelength and gap size affects diffraction through a gap

• Describe how wavelength affects diffraction at an edge

Worksheets;

02 link v, f & L-1.doc

06 water waves.doc

Diffraction: Waves spread out after an object of opening with a size similar to the wavelength of the wave.

Reflection and refraction of Waves from physics.usask.caSupplement

• Recall and use the equation v = f λ

• Interpret reflection, refraction and diffraction using wave theory

04 wave equation.doc

TOP TIPS FOR PHYSICS CALCULATIONS.( 1.) Using letters for short write down all the information given in the question.( 2.) Change all the numbers into the basic SI units.( 3.) Pick an equation that might be useful.( 4.) If you need to re-arrange it using the formula triangle.( 5.) Put in the numbers from part ( 1.)( 6.) Calculator.( 7.) Show the final units.( 8.) Check the answer is sensible.( 9.) Remember, you always get marks for showing your working out !Speed of light: All EM waves travel at 300 million m/s in a vacuum

Example 1)

What is the speed of a sound wave if it has a frequency of 110 Hz and a wavelength of 3m ?

Frequency f =

Wavelength λ =

Speed v = ?

Example 2)

If the speed of sound in air is 330 m /s and a tuning fork produces a wave with a frequency of 165 Hz what is it’s wavelength ?

Frequency f =

Speed v =

Wavelength λ = ?

Example 3)

If a water wave moves at 25 cm / s and it’s crests are 50 cm apart what is it’s frequency ?

Speed v =

Wavelength λ =

Frequency f =

Example 4)

A sound wave has a frequency of 384Hz and a wavelength of 0.86m. Calculate its speed in m/s.

Example 5)

Another sound wave has a frequeny of 38400 Hz. Would you be able to hear this sound wave? Explain your answer.

REVISION notesPhysics classroom