IGCSE+General+wave+properties

3.1 General wave properties A disturbance, oscillation, or vibration propagated (moving through) a medium or space. Examples: Sound waves, Water waves, Light waves
 * 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.

• Demonstrate understanding that waves transfer energy without transferring matter There are many different types of waves that propagate through space or a medium. Most of waves, we are unable to see and require a medium to transmit energy. We will use slinkys in order to observe the properties of the two different types of waves (Longitudinal and transverse).

TASK: In groups of three or four, make a short MOVIE reflecting the lesson objectives below. Upload your videoclip or share the link of your movie before the end of class. UPLOAD your research reflecting the objectives. You will use a slinky in order to simulate wave energy and measure the results using different measuring techniques.

Objectives to achieve: I. Produce and observe the different types of waves through the medium of a slinky and be able to identify them. 1. Using your transverse and longitudinal wave that your group produced, find the wavelength, frequency and then calculate the velocity of the wave. 2. Can we change the velocity of a wave produdced in your slinky? Compare two transverse waves and calculate the velocity of each wave. (Evidence needed: screen shots of your waves. ) 3. Compare and contrast "Transverse and Longitudinal waves". || II. Observe how the same wave propagates differently depending on the medium and be able to articulate the cause for the changes.
 * Questions to help address objective I.
 * [[file:Wave_energy_-_Andrew_Tran.docx]] || [[file:Wave_energy_Uyen.docx]] Thank you Andrew and Uyen for sharing your precious work! ||

• Describe what is meant by wave motion as illustrated by vibration in ropes and springs and by experiments using water waves media type="custom" key="29615483" Task with Phet simulation [|WAVE ON A STRING]

1. Open the simulation and click "Oscillate" and "No End". 2. Set up the simulation with Amplitude 1 cm, Frequency 1.5 Hz, No damping and High tension. 3. Present "Rulers" and "Timer". Play the simulation to measure the values given below. 4. Label them and take a screen shot. Save your work in Word and submit it on MB before the end of class.
 * a. Amplitude ( Symbol and unit )
 * b. Period ( Symbol and unit ) : You can either measure it using the Timer or calculate it using the value of frequency given.
 * c. Wavelength ( Symbol and unit )
 * d. Calculate the velocity of the wave using the equation v=f l

• Give the meaning of speed, frequency, wavelength and amplitude • Distinguish between transverse and longitudinal waves and give suitable examples



Definitions
Simple harmonic motion: The back-and-forth vibratory motion of a swinging pendulum. Simple warm up exercise: Make a question to answer the word given below. Peak, Trough, Transverse, Longitudinal, Wavelength, Rarefaction, Compression, Amplitude, Frequency, Period, Hertz ||
 * Crest,

Oscillation is __ perpendicular __ to direction __ energ __ y travels.
 * Transverse wave:** A wave with vibration at right angles to the direction the wave is traveling.

Oscillation is __ parallel __ to direction __ energ __ y travels.
 * Longitudinal wave:**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 __ lowest __ or 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.

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

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


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


 * Period:** __ Time __ taken for one oscillation. The time required to complete a single cycle.


 * Frequency:** Number of __ oscillations __ in __ one __ __ second __.


 * Hertz:** The SI unit of __ frequenc __ y . 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.

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.
 * In 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.
 * Out of Phase:**

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]
 * media type="youtube" key="y53z2zVipAs" width="560" height="315" || media type="youtube" key="8Oc08LElPr0" width="560" height="315" || media type="youtube" key="BH0NfVUTWG4" width="560" height="315" ||
 * Properties of Waves - [|Exploring Wave Motion] (1/5) [|OpenLearn from The Open University] || Oscillation and Wave Speed - [|Exploring Wave Motion] (2/5) || Apertures and Diffraction - [|Exploring Wave Motion] (3/5) ||

• 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 how waves can undergo: – reflection at a plane surface – refraction due to a change of speed – diffraction through narrow gap

• 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; 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.ca**



Supplement • Recall and use the equation v = f λ


 * __ 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 notes]**
 * Physics classroom**