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Rogue Physicist.  Free resources for physics education © 2006-2016 Dorian Pascoe.  Email: dorian.pascoe@hotmail.co.uk

Most resources are available under a Creative Commons Licence.  Visit our mirror at www.physicsweb.altervista.org

 

 

 

...waves...

 

 

 

Objectives:

 

  
 

 

Pretty waves!

  

 

• Know that there are two types of wave - transverse and longitudinal.

 

 

• Be able to give examples of each type of wave.

 

 

• Be able to describe waves in terms of frequency, wavelength, speed and amplitude.

 

 

• Be able to sketch and label diagrams of transverse and longitudinal waves.

 

  

 

 

 

 

 

 

 

Task 1 - Starter

 

  
 

 

I know the answer!

 

 

  

 

There are lots of examples of waves all around you.  Discuss in pairs or threes:

 

 

 

1) How many examples of waves can you think of?

 

 

2) Which types of waves are in the room with you right now?

 

 

3) What do all of these waves transfer?

 

 

You have one minute!

 

 

Your teacher will tell you which questions to discuss.

  

 

 

 

 

 

 

Examples of waves

 

  
 

 

Lots of waves!

 

 

 

  

 

How many different examples of waves did you think of?  There are lots:

 

 

 

• light waves  • sound waves
• infrared waves

 • mexican waves
• radio waves  • ocean surface waves
• ultraviolet waves  • ripples in a pond
• seismic waves  

 

 

 

...and many more!

 

  

 

 

 

 

 

 

 

 

Task 2 - Wave demonstrations

 

  
 

 

My brain uses electrical waves.

 

 

  

 

There are two types of waves: transverse waves, and longitudinal waves.

 

 

Transverse waves can travel along a rope.

 

Transverse waves on a rope.

 

 

 

Longitudinal waves and transverse waves can both travel along a helical slinky spring.

 

Transverse & longitudinal waves on a helical spring.

 

 

Your teacher will demonstrate these to you.  Try to remember the technical scientific terms used to describe the waves!

 

 

 

You may also want to look at the wave simulations below.

 

  

 

 

 

 

 

 

 

Simulation - Transverse waves

 

  
 

 

Thanks to PhET for creating this awesome simulation!

 

 

This applet is HTML5, so it works on tablets and mobile devices too!

 

 

Flash version available too.  Click here to load.

 

 

  

 

This simulation allows you to investigate the characteristics of a transverse wave on a string.

 

 

Set to oscillate with no end and no damping, and adjust from there.

Applet credit: PheT.

 

 

Click below to load the simulation in full screen mode.  You can also set up standing waves by selecting fixed end or open end, and selecting appropriate frequencies.

 

 

 

 

How does the wave change if...

 

  • the amplitude is increased?

 

  • the amplitude is decreased?

 

  • the frequency is increased?

 

  • some damping is added?

 

 

  

 

 

 

 

 

 

 

 

Task 3a - Wave diagrams

 

  
 

 

Pretty waves :)

 

 

 

  

 

Draw a diagram of a transverse wave in your exercise book.

 

 

 

• Use a pencil and ruler.

 

• Show three oscillations of the wave

 

• Label your diagram using the correct technical terms:

 

 

 

amplitude          wavelength

 

peak          trough        rest position

 

 

 

Show three different places you could measure the wavelength.

Show two places you could measure the amplitude.

 

  

 

 

 

 

 

 

 

Task 3b - Wave diagrams

 

  
 

 

 

Think hard!

 

  

 

Draw diagram of a longitudinal wave in your notebook, and label the following features:

 

 

 

 

 

• a compression.

 

• a rarefaction.

 

• the wavelength.

 

 

Teacher note: there is also a printable diagram here.

 

  

 

 

 

 

 

 

 

 

Task 4

 

  
 

 

 

Think hard!

 

  

 

A

 

 

 

 

  

 

 

 

 

 

 

 

Homework

 

  
 

 

Let's catch some waves!

 

 

 

 

  

 

1.) Write definitions for each of the following terms in words you can understand.

 

 a) Wavelength

 

 b) Amplitude

 

 c) Frequency

 

 d) Rest position

 

 e) Oscillation

 

 f) Polarisation

 

 

 

2.) Give the units we use to measure each quantity for the first three.

 

 

Click the image below to download this homework task.

 

  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

OLD CONTENT TO BE ARCHIVED

Now look at this simulation of a wave on a string.

Remind the person next to you:

Teacher note: click here for a full-screen version.  Set to oscillate with an amplitude of 50, frequency of 25, no damping, no end.

 

Try to remember the technical terms we used to describe the waves you have just seen. Your teacher will help to remind you!

 

Now:

1.) Count the number of waves passing a point on the screen in 10 seconds.

2.) Pause the simulation and increase the frequency using the slider. What do you expect will be different this time? Count the number of waves in 10 seconds again. What do you notice? Did anything else change other than the frequency?

3.) Pause the simulation again, and this time decrease the amplitude. What do you expect to change? Now restart the animation and check if you were right!