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

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

 

 

 

...the wave equation...

 

 

 

Objectives:

 

  
 

 

Pretty waves :)

  

 

• Know that frequency, wavelength and wave velocity are connected by the wave equation.

 

 

• Be able to use the wave equation to solve numerical problems involving speed, frequency, and wavelength.

 

 

• Be able to use the formula Distance = Speed x time to work out the distance travelled by a wave.

 

 

  

 

 

 

 

 

 

 

Task 1 - Starter

 

  
 

 

I know the answer!

 

 

  

 

Find someone who knows:

 

 

1) The definition of a transverse wave.

 

2) The definition of a longitudinal wave.

 

3) What is meant by the frequency of a wave.

 

4) The units used to measure frequency.

 

5) What is meant by the amplitude of a wave.

 

6) What is meant by the wavelength of a wave.

 

 

 

Your teacher will tell you which questions to discuss.

 

  

 

 

 

 

 

 

 

Task 2a - The wave equation

 

  
 

 

Lots of waves!

 

 

 

  

 

Frequency, wave speed and wavelength are connected by a simple formula:

 

wavespeed = frequency × wavelength

 

or

 

v = f × λ

 

 

Where:

v = wave velocity (metres per second, m/s or ms-1)

f = frequency, (Hertz, Hz)

λ = wavelength (metres, m)

 

 

You teacher will show you how to rearrange the formula using an equation triangle.

 

  

 

 

 

 
 
 

 

 

Task 2b - Wave calculations

 

  
 

 

My brain uses electrical waves.

 

 

  

 

Solve the problems below using the wave equation.  Your teacher will show you how to do the first one as an example.

 

 

 

These simple questions are good for foundation tier students.

Click the image above to download these questions as a word document.

 

 

These questions are a little more difficult.  Great for higher tier students.

Click the image above to download these questions as a word document.

 

 

These questions are also great for higher tier students.

Click the image above to download these questions as a word document.

 

  

 

 

 

 

 

 

 

 

 

Task 3a - Calculating wave motion

 

  
 

 

 

Think hard!

 

  

 

This formula is used to calculate the distance travelled by a wave:

 

 

Distance = Speed × time

 

or

 

D = S × t

 

 

Where:

D = distance travelled (metres, m)

S = speed (metres per second, m/s or ms-1)

t = time (seconds, s)

 

 

 

Once again, your teacher will show you how to rearrange the formula using an equation triangle.

 

  

 

 

 

 

 

 

 

 

Task 3b - More calculations!

 

  
 

 

 

Think hard!

 

  

 

Use the equation to help you solve these problems.

 

 

Click the image above to download this task.

 

 

Your teacher will show you how to do the first two as examples.

 

  

 

 

 

 

 

 

 

 

 

 

Homework

 

  
 

 

Let's catch some waves!

 

 

 

 

  

 

Try these mixed wave equation questions.  You will need to use both the formulae you have learned.

 

 

 

 

• Read each question carefully.

• Decide which formula you will need.

• Show full working for your calculation.