1. Learning Objective
To be able to:
Describe the two types of waves, including key features of each
Key Words:
Longitudinal, transverse, particles

2. Can you match the key word to the definition?
Sunday, 26 May 2019
Types of Waves
Date and title in books. You need a pen, pencil & ruler.
Starter Activity – 5 minutes
Can you match the key word to the definition?

3. Learning Outcomes Explain the different movement of both types of wave
Target 1-9
Identify the name of the two types of waves
(F/H)
Target 4-9
Draw and describe a longitudinal wave and a transverse wave
Calculate the time period and frequency for a wave
(H)
Target 5-9
Explain the different movement of both types of wave
Extension: Application of Knowledge
Target 8/9
Discuss why it is important that waves from the sun are transverse and not longitudinal
Learning Outcomes

4. Transverse Waves
A transverse wave is a wave that oscillates (moves up and down) at right angles to the direction of the wave.
Examples of Transverse waves:
Ripples on a water surface
Light
X-rays
Ultraviolet rays
Transverse waves do not need a medium to move (e.g. they don’t need a solid, liquid or gas to move)

6. Longitudinal Waves
A longitudinal wave has particles that move parallel to the direction of motion.
Examples of Longitudinal Wave:
Sound
Ultrasound

8. Time period and frequency
How long does it take for one wave to pass?
This is called the time period and we calculate it using:
𝑇= 1 𝑓

9. Calculations The frequency of a wave is 20Hz. What is the time period?
A wave passes by 30 times per second. What is the time period?
A wave has a time period of 50seconds. What is its frequency?

10. Quick think! Which sound has the highest pitch? Elephant roar
Whale song
Dog whistle
Woman's voice
Drum banging
Leaves rustling
Mans voice
Cargo truck
Question: What is pitch?

11. How do you think these waves will sound?
Look at the pictures!
Look at the two pictures. Which has more waves on it?
How do you think these waves will sound?
A high pitch sound.
 A low pitch sound.

12. Look at the pictures!
Picture one has a high frequency. The waves are more frequent. There are lots of particles vibrating.
Picture two has a low frequency. The waves are less frequent. There a fewer particles vibrating.

13. Pitch: Quick Check Which picture has the highest pitch?
Which picture shows a high frequency?
Describe how much the particles are vibrating in each picture.

14. How do you think these waves will sound?
Look at the pictures!
Look at the two pictures. Which one has a larger wave?
How do you think these waves will sound?
 A quiet sound.
 A louder sound.

15. Look at the pictures! Picture 1 has smaller waves.
The smaller waves tell us there is less amplitude.
A lower amplitude means a quieter sound.
There means the particle vibrations are smaller.

16. Amplitude: Quick Check
Picture 1
Picture 2
Which picture has the loudest sound?
Which picture shows a high amplitude?
Describe how much the particles are vibrating in each picture.

17. Echo, echo, echo An echo is a reflection of sound.
Where are echoes heard?
Questions – answers in full sentences.
Why do we hear an echo in an empty room with no carpets?
Why can we not hear any echoes in a room with carpets and furniture?