1. Properties of Waves Light and The Eye: Week 1

2. I Can… G I Can: describe the five properties of waves. G Amplitude G Wavelength G Frequency G Energy G Speed G I Can: describe the five properties of waves. G Amplitude G Wavelength G Frequency G Energy G Speed

3. Vocabulary G Wave G Energy G Medium G Mechanical Wave G Amplitude G Crest G Trough G Wavelength G Frequency G Wave G Energy G Medium G Mechanical Wave G Amplitude G Crest G Trough G Wavelength G Frequency

4. What is a wave? G A wave is a disturbance that transfers energy from place to place. G There are many types of waves… G Water waves G Stadium “Waves” G Light Waves G Sound Waves G Seismic Waves G A wave is a disturbance that transfers energy from place to place. G There are many types of waves… G Water waves G Stadium “Waves” G Light Waves G Sound Waves G Seismic Waves

5. Waves in Life

6. What is Energy? G The ability to do work G So, waves “pass” on energy or the ability to do work. G The ability to do work G So, waves “pass” on energy or the ability to do work. Have you ever felt the power of a wave on the beach?

7. What is a medium? G Most kinds of waves need something to travel through--we call this a medium. G Gases (such as air), liquids (such as water), and solids (such as rope) can all act as mediums. G Most kinds of waves need something to travel through--we call this a medium. G Gases (such as air), liquids (such as water), and solids (such as rope) can all act as mediums. Sound waves in air Water waves Ground destruction after seismic waves

8. Mechanical Waves G Waves that require a medium to travel through are called mechanical waves. G Tomorrow we will learn about a different type of wave… G Waves that require a medium to travel through are called mechanical waves. G Tomorrow we will learn about a different type of wave…

9. Properties of a Wave G The 5 basic properties of a wave are: G Amplitude G Wavelength G Frequency G Energy G Speed G The 5 basic properties of a wave are: G Amplitude G Wavelength G Frequency G Energy G Speed

10. 1. Amplitude G Crest: the top of a wave. G Trough: the bottom of a wave. G Amplitude: the maximum distance that the medium’s particles move from their starting position. G Crest: the top of a wave. G Trough: the bottom of a wave. G Amplitude: the maximum distance that the medium’s particles move from their starting position. Crest Trough The more energy a wave has the GREATER its amplitude.

11. 2. Wavelength G The distance between two crests or two troughs. G A longer wavelength has more distance in between the two points. G A shorter wavelength has less distance in between the two points.

12. 3. Frequency G The number of complete waves that pass a given point in a time. higher frequency G A higher frequency means that there are more waves in a given time. G A lower frequency means that there are fewer waves in a given time. G The number of complete waves that pass a given point in a time. higher frequency G A higher frequency means that there are more waves in a given time. G A lower frequency means that there are fewer waves in a given time. In the amount of time shown below, how many complete waves do you see for the top? The bottom? Which has a higher frequency? 123456 123 60 Seconds

13. 4. Energy G When waves travel through a medium-- they do NOT carry the medium along with them. G When a wave hits a medium it transfers its ENERGY to the medium’s particles. G When waves travel through a medium-- they do NOT carry the medium along with them. G When a wave hits a medium it transfers its ENERGY to the medium’s particles. The rope just moves up and down--the energy is moved along. Direction of wave = direction of energy

14. 5. Speed G Different waves travel at different speeds. G Speed: how far a wave travels in a given amount of time. G Just like the rate we calculate in math….RATE=Distance Time G Different waves travel at different speeds. G Speed: how far a wave travels in a given amount of time. G Just like the rate we calculate in math….RATE=Distance Time

15. The Relationships between Properties Creating Waves Activity

16. Creating Waves G Directions: In your lab groups, work to create the type of waves described on the handout. G TRY NOT to spill the water out of the tub G There is no right or wrong answer-- experiment for yourselves! G Record your answers in complete sentences. G Raise your hand to call for my help. G Directions: In your lab groups, work to create the type of waves described on the handout. G TRY NOT to spill the water out of the tub G There is no right or wrong answer-- experiment for yourselves! G Record your answers in complete sentences. G Raise your hand to call for my help.

17. Frequency & Wavelength G The higher the frequency, the shorter the wavelength. G The lower the frequency, the longer the wavelength.

18. Energy and Frequency G High frequency waves have more power. G Low frequency waves have less power. G High frequency waves have more power. G Low frequency waves have less power.

19. G The frequency and energy of a wave are POSITIVELY CORRELATED. G Low frequency (slow) = Low energy (weak) G High frequency (fast) = High energy (strong) G The frequency and energy of a wave are POSITIVELY CORRELATED. G Low frequency (slow) = Low energy (weak) G High frequency (fast) = High energy (strong) G The wavelength and frequency of a wave are NEGATIVELY CORRELATED. G Long wavelength = Low frequency (slow) G Short wavelength = High frequency (fast) G The wavelength and frequency of a wave are NEGATIVELY CORRELATED. G Long wavelength = Low frequency (slow) G Short wavelength = High frequency (fast) Shorter Wavelength Longer Wavelength Higher Frequency Lower Frequency Lower Energy Higher Energy

20. Let’s sum it all up…. Short Wavelength = High Frequency = High Energy Long Wavelength = Low Frequency = Low Energy Short Wavelength = High Frequency = High Energy Long Wavelength = Low Frequency = Low Energy

21. Therefore… G If you have information about one of the three (frequency, wavelength, energy), you can also figure out the other two. Let’s practice! G If a wave has a high frequency, it has a _________ wavelength and _________ energy. G If a wave has a low frequency, it has a _________ wavelength and _________ energy. G If you have information about one of the three (frequency, wavelength, energy), you can also figure out the other two. Let’s practice! G If a wave has a high frequency, it has a _________ wavelength and _________ energy. G If a wave has a low frequency, it has a _________ wavelength and _________ energy.

22. Exit Quiz 1. Draw a diagram of a wave and label the crest, trough, amplitude, and wavelength. 2. What is the difference between the frequency and the speed of a wave. 3. Given a low frequency we can predict a ________wavelength and ____energy. 1. Draw a diagram of a wave and label the crest, trough, amplitude, and wavelength. 2. What is the difference between the frequency and the speed of a wave. 3. Given a low frequency we can predict a ________wavelength and ____energy.