A community of VALUED individuals. Versatile Aspirational Learning Understanding Engaged Determined. Year 7 Physics Sound Name. Red, amber or Green?

Similar documents
Unit 4P.1: Sound. How sounds are made? Loudness and pitch Hearing sound Noise Traveling of sound Echo

Science Year Unit 8L Sound and hearing About the unit Expectations At the end of this unit in terms of scientific enquiry most pupils will:

Sound Workshop. What is sound Longitudinal Waves Frequency and pitch Hearing ranges Sounds in solids, liquids and gases Sound in a vacuum

Directions: Review the sound vocabulary words. In the pre column place a 2, 1, or 0 2 = expert 1 = heard of it 0 = do not know it

Science5 (SoundMulberry4th)

Sound and hearing 2 The outside of the ear. Sound and hearing 1 How sounds get to our ears

Science - Year 4. Sound Block 4S. Listen Up! Session 2 Resource Pack

9.3 Sound The frequency of sound Frequency and pitch pitch Most sound has more than one frequency The frequency spectrum

GRADE 4: Physical processes 1. UNIT 4P.1 11 hours. Sound. Resources. About this unit. Previous learning. Expectations

Transfer of Sound Energy through Vibrations

17.4 Sound and Hearing

When hearing is painful. Can we damage our ears?

9.3 Sound. The frequency of sound. pitch - the perception of high or low that you hear at different frequencies of sound.

Chapter 17 Sound Sound and Hearing. Properties of Sound Waves 1/20/2017. Pearson Prentice Hall Physical Science: Concepts in Action

Sound A Science A Z Physical Series Word Count: 1,093

Prisoner of Echo. 45 minutes. A sound wave needs a medium through which it is transmitted.

Please visit the website hearingandsound.weebly.com to help you study, as well as viewing the videos and booklet posted.

Sound Waves. Making Sound Waves

Producing and Detecting Sound

Hearing and Sound Study Guide

Norwood Science Center

The Human Ear. Grade Level: 4 6

Sound Waves. Sound waves can only travel through matter. The energy carried by a sound wave is transferred by the collisions between the

Draw a cross section of the human ear and label its parts.

Dalkeith High School Level 4 Physics. Waves and Sound

Fact cards. Sounds can be high or low in pitch. Sounds can be loud or quiet. Many animals, including humans, use sound to communicate.

Sound (11-16) Click here to buy the clear version of Sound (11-16). This pdf file can be downloaded and used on your PC or tablet.

DeltaScience. Content Readers. Summary. Science Background. Objectives. Reading Comprehension Skills. Supporting English Learners

Formatting notes: Bold black text are questions to ask your students to answer Blue bold: learning goals write these on the board.

Sound. Audition. Physics of Sound. Properties of sound. Perception of sound works the same way as light.

Audition. Sound. Physics of Sound. Perception of sound works the same way as light.

ISLAMABAD ACADEMY PHYSICS FOR 10TH CLASS (UNIT # 13)

Protect Your Hearing!

5. Which word refers to making

This test contains questions that are borrowed from other sources. It was not accepted to the exchange but is included in this folder because it was

DOLPHIN RESEARCH CENTER Acoustics

Sounds Good to Me. Engagement. Next Generation Science Standards (NGSS)

2. Drumming on My Ear BUILD KNOWLEDGE

Sound Unit Teacher Masters: Table of Contents

Low? High or. v vv \T\ \ C\ [ \(\(\(\(\ PITCH FREQUENCY CHAPTER4

Hearing. istockphoto/thinkstock

Sound. Chapter Test A. Multiple Choice. 1 Pearson Education, Inc., or its affiliates. All rights reserved.

SUBJECT: Physics TEACHER: Mr. S. Campbell DATE: 15/1/2017 GRADE: DURATION: 1 wk GENERAL TOPIC: The Physics Of Hearing

E4061 Hearing Conservation: Are You Listening, Jim? Leader s Guide

COMMON CORE Lessons & Activities SAMPLE

SOUNDS LIKE FUN SCIENCE GRADE 4 STELLA BIZZIO. TIME ALLOTMENT: One 50-minute class.

McGraw-Hill Science 2000, Texas Edition TAKS Practice Test. Grade 5, Chapter 5 Sound. Name. Date

TAKS TEST PREPARATION FOR MATH IN SCIENCE

Wonderlab. Sound. The Statoil Gallery. The science and maths behind the exhibits LIGHT WONDERLAB: THE STATOIL GALLERY LEVEL 3, SCIENCE MUSEUM LONDON

How Do Our Ears Work? Quiz

1.34 Intensity and Loudness of Sound

Biological Psychology. Unit Two AE Mr. Cline Marshall High School Psychology

Learning Targets. Module 20. Hearing Explain how the ear transforms sound energy into neural messages.

Sound and Music. Acoustical Society of America 2

Hearing Lab. Name. Materials: tuning forks, sterile cotton

X-Plain Tinnitus Reference Summary

Ganglion Cells Blind Spot Cornea Pupil Visual Area of the Bipolar Cells Thalamus Rods and Cones Lens Visual cortex of the occipital lobe

INTERACTIVE SCIENCE 2B

Become a good listener LESSON PLAN / MARCH 2015 SPONSORED BY

TERRESTRIAL S Traveling Noise

LISTEN! You might be going deaf DEPARTMENT OF LABOUR TE TARI MAHI OCCUPATIONAL SAFETY & HEALTH SERVICE

SENDING SECRET MESSAGES (1 Hour)

THE MECHANICS OF HEARING

The bloom guide to better hearing. Find out what you need to know about hearing loss and hearing aids with this helpful guide

Sound Travels How sound travels is explained and demonstrated using a spoon and some string to get the vibrations, then sound, to the students ears.

AND THE EARS HAVE IT! (1 Hour)

Ear Exam and Hearing Tests

TEAK Bioengineering Artificial Hearing Lesson Plan Page 1 TEAK Traveling Engineering Activity Kits

Hearing for life Facts about hearing. How hearing works, how hearing fades and how to assist your hearing

Perception of Sound. To hear sound, your ear has to do three basic things:

Loud or Soft? BROWARD COUNTY ELEMENTARY SCIENCE BENCHMARK PLAN. SC.B The student recognizes systems of matter and energy.

IT S A SECRET! (1 Hour) Addresses NGSS Level of Difficulty: 4 Grade Range: K-2

Auditory Physiology PSY 310 Greg Francis. Lecture 29. Hearing

PSY 310: Sensory and Perceptual Processes 1

A Kazoo For You. Science Activity.

The Nature of Sound. Section 1: What Is Sound? (p. 534)

Q1. The diagram shows an ultrasound monitor being used to scan a fetus.

Sound and its characteristics. The decibel scale. Structure and function of the ear. Békésy s theory. Molecular basis of hair cell function.

HEAR YE! HEAR YE! (1.5 Hours)

Table of Contents Science Action Labs

How Sound Works. Visit for thousands of books and materials.

Noise and hearing - children and teenagers

Protect your Hearing

Noise Exposure Module Quiz

Chapter 13 Physics of the Ear and Hearing

Hearing for life Protecting your hearing. Tips on how you can best preserve your hearing

Hearing The ice show was in its final moments and the music was louder than ever. There was a final chord that echoed across the arena.

Hearing. PSYCHOLOGY (8th Edition, in Modules) David Myers. Module 14. Hearing. Hearing

Sound Waves. Sensation and Perception. Sound Waves. Sound Waves. Sound Waves

College of Medicine Dept. of Medical physics Physics of ear and hearing /CH

Hearing Loss. Understanding hearing loss, its effects and available solutions.

Music and Hearing in the Older Population: an Audiologist's Perspective

Lecture 9: Sound Localization

managing safely Noise at Work Course Notes Mark Mallen Group Health and Safety Manager December 2005 Noise at Work: Version 1 Page 1 of 23

Audiology - Hearing Care Torbay and South Devon. Before you receive your hearing aid

SENSORY SYSTEM VII THE EAR PART 1

Safety Science Tools

Meet the Science Expert

FUNNELS OF SOUND. Activity Pack. Explore how sound travels using ear defenders and funnels to create giant ears. Neurosciences and Mental Health

Receptors / physiology

Transcription:

A community of VALUED individuals Versatile Aspirational Learning Understanding Engaged Determined Year 7 Physics Sound Name Part 1 What are Waves? I was present for this lesson (tick) Red, amber or Green? R A G 2 How can sound transfer energy? 3 What are Loudness and pitch? 4 How can we detect sound? 5 What about echoes and ultrasound? Mini test 1 Mark: Grade: Successes in this topic: Developments:

Key words age air amplitude animals anvil audio bats bell causes changes cochlea communication damages decibel density detect differences directions distance drum ear eardrum echo location effects exposure faster frequency funnel gas guitar hammer harmful hearing hertz higher hydrophone impaired inherited deafness inner ear instruments insulation intensity light liquid locations loudness loudspeaker materials medium membrane metres microphone movement navigate nerves nervous noise notes oscillations ossicles peak percussion pinna pitch pollution polystyrene ball possible power level question quiet reduced response sensations sensitivity signal slinky solid sound source speed stapes stirrup striking telephone thickness through timbre time tinnitus transmission travels tuning fork ultrasound vacuum vibrations visual volume water waves whistles

Checklist Lesson Developing Secure P1 2.1 Waves I can state some features of waves. I can state what happens when a wave hits a barrier. I can state that waves in the same place affect each other. I can describe the different types of waves and their features. I can describe what happens when water waves hit a barrier. I can describe what happens when waves superpose. I can compa waves and t I can explain wave occurs I can explain superpositio I can name some sources of sound. I can describe how sound is produced and travels. I can explain supersonic t P1 2.2 Sound and energy transfer I can name materials that sound can travel through. I can state that sound travels more slowly than light. I can state the link between loudness and amplitude. I can explain why the speed of sound is different in different media. I can contrast the speed of sound and the speed of light. I can describe the link between loudness and amplitude. I can describ transfer of e vibrations a cannot trave I can compa sound and l same distan I can compa waves of dif using a diag P1 2.3 Loudness and pitch I can state that frequency is measured in hertz. I can state the range of human hearing. I can describe the link between pitch and frequency. I can state the range of human hearing and describe how it differs from the range of hearing in animals. I can compa waves of dif using a diag I can explain the same so P1 2.4 Detecting sound P1 2.5 Echoes and ultrasound I can name some parts of the ear. I can state some ways that hearing can be damaged. I can state that a microphone detects sound waves. I can state simply what ultrasound is. I can state some uses of ultrasound. I can describe how the ear works. I can describe how your hearing can be damaged. I can describe how a microphone detects sound. I can describe what ultrasound is. I can describe some uses of ultrasound. I can explain transfer vibr I can explain can be dam I can compa ear and the I can explain be analysed I can explain ultrasound. 5

THINK PAIR SHARE WRITE CWK What are waves? / / I can describe what happens when water waves hit a barrier. I can describe the different types of waves. I can describe what happens when waves superpose. Key words to help with your answers: wave wavelength frequency direction parallel reflected Start here A Three properties of a wave are amplitude f and. [challenge] B The direction of the oscillation of a longitudinal wave is...... to the.. of the wave. [Extra challenge] 6

C State the name of the wave that hits the barrier. Stick your work in your book. Making music part 1 Work as a group to use objects in the room to make a tune. E.g. Twinkle twinkle little star, or the first seven notes of the EastEnders theme tune. Safety ask if the item is fragile or if water is needed, make sure the container does not break if you hit it. Report Our group used the following to make our different notes:.. The sound was made when the items. High pitch notes happened when the vibrations were.. and low pitch notes happened when the vibrations were.. 7

Extension See what you can do with straws in Making music part 2 Making music part 2 - Make Music With Straws Make music with drinking straws and learn about how sound works. You can entertain your family and friends by playing some well-known songs. What You'll Need 8 straws, Scissors, Ruler, Masking tape, Pen or marker What to Do 1. Measure and cut the straws into these lengths: 19.5 centimeters, 17.0 cm, 15.5 cm, 14.5 cm, 13.0 cm, 11.5 cm, 10.0 cm, 9.5 cm. Label the longest straw #1, the next longest straw #2, and so on. The smallest straw should be labeled #8. 2. Tape the straws together in order from longest to shortest. You can use small pieces of straw (about 2 cm long) as spacers between the longer straws. This is called a pan pipe. 3. Hold the pan pipe vertically below your lips. Blow across the tops of the straws as though you are blowing across the top of a pop bottle. 4. Try playing one of the songs below, or make up your own songs. Remember: 1 is the longest straw and 8 is the smallest straw. Twinkle, Twinkle Little Star 11 55 66 5_ 44 33 22 1_ 55 44 33 2_ 55 44 33 2_ 11 55 66 5 44 33 22 1 Jingle Bells: 333 333 35123 444 4433 3355421 Mary Had a Little Lamb: 3212333 222 355 3212333 322321 What's Happening? vibrates ears outward scale pitch low length high As you blow across a straw, the air in the straw.. These vibrations travel.. and reach our. sounding like the notes of a You can change the. (highness or lowness of a sound) by changing the. of the straw. A long straw produces a note. A short straw produces a. note. 8

Homework Summary questions answer 1 question Q1, 2 or 3 Choose your challenge [Extra challenge] Underline the correct word in bold [Super challenge] Homework Summary questions answer 1 question Q1, 2 or 3 Choose your challenge [Extra challenge] Underline the correct word in bold [Super challenge] 9

10

CWK How can sound transfer energy? / / Start here: Think Pair Share 1a Waves have three important features match the name to its correct description: amplitude The number of waves that go past a point per second. frequency The distance from one point on a wave to the same point on the next wave. wavelength The distance from the middle to the top of a wave. 1b State the name for the top of a transverse wave... 1c State the name for the bottom of a transverse wave.... Learning objectives: Check your learning I can describe how sound is produced and travels. I can explain why the speed of sound is different in different materials. I can contrast the speed of sound and speed of light. Key words to help with your answers: liquid solid gas vibration 340 m/s 300 000 000m/s crest trough A A sound wave is produced by a.. [challenge] 11

B The speed of sound in air is.[extra challenge] Super Challenge: C Name the three types of medium that sound can travel through 1. 2. 3. D Which is faster, sound or light? Give evidence to support your answer.. Measuring the speed of sound in air. A friend to help with the experiment A tape measure Blocks to bang together Check your learning and then complete the practical. Instructions: 1. Find a large empty area, such as a field or large court. 2. Choose two spots on opposite ends of the area where each person will stand. 3. Measure the distance between the two spots using a tape measure. Ideally you want as large a distance as you can manage. 100m would be ideal. 4. Have your friend take the blocks and stand at one spot, holding them up high. 5. Take the stopwatch and stand at the other spot. Make sure you have a clear view of the blocks. 6. Signal your friend to bang the two blocks together hard, by raising your arm and letting it drop. [if there are no blocks shout now and raise your arm at the same time] 7. Start the stopwatch as soon as you see the blocks hit each other. 8. Press stop as soon as you hear the sound from the blocks. 9. Calculate the speed of the sound by dividing the distance between you and your friend by the time. 10. To get a more accurate measurement, repeat the above steps a few times and then take an average of the results 12

Time(s) Group Time 1 Time 2 Time 3 Time 4 Time 5 Average time 1 2 3 4 Distance sound travels (m) Speed = distance time (m/s) Average speed of sound (m/s) Conclusions a) I found that my speed of sound was.. m/s b) The group average for the speed of sound was m/s c) The actual speed of sound in air is.. m/s d) My results was m/s different. This may be because.. Summary questions 2 and 3 in your exercise book Choose your challenge [Extra challenge] [Fill in the gaps] [Super challenge] 13

Extension/Homework The speed of sound Setting the scene Sounds do not reach us straightaway. You will learn why sounds travel at different speeds through solids, liquids, and gases. Aims In this activity you will: state the speed of sound in air state how the speed of sound varies in solids, liquids, and gases be able to link the particle arrangement in solids, liquids, and gases with the speed of sound. You will be working scientifically to: make predictions using scientific knowledge ask questions based on observations of the real world, and use previous knowledge and experience. Task Read the text and answer the questions that follow. After an earthquake, rescuers search for survivors under the rubble of fallen buildings. Every few minutes everyone stops what he or she is doing to listen very carefully. The rescuers are listening for shouts from survivors but more often they can hear tapping sounds when survivors tap stones or metal pipes. One person was rescued after 11 days trapped under rubble when the rescuers heard faint tapping sounds. The table shows the speeds of sound in different materials Material Speed of sound (m/s) Type of substance aluminium 6 400 solid metal steel 5 800 solid metal brick 4 200 solid non-metal wood 3 600 solid non-metal glycerol 1 900 liquid water 1 500 liquid mercury 1 450 liquid metal helium 970 gas air 340 gas carbon dioxide 260 gas 14

Questions 1 State the speed of sound in air. Give the units. 2 State whether sound travel fastest in solids, liquids, or gases. 3 Explain why a sound travelling along a steel rod and an identical wooden rod reaches the end of the steel rod sooner. 4 Sounds travel through materials by passing vibrations from particle to particle. Particles in solids are very close together. They pass on vibrations better than particles in gases, which are far apart. Use this information to explain why tapping sounds from survivors after earthquakes travel better than shouting for help. Extension 1 Fill in the boxes to show how particles are arranged in solids, in liquids, and in gases. Solid Liquid Gas 15

2 Explain why sounds do not travel as quickly through liquids as through solids. 3 The Sun is incredibly noisy. The space between Earth and the Sun is called a vacuum, a place where there are no particles. Use these ideas to explain whether sounds from the Sun can reach Earth. 16

CWK What are Loudness and pitch? / / I can state the range of human hearing I can describe the link between loudness and pitch. I can describe the link between frequency and pitch. I can describe how the range of human hearing differs from the ranges of hearing in animals. I can Explain how sounds differ in different situations Key words to help with your answers: Frequency amplitude Hertz (Hz) 20Hz 20 000Hz Shorter vibrations thicker longer thinner faster slower Start here: 1a Work with your learning partner to unscramble these anagrams linked to sound: a r t i b e v o i l s d s u a m c v u A If a sound is louder the sound wave will have a bigger [challenge] B How high or low a sound is (its pitch) depends on the waves [Extra challenge] 17

C State the unit that frequency is measured in. [Extra challenge] D Describe the difference in frequency between high and low pitched sounds. [Super challenge] In your book: Underline the correct words in bold. 18

Making music part 2 - Make Music With Straws Make music with drinking straws and learn about how sound works. You can entertain your family and friends by playing some well-known songs. What You'll Need: 8 straws, Scissors, Ruler, Masking tape, Pen or marker What to Do 1. Measure and cut the straws into these lengths: 19.5 centimeters, 17.0 cm, 15.5 cm, 14.5 cm, 13.0 cm, 11.5 cm, 10.0 cm, 9.5 cm. Label the longest straw #1, the next longest straw #2, and so on. The smallest straw should be labeled #8. 2. Tape the straws together in order from longest to shortest. You can use small pieces of straw (about 2 cm long) as spacers between the longer straws. This is called a pan pipe. 3. 4. Hold the pan pipe vertically below your lips. Blow across the tops of the straws as though you are blowing across the top of a pop bottle. 5. Try playing one of the songs below, or make up your own songs. Remember: 1 is the longest straw and 8 is the smallest straw. Twinkle, Twinkle Little Star 11 55 66 5_ 44 33 22 1_ 55 44 33 2_ 55 44 33 2_ 11 55 66 5 44 33 22 1 Jingle Bells 333 333 35123 444 4433 3355421 Mary Had a Little Lamb 3212333 222 355 3212333 322321 What's Happening? vibrates ears outward scale pitch low length high As you blow across a straw, the air in the straw.. These vibrations travel.. and reach our. sounding like the notes of a You can change the. (highness or lowness of a sound) by changing the. of the straw. A long straw produces a note. A short straw produces a. note. 19

Wave diagrams Setting the scene We can see sound waves using an oscilloscope. The oscilloscope shows the sound wave as a transverse wave which changes shape when it gets louder or softer or changes pitch. In this activity you will draw diagrams to represent sound waves. Wave diagrams - help Use the following facts to help you answer the questions on your activity sheet. High-pitched sounds have a high frequency (waves appear closer together). Low-pitched sounds have a low frequency (waves are further apart). The loudest sounds have the highest decibel number. Animals that can hear sounds above the human hearing range hear sounds above 20 000 Hz. Animals that can hear sounds below a dog s hearing range hear sounds lower than 40 Hz. The range of hearing is the difference between the highest frequency and the lowest frequency heard by an animal. Task 1 The diagram shows a transverse wave. Fill in the table to name the parts of the wave shown in the diagram. Choose from these words: amplitude peak trough wavelength Part of the wave Part of the diagram B D A C 20

2 Look at this diagram. It shows three different sounds. Describe how the sounds are different. Explain why you made this prediction.. 3 Look at this diagram. It shows two different sounds. Describe how the sounds are different. Explain why you made this prediction. 21

Homework Questions 3 The table includes information about animals and the sounds they make and hear. The loudness of sounds is measured in decibels (db). The loudest sound has the most decibels. Animal Hearing range (Hz) Loudest sound produced (db) human 20 20 000 90 dog 40 60 000 113 elephant 10 10 000 117 howler monkey 100 30 000 140 cat 30 50 000 100 bat 3 000 120 000 100 1 Name the animal that can hear the highest sounds. 2 Name the animal that can hear the lowest sounds. 3 Name the animal that can make the loudest sounds. 5 Name all the animals that can hear sounds too high for humans to hear. 6 Calculate the range of human hearing. Show your working. 7 Explain why a dog cannot hear the same sounds as an elephant. Use the data from the table. 8 Explain why bats can hear more sounds than any other animals in the table. 22

CWK How can we detect sound? / / I can state the main parts of the ear. I can describe how the ear works. I can describe how your hearing can be damaged. I can describe how a microphone detects sound. I can explain some risks of loud music. Start here in pairs please. 23

Summary question damaged ossicles ear drum oval window cochlea hairs auditory nerve decibels diaphragm 1. When a sound wave enters your ear it makes the.. vibrate. This makes the. vibrate. The.. vibrates and this makes the liquid inside your.. vibrate. Little. inside your... produce an electrical signal that travels up your. to your brain. Sound intensity is measure in.. your hearing can be. By loud sounds. In a microphone a. Vibrates which produces and electrical signal. 24

Investigating sound proofing Key words Sound level decibels control comparison proofing lowest meter Equipment Power supply, wires, buzzer, switch, paper, cloth, cotton wool, bubble wrap, sound meter Method 1. Set up a circuit that contains a switch and a buzzer. 2. Use the sound meter to measure how loud the buzzer is. 3. Place a material over the buzzer and measure how loud the buzzer now is. 4. Repeat step 3 for other materials. 5. If there is time repeat the experiment. Results Material None Sound level (Db) Try 1 Try 2 Average Paper Cloth Cotton wool Bubble wrap Conclusions 1. Identify which material was the best at soundproofing. Challenge 2. State how the results support your answer to part 1. Extra challenge....... 25

3. Explain why you measured the sound level of the buzzer with no soundproofing? Super C......... 26

HOMEWORK 4 Hearing and how it is damaged Setting the scene Our ears can be damaged over a period of time through exposure to high levels of noise. This activity sheet helps you understand how hearing is damaged and what you can do to prevent harm. Task 1 The diagram shows the structure of the ear. Complete the table with the correct name for each labelled part of the ear: Label Part of the ear A B C D E 27

2 Read the text and answer the questions below: Joe Joe played the drums in a rock band several times a month and sat next to the loudspeakers. After each gig Joe s ears would ring and he couldn t hear conversations but his hearing recovered after a few hours. Joe s friends asked him to wear earplugs or sit somewhere else but he wouldn t. When Joe wasn t playing at a gig he was listening to his favourite bands on his mp3 player for inspiration. He used earbud headphones to block out other sounds. After a few months Joe couldn t hear conversations clearly and needed to turn up the volume on his mp3 player. Joe started hearing a ringing sound in his ears most of the time and music sounded muffled. Joe s dad Joe s dad worked in a factory with constant noise from machinery. All workers wore earmuffs to protect their hearing from the constant noise. Joe s dad said the ringing sound was noise-induced tinnitus and it would get worse unless Joe stopped damaging his hearing. Joe and his dad both damaged their hearing because of noise exposure. Loud noises over a period of time damage hairs in the cochlea. Decibels measure how loud sounds are. Sounds less than 80 decibels do not damage these hairs but loud music through headphones (90 decibels) for half an hour a day will. Damage from a rock concert (100 decibels) can happen after just 15 minutes. The factory where Sam s dad worked produced sound levels of 95 decibels. To begin with, the hairs can recover and the damage is reversible but after a while the damage becomes permanent. Questions 1 Describe how Joe damaged his hearing. Include the length of time that each activity needs to go on to cause damage. 2 Describe three effects of damaged hearing. 3 Suggest two ways that Joe can protect his hearing. CWK What about Echoes and ultrasound? / / 28

I can describe what ultrasound is. I can describe some uses of ultrasound. I can explain with reasons why animals us echo-location. Key words to help with your answers: reflects ultrasound absorbs echo high frequency A B An echo is when sound off a surface and bounces back to where the original sound was made. [challenge] The frequency of ultrasound is. [Extra challenge] Summary questions 2 and 3 in your exercise book 29

Fill in the gaps [Extra challenge] [Super challenge] Using echoes Echoes are reflections of sound waves. You will have come across different examples of this in everyday life and may not have realised it. In this activity you will learn about the usefulness of echoes. Task Read the text and answer the questions that follow. If you walk into a large empty hall with stone walls and floors you may hear your footsteps echoing. Echoes are the sound reflections from hard surfaces. In a very large room, the echo is quiet and takes a long time to be heard. Echoes help animals find their position even if they cannot see, for example, at night or underwater. Dolphins make clicking sounds which reflect from nearby objects. As soon as the dolphin hears an echo it produces the next click. The clicks are heard in both ears so the dolphin can work out the distance and direction of the object. Questions 30

1 State what is meant by an echo. 2 Suggest why it is hard to hear an echo in the classroom. 3 Write down two ways dolphins use echoes. 4 Try this short experiment with a partner. One of you closes your eyes. The other person clicks their fingers near your head, for example, behind your head or to one side. Work out where the sound is coming from. 5 Use your experiment to explain how dolphins tell which direction the object is in. What have you learned this lesson? This lesson I learned about: Rate your learning for this lesson: Green Amber Red I understood all of the lesson and made excellent progress. My next step is: I understood most of the lesson and made good progress. I still need to learn about: I didn t really understand:...... 31

32

Extension 1 Explain how noise levels, and how long we listen to loud noises, are connected with the damage caused. 2 Use your knowledge to suggest two ways young people could protect their hearing at a concert. Suggest which way is likely to work best. What have you learned this lesson? This lesson I learned about: 33

34

End of booklet question raffle. Write 1 to 9 on some pieces of paper, place them face down and mix them up. Take it in turns to choose which question you are to answer. Share your answer with your partner and they will share their answer with you. Discuss whether you agree or not before writing your answer. 35

36