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Hearing. 11. 3. Hearing. Hearing allows us to…. communicate. Hearing. Hearing allows us to…. enjoy music. Hearing. Hearing allows us to…. avoid danger. How is sound produced?. Let’s learn about how sound is produced. 11.5. Experiment video. Producing sound. 1. rubber band. 11.5.
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Hearing 11.3
Hearing Hearing allows us to… communicate
Hearing Hearing allows us to… enjoy music
Hearing Hearing allows us to… avoid danger
How is sound produced? Let’s learn about how sound is produced.
11.5 Experiment video Producing sound 1 rubber band
11.5 1
11.5 a Does the rubber band produce any sound? Yes.
11.5 b What do your hands feel? The rubber band is vibrating.
11.5 2 Ah~ put fingers gently on the throat
11.5 a What do you feel on your throat when you speak? There is vibration on my throat. Ah~
11.5 b What do you feel on your throat when you stop speaking? The vibration stops. Ah~
11.5 3 tuning fork rubber stopper
11.5 3
11.5 What do you observe? The tuning fork produces sound. 3
11.5 4 plastic basin with water
11.5 What do you observe? Ripples form on the water surface. 4
11.5 5 What do the results in steps 1 to 4 show? They show that sound is produced by __________________ vibration of objects.
How is sound produced? All sound sources, such as musical instruments, have parts that vibrate. string hammer vibrates strike the strings sound
11.5 From which parts of the instruments are the musical notes produced? Write down the vibrating parts of the musical instruments which produce sound.
11.5 Hong Kong Chinese Orchestra
11.5 1 Erhu (二胡) string
11.5 2 Cymbals (鈸) metal pieces
11.5 3 Drum (鼓) leather
11.5 4 Suona (嗩吶) air column
11.5 5 Dizi (笛子) air column
11.5 6 Zheng (箏) string
How is sound produced? Sound is produced by _________ of objects. vibration
11.6 Experiment video How sound travels 1 plastic wrap large bowl
11.6 2 rice grains
11.6 3 strike gong
11.6 a What happens to the rice grains on the plastic wrap? They move/jump up and down.
11.6 b Suggest a reason for the observation in a. The vibration of the gong is transmitted through the air to the plastic wrap and the rice grains.
How does sound travel? When we strike a fork... vibration of the fork
How does sound travel? vibration of air particles transmitted through the air to our ears
How does sound travel? vibration of air particles Sound can travel through air.
How does sound travel? Can sound travel through solids or liquids?
11.7 Experiment video Can sound travel through solids? Design a test to find out whether sound can travel through solids or not.
11.7 1 Write down the apparatus and materials you need. A bench in the laboratory
11.7 2 Draw the design of your set-up. Write down the steps of your test. 1 Form into groups of two Ss.
11.7 2 Draw the design of your set-up. Write down the steps of your test. 2 Student A taps one end of the bench. Student B puts his/her ear against the bench and listens carefully.
11.7 2 student A student B
11.7 3 Carry out your test after getting approval from your teacher. Write down your observations. Student B can hear the tapping sound made by student A.
11.7 4 What can you conclude from your test? Sound can travel through wood (solids).
11.8 Experiment video Can sound travel through liquids? Design a test to find out whether sound can travel through liquids or not.
11.8 1 Write down the apparatus and materials you need. buzzer 1 1000 mL beaker 1 small plastic bag 1 stethoscope 1 water
11.8 2 Draw the design of your set-up. Write down the steps of your test. 1 Turn on a buzzer. Put it into a plastic bag and seal the bag.
11.8 2 Draw the design of your set-up. Write down the steps of your test. 2 Put the bag into a beaker of water.
11.8 2 Draw the design of your set-up. Write down the steps of your test. 3 Put the chestpiece of the stethoscope into the water and listen through the earpiece.
