Good Vibrations Aim I can describe and explain
Good Vibrations
Aim • I can describe and explain sound sources. Success Criteria • I can identify and describe sound sources around school. • I can explain how sources of sound vibrate, creating sound.
What is Sound? What do you already know about sound and do you know anything about how sounds are made? Complete your Sound Mind Map to show what you already know, and to ask questions about what you want to find out.
What is Sound? Watch this clip to see how the different families of musical instrument create different sounds. Click on this image to play the video in a new window.
What is Sound? Did you come up with some words to explain how the musical instruments make sounds? Look at the words below. Did you choose any of these words? Vibrate Vibration Twang Blow Bang Scrape Shake Pluck
Vibrations All the instruments are played in different ways, but they all have something in common. They all create sounds by vibrating. The strings of the guitar and the gopichand vibrate when they are plucked. The pan pipes and horn are filled with air, which vibrates when they are blown. The balafon and the bongos make sounds when they are hit or banged, causing the blocks or the skin to vibrate. But what is a vibration?
Vibrations We can see and feel vibrations whenever sounds are made. Gently place your hand on your throat. Say ‘Ah!’ Can you feel the vibrations from your vocal cords? Ahh
Vibrations Place a few grains of rice on a drum skin and gently bang the drum. What do you observe? The grains of rice bounce on the drum skin when it is hit. This is because the drum skin vibrates, and the vibrations pass to the grains of rice, which also vibrate.
Vibrations Sounds are made when something vibrates. Talk to your partner about what is vibrating in each of these pictures to make a sound.
Vibrations By placing rice on a drum, you can see the vibrations when you hit the drum, as well as hearing the sound.
Loud and Quiet Try this mini investigation to find out if the vibrations change when the loudness of the sound changes. Place some rice on the skin of a drum. Bang the drum three times: gentle, medium and hard. Observe the way the rice vibrates each time. Is there a link between the loudness of the sound and the size of the vibrations?
Loud and Quiet The louder the sound, the bigger the vibration. You should have noticed that the rice grains vibrated more when you hit the drum harder, creating a louder sound. The size of the vibration is called the amplitude. Quieter sounds have a smaller amplitude, and louder sounds have a bigger amplitude.
Check out these different instruments – how are they making sound? https: //www. bbc. co. uk/teach/class-clips-video/music--science-ks 2 -what-issound/zbnmhbk
How Does Sound Travel So we know that sounds are caused by vibrations, and the louder sounds have bigger vibrations. But how do these different sounds reach our ears? These children have been talking about their ideas. What do you think of their ideas? I think sound can travel through the air because the air is lighter and easier to get through than solids or liquids. Sound moves the air from the source of the vibration into our ears. If we are listening, we will hear the sound.
How Does Sound Travel Watch this clip to see if you can identify how different sounds travel. Click on this image to play the video in a new window.
How Does Sound Travel? Sound can travel through solids, liquids and gases. Sound travels as a wave, vibrating the particles in the medium it is travelling in. So in our example, when you hit the drum, the drum skin vibrated. This made the air particles closest to the drum start to vibrate as well. The vibrations then passed to the next air particle, then the next. This carried on until the air particles closest to your ear vibrated, passing the vibrations into your ear.
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