Unknown Story
Kuvakäsikirjoitus Teksti
- Maám! Sound is the energy things produce when they vibrate
- okay class, what is sound?
- forcing the air all around it to vibrate. as the air moves it carries energy out from the drum in all direction.
- Maám, example if you bang a drum, the thin skin will vibrate at a very high speed.
- Give me an example.
- there's a psychological process that happens inside our ears and brains, which convert the incoming sound energy into sensations we interpret as noises, speech, and music.
- a physical process that produces sound energy to start with and sends it shooting through the air,
- okay, give the two different aspects to sound?
- Do you guys know that Sound is like light in some ways: it travels out from a definite source just as light travels out from the Sun or a light bulb.
- Sound, however, cannot travel through a vacuum: it always has to have something to travel through (known as a medium), such as air, water, glass, or metal.
- But there are some very important differences between light and sound as well. We know light can travel through a vacuum because sun-light has to race through the vacuum of space to reach us on Earth.
- nothing maám, I understand the lesson already.
- me too maám, I don't have any questions.
- okay, any question?
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