Unit: SOUND ENERGY
Lesson objective: The
learner should be able to define sound and list some sources of sound.
Key unit competence: The learner
defines the term sound.
The learner mentions the sources of sound.
The learner describes the nature
Sound is a form of energy which stimulates our sense of hearing.
Sources of Sound
It comes from all around us. It comes from:
people when they talk.
radios when they play.
airplanes when they fly.
Even breathing makes a low sound.
is sound produced?
is produced by vibration.
we hit the drum, its membrane moves back and forth very quickly. This fast
movement is called vibration. It makes the sound.
Nature of Sound
Why is that sound doesn’t travel through a vacuum?
doesn’t travel in vacuum because it needs a medium to travel.
other nature of sound is:
Sound is a form of energy, just like electricity and light.
It is always produced by a source.
Sound waves cannot be transmitted through vacuum.
Speed of sound varies in all three media.
Sound Propagation and Transmission
is sound propagation?
propagation means the transmission of sound in different states of matter.
a speaker is tuned on, you will feel vibration of the speaker. Its back and
forth movements make the sound propagate towards your ears. When any object
vibrates, it causes movement of the air particles. These particles push the
particles close to them. It makes them vibrate too. This movement creates sound
waves. If your ear is within range of the vibrations, you hear the sound.
Exploring the Medium of
sound travel through solids?
Try the experiments below.