Lesson 7 of 7

Using sound

Goal: Describe uses of sound and ultrasound.

Puzzles for this lesson

Sound waves carry energy and information. Ultrasound is sound too high for us to hear: above 20 000 Hz.

An ultrasound scan sends ultrasound into the body. The echoes build a picture, such as one of a baby before it is born.
Sonar on a ship sends a pulse of sound down to the sea bed and times the echo, to find how deep the water is.
Ultrasound can clean. It makes a liquid vibrate so fast that tiny bubbles form and burst, which knocks the dirt off jewellery or glasses.
A microphone turns a sound wave into an electrical signal. A loudspeaker turns the signal back into sound.

This is how a phone call, a radio or a school hall speaker system carries your voice.

Your turn

This lesson’s activity starts here in a moment.

I can say what ultrasound is and give two uses.I can say what a microphone does.

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Wave A vibration that carries energy from place to place, but not matter

Echo A sound reflected back from a surface

Ultrasound Sound with a frequency too high for humans to hear

Microphone Turns a sound wave into an electrical signal

Loudspeaker Turns an electrical signal into a sound wave

For teachers: AQA 3.4.3 · Pearson Edexcel 37.2