# De Lisle Catholic Science College

## Presentation on theme: "De Lisle Catholic Science College"— Presentation transcript:

De Lisle Catholic Science College
KS 3 laboratory Sound De Lisle Catholic Science College Science department

What is sound Sound variables Sound wave models Speed of sound

Sound introduction Answers What is sound? sound is energy
How does sound travel? sound travels in the form of waves How are sound waves made? sound waves are made by vibrating objects What sort of things make sound waves when they vibrate? musical instruments, bees wings, vocal cords, loudspeakers

Use mouse wheel or curser keys to animate
Creating a sound wave Vibrating wooden lath Air particles pushed together Energy flow Vibrating wooden lath Air particles pulled apart Energy flow Use mouse wheel or curser keys to animate

Particle vibration in a sound wave
Direction of particle movement Direction of energy transfer Use mouse wheel or curser keys to animate

Sound variables Amount of vibration Loudness of sound Small movements
Large movements Quiet Loud Add values Speed of vibration Pitch of sound Slow Fast Low High

Units for sound variables
Answers Loudness (or volume) decibel (dB) The loudest human voice is 112dB Frequency (or pitch) hertz (Hz) A sound frequency of 20Hz is twenty waves per second: a low rumble A sound frequency of Hz is heard as a high pitched squeak

Sound wave model Wavelength Amplitude

Quiet sound (low volume) Loud sound (high volume)
Quiet and loud sounds High amplitude Low amplitude Change loudness Quiet sound (low volume) Add values Loud sound (high volume)

Low and high frequency sounds
Wavelength Wavelength Add variables and values Change frequency Time = 0.1s Time = 0.1s Low frequency sound (20Hz) Higher frequency sound (50Hz)

Speed of sound help triangle
m Add units m/s Distance Speed Time X Add variables s Speed = Distance Time

Measuring the speed of sound
Sound waves 00:00.50 00:00.00 Clappers Bang clappers together Sound waves travel 165m Timer Calculation: Speed of sound = Distance Time = 0.5 = m/s Do calculation

Vocal cords – changing voice loudness
Volume of air blown over cords Amount of vocal cord movement Loudness of sound produced Small Large Small Quiet Loud Large Add values

Vocal cords – changing voice pitch
Condition of vocal cords Speed of vibration Pitch of sound produced More tight Less tight Faster Higher Slower Lower Add values

De Lisle Catholic Science College
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