Sound

Sound is caused by

• vibrations

• noises

• waves

• musical instruments

Sound travels in

When ​ (a)   is put into a ​ (b)   it will ​ (c)   . The vibrations travel through a medium such as air to the ​ (d)   . The ​ (e)   vibrates and the energy is transferred to the brain which we hear as a sound.

• energy
• sound source
• vibrate
• ear
• eardrum

Identify the parts of the wave.

a

b

c

Peak

Trough

Wavelength

Match these sound wave diagrams to their sources

a

b

c

Person whispering

Person talking

Person shouting

Match these sound wave diagrams to their pitches

a

b

c

Medium pitch

High pitch

Low pitch

Sound can travel through

• solid (like metal)

• liquid (like water)

• gas (like air)

• vacuum (nothing)

Sound is measured in ​ (a)   . The further away, the ​ (b)   the sound. The closer, the ​ (c)   the sound. Sounds can also be made ​ (d)   by putting more​ (e)   into the sound source.

• Decibels (dB)
• quieter
• louder
• energy