330 likes | 645 Views
Sound waves. Lesson objectives. state that: sound cannot travel through a vacuum but can travel through solids, liquids and gases describe how sounds travel through solids, liquids and gases explain in terms of the particle model why sound needs a medium.
E N D
Sound waves Lesson objectives • state that: • sound cannot travel through a vacuum but can travel through solids, liquids • and gases • describe how sounds travel through solids, liquids and gases • explain in terms of the particle model why sound needs a medium. • explain how sound travels at different speeds in different types of material • explain everyday phenomena in terms of the different speeds at which sound travels • in air and solids • Key words: • vibrations ,molecules,medium, • vacuum, solid, liquid, • gas, longitudinal,wavelength
Sound waves Sound can travel through solids, I know this because ………………………….. ………………………………………………. …………………………………………………. Sound can travel through liquids, I know this because ………………………….. …………………………………………………. …………………………………………………. Sound can travel through gases, I know this because ………………………….. …………………………………………………. ………………………………………………….
In a sound wave the molecules vibrate backwards and forwards R R R C C C Compression; air molecules are squashed together Rarefaction; air molecules are further apart Sound waves
Sound waves Sound waves spread like ripples on a pond. speaker cone vibrates. Air molecule
Sound waves Can you hear a space craft explode in space or on the moon? Explain! If you listen carefully you might. Explain how!
P 3 2.6 SOUND For a C grade you should be able to: • State the range of hearing for a typical human. • Describe the properties of a sound wave, including its longitudinal nature. • Describe the behaviour of a sound wave, including reflection and refraction. For an a grade you should also be able to: • Explain why mechanical vibrations produce sound waves.
Mechanical waves electromagnetic waves
Mechanical waves electromagnetic waves
Mechanical waves electromagnetic waves
Mechanical waves electromagnetic waves
Reflecting sound Echoes