Lesson 2 — 5.1 Sound, vibrations, and energy transfer

• Sound
• Basisschool
• Groep 2

Period 2

Sound

This lesson

What is a sound wave?

Medium – The speed of sound in different mediums

Compression & refraction

Longitudinal and transverse waves

Learning goals

• Describe how sound waves are produced and how they travel.
  

• Explain what is meant by compression and rarefaction.
  

• Explain what is meant by a medium.
  

• Name the speed of sound in several materials.
  

•  Explain what is meant by longitudinal and transverse waves.
  

What is sound?

Sound is a vibration

• A vibration Causes a wave
  
• A sound wave

A sound wave simulation

Link

Where do you the compression and rarefaction?

Where do you the compression and rarefaction?

Compression

Where do you the compression and rarefaction?

Compression

Rarefaction

Sound waves require a medium

• Air
  
• Water
  
• Metal
  

Link

Sound waves require a medium

• Air (gas)
  
• Water (liquid)
  
• Metal (solid)
  

Link

Sound waves require a medium

• Air (gas) — 343 m/s
  
• Water (liquid) — 1500 m/s
  
• Metal (solid) — 5100 m/s
  

Link

How sound works

• A sound source creates a vibration
  
• This vibration creates sound waves that travels through a medium to our ears.
  
• Our ear sends a signal to our brain.
  
• Our brain turns that signal into the sound we hear.
  

Longitudinal vs transverse waves

Link

Exercise

A) A person standing 3 meter behind a 0,4 meter thick concrete wall claps two piece of wood together. You are standing four meters in front of the wall. The speed of sound in concrete is 3700 m/s. The speed of sound in air is 343 m/s. Calculate how long it takes before you hear the sound of the clap.

B) A water proof speaker is placed 30 meters underwater in a lake. On top of the liquid water lies a frozen sheet of 2 meter thick ice. A geese flies 100 meter above the lake. The speed of sound in water is 1500 m/s, the speed of sound in ice is 1830 m/s, the speed of sound in air is 343 m/s. Calculate how long it would take for a sound wave to travel to the hight of the geese.

Learning goals

• Describe how sound waves are produced and how they travel.
  

• Explain what is meant by compression and rarefaction.
  

• Explain what is meant by a medium.
  

• Name the speed of sound in several materials.
  

•  Explain what is meant by longitudinal and transverse waves.