While waves do travel out in all directions from a source, they inevitably run into something. The material that surface is made of will determine what happens to the wave.
- Sound waves don’t really travel up and down, they travel through substances pushing and pulling on particles in more of a forward and backward COMPRESSION WAVE.
- Sections where particles are close together is the PEAK.
- Sections where particles are spaced apart is the TROUGH.
- Keep your eye on one particle in the gif or video examples. Notice how the particle just “sways” back and forth as the wave moves through the entire substance.
- When sound waves hit an object and bounce off we call that REFLECTION.
- You may have encountered this if you’ve ever heard an ECHO.
- Hard, smooth substances like concrete and tile tend to reflect sound waves well.
- When sound waves hit an object and get “lost” in the substance we consider the wave ABSORBED.
- Soft, squishy, rough materials like foam and carpet tend to absorb sound waves well.
- When sound waves encounter and object and travel right through it we consider the wave TRASMITTED.
- Hard, smooth and elastic surfaces like metals are great conductors of sound waves.
The speed of sound waves is dependent on the MEDIUM (material) the wave is passing through.
- Solid, dense mediums like metals the best conductors of sound with their close particles so sound travels quickly.
- Liquid materials have more space between their particles so sound travels through them much more slowly.
- Sound travels slowest between gas particles.
- Within each state, lighter particles vibrate faster so sound travels through them faster.
- Sound vibrates solid Aluminum’s lightweight atoms much faster than the heavier atoms of Gold.
- Sound travels much faster light gases like Hydrogen or Helium because they have small, light particles which is why your voice sounds high when you play with balloons.
What’s next?
I’m lost😱
Wait… sound travels in waves? What are those?
I need practice 🤔
I think I get it, but would like some more practice!
Let’s move on👍
I’ve got Energy Forms under control, Let’s learn how they make everything work!