Waves Class Notes- Nov. 30-Dec. 1, 2009

Topic: Waves


Class Notes



Waves are rhythmic disturbances that carry energy without carrying matter.



Mechanical waves are waves which use matter to transfer energy.



A medium is matter through which a mechanical wave travels. Solids, liquids, gasses. Energy is transferred from particle to particle in the medium. Example: a ripple in the pond –water is the medium.




There are two types of mechanical waves:
1.Transverse Waves
2.Compressional Waves (also called longitudinal waves)


Longitudinal and Transverse Wave Motion


In transverse waves:
The energy causes the matter in the medium to move up and down or back and forth to the direction the wave moves. (Perpendicular)
the vibrations move at right angles
the peaks are called crests, and the valleys are called troughs.
Example: ocean waves




Longitudinal and Transverse Wave Motion
In compressional/longitudinal waves:
the matter in the medium moves forward and backward in the same direction that the wave travels.
the energy travels in the direction of the wave, but the medium does not travel.
The vibrations move in the direction of wave movement.
Example: sound waves




Compressions are when molecules in the wave are squeezed together.



Rarefactions are when molecules have more room and move away from each other.

Science Websites- Waves - Week of Dec. 1-4, 2009

Week of November 30- December 8, 2009- 7th & 8th Science Computer Technology Lessons

http://highered.mcgraw-hill.com/sites/dl/free/0078617766/161383/00053404.html - This website is about compressional waves - Complete the quiz

http://guest.portaportal.com/fchs307 - Click on the energy transfer link - then Summarize in 2 sentences and one drawing each of the categories explaining the scientific process on waves

http://www.iknowthat.com/ScienceIllustrations/sound/science_desk.swf - Complete the interactive lab on sound waves and write a 2 sentence summary.

http://www.bbc.co.uk/schools/gcsebitesize/science/edexcel/waves/ - Complete the activity - then complete the test

http://www.bbc.co.uk/schools/ks3bitesize/science/ - Review this website for fun science topics