1. ·Are repeating disturbances or vibrations that transfers or moves energy from place to place.
Waves:

2. ·Are created when a source of energy causes a vibration.

3. ·Carry energy, but NOT matter.

4. Two types of waves
longitudinal
transverse

5. LONGITUDINAL WAVES

6. TRANSVERSE WAVES

7. by Dr. Michael R. Gallis
Penn State Schuylkill
click for movie

8. ·Example: sound waves, springs
·a wave in which the particles move parallel to the path of the wave -also called compressional waves
·Example: sound waves, springs
longitudinal
wave

9. ·When the particles are squished together it is called a compression
·When the particles are spread apart it is called a rarefaction
Compression
wave parts

10. PARTS OF A LONGITUDINAL WAVE
compression
rarefaction
wavelength

11. ·particles vibrate with an up-and-down motion.
·Transverse means “moving across”
·The particles move perpendicular to the direction the wave is traveling
·Example:
·Ocean Wave
·Radio Wave
Transverse

12. Transverse Wave Parts ·Crest- top peak ·Trough- bottom
·Wavelength- distance from crest to crest (or trough to trough)
·Amplitude-distance from center line to crest (or trough)
crest
wavelength
amplitude
trough

13. PARTS OF A TRANSVERSE WAVE
amplitude
crest
trough
wavelength

14. ·A medium is a material through which waves travel – it can be a solid, liquid, or gas.

15. Waves are classified as:
Mechanical
Electromagnetic
·Need to travel through a medium to vibrate in order for energy to be transferred.
·Can be transverse or compressional.
·Examples: sound waves, water, and seismic.
·Can travel through a medium or empty space.
·Are transverse waves only
·Examples: radio waves, microwaves, infrared rays, visible light, ultraviolet waves, and x-rays.

18. Click on the picture for a short video
Electromagnetic spectrum

19. Draw a Venn diagram for electromagnetic and mechanical waves.

22. Properties of Waves ·Frequency
· is the number of waves that occur in a given amount of time
·1 wave is measured by 1 wavelength
·Measured in hertz (Hz)
·Higher frequency = more energy

23. ·A higher frequency causes a shorter wavelength and has greater energy.
·A lower frequency has a longer wavelength and has less energy.

24. Properties of Waves · is the height of a wave ·Amplitude
·Larger amplitude = more energy

25. Properties of Waves · is the distance between crests or troughs
·In longitudinal waves it is between adjacent compressions or rarefactions
·Wavelength

26. Wavelength:
·The measure of the distance from crest to crest in a transverse wave.

27. ·measure from rarefaction to rarefaction in a compression wave.
wavelength

28. Properties of Waves ·Wave speed
· is the speed that a wave travels (distance a wave travels divided by time)
·Depends on the medium the wave is traveling through
· v = λ X f (v is velocity, λ is wavelength, f is frequency)

31. http://liology. files. wordpress
·In a transverse wave, the greater the amplitude, the more energy it has.

32. ·Sound waves with greater amplitudes will be louder.

33. ·Light waves with greater amplitude will be brighter.

35. compression
compression wave
wavelength
transverse wave
wavelength
rarefaction
amplitude
crest
trough

36. Write the formula for wave speed:

37. 1) A wave with a frequency of 500 hz has a speed of 200 m/s
1) A wave with a frequency of 500 hz has a speed of 200 m/s. What is the wavelength?
2) A radio wave with a wavelength of 100 m has a frequency of 500 hz. What is its speed?

38. http://www. science-class. net/Notes/Images_8th_Notes/Transverse-Wave

39.
good web sit for NASA EM site