1. The Energy of Waves!!!! Students will describe how waves transfer energy, types of waves, properties of waves, and different wave interactions

2. Waves Carry Energy Energy can be carried away from its source by a wave. A source is whatever is creating the energy -Such as an earthquake -A fish’s flippers making waves in a pond -Clapping your hands to create sound waves

3. Waves Carry Energy The material through which the wave travels does not move with the wave, but simply moves back and forth in place -Light beams moving through the atmosphere -Music sounds moving through the classroom

4. Energy moves through the medium A medium is what the wave is moving through -Air would be a medium for light waves or sound waves -Water would be a medium for surf’n waves

5. Energy Moves through the Medium The particles in the medium transfer energy from one to another (Like a bunch of kids in line pushing on each other) Each particle passes energy on to the surrounding particles

6. Sound Sound waves require a medium in which to travel Sound can travel through solids, liquids, and gasses, but not through a vacuum

7. Mechanical Waves Sound is a mechanical-type wave because it requires a medium to move through Any type of wave that requires a medium is considered a mechanical wave

8. Vacuums A vacuum is like deep outer space – very few or NO particles A vacuum is NOT a medium

9. Electromagnetic Radiation …Or light… or visible light (other names) Does not require a medium to travel through Can move through space How we get light from the sun!!! Or stars…!!!

10. Types of Waves Transverse Waves Longitudinal Waves Combination Waves

11. Transverse Waves The particles in a transverse wave move across or perpendicular to the direction of the wave Remember the energy is what the wave is carrying. The medium does not move down with the wave, only across or perpendicular to the wave.

12. Transverse Waves Transverse waves is like a rope being wiggled. The bottom portions of the transverse wave form are called troughs The top portion of the transverse wave form is called a crest. Crest Trough

13. Longitudinal Waves The particles in a longitudinal (or also called compression) wave move back and forth or parallel to the direction of the wave.

14. Longitudinal Waves The portions where the particles are crowded together are called compressions, the regions where there are less particles are called rarefactions. What would this look like with the slinky?

15. Combination Waves A longitudinal and transverse wave can combine to form a surface wave. An example would be the waves of the ocean.

16. Properties of Waves Amplitude Wavelength Frequency Speed

17. Properties of Waves Amplitude The height of the wave or maximum distance it vibrates from its rest position Example: turning up the volume and sound-level on your stereo

18. Properties of Waves Wavelength- The distance between two crests or two troughs

19. Properties of Waves Frequency ~The number of complete waves passing a given point in a certain amount of time. ~Count either crests or troughs ~Higher frequency relates to higher energy and shorter wavelength Why?????

20. Properties of Waves Speed The speed at which a wave travels Light travels at 3x10 8 m/s which is 300,000,000 m/s

21. Wave Interactions Reflection Refraction Diffraction Interference

22. Wave Interactions A wave bouncing back -Water waves on the shore -Light reflected in the mirror -Echoes Reflection

23. Wave Interactions The bending of a wave from one medium to another This changes the speed of the wave and the angle at which it enters the new medium Refraction

24. Wave Interactions When waves bend around corners (such as barrier or opening) Water out of a hose Opening must be smaller than the wavelength of the wave Diffraction

25. Wave Interactions When waves overlap Constructive interference increases the amplitude (two crests or troughs meet) Destructive interference decreases the amplitude (a crest and trough meet) Inference

26. Standing Waves Interference can also create standing waves A stationary pattern –Constructive interference –Destructive interference

27. Students will describe how waves transfer energy, types of waves, properties of waves, and different wave interactions