INTRODUCTION TO WAVES

1. INTRODUCTION TO WAVES Standard 8.P.3 Students will demonstrate an understanding of the properties and behaviors of waves. Performance Indicator
8.P.3A.1: Construct explanations of the relationship between matter and energy based on the characteristics of mechanical and light waves.

2. LESSON OBJECTIVES By the end of the lesson, I will be able to: • Define a wave • State what waves carry • Define medium • Identify states of matter through which certain waves travel

3. What is a Wave? A wave is a repeating disturbance or vibration that transfers or moves energyfrom place to place but not matter

5. PROPERTIES OF A WAVE • Waves are created when a source of energy (FORCE) causes a vibration. • A vibration is a repeated back-and-forth or up-and-down motion. 
 • Waves carry energy through empty space or through a medium without transporting matter

6. PROPERTIES OF A WAVE • While all waves can transmit energy through a medium, certain waves can also transmit energy through empty space. 
 • A medium is a material through which waves can travel. It can be a solid, liquid, or gas. • When waves travel through a medium, the particles of the medium are carried along with the wave. 


7. PROPERTIES OF A WAVE •  When there is no medium, certain waves (electromagnetic) can travel through empty space or a vacuum. • * Oscillation is when a wave move or swing back and forth at a regular speed.

8. CHECK POINT • The back and forth movement of matter is called 2. A wave carries: a] energy only c] matter only b]energy and matter d] neither a nor b 3. A material through which waves can travel is called: _______ 4. Waves can carry energy through empty space or a _______ 5. What states of matter can be medium for waves?

9. Complete the chart below

10. Introduction to waves Part 2 SWBAT • State what is a mechanical wave • Give 2 examples of mechanical waves. • State what is an electromagnetic wave • Give 2 examples electromagnetic waves.

12. Mechanical Waves • Mechanical waves require the particles of the mediumto vibrate in order for energy to be transferred. 
 • Examples include ocean waves; ripples in water; seismic waves; sound, and waves along a spring or rope; wave of people at a sporting event.

13. Some examples of Mechanical Waves

14. Sound waves, as with all mechanical waves, cannot be transferred or transmitted through empty space 
or a (vacuum). * Mechanical waves can be either transverse or longitudinal/compressional based on how they move.

15. Transverse Waves • Waves in which the particles of matter in the medium vibrate by moving back and forth, up and down and perpendicular (at right angles) to the direction the wave travels. • Examples include guitar strings, waves in piano strings

16. Longitudinal or Compressional Wave • Waves in which the particles of matter in the medium vibrate by pushing together and moving apartparallel to the direction in which the wave travels. 
 • Each line or wave represents force/energy. • Examples include sound waves, waves through fluids, liquids, gases or plasma

17. Check point • Another name for longitudinal wave is _________. • How do transverse waves move? • Mechanical waves require _______ to pass. • How do longitudinal waves move? • True/False: Mechanical waves can travel through empty space and a medium.

18. Parts of a Transverse Wave The crest is the highest point on a wave.

19. Parts of a Transverse Wave The trough is the valley between two waves, is the lowest point.

20. Parts of a Transverse Wave The wavelength is the horizontal distance, either between the crests or troughs of two consecutive waves.

21. Parts of a Transverse Wave The amplitude is the peak (greatest) value (either positive or negative) of a wave. The distance from the undisturbed level to the trough or crest.

22. Parts of a Compressional Wave (Longitudinal) The compression is the part of the compressional wave where the particles are crowded together.

23. Parts of a Compressional Wave (Longitudinal) The rarefaction is the part of the compressional wave where the particles are spread apart.

24. Check point • What is the lowest part of a transverse wave called? • What is the highest point of a transverse wave called? • The particles that are spread out in a longitudinal wave are called…… • What is compression?

25. Electromagnetic Waves ELECTROMAGNETIC WAVES TRAVEL THROUGH EMPTY SPACEOR A VACUUM. Examples: radiation, TV & radio waves, X-rays, microwaves, lasers, energy from the sun, visible light All Electromagnetic waves are considered transverse waves because they have similar characteristics; therefore, they have the same parts.

26. REAL MEN IN VIRGINA UNDERSTANDS X-GIRLFRIENDS

28. Light waves • ●  Are considered electromagnetic waves which are waves that can travel through matter or EMPTY SPACE where matter is not present. 
 • ●  Light waves are the only part of the electromagnetic spectrum that is VISIBLE to the human eye. • ●  Light waves are ELECTROMAGNETIC waves that can travel without a medium through EMPTY SPACE.

29. Check point • True or False: Electromagnetic waves can travel through medium and empty space • All of the following are examples of electromagnetic waves EXCEPT: radio waves, microwaves, sound waves, visible light • Which of the following electromagnetic waves have the shortest wavelength? Gamma ray; radio or microwave