1 / 24

Waves

Waves. Physics Ms. Shaver. Coyle, Greece 2005, North Aegean Sea. Wave Topics. Waves and their characteristics Velocity of a wave Types of waves. Oscillation. Object moves back and forth about an equilibrium position. Pulse: A single disturbance travelling through a medium.

maris
Télécharger la présentation

Waves

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Waves PhysicsMs. Shaver Coyle, Greece 2005, North Aegean Sea

  2. Wave Topics • Waves and their characteristics • Velocity of a wave • Types of waves

  3. Oscillation • Object moves back and forth about an equilibrium position.

  4. Pulse: A single disturbance travelling through a medium. http://www.dacc.edu/~qchen/P102/labs/LAB5.HTM

  5. Wave Train (Travelling Wave or simply wave): • A series of pulses at regular intervals. http://micromachine.stanford.edu/~hopcroft/Research/resonator_images/sin_mov1.gif

  6. Wave on a String • (Applet) http://phet.colorado.edu/sims/wave-on-a-string/wave-on-a-string_en.html

  7. Graph of Displacement vs Time

  8. Displacement vs Distance Traveled Crest Trough

  9. Speed of a Wave, v v= d/t v = l/T v =lf

  10. Types of Waves • Transverse • Longitudinal

  11. Transverse The particles vibrate perpendicular to the direction of the wave's propagation (ex: waves along a string, electromagnetic waves).

  12. Example: S Earthquake Wave http://web.ics.purdue.edu/~braile/edumod/waves/Swave_files/image001.gif

  13. Longitudinal Waves • The particle displacement is parallel to the direction of wave propagation (ex: sound)

  14. Torsional Waves • A 2D transverse wave that twists along a given medium. • Video link on Web : Collapse of Takoma Narrows Bridge, Washington State, 1940 • http://www.youtube.com/watch?v=shX4Q0QV8VI

  15. Elliptical Waves Result when longitudinal and transverse waves are superpositioned. (ex: surface water waves)

  16. Ocean Wave

  17. Ocean Wave http://www.pa.uky.edu/~crawford/phy361_sp10/home.html

  18. Note • Waves transfer of energy from one point to another. • Waves do not transfer matter.

  19. Types of Waves • MechanicalWaves • Electromagnetic Waves

  20. Mechanical Waves require a medium. Examples: • Water waves( Tsunami) • Sound waves (v= 340 m/sec in air but varies for different media) • Earthquake waves

  21. Electromagnetic Waves do not require a medium and can travel through the empty space (vacuum). Example:  • Light from the sun travels through space and reaches us. Note: All EM waves have a speed through vacuum of 3 x 108 m/sec.

  22. Problem 1 • What is the distance a sound wave in air traveled in 2 sec? • Speed of sound = 340 m/s in air • Answer: 680m v = d/t 340 m/s = d/2 s 2 s * 340 m/s = 680 m

  23. Problem 2 • What is the frequency of a light wave of wave length 550x 10-9 m? • Answer: 5.5 x 10 14 Hz v = λf 3 x 108 m/s = 550 x 10-9 m * f f = 3 x 108 m/s / 550 x 10-9 = 5.5 x 1014 Hz

  24. Problem 3 • A SONAR (Sound Navigation and Ranging) sends a signal to the bottom of the ocean. The speed of sound in water is 1435 m/s. If the signal echo returned in 0.4 sec, how deep was the water? • Answer: 287m V = d/t 1435 m/s = d / 0.4s D = 574 m Distance here is the distance to the bottom and back, so divide by two to get the water depth: 574 m/ 2 = 287 m.

More Related