1 / 22

Do Now: 4/16

Do Now: 4/16. A radio wave broadcasts at 700 kHz and travels the speed of light (3x10 8 m/s). 1.What is the period? 2.What is the wavelength?. Properties of Sound. 4/6/11. Sound waves. Sound wave: a mechanical wave transmitted through matter (a material medium ). Sound Waves:.

meris
Télécharger la présentation

Do Now: 4/16

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. Do Now: 4/16 A radio wave broadcasts at 700 kHz and travels the speed of light (3x108m/s). 1.What is the period? 2.What is the wavelength?

  2. Properties of Sound 4/6/11

  3. Sound waves • Sound wave: a mechanical wave transmitted through matter (a material medium)

  4. Sound Waves: • Sound is a longitudinal wave:

  5. Pressure Variations • Compression: particles closer together • Rarefaction: particles farther apart

  6. Properties of Sound: Pitch • Pitch: The sensation of a frequency Higher pitch! 

  7. http://www.physicsclassroom.com/class/sound/U11l2a.cfm

  8. Music Consonant: Certain sound waves which, when played simultaneously, will produce a pleasant sound

  9. Example: Two musical notes that have a frequency ratio of 2:1 are said to be separated by an octave. A musical note that is separated by an octave from middle C (256 Hz) has a frequency of _____. a. 128 Hz b. 254 Hz c. 258 Hz d. 345 Hz e. none of these

  10. Review: Amplitude • Amplitude represents energy

  11. Properties of Sound: Loudness • Loudness depends on the amplitude of sound waves; measured in decibels (dB) • Intensity (I): how loud a sound is in relation to another

  12. Example: A mosquito's buzz is often rated with a decibel rating of 40 dB. Normal conversation is often rated at 60 dB. How many times more intense is normal conversation compared to a mosquito's buzz? a. 2 b. 20 c. 100 d. 200 e. 400

  13. Speed of Sound: The speed of sound depends primarily on medium but also on temperature: v = 331 m/s + (0.6 m/s/C)•T

  14. Example: Determine the speed of a sound wave in air at a temperature of 20ºC. v = 331 m/s + (0.6 m/s/C)•T v = 331 m/s + (0.6m/s/C)•(20 C) v = 331 m/s + 12 m/s v = 343 m/s

  15. Echo: • echo: a reflected sound; will take twice the time to travel the same distance • Example: a sound wave travels 500 m to a cliff, then returns to where it started. If the sound wave traveled 330 m/s, how long does it take the sound to return to where it started?

  16. Practice: • Use the rest of class to work on the worksheet “Sound Waves.” • Be prepared to answer an exit question at the end of class

  17. Exit Question: • Which property of sound is determined by amplitude? • Which property of sound is determined by frequency?

  18. Do Now (4/17/12): • Which property of sound is determined by amplitude? • Which property of sound is determined by frequency? • What is the velocity of sound when the temperature is 44˚ C?

  19. Agenda: • 4th Q Project • Homework questions • Extra credit (optional)

  20. Fourth quarter project • Deadline 1: TOMORROW Bring in your favorite piece of art, or any art piece that speaks to you. It can be a drawing, a painting, a sculpture, etc. You may make a photocopy, or print it from a computer, but you MUST have a hard copy with you… on your phone doesn’t count!!! You will also write a paragraph about your piece, but we will do that tomorrow.

  21. Practice: • Work on homework • Work on extra credit (optional) – if you want extra credit, the work must be submitted by the end of class • Begin thinking about your art piece – feel free to look through your history or English textbook once you have finished your work.

More Related