1 / 22

Chapter 12.1-SOUND

Chapter 12.1-SOUND. 4. SPEED OF SOUND. Much slower than light Thunder and Lightning Five second delay per mile Depends on wind, temperature, humidity. Speed of Sound. The Speed of Sound depends on the density of the medium through which the sound waves travel. Reflection.

mayes
Download Presentation

Chapter 12.1-SOUND

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. Chapter 12.1-SOUND

  2. 4. SPEED OF SOUND • Much slower than light • Thunder and Lightning • Five second delay per mile • Depends on wind, temperature, humidity

  3. Speed of Sound The Speed of Sound depends on the density of the medium through which the sound waves travel.

  4. Reflection

  5. Loudness is related to the energy (amplitude) in the sound wave. The pitch of a sound refers to whether it is high, like a flute, or low like string bass. The lower the frequency of sound, the lower the pitch.

  6. ENERGY IN SOUND WAVES • Energy in sound is weak when compared to the energy in light. • The human ear is a remarkable detector. 10 million people speaking at the same time produce approximately enough energy to light one flashlight.

  7. Loudness Intensitymeasured in decibels

  8. Pitch • Relative highness or lowness of a note. • adding PITCH to rhythm and amplitude creates melody

  9. Frequency • A sound that vibrates back and forth 1,000 times per second like a tuning fork has a frequency of a 1,000 Hz • The frequency of the human auditory system has a range from 20 Hz to 20,000 Hz

  10. Frequencies for musical notes

  11. Octave • a pitch an octave higher than another has [ii:20]double its frequency • Example: 440 Hertz * 2 = 880 Hertz • a pitch an octave lower has [ii:21]half the frequency • Example: 440 Hertz * .5 = 220 Hertz A3 A4 A5

  12. Standing waves in instruments • Guitar & all stringed instruments have sounding boards or boxes to amplify sound! • (hyperlink on picture)

  13. Ultrasonic Sound • Anything above frequencies, anything above 20,000 Hz • Used for communication and navigation by bats and dolphins

  14. Ultrasonic Waves • Ultrasonic waves are short • Widespread medical applications • Used to produce images inside the human body • hyperlinks on each image

  15. Infrasonic Waves • Sound waves with frequencies less than 20 Hz. • They are produced by such things as heavy machinery and thunder. • They are really low pitched sounds. • Elephants can communicate from kilometers away using infrasonic waves.

  16. Elephants “hear” through their feet. • Flexible, soft skin of the foot acts like a drum head, which sense vibrations which travel from the toe nails to the ear by bone conduction. Foot stomping and low frequency rumbling generated by one group of elephants are picked up by another group far away.

  17. FORCED VIBRATIONS • Demo - Tuning Fork Touching a Table • Sound is intensified because of the larger surface area that can vibrate the air. • The surface is forced to vibrate at the frequency of the tuning fork. (It is not a resonance phenomenon.) • Examples: Musical sounding boards

  18. NATURAL FREQUENCY • Demo - Drop Different Sounding Objects • Objects have natural frequencies at which they vibrate. • The natural frequency depends on elasticity and shape.

  19. RESONANCE • Resonance occurs when we force a vibration at the • same frequency in • another object.

  20. Middle Ear Schematic

More Related