1 / 23

Vibration and Waves

Vibration and Waves. Vibrations. What is it? A vibration is an oscillation A back and forward motion that repeats How does a bell work? . Wave. What is a wave? Give an example Waves are disturbances in time an space without the transfer of matter Sound waves, light waves, water waves.

arich
Télécharger la présentation

Vibration and 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. Vibration and Waves

  2. Vibrations • What is it? • A vibration is an oscillation • A back and forward motion that repeats • How does a bell work?

  3. Wave • What is a wave? Give an example • Waves are disturbances in time an space without the transfer of matter • Sound waves, light waves, water waves

  4. Wave of a Pendulum T = 2π√(L ∕g) • Does the mass of the pendulum effect the time it takes for it to swing back and forth. • Period is the time is takes for a pendulum to swing back and forth, or to complete a full cycle

  5. Simple Harmonic Motion • Periodic motion where acceleration is proportional to the equilibrium position and is directed towards that position.

  6. Label each part

  7. Wave Motion • When you drop a stone in a pond, what happens? • Is the water moving? • What about a string that vibrates?

  8. Wave speed • v = λf • v – is wave speed Units: m/s • λ - wavelength m • f- is the frequency Hz or 1/s • Wave speed depends on the medium that it travels through.

  9. Transverse and Longitudinal waves

  10. Interference Constructive Destructive

  11. Standing Waves

  12. The Doppler Effect • What happens if a bug remains stationary and jumps up and down on the waters surface.

  13. Why does a siren sound different when it changes positions. • Put yourself as a the stationary position, and you witness the vehicle with the siren, describe the noises • Draw it on your notebook

  14. If the object moves slower than the wavespeed

  15. Sound Waves

  16. Origin • Sound is produced from the vibrations of materials • All sound waves are longitudinal waves • Pitch: is the frequency of sound • Higher pitched sounds have high frequencies • Lower pitched sounds have lower frequencies

  17. Ultrasonic and infrasonic • Ultrasonic waves are sound waves that have a frequency above 20,000 Hz • Infrasonic waves are sound waves that have a frequency lower than 20 Hz • We as humans can not hear either of these waves since our hearing range is between the two ranges and it continues to shrink as we get older.

  18. Sounds and Media • Sound waves travel best through which media? • A) Gases • B) Solids • C) Liquids • What about a vacuum?

  19. Speed of sound and Loudness • In dry air, the speed of sound is 330 m/s at 0°C • As the air get more humid the speed increases, why? • As the temperature increases, the speed increases, why? • Loudness is determined by the intensity of the sound which in turn is the square of the amplitude

  20. Natural Frequency and Resonance • Natural Frequency:A frequency at which an elastic object once energized will vibrate. • Essentially it is the vibration that occurs in every substance when it is disturbed. • Ex dropping a wrench and a baseball bat at the same time, do they sound the same? • This is opposite to Forced vibrations, which are disturbances caused by unnatural sources • Hitting a guitar string

  21. Resonance • This is when the natural frequency and the frequency of the forced vibration match. • What occurs is the amplitude of the sound waves increase dramatically. This bridge collapased and injured 40 of the 3000 men were injured.

  22. Beats • Two tones of slightly different frequencies are sounded together. • You get both constructive and destructive interferences • This is what we call a variation of loudness

More Related