Upcoming SlideShare
×

# Intro to waves

1,455 views

Published on

Introduction Waves

Published in: Technology, Health & Medicine
• Full Name
Comment goes here.

Are you sure you want to Yes No
• Be the first to comment

### Intro to waves

1. 1. Draw me a wave! YouTube - Water bubble in Space (zero gravity)
2. 2. Learning Outcomes Everyone should: •Define a wave •Differentiate between longitudinal and transverse waves (with examples) Most will: •Define amplitude, wavelength, frequency and period of a wave •Describe the relationship between frequency and period Some might: •Use the wave equation
3. 3. Waves Waves can transfer energy and information without a net motion of the medium through which they travel. They involve vibrations (oscillations) of some sort.
4. 4. Rays Rays indicates the direction of energy transfer.
5. 5. Transverse waves The oscillations are perpendicular to the direction of energy transfer. Direction of energy transfer oscillation
6. 6. Transverse waves Peak/crest trough
7. 7. Transverse waves • Water ripples • Light • On a rope/slinky • Earthquake
8. 8. Longitudinal waves The oscillations are parallel to the direction of energy transfer. Direction of energy transfer oscillation
9. 9. Longitudinal waves compression rarefraction
10. 10. Longitudinal waves • Sound • Slinky • Earthquake
11. 11. Wave measurements
12. 12. Amplitude - A The maximum height of the wave from the middle line position. amplitude
13. 13. Frequency - f The number of complete waves (oscillations) in one second. Measured in Hertz. 50 Hz = 50 vibrations/waves/oscillations in one second.
14. 14. 1 2 0 2 1 1 2 Height (m) Time (s) Frequency – The number of waves per second. If one wave passes in one second it has a frequency of one Hertz or Hz. This is the unit of frequency.
15. 15. Wavelength - λ The length of one complete wave. wavelength
16. 16. Wave speed - v The speed at which the wave fronts pass a stationary observer. 330 m.s-1
17. 17. The Wave Equation V = speed of wave (m/s) f = frequency of wave (Hz) λ = wavelength (m) v = fλv λf x
18. 18. 1) A water wave has a frequency of 2Hz and a wavelength of 0.3m. How fast is it moving? 2) A water wave travels through a pond with a speed of 1m/s and a frequency of 5Hz. What is the wavelength of the waves? 3) The speed of sound is 330m/s (in air). When Dave hears this sound his ear vibrates 660 times a second. What was the wavelength of the sound? 4) Purple light has a wavelength of around 6x10-7 m and a frequency of 5x1014 Hz. What is the speed of purple light? Group wave equation questions 0.2m 0.5m 0.6m/s 3x108 m/s
19. 19. Wave equation questions v λf x