# harmonic waves

Post on 15-Aug-2015

41 views

Embed Size (px)

TRANSCRIPT

- 1. Harmonic Waves LEARNING OBJECT LG2- ALISON WU
- 2. What is a Harmonic Wave? If a wave is undergoing harmonic motion it is considered a harmonic wave. Simple harmonic motion is the type of periodic motion in which the restoring force is directly proportional to the displacement It is also known as a sinusoidal wave (a sin graph) It has a smooth repetitive oscillation
- 3. Which graph represents a harmonic wave? a) b) c)
- 4. Solution A)
- 5. Since a harmonic wave is described by a sine (or a cosine) function, its properties are determined by the amplitude (A), its wavelength () and its period (T)
- 6. Characteristics of a Harmonic wave Amplitude: Corresponds to the maximum displacement from the equilibrium position of any element. Amplitude is always a positive quantity. Wavelength: The shortest distance over which a wave shape repeats is called the wavelength. Represented by the symbol lambda () Wave number: the reciprocal of the wavelength Period: the time for a particle make one complete cycle T=1/f Frequency: the number of wave cycles passing a fixed point of the medium in one section Phase shift () : a horizontal shift by how many units the "starting point" (0,0) of a standard sine curve, y = sin(x), has moved to the right or left.
- 7. What is the amplitude of the graph? a)-0.5 b)1 c)0.5 d)0.25
- 8. What is the wave number of the graph? a)pi b)pi/2 c)1/2 d)2
- 9. What is the phase shift? a)2pi b)2pi/3 c)pi/3 d)pi
- 10. Solutions 1. c) 0.5 2. d) 2 3. b)2pi/3
- 11. Speed of the Wave To calculate the speed of the wave you multiply the wavelength of the graph to the frequency.
- 12. Find the angular frequency when the wave has a velocity of 100m/s, a wave number of 2. a) 50 b) 0 c) 200 d) 30
- 13. Solutions 1. plug the numbers into the equation, we know that wavelength is equal to 2pi/k and frequency is equal to w/2pi 2. Sub those equations into the original formula and you will get v= w/k 3. rearrange to solve for angular frequency w=vk 4. plug in your number 5.w=100*2 w=200 c)
- 14. If the frequency increased what would happen to the velocity? a) it remains constant b) it would decrease c) it would increase
- 15. Solution C) it would increase All three factors are in direct correlation so if the frequency increased the velocity would increase to.

Recommended

View more >