1. Mechanical & Electromagnetic -Transverse -Longitudinal ---Surface http://phet.colorado.edu/new/simulations/sims.php?sim=Wave_on_a_String http://www2.biglobe.ne.jp/~norimari/science/JavaApp/nami1/e-nami.html Radio waves Microwaves Visible Light X-Rays

2. “Let’s Do the WAVE" Transverse wave on a string Surface (water) waves Electromagnetic waves Longitudinal (compression) sound waves

3. WAVES- transport energy from one location to another 1- Disturbance (vibration) 2- Travels (propagation/movement) 3- Medium (the material) 4- Energy (the wave) A WAVE can be described as a disturbance which travels through a medium, transporting energy from one location (its source) to another location -- without permanently transporting matter.

4. Wavelength (m) – the length of one complete wave cycle. Crests, Troughs, Amplitude, Midpoint (vibration cycle) λ How would a higher energy wave look different from this one?

5. Frequency (Hz) – the number of vibrations cycles per amount of time Hertz (1/sec) - vibrations cycles per second Period (sec) – the time needed to complete one vibration cycle (one wavelength)

6. Frequency (Hertz) - cycles per second(1/sec) Period –time of one cycle (one wavelength) (sec) 2 sec Frequency = Period = 340 Hz means what? 3 Hz 6 cycles / 2 sec = 3 Hz 1/3 sec 340 cycles (wavelengths) in one sec

7. 1) If the frequency of a wave is 400 Hz, then what is the period of the wave? 2) If the period of a wave is 10 seconds, then the frequency of the wave is? 3) As the frequency of a wave increases, the period ________. = 1 / 400 = 1 / 400 T = 1/f = 0.0025 sec = 0.0025 sec = 1 / 10 = 1 / 10 f = 1/T = 0.1 Hz = 0.1 Hz Decreases T = 1/f

8. Wave Speed (m/s) – how fast the wave is traveling 2 sec 1 meter 2 meter 3 m/s 6 meters/ 2 seconds = 3 m/s 6 m/s 12 meters/ 2 seconds = 6 m/s 5 meter 15 m/s 30 meters/ 2 seconds = 15 m/s Frequency = Hertz Frequency (1/sec) - cycles per second (Hertz) λ 3 Hz 6 cycles / 2 sec = 3 Hz CAUTION: Wave Speed (m/s) is different from Frequency (1/sec)

9. Wave Speed (m/s) – how fast the wave is traveling v = f x λ Frequency (1/sec) - cycles per second Wavelength (m) – the length of one complete wave cycle λ f v (1/s) x(m) (m/s) = f x λ = v Wave Speed v = f * λ Speed of sound is constant within a given medium

10. 2 sec Frequency = 3 Hz What is the wave speed if the wave length is: 2 meter 5 meter 6 m/s 15 m/s 3 m/s 1 meter6 meters/ 2 seconds = 12 meters/ 2 seconds = 30 meters/ 2 seconds = (distance/time) 3 Hz x 1 meter = 3 Hz x 2 meter = 3 Hz x 5 meter = Wave Speed v = f x λ (1/s) x(m) (m/s) = Wave Speed Frequency Wavelength λ fv Wave speed depends on the elastic and inertial properties of the medium it is traveling through. (Not just v = f x λ

11. Medium - a substance which carries a wave - a collection of interacting particles (the substance) (wire, rope, spring) (air) (water) (Earth) (spring)

12. Medium - Carries the Wave - Is not the wave None of the actual material (particles) are transported. The particles are temporarily displaced from their rest position. (Energy is traveling through the medium, caused by an initial disturbance) Energy is what is being transported from A  B (Energy is traveling through the medium, caused by an initial disturbance) 4- Energy (the wave) 1- Disturbance (vibration) 3- Medium (the material) 2- Travels (propagation/movement) - Does not make the wave - Does not move from A  B - The particles of the Medium do not move from A  B

13. °C m/s −10325.2 −5328.3 0331.3 +5334.3 +10337.3 +15340.3 +20343.2 +25346.1 +30349.0 Speed of sound (In general) solids > liquids > gases Wave speed depends on the properties of the MEDIUM in which it propagates. Not upon the properties of the wave. Wavelength, frequency, period, amplitude, (these properties are dictated by the medium) Temperature, Elastic Modulus (stiffness), Tension, Density, Chemical Composition A WAVE can be described as a disturbance which travels through a medium, transporting energy from one location (its source) to another location. Wave = transportation of energy through a medium

14. In a given medium, the speed of sound will be the same v f λ v = f x λ  A change in frequency or wavelength will NOT cause a change in wave speed.  But, a change in the medium ________. v f v = f x 340 m/s = 20 Hz * 17 m 340 m/s = 5 Hz * 68 m λ λ 68 Hz * 5 m 340 m/s =

15. (wire, rope, spring) (air) (water) (Earth) (spring) More on this later Wave speed depends on the elastic and inertial properties of the medium it is traveling through. – More on this later Refraction – the bending of light. As light passes from one transparent medium to another, it changes speed, and bends.

16. E α A² Energy is proportional to the square of the amplitude. E α A² Putting energy into a wave (pulse) will not effect: -- the wavelength -- the frequency -- or the wave speed The energy imparted to a wave (pulse) will only effect the amplitude of that wave (pulse). E α A²

17. Question The energy of a wave can be increased by_____ a. increasing the wave speed of the wave b. increasing the frequency of the wave c. increasing the amplitude of the wave d. all of the above E α A²

18. Question An ocean wave has an amplitude of 5 m. Weather conditions suddenly change such that the wave has an amplitude of 10.0 m. The amount of energy transported by the wave is __________. a. halved b. doubled c. quadrupled d. remains the same E α A² 25 α (5)² 25 α (5)² 100 α (10)²

19. Question What could cause the speed of sound (in air) to change from 340 m/s to 680 m/s? a. drastically increasing the temperature of the air. b. doubling the frequency of the wave c. doubling the wavelength of the wave d. (either b or c above)  A change in frequency or wavelength will NOT cause a change in wave speed.  But, a change in the medium ________. v = f * λ Speed of sound is constant within a given medium

20. Question If a large tuning fork has a period of 0.02 seconds, then what is the frequency of the tuning fork? a. 0.02 Hz b. 2.0 Hz c. 50.0 Hz d. There is not enough information to solve this problem. f = 1 / T = 1 / 0.02 = 50 Hz

21. A medium is able to transport a wave from one location to another because the particles of the medium are ____. a. frictionless b. isolated from one another c. able to interact d. very light Question

22. The wavelength of the wave in the diagram above is given by letter ______. The amplitude of the wave in the diagram above is given by letter _____. Question

23. Indicate the interval which represents one full wavelength. a. A to C b. B to D c. A to G d. C to G Question

24. Question At the top of a mountain, a sound wave with a wave length of 5 m has a wave speed of 300 m/s. The frequency of this wave would be _______. What would be the frequency of a sound wave if the wave length was 10 m? a. 30 Hz b. 50 Hz c. 60 Hz d. 600 Hz 300 m/s = 60 Hz * 5 m v f λ v = f x λ 300 m/s = 30 Hz * 100 m

25. Question If a dragon flaps its wings 20 times in 80 seconds, what is the frequency of the flaps in terms of hertz? a. 0.25 Hz b. 20 Hz c. 80 Hz d. 160 Hz 0.25 Hz Frequency = cycles/sec = 20/80 = 0.25 Hz

26. Question A teacher attaches a slinky to the wall and begins introducing pulses with different amplitudes. Which of the two pulses below will travel from the hand to the wall in the least amount of time? a.Wave A b.Wave B c.They will arrive at the same time d.It is not possible to change the amplitude. Amplitude is proportional to the magnitude of energy, not the wave speed.

27. The teacher then begins introducing pulses with a different wavelength. Which of the two pulses will travel from the hand to the wall in the least amount of time ? a.They will arrive at the same time b.It is not possible to change the wave length. c.Wave C d.Wave D Question

28. A wave has an amplitude of 4 cm, a frequency of 20 Hz, a period of 0.05 seconds, and a wave length of 10 cm. 1. What is the wave speed? a. 0.20 cm/sec b. 40 cm/sec c. 200 cm/sec d. 8,000 cm/sec Question v = f x λ200 cm/sec v = f x λ = 20 Hz x 10 cm = 200 cm/sec

29. A wave has an amplitude of 4 cm, a frequency of 20 Hz, a period of 0.05 seconds, and a wave length of 10 cm. 2. What would happen to the wave speed if the amplitude was doubled? a. the wave speed would double b. the wave speed would be halved c. the wave speed would not change Question Amplitude is proportional to the magnitude of energy, not the wave speed.

30. 12345671234567  Waves carry energy from one place to another.  Transverse and longitudinal waves exist in mechanical media, such as springs and ropes, and in the Earth as seismic waves.  Wavelength, frequency and wave speed are related.  Sound is a longitudinal wave whose speed depends on the properties of the medium in which it propagates.  Radio waves, light and X-rays are different wavelength bands in the spectrum of electromagnetic waves, the speed of which in a vacuum is approximately 3 x 10 8 m/s, and less when passing through other media.  Waves have characteristic behaviors, such as interference, diffraction, refraction and polarization.  Beats and the Doppler Effect result from the characteristic behavior of waves. Waves have characteristic properties that do not depend on the type of wave.