2. 1. What is a wave? It is a disturbance that is transmitted progressively from one place to the next with no actual transport of matter.

3. 2. Define crest, trough, wavelength and amplitude. The high points on a wave are called crests. The low points on a wave are called troughs. The term amplitude refers to the distance from the midpoint to the crest (or trough) of the wave. The amplitude is the maximum displacement from equilibrium. The wavelength of a wave is the distance from the top of one crest to the top of the next one.

4. 3. Draw a wave with a wavelength of 4 meters and an amplitude of 2 meters. 4 meters 2 meters

5. 4. What’s the difference between the two different types of waves? Longitudinal Waves In a longitudinal wave the particle displacement is parallel to the direction of wave propagation. Transverse Waves In a transverse wave the particle displacement is perpendicular to the direction of wave propagation

6. 5. Define period and frequency of a wave, and explain the difference between the two concepts. The period is the amount of time it takes a complete wave to pass a certain point. Frequency is how many wave(s) passes a certain point in a given time. The period is the inverse of the frequency and vice versa.

7. 6. What are the units of frequency and periods? The unit for frequency is Hz or cycles per second. The unit for period is seconds.

8. 7. What is transferred by a wave? It is the energy that causes the vibrations in the medium.

9. 8. What is the equation for determining the velocity of a wave? Identify the variables and their units. v = f v = velocity: m/s f = frequency: Hz = wavelength: m

10. 9. What is wave interference? Waves interference is when waves from different sources arrive at the same point at the same time.

11. 10. Explain the differences between the two types of wave interference. In constructive interference, the crest of one wave overlaps the crest of another and their individual effects add together. The result is a wave of increased amplitude, called reinforcement. In destructive interference, the crest of one wave overlaps the trough of another and their individual effects are reduced. The high part of one wave fills in the low part of another, called cancellation.

12. 11. Draw and explain an example of each type of interference you created during the slinky lab. Constructive interference: Causing a disturbance on the same side of the slinky produced constructive interference. destructive interference: Causing a disturbance on the opposite sides of the slinky produced destructive interference.

13. 12. Explain the concept of being “out of phase” and “in phase” as it relates to wave interference. When waves are out of phase, the crests of one wave overlap the troughs of another to produce regions of zero amplitude. When waves are in phase, the crests of one wave overlap the crests of the other, and the troughs overlap as well.

14. 13. Explain how standing waves are created. A standing wave forms only if half a wavelength or a multiple of half a wavelength fits exactly into the length of the vibrating medium

15. 14. Explain the differences between nodes and antinodes. Nodes are the stationary points on a standing wave. Hold your fingers on either side of the rope at a node, and the rope will not touch them. The positions on a standing wave with the largest amplitudes are known as antinodes. Antinodes occur halfway between nodes.

16. 15. Draw an example of standing waves with three nodes and two antinodes.

17. 16. How do the numbers of nodes of standing waves relates to the wavelength? 2 nodes = ½ wavelength 3 nodes = 1 wavelength 4 nodes = 1 ½ wavelength and so on.

18. 17. What is the Doppler Effect? It is the increase or decrease in frequency as the source of the wave propagation moves closer or further away from an observer.

19. 18. How are frequencies of waves relate to the source of the wave? The frequency of the wave is the same as the frequency of its source.

20. 19. Explain blue shift and red shift. Increasing frequency is called a blue shift, because the increase is toward the high-frequency, or blue, end of the spectrum. Decreasing frequency is called a red shift, referring to the low-frequency, or red, end of the color spectrum.

21. 20. What is a bow wave and how are they produced? Bow wave, progressive disturbance propagated through a fluid such as water or air as the result of displacement by the foremost point of an object moving through it at a speed greater than the speed of a wave moving across the water. A bow wave occurs when a wave source moves faster than the waves it produces.

22. 21. What is a sonic boom? The sharp crack heard when the shock wave that sweeps behind a supersonic aircraft reaches the listeners is called a sonic boom.

23. 22. List three things that may cause a mini sonic boom. A supersonic bullet passing overhead produces a crack, which is a small sonic boom. When a lion tamer cracks a circus whip, the cracking sound is actually a sonic boom produced by the tip of the whip. Snap a towel and the end can exceed the speed of sound and produce a mini sonic boom.

24. 1. The average wavelength in a series of ocean waves is 15.0 m. A wave crest arrives at the shore on average every 10.0 s, so the frequency is 0.100 Hz. What is the average speed of the wave? v = f v = (0.1) (15) v = 1.5 m/s

25. 2. The speed of sound in air is about 340 m/s. What is the wavelength of a sound wave with a frequency of 220 Hz (on a piano, the A below the middle C)? v = f 340 = 220 = 340/220 = 1.54 m

26. 3. A wave along a guitar string has a frequency of 440 Hz and a wavelength of 1.5 m. What is the speed of the wave? v = f v = (440)(15) v = 6600 m/s

27. 4. The speed of sound in air is about 340 m/s. What is the wavelength of sound waves produced by a guitar string vibrating at 440 Hz? v = f 340 = 440 = 340/440 = 0.772 m

28. 5. A wave travelling on a string has a wavelength of 0.10 m and a frequency of 7 Hz. Calculate the speed of the wave. v = f v = (7) (0.1) = 0.7 m/s

29. 6. A sound wave travelling in water at 1,440 m/s has a wavelength of 0.5 m. Determine the frequency of the wave. v = f 1440 = f (0.5) f = 1440/0.5 = 2880 Hz

30. 7. An electromagnetic wave moving through free space at 3 x 10 8 m/s has a frequency of 4.62 x 10 14 Hz. Find the wavelength of this wave. v = f 3 x 10 8 = (4.62 x 10 14 ) = (3 x 10 8 )/(4.62 x 10 14 ) = 6.49x10 -7

31. 8. A wave has a wavelength of 2 m and a frequency of 2.5 Hz. Calculate the speed of this wave. v = f v = (2.5)(2) v = 5 m/s

32. 9. A wave has a wavelength of 0.65 m and a frequency of 512 Hz. Calculate the speed of this wave. v = f v = (512)(0.65) v = 332.8 m/s

33. 10. Find the frequency of a sound wave whose wavelength is known to be 8 m given the velocity of sound is 330 m/s. v = f 330 = f (8) f = 330/8 =41.25 Hz

34. 11. Calculate the speed of a wave in meters per second given a wavelength of 3.0 m and a frequency of 250 Hz. v = f v = (250)(3) v = 750 m/s

35. 12. A tidal wave travels at a speed of 25 m/sec. Calculate the frequency of this wave given the wavelength of 5,900 m. v = f 25 = f (5900) f = 25/5900 = 0.004 Hz

36. 13. Suppose a wave has a velocity of 125 m/s and a frequency of 25 Hz. Determine its wavelength. v = f 125 = (25) = 125/25 = 5 m

37. 14. The frequency of a wave pattern is 88 Hz and its wavelength is 6.5 meters. Calculate its speed in meters per second. v = f v = (88)(6.5) = 572 m/s

38. 15. Suppose the velocity of a wave is 88 meters/sec and its wavelength is 12 meters. What is its frequency? v = f 88 m/s = f (12) f = 88/12 = 7.33 Hz