1. Waves & Sound Created by Craig Smiley (Harrison HS, West Lafayette, IN) Supported by grant PHY-0851826 from the National Science Foundation and by Purdue University

2. Lesson 1 - Wave Intro & Sound Waves

3. Characteristics of a Wave On this wave, the wavelength and amplitude (in that order) are represented as segments A. BD and HC B.BD and IC C.CE and IC D.CG and HC E.None of these

4. Period vs Frequency If a spring oscillates up and down 8 times in 2 seconds, what is the period? A.0.25 s B.2 s C.4 s D.8 s E.16 s Follow-up: What is the frequency?

5. Period vs Frequency If a pendulum oscillates back and forth 4 times in 12 seconds, what is the frequency? A.0.33 Hz B.3 Hz C.4 Hz D.12 Hz E.48 Hz Follow-up: What is the period?

6. Speed of a Wave Waves in the ocean measure about 5m apart, and about 1.5m tall. They crash on the shore once every 2.5 seconds. What is the approximate speed of these ocean waves? A.0.6 m/s B.2 m/s C.2.6 m/s D.3.75 m/s E.12.5 m/s 5m 2.5m

7. Speed of a Wave A sound wave with a wavelength 0.725m, a period of 5 × 10 -4 s, and a frequency of 2,000 Hz traveling through water can go 4.35 km in 3 seconds. What is the speed of the sound wave. A.3.625 × 10 -4 m/s B.1.45 m/s C.0.24 m/s D.8700 m/s E.None of these

8. Lesson 2 – Interference Tuning forks, Oscilliscope, Slinky, 2 speakers

9. Tuning Forks Which tuning fork is going to have a higher pitch? A.A shorter tuning fork B.A longer tuning fork C.It can’t be determined by the length

10. Octave What happens to the frequency when you go up an octave? Example: middle C has a frequency of 256Hz, what is the frequency of the C above that? A.264Hz (f + 8Hz) B.257Hz (f + 1Hz) C.512Hz (2f) D.2560Hz (10f) E.There is no logical pattern.

11. Superposition of Waves What is the resultant wave pattern formed when these two waves overlap? A.B. C.D.E. None of these

12. Superposition of Waves What is the resultant wave pattern formed when these two waves overlap? A.B. C.D.E. None of these

13. Beats Let’s say that the tuning fork without the mass has a frequency of 200Hz. If you hear a beat with a frequency of 4 cycles every second, what is the frequency of the tuning fork with the mass on it? A.800 Hz B.204 Hz C.196 Hz D.50 Hz

14. Beats As the two notes get closer to being “in tune” with each other (having the same note), what happens to the frequency at which the beats occur? A.Increases B.Decreases C.Stays the same

15. Lesson 3 – Standing Waves & Instruments Slinky, Long Springs, Instruments, whirling pipe

16. Guitar String If I press my finger on a string, it makes the string shorter. What does that do to the frequency, and the perceived pitch (note)? A.Frequency: increasesPitch: raises B.Frequency: increasesPitch: lowers C.Frequency: decreasesPitch: raises D.Frequency: decreasesPitch: lowers E.None of these

17. Guitar String When I tighten a string, what does that do to the frequency, and why? A.Increases, because the speed of the wave increases B.Increases, because it is a higher harmonic C.Increases because the length of the string increases D.Decreases because the length of the string increases E.None of these

18. Flute Starting with all the valves closed, what happens to the pitch as I open the valves in order? Why? A.Pitch increases b/c the length is increasing B.Pitch increases b/c the length is decreasing C.Pitch decreases b/c the length is increasing D.Pitch decreases b/c the length is decreasing E.Pitch increases b/c the harmonics are increasing

19. Whirling Pipe What will happen to the pitch if I whirl the tube around faster? Why? A.Pitch increases, because the speed of the wave in the pipe is increasing B.Pitch increases, because the value of the harmonics are increasing C.Pitch remains the same because the length doesn’t change, nor does the speed of the wave D.None of these

20. Trombone What would have to happen to play a lower note on a trombone without changing the number of harmonics? A.Increase the length B.Decrease the length C.Increase the length & blow faster D.Increase the length & blow slower E.Decrease the length & blow slower

21. Open-End vs Closed-End Tube If both an open-ended instrument and a closed-end instrument are playing the same note at the same harmonic, which instrument has a longer tube? A.Open-end B.Closed-end C.The same D.Can’t be determined

22. Lesson 4 - Decibels

23. Intensity What happens to the intensity of a sound wave as you triple your distance away from the source? A.Increases by 9x B.Increases by 3x C.Stays the same D.Decreases by 1/3x E.Decreases by 1/9x

24. Intensity If there was a guitar player jamming producing an intensity of 400, what would the intensity be if there were 3 guitarist playing? A.400 B.403 C.1200 D.400,000 E.64,000,000

25. Intensity If a single guitar player jamming producing an intensity of 400, what would the intensity be if the perceived volume was doubled? A.402 B.800 C.4,000 D.160,000 E.4,000,000

26. Intensity If there was a guitar player jamming, how many guitar players jamming would be needed to double the perceived volume? A.2 B.4 C.10 D.20 E.100

27. Intensity How many guitar players jamming would be needed to double the perceived volume of 2 guitar players? A.4 B.8 C.14 D.20 E.100

28. Intensity How many guitar players jamming would be needed to have half of the perceived volume of 30 guitar players? A.3 B.9 C.10 D.15 E.20

29. Decibels If you doubled the volume of one blaring car horn, how many decibels is that? A.74 dB B.128 dB C.640 dB D.4096 dB E.None of these

30. Decibels If you doubled the volume of 4 blaring car horns, which produced 70dB, how many horns would be needed and how many decibels would that be? A.8 horns, 140 dB B.8 horns, 80 dB C.40 horns, 140 dB D.40 horns, 80 dB E.None of these

31. Decibels If your headphones produced 95 dB, and then you turned them down to 75 dB, by how much did the intensity change? A.Decreased to 1/4 of the intensity B.Decreased to 1/20 of the intensity C.Decreased to 1/100 of the intensity D.Decreased to 1/200 of the intensity E.Decreased to 1/400 of the intensity

32. Lesson 5 - Doppler Effect

33. Doppler Effect Which water spider is moving faster along surface of the water based upon the water-wave pattern it is creating? A.B.C. D. All the same E. Can’t be determined

34. Doppler Effect What is heard if the source of a sound wave is coming towards you according to the Doppler effect? A.It gets louder B.It is a higher pitch C.Both of these D.None of these

35. Doppler Effect Which object is the Doppler Effect going to be demonstrated in a more drastic way (greater change in frequency)? A.An object emitting a louder sound B.An object moving faster C.An object emitting a higher pitch sound D.All of these

36. Doppler Effect Whistles were put on bombs that were dropped from airplanes in WWII as a means of psychological warfare. When recorded from the plane as a bomb fell, it sounded like this: Why? http://soundbible.com/30-Bomb-Dropping.htmlhttp://www.youtube.com/watch?v=cGigkA-Xh5E A.It was moving away from the plane B.It was speeding up C.Both A & B D.It was falling down E.It was made to sound like that

37. Doppler Effect If you were on the ground as a whistling bomb approached you after being released from a plane, what would you hear before the bomb hit the ground? A.A decreasing pitch (just like we just heard) B.A constant higher pitch C.An increasing pitch (reverse to what we just heard) D.Nothing

38. Doppler Effect If the source of the sound wave was stationary and you (the observer) were moving past the source, would you observe the Doppler Effect? A.Yes B.Yes, but the shift in frequency would go from low to high, instead of high to low C.No