1. © 2007 Pearson Prentice Hall This work is protected by United States copyright laws and is provided solely for the use of instructors in teaching their courses and assessing student learning. Dissemination or sale of any part of this work (including on the World Wide Web) will destroy the integrity of the work and is not permitted. The work and materials from it should never be made available to students except by instructors using the accompanying text in their classes. All recipients of this work are expected to abide by these restrictions and to honor the intended pedagogical purposes and the needs of other instructors who rely on these materials. Clicker Question ConcepTests PRS-Enabled Chapter 14 Physics, 3 rd Edition James S. Walker

2. 1) yes 2) no 3) it depends on the medium the wave is in ConcepTest 14.1Sound It Out ConcepTest 14.1 Sound It Out Does a longitudinal wave, such as a sound wave, have an amplitude ? low high normalairpressurex A

3. At a football game, the “wave” might circulate through the stands and move around the stadium. In this wave motion, people stand up and sit down as the wave passes. What type of wave would this be characterized as? 1) polarized wave 2) longitudinal wave 3) lateral wave 4) transverse wave 5) soliton wave ConcepTest 14.2The Wave ConcepTest 14.2 The Wave

4. ConcepTest 14.3Out to Sea ConcepTest 14.3 Out to Sea t t +  t 1) 1 second 2) 2 seconds 3) 4 seconds 4) 8 seconds 5) 16 seconds A boat is moored in a fixed location, and waves make it move up and down. If the spacing between wave crests is 20 m and the speed of the waves is 5 m/s, how long does it take the boat to go from the top of a crest to the bottom of a trough ?

5. ConcepTest 14.4Lunch Time ConcepTest 14.4 Lunch Time 1) 0.3 mm 2) 3 cm 3) 30 cm 4) 300 m 5) 3 km Microwaves travel with the speed of light, c = 3  10 8 m/s. At a frequency of 10 GHz these waves cause the water molecules in your burrito to vibrate. What is their wavelength? 1 GHz = 1 Gigahertz = 10 9 cycles/sec H H O

6. ConcepTest 14.5 ConcepTest 14.5 Sound Bite I 1) the frequency f 2) the wavelength 3) the speed of the wave 4) both f and 5) both v wave and When a sound wave passes from air into water, what properties of the wave will change?

7. We just determined that the wavelength of the sound wave will change when it passes from air into water. How will the wavelength change? 1) wavelength will increase 2) wavelength will not change 3) wavelength will decrease ConcepTest 14.6 ConcepTest 14.6 Sound Bite II

8. (1) water (2) ice (3) same speed in both (4) sound can only travel in a gas Do sound waves travel faster in water or in ice? ConcepTest 14.7 ConcepTest 14.7 Speed of Sound I

9. Do you expect an echo to return to you more quickly or less quickly on a hot day, as compared to a cold day? 1) more quickly on a hot day 2) equal times on both days 3) more quickly on a cold day ConcepTest 14.8 ConcepTest 14.8 Speed of Sound II

10. If you fill your lungs with helium and then try talking, you sound like Donald Duck. What conclusion can you reach about the speed of sound in helium? 1) speed of sound is less in helium 2) speed of sound is the same in helium 3) speed of sound is greater in helium 4) this effect has nothing to do with the speed in helium ConcepTest 14.9 ConcepTest 14.9 Speed of Sound III

11. You drop a rock into a well, and you hear the splash 1.5 s later. If the depth of the well were doubled, how long after you drop the rock would you hear the splash in this case? 1) more than 3 s later 2) 3 s later 3) between 1.5 s and 3 s later 4) 1.5 s later 5) less than 1.5 s later ConcepTest 14.10 ConcepTest 14.10 Wishing Well

12. (1) the long pipe (2) the short pipe (3) both have the same frequency (4) depends on the speed of sound in the pipe You have a long pipe and a short pipe. Which one has the higher frequency? ConcepTest 14.11 ConcepTest 14.11 Pied Piper I

13. A wood whistle has a variable length. You just heard the tone from the whistle at maximum length. If the air column is made shorter by moving the end stop, what happens to the frequency? 1) frequency will increase 2) frequency will not change 3) frequency will decrease ConcepTest 14.12 ConcepTest 14.12 Pied Piper II

14. If you blow across the opening of a partially filled soda bottle, you hear a tone. If you take a big sip of soda and then blow across the opening again, how will the frequency of the tone change? 1) frequency will increase 2) frequency will not change 3) frequency will decrease ConcepTest 14.13 ConcepTest 14.13 Pied Piper III

15. 1) depends on the speed of sound in the pipe 2) you hear the same frequency 3) you hear a higher frequency 4) you hear a lower frequency You blow into an open pipe and produce a tone. What happens to the frequency of the tone if you close the end of the pipe and blow into it again? ConcepTest 14.14 ConcepTest 14.14 Open and Closed Pipes

16. When you tune a guitar string, what physical characteristic of the string are you actually changing? 1) the tension in the string 2) the mass per unit length of the string 3) the composition of the string 4) the overall length of the string 5) the inertia of the string ConcepTest 14.15 ConcepTest 14.15 Out of Tune

17. Observers A, B and C listen to a moving source of sound. The location of the wave fronts of the moving source with respect to the observers is shown below. Which of the following is true? 1) frequency is highest at A 2) frequency is highest at B 3) frequency is highest at C 4) frequency is the same at all three points ConcepTest 14.16 ConcepTest 14.16 Doppler Effect I

18. You are heading toward an island in a speedboat and you see your friend standing on the shore, at the base of a cliff. You sound the boat’s horn to alert your friend of your arrival. If the horn has a rest frequency of f 0, what frequency does your friend hear ? 1) lower than f 0 2) equal to f 0 3) higher than f 0 ConcepTest 14.17 ConcepTest 14.17 Doppler Effect II

19. In the previous question, the horn had a rest frequency of f 0, and we found that your friend heard a higher frequency f 1 due to the Doppler shift. The sound from the boat hits the cliff behind your friend and returns to you as an echo. What is the frequency of the echo that you hear? 1) lower than f 0 2) equal to f 0 3) higher than f 0 but lower than f 1 4) equal to f 1 5) higher than f 1 ConcepTest 14.18 ConcepTest 14.18 Doppler Effect III

20. ConcepTest 14.19Standing Waves I ConcepTest 14.19 Standing Waves I A string is clamped at both ends and plucked so it vibrates in a standing mode between two extreme positions a and b. Let upward motion correspond to positive velocities. When the string is in position b, the instantaneous velocity of points on the string: a b 1) is zero everywhere 2) is positive everywhere 3) is negative everywhere 4) depends on the position along the string

21. Pair 1Pair 2 1) pair 1 2) pair 2 3) same for both pairs 4) impossible to tell by just looking The traces below show beats that occur when two different pairs of waves interfere. For which case is the difference in frequency of the original waves greater? ConcepTest 14.20 ConcepTest 14.20 Beats