Chapter 15 Waves and Energy Transfer Review

1. The speed of an ocean wave on the coast is 42 m/s; the wavelength is 1.5 m. What is the frequency with which the wave hits the beach?

2. If the speed of sound in air is 340 m/s and the wavelength of a sound is 5.0 m, what is the frequency of the sound? What is the frequency of this sound as it moves into water?

3. What is the wavelength of a sound emitted by a tuning fork of frequency 440 vibrations per second? The speed of sound is 332 m/sec at 0.0°C and increases 0.60 m/s for each degree temperature rise. The tuning fork is at 32°C.

4. Radio waves travel at the speed of light, 3.0 x 108 m/s. What is the wavelength of a radio wave from an AM station broadcasting at a frequency of 750 kHz? Find the frequency in m and km and compare it to some familiar object of similar length.

5. A standing wave in a clothesline has 4 nodes and 3 antinodes. The clothesline is 12 m long and is vibrating at 0.50 vibrations per second. What is the speed of the wave?

6. A wave travels from one medium to another, and the wavelength decreases. What happens to the velocity and the frequency?

A. Completing Concepts

1. __________ waves require a material medium for energy transfer.

2. A(n) __________ wave causes the particles of the medium to vibrate in a direction perpendicular to the direction in which the wave is traveling.

3. __________ waves need no medium for travel.

4. A(n) __________ is a single disturbance traveling through a medium.

5. The __________ of a wave is the number of waves that pass a given point per second.

6. The __________ of a wave is the reciprocal of its frequency.

7. The __________ of a wave is the linear distance between any two corresponding points on consecutive waves.

8. The energy content of a mechanical wave is characterized by its __________.

9. __________ is the process involved when two waves meet and superimpose their amplitudes.

10. The __________ of a mechanical wave depends on the medium.

11. When waves pass from one medium into another, their __________ remains unchanged.

12. A(n) __________ wave is produced when a wave train moving in one direction meets an identical wave train moving in the opposite direction.

13. Two pulses with identical shapes but opposite displacements move toward each other in a medium. The point in the medium that is never displaced is a(n) __________.

14. __________ is the direction change of waves at the boundary between different media.

15. __________ is the bending of a wave around an obstacle.

16. __________ are undisturbed areas that are formed when two sets of waves interact with one another.

17. The __________ is a line perpendicular to a barrier at the point where an incident ray strikes the barrier.

18. When a wave is reflected from a barrier, the angle of __________ equals the angle of reflection.

B. Understanding Concepts

1. Waves provide a means of transferring

a. matter.

b. particles.

c. liquids.

d. energy

2. A 10-Hz wave has a 2-cm wavelength. The velocity of this wave is

a. 5 cm/s.

b. 8 cm/s.

c. 12 cm/s.

d. 20 cm/s.

3. A sound travels from A to B. In which direction do the particles of the medium vibrate?

4. Which of the mechanical waves represented below has the greatest energy?

5. If an incident wave makes a 20° angle with a barrier, the reflected wave makes a __________ angle with a perpendicular drawn to the barrier.

a. 10°

b. 20°

c. 50°

d. 70°

6. A is an incident ray. Which is the corresponding reflected ray?

7. If the amplitude of the reflected pulse is __________ when a wave passes from one medium to another, most of the energy has been transmitted.

a. inverted

b. erect

c. large

d. small

8. Which two points are in phase?

a. A and C

b. B and C

c A and D

d. B and D

9. Pulses are going from medium A to medium B as shown. The speed of the waves in B is greater. Which diagram best describes the pulses in B?

10. Which diagram below will lead to deconstructive interference?

11. When waves refract, the waves do not change

a. speed.

b. frequency.

c. wavelength.

d. direction.

If you have any questions, please email Ms. Cummings