Page 204 - Schaum's Outline of Theory and Problems of Applied Physics

CHAP. 15] WAVES AND SOUND 189

15.17. The car and train of Prob. 15.16 pass each other and continue moving at the same velocities. What frequency is heard
by the people in the car now?

15.18. A spacecraft moving away from the earth at 97 percent of the velocity of light transmits data at the rate of 1 × 10 4
pulses/s. At what rate is the data received on the earth? (Actual spacecraft do not travel this fast; the highest velocity
of the Apollo 11 spacecraft that went to the moon was only 0.0036 percent of the velocity of light.)

Answers to Multiple-Choice Questions

15.1. (b) 15.7. (b)

15.2. (b) 15.8. (b)

15.3. (a) 15.9. (c)

15.4. (d) 15.10. (d)

15.5. (c) 15.11. (c)
15.6. (c)

Answers to Supplementary Problems

15.1. Energy 15.10. 16 dB

15.2. 78 cm 15.11. 98 dB
15.3. 1500 m/s 15.12. 1000

15.4. f 2 = f 1 ,λ 2 = 2λ 1 15.13. 25 µW

15.5. 266 vibrations 15.14. 793 W

15.6. 10 W/m 2 15.15. 70 dB
4
15.7. 10 = 10, 000 times more intense 15.16. 939 Hz
15.8. 120 dB 15.17. 678 Hz

15.9. 9.5 km 15.18. 1.23 pulses/s