Doppler Effect

Practice Problems
Doppler Effect

Directions: On this worksheet, you may assume that the speed of sound in air is 340 m/sec unless otherwise stated.

omit

Question 1 A 'clicker' is sounding at 10 Hz; if you are moving towards the 'clicker' at 28 m/sec what apparent frequency do you hear instead?

13.57 Hz10.82 Hz9.18 Hz6.43 Hz

omit

Question 2 You are riding a bike away from a street musician at 14 m/sec; when the trumpet player hits an 'A'. You know that the frequency of an 'A' should be 440 Hz, what apparent frequency do you hear instead?

451 Hz429 Hz422 Hz458 Hz

omit

Question 3 You are in an ambulance driving towards an accident at 38 m/sec. You hear the horns of the cars in the accident sounding at a frequency of 466 Hz, what is the actual frequency of the car horns.

525 Hz414 Hz518 Hz419 Hz

omit

Question 4 You are riding in a boat into oncoming waves and measure the frequency of the waves to be 28 crests every 10 seconds. Shortly afterwards you come to rest on the water and measure the waves to have an actual frequency of 5 every 10 seconds with a wave speed of 12.7 m/sec. How fast was your boat traveling before?

83.8 m/sec2.8 m/sec58.4 m/sec1.9 m/sec

omit

Question 5 You are speeding away from a loud speaker. If the original frequency of 466 Hz is shifted to 428 Hz, what is your speed away from the speaker?

9 m/sec27.7 m/sec30 m/sec31 m/sec

omit

Question 6 You are measuring the speed of a projectile using sonar. If a frequency of 233 Hz is reflected back at 219 Hz, what is the speed of the projectile?

20.4 m/sec24.3 m/sec32.0 m/sec21.7 m/sec

omit

Question 7 In what direction was the projectile in Question 6 moving relative to the sonar device?

cannot be determinedtowards the sonaraway from the sonar