20 Physics Sound Review

1. Find the wavelength of sound with a frequency of 365 Hz when it is traveling with a speed of 1230 m/s.

2. What is the frequency of a sound wave with a wavelength of 6.6 m traveling at 350 m/s?

3. A gun is fired 2.0 km away from a mountain. The speed of the shot travels at 340 m/s. a) How long will it take the person who fired the gun to hear the echo?

b) What was the wavelength of the sound if the frequency was 150 Hz?

4. The whistle on a train has a frequency of 440 Hz. The train is moving at 35.0 m/s toward a person standing on the platform. If sound travels at 350 m/s, what is the wavelength of the sound heard by the person?

5. An auto with a siren having a frequency of 365 Hz is approaching a stationary detector at a speed of 75 km/hr. What will the frequency of the siren appear to be if sound travels at 345 m/s?

6. A tube closed at one end is used to determine the speed of sound in air. Resonance occurs every 32 cm when a frequency 530 Hz tuning fork is vibrated. What is the velocity of sound?

7. Using a tube closed at one end, the speed of sound was found to be 335 m/s with a 340 Hz tuning fork. What was the length of the tube?

8. Using 343 m/s as the speed of sound, find the lowest frequency that can be played on an instrument having an open pipe 55 cm long?

9. What is the next to lowest frequency that can be played on an instrument that is an open pipe 75 cm long? Assume sound travels at 343 m/s.

10. Two sources of sound emit frequencies of 545 Hz and 548 Hz simultaneously. What beat frequency will be heard?

11. A violin string with a mass to length ratio of 35 g/m vibrates with a frequency of 587 Hz. Consider a second violin string with the same length, diameter and tension but with a mass to length ratio of 22 g/m. What will be its frequency of vibration?

12. A guitar string 75 cm long vibrates with a frequency of 230 Hz when its tension is 340 N. What will be its frequency of vibration if the sting is shortened to 50 cm and the tension is increased to 500 N?