# Q8S - a. What is the phase difference between the waves as...

This preview shows pages 1–2. Sign up to view the full content.

Quiz 8 Solutions Check the best answer. 1. A pipe of length L , open at one end and closed at the other, is supporting standing sound waves. Which of the following is NOT true? There is a pressure node at one end and an antinode at the other. At the open end there is a pressure node. The frequencies are odd multiples of the fundamental frequency. For the fundamental, λ = 3 L . [4 L .] Check T or F depending on whether the statement is true or false. 2. A piano tuner sounds two adjacent strings for the same note and hears 3 beats/s. When he increases the tension of the string on the left the beats disappear. The original frequency of that string was lower than that of the string on the right. T F Physics 53 Summer 2010 1

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
3. Two speakers driven by the same source are arranged as shown from above. A listener is at the point shown. Initially the speakers emit sound of frequency 170 Hz. Take the speed of sound to be 340 m/s.
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: a. What is the phase difference between the waves as they arrive at the listener? b. If each speaker separately would result in sound of intensity I at the listener, what intensity does the listener receive with both speakers active? c. As the frequency emitted by the speakers is increased, what is the Frst frequency for which the listener hears no sound? a. The wavelength is 340/170 = 2 m. The distance from the bottom speaker to the listener is 5 m (3-4-5 triangle) so the path difference is r = 2 m, which is the same as . The phase difference is therefore = 2 . b. This is constructive interference, so I = 4 I . c. Increasing f decreases and therefore increases . The next value for destructive interference is = 3 , so k r = 3 . This gives = 4/3 m and f = 255 Hz. listener 3 m 4 m Physics 53 Summer 2010 2...
View Full Document

## This note was uploaded on 10/19/2011 for the course PHYSICS 53L taught by Professor Mueller during the Spring '07 term at Duke.

### Page1 / 2

Q8S - a. What is the phase difference between the waves as...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online