Physics chapter 16 multiple choice

An organ pipe open at both ends is tuned so that its fundamental frequency is a G. How long is the pipe? A. 43 cm B. 87 cm C. 130 cm D. 173 cm

A

At x = 3 cm, what is the earliest time that y will equal 2 mm? A. 0.5 s B. 0.7 s C. 1.0 s D. 1.5 s E. 2.5 s

A

In a tube, standing-wave modes are found at 200 Hz and 400 Hz. The tube could not be A. open-closed B. open-open C. closed-closed D. it could be any of these

A

Two in-phase sources emit sound waves of equal wavelength and intensity. At the position of the dot, A. The interference is constructive B. The interference is destructive C. The interference is somewhere between constructive and destructive D. Not enough info

A

Two speakers are emitting identical sound waves with a wavelength of 4.0 m. The speakers are 8.0 m apart and directed toward each other, as in the following diagram. At each of the noted points the interference is?

A (A. C. E.) B (b, d)

A student in her physics lab measures the standing-wave modes of a tube. The lowest frequency that makes a resonance is 20 Hz. As the frequency is increased, the next resonance is at 60 Hz. What will be the next resonance after this? A. 80 Hz B. 100 Hz C. 120 Hz D. 180 Hz

B

An organ pipe is tuned exactly 384 Hz when the temperature in the room is 20 degrees celsius. Later when the air has warmed up to 25 degrees celsius, the frequency is A. greater than 384 Hz B. 384 Hz C. less than 384 Hz

B

At t = 1.5 s, what is the value of y at x = 10 cm? A. -2.0 mm B. -1.0 mm C. -0.5 mm D. 0 mm E. 1.0 mm

B

Resonances of the ear canal lead to increased sensitivity of hearing, as we've seen. Dogs have a much longer ear canal—5.2 cm—than humans. What are the two lowest frequencies at which dogs have an increase in sensitivity? The speed of sound in the warm air of the ear is 350 m/s. A. 1700 Hz, 3400 Hz B. 1700 Hz, 5100 Hz C. 3400 Hz, 6800 Hz D. 3400 Hz, 10,200 Hz

B

Two speakers emit sounds of nearly equal frequency, as shown. At a point between the two speakers, the sound varies from loud to soft. How much time elapses between two successive loud moments? A. 0.5 s B. 1.0 s C. 2.0 s D. 4.0 s

B

Two wave pulses on a string approach each other at speeds of 1 m/s. How does the string look at t = 3 s?

B

What is the beat frequency between the second harmonic of G and the third harmonic of C? A. 1 Hz B. 2 Hz C. 4 Hz D. 6 Hz

B

Would a G-flat (frequency 370 Hz) and a C played together be consonant or dissonant? A. Consonant B. Dissonant

B

| If the C were played on an organ pipe that was open at one end and closed at the other, which of the harmonic frequencies in Figure P16.72 would be present? A. All of the harmonics in the figure would be present. B. 262, 786, and 1310 Hz C. 524, 1048, and 1572 Hz D. 262, 524, and 1048 Hz

B

The frequency of the lowest standing-wave mode on a 1.0-m-long string is 20 Hz. What is the wave speed on the string? A. 10 m/s B. 20 m/s C. 30 m/s D. 40 m/s

C

Two loudspeakers emit sound waves with the same wavelength and the same amplitude. The waves are shown displaced, for clarity, but assume that both are traveling along the same axis. At the point where the dot is, A. The interference is constructive B. The interference is destructive C. The interference is somewhere between constructive and destructive D. There's not enough information to tell

C

Two wave pulses on a string approach each other at speeds of 1 m/s. How does the string look at t = 3 s?

C

At t = 1 s what is the displacement y of the string x = 7 cm? A. -1.0 mm B. 0 mm C. 0.5 mm D. 1.0 mm E. 2.0 mm

D

Suppose you pluck a string on a guitar and it produces the note A at a frequency of 440 Hz. Now you press your finger down on the string against one of the frets, making this point the new end of the string. The newly shortened string has the length of the full string. When you pluck the string, its frequency will be A. 350 Hz B. 440 Hz C. 490 Hz D. 550 Hz

D

When two waves overlap, the displacement of the medium is the sum of the displacements of the two individual waves. This is the principle of? A. Constructive interference B. Destructive interference C. standing waves D. Superposition

D