As shown below, a garden room has three walls, a floor, and a roof, but is open to the garden on one side. The wall widths are
L and
w. The roof height is
h. When traveling sound waves enter the room, standing sound waves can be present in the room if the wavelength of the standing waves is
a.
, where
n is a positive integer.
b.
, where
n is an odd integer.
c.
, where
n is an even integer.
d.
in all cases listed above.
e.
given by (a) or (b) above, but not by (c).
[Ques. 2] An observer stands 3 m from speaker A and 4 m from speaker B. Both speakers, oscillating in phase, produce 170-Hz waves. The speed of sound in air is 340 m/s. What is the phase difference (in radians) between the waves from A and B at the observer's location, point P?
a.
0
b.
/2 c.
d.
2
e.
4
[Ques. 3] Two point sources emit sound waves of 1.0-m wavelength. The sources, 2.0 m apart, as shown below, emit waves which are in phase with each other at the instant of emission. Where, along the line between the sources, are the waves out of phase with each other by radians?
a.
x = 0, 1.0 m, 2.0 m
b.
x = 0.50 m, 1.5 m
c.
x = 0.50 m, 1.0 m, 1.5 m
d.
x = 0.75 m, 1.25 m
e.
x = 0.25 m, 0.75 m, 1.25 m, 1.75 m
[Ques. 4] The path difference between two waves is 5 m. If the wavelength of the waves emitted by the two sources is 4 m, what is the phase difference (in degrees)?
a.
90
b.
400
c.
1.57
d.
7.85
e.
15
[Ques. 5] Exhibit 17-2
The figure below shows a sine wave on a string at one instant of time.
Use this exhibit to answer the following question(s).
Refer to Exhibit 17-2. Which of the graphs below shows a wave where the wavelength is twice as large?
a.
b.
c.
d.
e.
[Ques. 6] Exhibit 17-2
The figure below shows a sine wave on a string at one instant of time.
Use this exhibit to answer the following question(s).
Refer to Exhibit 17-2. Which of the graphs below shows a wave where the frequency and wave velocity are both doubled?
a.
b.
c.
d.
e.