Question

In: Physics

When a sound wave travels directly toward a hard wall, the incoming and reflected waves can...

When a sound wave travels directly toward a hard wall, the incoming and reflected waves can combine to produce a standing wave. There is an antinode right at the wall, just as at the end of a closed tube, so the sound near the wall is loud. You are standing beside a brick wall listening to a 80Hz tone from a distant loudspeaker.

How far from the wall must you move to find the first quiet spot? Assume a sound speed of 340 m/s.

Solutions

Expert Solution

The frequency of the wave in a pipe closed at one end is, \(f=\frac{v}{4 L}\)

The length of the pipe is, \(\begin{aligned} L &=\frac{v}{4 f} \\ &=\frac{340 \mathrm{~m} / \mathrm{s}}{4(80 \mathrm{~Hz})} \\ &=1.06 \mathrm{~m} \end{aligned}\)


Related Solutions

Describe the process that occurs when the sound wave energy travels across the room.
Describe the process that occurs when the sound wave energy travels across the room.
Bats use echolocation to navigate and find food by emitting sound waves that are reflected off...
Bats use echolocation to navigate and find food by emitting sound waves that are reflected off their surroundings. If something nearby is moving, the reflected wave will return to the bat with a different frequency. Take the temperature of air to be 18 ° a. A bat is hanging from the roof of a cave and emits a sound pulse every 0.6 seconds trying to find a bug to eat. If it takes 2.1 seconds for a pitch of 1.61...
We saw in lecture that light waves can be polarized. Can sound waves be polarized? If...
We saw in lecture that light waves can be polarized. Can sound waves be polarized? If so, give an example of polarized sound. If not, explain why not.
A sound source A and a reflecting surface B move directly toward each other. Relative to...
A sound source A and a reflecting surface B move directly toward each other. Relative to the air, the speed of source A is 29.7 m/s, the speed of surface B is 63.5 m/s, and the speed of sound is 330 m/s. The source emits waves at frequency 1350 Hz as measured in the source frame. In the reflector frame, what are (a) the frequency and (b) the wavelength of the arriving sound waves? In the source frame, what are...
A student launches an elastic ball from the ground level directly toward a tall vertical wall....
A student launches an elastic ball from the ground level directly toward a tall vertical wall. After the first launch, the ball bounces off the wall and then hits the ground. The student notices that the launch point is equidistant from the landing point and from the wall. The student then moves the launching point 20 m in the direction perpendicular to the wall and launches the ball again. After the ball bounces off the wall and lands, the student...
Describe the process that occurs when an object is put into vibration and the sound wave...
Describe the process that occurs when an object is put into vibration and the sound wave energy travels across the room. How does it get there? And how does it eventually become electrical energy in your brain? Please describe the processes of auditory transduction from acoustic to mechanical to hydraulic to electrical, describing the parts of the auditory system involved at each change.
Two loudspeakers emit sound waves along the x-axis. The sound has maximum intensity when the speakers...
Two loudspeakers emit sound waves along the x-axis. The sound has maximum intensity when the speakers are 19 cm apart. The sound intensity decreases as the distance between the speakers is increased, reaching zero at a separation of 29 cm. What is the wavelength of the sound? Express your answer using two significant figures. If the distance between the speakers continues to increase, at what separation will the sound intensity again be a maximum? Express your answer using two significant...
Bats are not blind, but they can hunt in complete darkness, using ultrasonic sound waves to...
Bats are not blind, but they can hunt in complete darkness, using ultrasonic sound waves to detect both the position and the motion of their prey. (“Ultrasonic” means at a higher frequency than humans can hear. “Supersonic” means faster than the speed of sound.) High-intensity, high-frequency sound pulses are emitted from their snouts, and they hear echoes from sound waves reflected from the prey. This process is known as echolocation. a) Suppose the friendly and graceful bat pictured above tries...
Light energy of sufficient intensity can cause materials to emit sound waves depending on their light...
Light energy of sufficient intensity can cause materials to emit sound waves depending on their light absorption. Propose a system to make 2D images of these optoacoustic properties of an object
READING 2 The eardrum is displaced surprisingly little when a sound wave strikes it. Some idea...
READING 2 The eardrum is displaced surprisingly little when a sound wave strikes it. Some idea of the displacement of the eardrum by a sound wave can be obtained by using Equation 7.1: Equation for wave energy The displacement amplitude, A, of the air molecules gives us a lower limit to the displacement of the eardrum. At the threshold of hearing at 3.4 kHz, the sound intensity is about 10−12W/m2. The threshold of pain begins at an intensity of 1.0W/m2...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT