Physics, 26.02.2020 21:05, kam3864

The back wall of an auditorium is 26.0 m from the stage. If you are seated in the middle row, how much time elapses between a sound from the stage reaching your ear directly and the same sound reaching your ear after reflecting from the back wall?

Answers: 3

Show answers

Answers

answered: andyboy336747

Δt=0.076s

Explanation:

Assuming that the speed of sound is 343 m/s at 20°C the time elapsed from the stage to you in the middle row is the distance divided by the speed of sound as:

$\frac{13m}{343m/s}=0.0379s\\$

The time elapsed for the same sound to get the reflected from back wall and reach your ear expressed as

$\frac{26m+13m}{343m/s}=0.1137s$

Hence we have difference in two times as:

0.1137s-0.0379s=0.076s

Δt=0.076s

answered: ctdavis

The time elapsed is 0.08 s

Explanation:

In order to get a good we need to understand that the concept used in this problem is the relation of time, speed and distance.

Initially, calculate the time taken by direct sound and the reflected sound to reach at the middle row using the relation of time, speed and distance. Finally, calculate the elapsed time by subtracting the time taken by direct sound from the time taken by reflected sound. let look at some fundamentals

Time, distance and speed:

The relation between the speed, time and the distance is,

$t = \frac{d}{v}$

Here, is the time, is the distance and is the speed.

Step 1 of 2

Distance traveled by direct sound from the wall to the middle row is $\frac{L}{2}$

Here, is the distance of the wall from the stage.

The time taken by direct sound from the wall to the middle row is,

$t_{d} = \frac{d_d}{v}$

Substitute $\frac{L}{2}$ for d_d

$t_{d} = \frac{\frac{L}{2} }{v}$

$\frac{L}{2v} -----(1)$

Distance traveled by reflected sound from the wall to the middle row is $[L +\frac{L}{2} ]$

The time taken by reflected sound from the wall to the middle row is,

$t_{r} = \frac{d_r}{v}$

Substitute $[L +\frac{L}{2} ]$ for d_r

$t_{r} = \frac{[L+\frac{L}{2} ]}{v}$

$= [\frac{\frac{3L}{2} }{v} ]$

$t_{r} = \frac{3L}{2v} ----(2)$

Note: The time taken by direct sound is calculated using the distance traveled by direct sound from the wall to the middle row. The distance traveled by the reflected sound is the sum of distance traveled by the direct sound and the distance between the wall and the stage.

Step 2 of 2

The elapsed time calculated as,

t = t_r +t_d -----(3)

Substitute equation (1) and equation (2) in equation (3).

$t = \frac{3L}{v}+ \frac{L}{2v}$

$= \frac{L}{v}$

Substitute 343 m/s for and 26 m for in the above expression.

$t = \frac{26m}{343m/s}$

=0.08 s

Note

The elapsed time is calculated by subtracting the time taken by direct sound from the time taken by reflected sound. Then, the value corresponding to the distance between wall and the stage and the value corresponding to the speed of sound are substituted in the expression of time.

answered: Guest

hope this : )

answered: Guest

It may possibly be c i think |-/

Other questions on the subject: Physics

Physics, 21.06.2019 16:40, genesis88

Three point charges, two positive and one negative, each having a magnitude of 20 μc are placed at the vertices of an equilateral triangle (30 cm on a side). what is the magnitude of the electrostatic force on the negative charge

Answers: 3

continue

Physics, 22.06.2019 04:20, ttrump03

Awave is produced in a rope. the wave has a speed of 33 m/s and a frequency of 22 hz.

Answers: 3

continue

Physics, 22.06.2019 05:00, bbygrl70

Aperson stands on a platform, initially at rest, that can rotate freely without friction. the moment of inertia of the person plus the platform is ip. the person holds a spinning bicycle wheel with its axis horizontal. the wheel has moment of inertia iw and angular velocity ωw. take the ωw direction counterclockwise when viewed from above. part a what will be the angular velocity ωp of the platform if the person moves the axis of the wheel so that it points vertically upward?

Answers: 1

continue

Physics, 22.06.2019 06:30, 1234fatimasm

What are similarities and differences between refraction, reflection, diffraction and absorption?

Answers: 3

continue

Do you know the correct answer?

The back wall of an auditorium is 26.0 m from the stage. If you are seated in the middle row, how mu...