Solve Sound Waves Problem: Calculate Speed of Sound + Wind Velocity

In summary: When A fires, the time it takes for the sound to reach B is 3.04 seconds. When B fires, the time it takes for the sound to reach A is 2.96 seconds. How fast is the sound traveling in each direction?
  • #1
EmoHeartz
3
0
Can someone help me with this question, I am stucked

A and B are two observers 1km apart . There is a steady wind blowing . When a gun is fired at A the time interval between the flash and report observed at B is 3.04s. When a gun is fired at B the time interval between the flash and report observed at A is 2.96s.
Calculate the valocity of sound in air and velocity component of wind in direction BA.

do i use the formula f=v/wavelenght or velocity=distance/time?
 
Physics news on Phys.org
  • #2
Think it through. How would the frequency/wavelength relation even be of any help? What speed would you put into it?

The problem is asking for the speed of sound and it gives you information about the travel times and the distance traveled. Which formula do you think would be helpful?

Once you decide that here's a hint:

The speed of sound relative to the ground must take into account that the fact that the sound is traveling through a medium that is itself moving.
 
  • #3
but it did not give me the distance between the gun and A.
does it mean i use 1km?
 
  • #4
"The gun is fired at A and the report is observed at B" ... therefore ...?
 
  • #5
EmoHeartz said:
but it did not give me the distance between the gun and A.
does it mean i use 1km?

No, "at" does not mean "1 km away"! :smile:

Wavelength and frequency relations are useless here because you are not told either of those.

Let u be the speed of sound, v be the speed of the wind. Since wind is moving air and sound moves through the air, the net speed of sound, in the direction the wind is blowing, is u+ v. The net speed of sound, in the opposite direction, is u- v. Does that help?
 
Last edited by a moderator:
  • #6
thanks..i think i understand now .but how do i find the velocity of the wind?
 
  • #7
You have two unknowns, u and v. You need to come up with two equations that you need to solve simultaneously to figure out u and v together.

A has a gun, and B has a gun. A fires, B listens. Then B fires, A listens.
 

What is the formula for calculating the speed of sound?

The formula for calculating the speed of sound is v = √(γRT), where v is the speed of sound, γ is the ratio of specific heats, R is the gas constant, and T is the temperature in Kelvin.

How does wind affect the speed of sound?

Wind can affect the speed of sound by either increasing or decreasing it, depending on the direction and strength of the wind. When wind blows in the same direction as the sound waves, it can increase the speed of sound. However, when wind blows in the opposite direction of the sound waves, it can decrease the speed of sound.

What is the significance of calculating the speed of sound and wind velocity?

Calculating the speed of sound and wind velocity is important in various fields such as aviation, meteorology, and seismology. It allows us to understand how sound waves travel and how they are affected by different factors, which can ultimately help in predicting and mitigating potential hazards.

How do you account for temperature and air density in the calculation?

Temperature and air density play a crucial role in the calculation of speed of sound. The speed of sound is directly proportional to the square root of temperature and inversely proportional to the square root of air density. This means that as temperature increases, the speed of sound also increases, while higher air density results in a slower speed of sound.

Can the speed of sound and wind velocity be measured in different units?

Yes, the speed of sound can be measured in various units such as meters per second, feet per second, or kilometers per hour. Similarly, wind velocity can also be measured in different units such as meters per second, miles per hour, or knots. It is important to ensure that the units are consistent when calculating and comparing these values.

Similar threads

Sound Wave Interference and Finding the Path Differences with Diagrams
    • Introductory Physics Homework Help
Replies
20
Views
2K
How to solve this sound problem (minimum sampling rate required)
    • Introductory Physics Homework Help
Replies
3
Views
1K
I Need to Calculate the Speed of Sound for a Lab
    • Introductory Physics Homework Help
Replies
4
Views
2K
Calculating τ by knowing I is proportional to A^2
    • Introductory Physics Homework Help
Replies
8
Views
2K
Stress, Strain, and Sound in a Projectile Steel Rod
    • Introductory Physics Homework Help
Replies
2
Views
1K
Calculating Intensities of Out-of-Phase Sound Waves
    • Introductory Physics Homework Help
Replies
1
Views
1K
Problem on Doppler effect and sound level
    • Introductory Physics Homework Help
Replies
1
Views
1K
Calculating Distance to a Wall Using Speed of Sound
    • Introductory Physics Homework Help
Replies
31
Views
2K
Constructive interference with sound -- word problem
    • Introductory Physics Homework Help
Replies
15
Views
2K
I How fast does a blastwave travel?
    • Classical Physics
7
Replies
236
Views
8K

Hot Threads

Recent Insights

Back
Top