Calculating Well Depth Using the Speed of Sound

  • Thread starter ramollari
  • Start date
In summary, the question involves finding the depth of a well based on the time it takes for a stone to hit the water and the sound to reach your ear. There is some discussion about whether the speed of sound should be taken into account in the calculation, but the main focus is on acceleration under gravity and solving a quadratic equation.
  • #1
ramollari
437
1
A stone is thrown into a well and the sound is heard after 3s. How deep is the well?
 
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  • #2
Write down the times the stone takes to hit the water and the sound takes to reach your ear.You'll find your answer in no time...

Daniel.
 
  • #3
You may also want to factor in the acceleration of the stone due to gravity.
 
  • #4
Dex, you silly!

This is an assignment about acceleration, not about the speed of sound!
 
  • #5
DaveC426913 said:
Dex, you silly!

This is an assignment about acceleration, not about the speed of sound!

:mad:

Coul you explain both of your sentences? :mad:

Daniel.
 
  • #6
Use 343 m/s for the speed of sound, and remember the time given has the time when the rock falls and then the sound wave gets to you. Also the sound will be moving with constant speed.
 
  • #7
dextercioby said:
:mad:

Coul you explain both of your sentences? :mad:

Daniel.

I believe you missed the forest for the trees.

Your response seems to focus on the amount of time it takes the sound to reach your ear from the bottom of the well.

I believe the question is not about the speed of sound, it is about acceleration under gravity. The only relevant time delay concerns how fast the rock falls due to gravity. One should assume the delay due to propogation of sound is not a factor.

Maybe. I could be wrong.

It's grade K-12 homework.
 
  • #8
DaveC426913 said:
I believe you missed the forest for the trees.

Your response seems to focus on the amount of time it takes the sound to reach your ear from the bottom of the well.

I believe the question is not about the speed of sound, it is about acceleration under gravity. The only relevant time delay concerns how fast the rock falls due to gravity. One should assume the delay due to propogation of sound is not a factor.

Maybe. I could be wrong.

It's grade K-12 homework.


Dave,i believe you need a pair of glasses... :tongue2: My answer focuses on solving the problem:
dextercioby said:
Write down the times the stone takes to hit the water and the sound takes to reach your ear.You'll find your answer in no time...
,not on the speed of sound.It never mentions the speed of sound...:rolleyes:

Since the solver needs to find the depth,a priori unknown,he must include the time of sound propagation,because he has no idea whether it can,or not be neglected.

Daniel.
 
  • #9
Doing it the "proper" way involves solving a quadratic. Assuming the speed of sound to be 340 m/s, there is an 8.5 % difference from the "easy" answer found by substitution.

I'm with Dexter on this one.
 
  • #10
You don't think the grade K-12 homework problem is more simply stated as:

"How far will an object fall in 3 seconds"

?
 
  • #11
DaveC426913 said:
You don't think the grade K-12 homework problem is more simply stated as:

"How far will an object fall in 3 seconds"

?

Don't u think that in the first 18 years of life one should know how to solve a quadratic equation?? :wink:

Daniel.
 
  • #12
edit: nvm nvm nvm
 
  • #13
d=.5at^2
d=.5(9.8)(3s)^2
d=44.1m


time*acceleration = velocity
time*velocity = distance
 
  • #14
ramollari did it say anything about the speed of sound in this question?
 

1. How deep is the well?

The depth of a well can vary greatly depending on its purpose and location. On average, a residential water well can range from 100-500 feet deep, while oil and gas wells can be thousands of feet deep.

2. What factors determine the depth of a well?

The depth of a well is primarily determined by the depth of the aquifer, or underground layer of water, that is being tapped. Other factors such as the type of well, drilling technology, and local geology can also play a role in determining the depth.

3. Is there a limit to how deep a well can be drilled?

Technically, there is no limit to how deep a well can be drilled. However, drilling beyond a certain depth becomes increasingly difficult and expensive. The deepest well in the world, the Z-44 Chayvo Well in Russia, is over 40,000 feet deep.

4. How deep does a well need to be to access clean water?

The depth necessary to access clean water can vary depending on the location and quality of the groundwater source. In some cases, a shallow well of just a few feet can provide clean water, while in other areas a well may need to be several hundred feet deep to reach safe and clean water sources.

5. Can the depth of a well change over time?

Yes, the depth of a well can change over time due to natural factors such as erosion or human activities like pumping. In some cases, wells may need to be deepened or re-drilled to maintain access to adequate water sources.

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