Calculate the height from the speed of sound

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To calculate the depth of a well based on the time taken to hear a splash after dropping a stone, the total time of 1.63 seconds is divided into two components: the time for the stone to hit the water (t1) and the time for the sound to travel back up (t2). The kinematic equation Δh = 1/2gt1² is used to express the distance fallen, while the speed of sound equation relates to the distance sound travels. The challenge arises from having three unknowns (height and both time values) with only two equations. A suggested approach is to equate the distances for the stone's fall and the sound's rise, simplifying the problem to a single unknown, which can then be solved using the quadratic formula. This method provides a clearer path to finding the well's depth.
Julio Cesar
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Homework Statement


You drop a stone down a well. You hear the 'splash' 1.63s later. How deep is the well? The speed of sound in air is 343m/s.


Homework Equations


Kinematic equation: Δh=V0t+1/2gt2

Also, I've narrowed the problem down to the total time of 1.63s is equal to...
1) the time the stone leaves the hand and hits the water bellow. This is t1
2) The time it takes for the sound to rise from the water and be heard above. This is t2

So 1.63s = t1 + t2

The Attempt at a Solution



Now since the initial velocity is zero. We can just say that Δh=1/2gt12

And the speed of sound is v=meters/sec (since I want the distance I can call meters displacement.) Right?

So now I have two equations that I can rearange for time (t1 and t2

And I also have the full total time of Ttotal which is equal to the sum of t1 + t2

But my question is this...I need to find the displacement (or height) but I have three unknowns (both time values and the height) but I also have two equations. So my brilliant self did this...

1.63s = √2(h)/g + h/vs

I tried to solve for "h" and that ended horribly. So now I'm stuck. I know I can get this. I desperately want to solve this now to prove to myself that I am not stupid. So I've been stuck for over a few hours (taking breaks of course) and going over it in my head as to how to either find one of the time values or the height altogether.

Please if someone can just give me a little tip. I don't want the answer nor a plug and chug final equation. I just need a little math tip as to what to do next (or what am I doing wrong)...

Thanks for any and all help, ya'll.
 
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You could solve that equation by taking the radical to one side, other terms to the other and squaring both sides. But the easier approach is to start with
distance down = distance up
1/2gt² = vt₂
1/2gt² = v(1.63 - t)
which has only one unknown.
 
You have already done the hard part. Nice job! Now...

Let y = √h, y2 = h, and solve your equation using the quadratic formula.
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

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