Understanding the Relationship Between Dripping Rate and Water Clock Design

  • Thread starter Thread starter That Neuron
  • Start date Start date
  • Tags Tags
    Decay Natural
That Neuron
Messages
75
Reaction score
0
Okay, this is a really simple question, so to anyone looking for some extraordinarily complex differential equation question turn away now, or be blinded by boredom.

My query is rooted in a question I had about building a water clock... so seemingly relevant to Differentials, I know. Anyways, I realized that the rate of dripping (though probably much more complex than a proportionality) was at simplest proportional to the height, or at least related to it.

Anyway, I was thinking that if the rate of change of the height is proportional to the pressure on the hole at the bottom out of which water drips (or pours) then I could create the differential dy/dt = -k (πr2 pg y(t), where p is equal to the density and g is the acceleration due to gravity, this equation translates to y = y(0) e-kπr2pgt.

But this function seems to decline too steeply for this application, am I doing this right?
 
Physics news on Phys.org
That Neuron said:
Okay, this is a really simple question, so to anyone looking for some extraordinarily complex differential equation question turn away now, or be blinded by boredom.

My query is rooted in a question I had about building a water clock... so seemingly relevant to Differentials, I know. Anyways, I realized that the rate of dripping (though probably much more complex than a proportionality) was at simplest proportional to the height, or at least related to it.

Anyway, I was thinking that if the rate of change of the height is proportional to the pressure on the hole at the bottom out of which water drips (or pours) then I could create the differential dy/dt = -k (πr2 pg y(t), where p is equal to the density and g is the acceleration due to gravity, this equation translates to y = y(0) e-kπr2pgt.

But this function seems to decline too steeply for this application, am I doing this right?

Is you're equation dy/dt=-k(...pg)y(t) where "y(t)" is y as a function of t. or the variable y times the variable t?
 
Oh, no y is a function of t!

Not the height!

I actually think that I found the correct function simply by playing around with the constant k. Let me revisit this!
 
There is the following linear Volterra equation of the second kind $$ y(x)+\int_{0}^{x} K(x-s) y(s)\,{\rm d}s = 1 $$ with kernel $$ K(x-s) = 1 - 4 \sum_{n=1}^{\infty} \dfrac{1}{\lambda_n^2} e^{-\beta \lambda_n^2 (x-s)} $$ where $y(0)=1$, $\beta>0$ and $\lambda_n$ is the $n$-th positive root of the equation $J_0(x)=0$ (here $n$ is a natural number that numbers these positive roots in the order of increasing their values), $J_0(x)$ is the Bessel function of the first kind of zero order. I...
Are there any good visualization tutorials, written or video, that show graphically how separation of variables works? I particularly have the time-independent Schrodinger Equation in mind. There are hundreds of demonstrations out there which essentially distill to copies of one another. However I am trying to visualize in my mind how this process looks graphically - for example plotting t on one axis and x on the other for f(x,t). I have seen other good visual representations of...
Back
Top