# Fluid dynamics

1. Jan 26, 2006

### Gamma

The velocity of the water that comes out of the opening in the attached diagram can be found using Bernoulli equation, as

v = sqrt (2gh)

Once the water exits the hole, I am not sure how to answer questions like the following: Can I use conservation of energy and momentum. Also can I use the equations in kinematics (ie. S = ut + 1/2 a t^2, v=u+at,...)

1. Time for the water to hit the ground,
2. What is the value of H
3. What is the horizontal distance of flight of water
4. What is the acceleration ( acce. of gravity??)

Thanks a lot.

Gamma.

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• ###### waterflow.JPG
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Last edited: Jan 26, 2006
2. Jan 26, 2006

### civil_dude

Usually the kinematic equations are all you need assuming you know the initial geometry of the set up. I see no picture, so I can't tell.

3. Jan 26, 2006

### Gamma

Yes the pic did not show up. It is there now. Sorry.

4. Jan 26, 2006

### Gamma

How about conservation of energy and momentum? I can cosider a mass of water that exits the hole per unit time as 'm' and write the conservation lows. Is seems ok to do that.

edit: May be momentum is not conserved in the vertical direction due to the force of gravity.?

Last edited: Jan 26, 2006
5. Jan 26, 2006

### civil_dude

You could use conservation laws also, I presume