Kinetic energy of water pouring

AI Thread Summary
The discussion focuses on calculating the kinetic energy of water flowing from a faucet, with a specific example of 5.6 liters over 30 seconds. The calculations yield a kinetic energy of approximately 61.3 millijoules, which the poster expected to be higher due to the water's pressure. A comparison is made between the kinetic energy of flowing water and the potential energy released when dropping the same volume from a height of 1mm, which is about 56 millijoules. This raises questions about energy distribution, as some energy may be lost to other forms during the flow. The poster seeks clarification on the relationship between kinetic energy and potential energy in this context.
kox
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Hello. It's not a homework but it is kind of exercise. I was wondering what's the kinetic energy of water flow (for a certain amount) from a faucet. But I'm not sure if I got it right. So I counted how much volume of water is dropped in 30 seconds. It turned out it's about 5.6liters.
m=5.6kg // as 1 liter of water is almost 1kg
t=30s
l=1.256*10E-3m^2 // area of water dropping, cross-sectional area
Vol=5.6*10E-3m^3 // volume of water
Ek=mv^2/2
v=s/t
s=Vol/l
s=5.6*10E-3/1.256*10E-3 [m^3/m^2=m]
s=4.45m
v=4.45m/30s
v=0.148m/s
Ek=5.6kg*(0.148m/s)^2/2
Ek=5.6*0.0219kg*m^2/s^2
Ek=0.0613J
Ek=61.3mJ
So I got that pouring 5.6 liters of water realeses 61.3 milijoules. I thought it woul be a little more when I see water dropping at high pressure.
Did I get that right?
I don't know if I posted it in the right section. I'm ew here. It's not a homework but I'm afraid I would get my post deleted if I posted it in classic physics. Sorry I didn't use the template provided,but they didn't fit my post too good.
 
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The kinetic energy of slowly moving masses is tiny. You get the same kinetic energy if you drop the water by a height of just ~1mm.
 
I don't understand how is it equal to dropping water (how much?) from 1mm height? The water was dropping from more height and was at pressure. Could you explain?
 
In that case, some energy went to something else.

Dropping 5.6kg of water by a height of 1mm gives releases potential energy of mgh=5.6kg*10m/s2*0.001m = 0.056J = 56mJ.
 
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