Fluid traveling uphill, where does the energy come from?

[Brainteaserfan]

When an oil candle burns, the oil travels up the wick and to the flame. In the same way, a twisted paper towel wil move small amounts of water 'up'. Since that must take energy, (you could put it through a turbine on the way down), I'm wondering where that energy is coming from. My hypothesis is that that minute amount of energy is coming from the heat in the water because every x amount of feet that water falls down a waterfall, it gains a degree. I think this is due to friction, but at least I can assume that when water goes up, it will do the reverse. Any alternative ways of thinking?

[CaptainPanic]

It's called capillary action.

 

You cannot put it through a turbine on the way down (well, you can, but it's not gonna do much good).

It requires more energy to get that oil out of the wick than the potential energy it contains. And it will require more energy to get the water out of the paper than the potential energy it has.

 

The liquid moves up because it is actually attracted to the solid material (the wick or the paper). So, in order to remove it from that wick or paper, you must overcome that additional attraction... and that costs energy.

 

It's like a magnet that attracts a piece of iron. The piece of iron can move against gravity, up towards a magnet. But since the magnet is able to move the iron up against gravity, you can bet that the piece of iron lost a little energy (it gains a little potential energy, loses some magnetic energy; and the combination will be a net loss). And in order to get the potential energy fromthe iron, you must overcome the magnetic attraction... so you must invest more than you will get out.

 

Same with a capillary.

[Brainteaserfan]

It's called capillary action.

 

You cannot put it through a turbine on the way down (well, you can, but it's not gonna do much good).

It requires more energy to get that oil out of the wick than the potential energy it contains. And it will require more energy to get the water out of the paper than the potential energy it has.

 

The liquid moves up because it is actually attracted to the solid material (the wick or the paper). So, in order to remove it from that wick or paper, you must overcome that additional attraction... and that costs energy.

 

It's like a magnet that attracts a piece of iron. The piece of iron can move against gravity, up towards a magnet. But since the magnet is able to move the iron up against gravity, you can bet that the piece of iron lost a little energy (it gains a little potential energy, loses some magnetic energy; and the combination will be a net loss). And in order to get the potential energy fromthe iron, you must overcome the magnetic attraction... so you must invest more than you will get out.

 

Same with a capillary.

 

Okay. I read in a science book that if you have a cupful of water on a chair, and a one end of a twisted paper towel in that cup and then the other end over the lip and about halfway down the side of a cup on a nearby table (the table is higher than the chair) then gravity would extract the water from the wick slowly until the cup was filled up to the same height as the one on the chair (relative to the wick). I am currently carrying out the experiment and will post the results. I expect the experiment to take a week, but I will also post the progress. Thanks for your input!

[rktpro]

Okay. I read in a science book that if you have a cupful of water on a chair, and a one end of a twisted paper towel in that cup and then the other end over the lip and about halfway down the side of a cup on a nearby table (the table is higher than the chair) then gravity would extract the water from the wick slowly until the cup was filled up to the same height as the one on the chair (relative to the wick). I am currently carrying out the experiment and will post the results. I expect the experiment to take a week, but I will also post the progress. Thanks for your input!

 

I have made a similar arrangement for watering my plants automatically when I go out for a week or so!

[Brainteaserfan]

I have made a similar arrangement for watering my plants automatically when I go out for a week or so!

 

What material do you use for a wick? And, is it in the dirt, dripping onto the dirt, or touching the roots?

Edited May 20, 2011 by Brainteaserfan

[rktpro]

What material do you use for a wick? And, is it in the dirt, dripping onto the dirt, or touching the roots?

 

It was cotton-cloth, clean with pores in it. It is put on the mud only.

[Brainteaserfan]

It was cotton-cloth, clean with pores in it. It is put on the mud only.

Thanks. My experiment isn't working. It's going about like Capt Panic said it would. Maybe I'll try cotton cloth and dig up that book again. In the meantime, I was wondering also, is your container that is providing the water on the same plane as, above, or below the pots which you are watering?

[rktpro]

Thanks. My experiment isn't working. It's going about like Capt Panic said it would. Maybe I'll try cotton cloth and dig up that book again. In the meantime, I was wondering also, is your container that is providing the water on the same plane as, above, or below the pots which you are watering?

 

It was above the level of the pots. It would work even if you put is 1 foot up from the plant.

[CaptainPanic]

If you have two vessels, and something with a capillary action between them, then I think (I'm not 100% sure) that the liquid can travel from the high vessel to the lower one (although extremely slow), but certainly not the other way around.