Perpetual Plumbing!!

[vineet_kiran]

But the drawing above  has several balls which have their own weight and total weight altogether act on the bottommost ball  pushing it to some extent inside mercury and storing initial potential energy in it. 

Ball is lighter than mercury and water.  When mercury is supporting such a lengthy column of water on left side,  will it allow the still lighter ball to penentrate through it?  Mercury will easily support weight of all the balls put together and will not allow the bottom most ball to penentrate through it to the extent shown in that figure.

[dieter]

Does it really need to be mercury? How about oil and water? At least, this could be tested easily. Will the oil and water surface level be the same? I know, it's a silly question. But I really never tried this.

[tinman]

Since mercury is a very heavy liquid,  the energy required to push the ball through it will be high.  So, whether this system works -  I don't know.

That is where the down fall is,and why it wont work. Since mercury is 13.5 times as heavy as water,it will take 13.5 times as much force to displace the mercury as it would the same amount of water at 4*c.

[Marsing]

negative........

[vineet_kiran]

Does it really need to be mercury? How about oil and water? At least, this could be tested easily. Will the oil and water surface level be the same? I know, it's a silly question. But I really never tried this.

You can use water with lighter oil like petrol or kerosene.

I had tried an experiment with water, kerosene and candle wax ball.  Candle wax sinks in kerosene but floats on water (unlike the ball used in the above experiment which floats on both liquids).  The wax ball was sinking down through kerosene and stop at the junction of two liquids.  In whatever fashion (angle) you keep the tube, ball will finally settle only at junction.

It reminded me of one important propery of liquids which says that " liquids communicate pressure equally in all directions".

Hence when ball reaches the junction of two liquids, it need not necessarily pass through and float on heavier liquid because the heavier liquid communicates the pressure in downward direction also and holds the ball at junction itself.

Conducting experiment is never a waste of time even if it doesnot work because you will learn lot of things from it. Since this experiment is simple and inexpensive, you can try and see.