Bending water – how is that possible???
Is it possible to bend a stream of water without actually touching it? Well, first let’s look at the water molecule pictured at the right. Water is made up of two hydrogen (H) atoms, and one oxygen (O) atom. Much like in a magnet, opposites are attracted and the negative particles, called electrons, of H form a bond with the positive particles, called protons, of O. Therefore, on, on the outer surface of the water molecule an electric dipole is formed. The H atoms at the top have a positive charge while the oxygen at the bottom has a negative charge. This is why the stream of water can be bent by a static electric charge. If we move a negatively charged object near the water molecule, the positive H side will bend towards it, and the negative O side will oppose it. This dipole is what causes water to be bent by static electricity. What do you think? Let’s do an experiment to see just what happens.
Let’s Try It.
Comb, piece of PVC pipe, or balloon and Kitchen faucet
||Rub the comb, PVC pipe, or balloon on a sweater or through your hair, to build up the static charge.
||Turn the faucet on so that the water stream is about 1/8 inch in diameter. You want a small but smooth stream.
||Move the comb or PVC pipe close to the stream of water.
Notice that the water stream bends towards the comb. This is because the comb has a negative charge. As you rub two objects together electrons are stripped from one object (hair) and transferred to the other (comb). As a result, your hair has a positive charge and the comb has a negative charge. Since water also has a positive and negative charge associated with the arrangement of the molecules, we can bend the stream of water.
What if we vary the size of the water stream? What if we use different objects? What if we change the temperature of the water? How will these changes affect the bend?