Explanation for Water Bending with Static Electricity

It's interesting to note the differing views regarding the explanation for how a thin stream of water can get bent when a charged object is placed near it. It started with these two videos from Veritasium: This video then sets out to disprove Veritasium's model of ions being removed from the water stream.

Water Bender

A thin stream of water can be easily bent using a plastic comb or ruler which was previously rubbed with wool. This demonstrates the attractive forces between unlike charges.

Materials

  1. Plastic ruler
  2. Wool
  3. Water from a tap

Procedure

  1. Turn on the faucet for the thinnest stream of water with a consistent flow.
  2. Rub the plastic ruler with the wool.
  3. Place the part of the ruler which was rubbed near the stream of water without touching.

Science Explained

Water molecules are polar in nature, which means that one side (where the oxygen atoms are) is more negative while another side (where the hydrogen atom is) is more positive. When wool is rubbed with plastic, it deposits electrons on the ruler.

The electrons will remain on the plastic as it is a poor conductor of electricity. When placed near the stream of water, the water molecules reorientate themselves such that the positive pole of each molecule is now nearer to the ruler than the negative pole.

The resulting attractive forces are stronger than the repulsive forces as the forces between charges decrease when the distance apart increases.

Leyden Jar

A Leyden jar is a device used to store static electric charge. It can beĀ used to conduct many experiments with electricity such as creating a spark across a gap.

Static Electricity

This question is meant for TA 2B and 2C Physics students. Other than the demonstrations we have tried out during class, could you think of any other way in which static electricity can be observed? Please leave your comments below. You may need to log in to Facebook while doing so.