Balloons with no charge
This week my first year classes have been doing a design experiment related to balloons. I started with my usual spiel about the physical properties of balloons, the pressure of the air inside them, bounciness, modes of vibration, popping, drag and of course their ability to hold charge. Zoe, helped by Daria (or Daria helped by Zoe, can't remember which) decided to investigate the relationship between the deflection of an electroscope leaf and the distance from a charged balloon. As soon as I opened the packet I knew their was something strange about the balloons - donated by the local shop, Joker Flekke . For a start they were extremely stiff requiring significant stretching before becoming possible to blow up, they also had a rather odd feel to them. Once inflated they behaved like any other balloon except that they were impossible to charge this caused Zoe and Daria a great deal of confusion, as you can see from the photo.
Well I guess that's the problem with free balloons, they have no charge.