Talking Physics

A discussion was being had on twitter about science club activities.

One of the ideas floated was getting the VdG out.

Here is an extension idea for the VdG using LEDs or a anti static pen

http://tinyurl.com/h2ktt7b

You could also make it less likely to give you a shock by attaching to a wooden ruler.

In the video you can see the LED only lights in one direction. You could work out the charge on your dome from which leg of the LED closest gives you light. The longer leg on an LED is the positive side.

This is a really good idea that I had not thought of before so thank you for sharing.

I like bending a stream of water with it too. I have heard you can do something with soap bubbles?

Hi Melissa,

You can point a bubble machine at the VdG and it will attract the bubbles. I always forget to do this even though I have a club sized bubble machine fill a classroom in 2 min. The thing to watch is getting soap solution on your belt. Someone once said to me get a student to stand with their hands on the dome and isolated (the same situation for hair raising) and point the bubbles at them. The bubbles will than stick to them and not the VdG.

Dave

Another good idea with a VdG is showing how sparks make radio waves. If you set up an old AM radio on the other side of the classroom you can hear the sparks on the radio.

 

In fact you can show this with any spark. Below I make a spark with a battery and a wire. Connect the wire only for short durations so as not to cause excessive heating of the battery.

 

 

 

 

That’s really cool, thank you!

Has anyone tried the cornflour mixed in vegetable oil one with the VdeG I keep meaning to give it a go. My VdeG is at school  so I can’t try  it. I have an EHT supply here but that probably isn’t enough.

In the theme of Van De Graaf generator, a really cool one is to put the cup cake tins on top of the dome, but to pass a thread throughthecentre of each tin and attach the thread at the top of the dome and the other end to the ceiling in a vertical line. The cake tins will separate at decreasing distances from each other.

That should illustrate the inverse square law nicely.

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