4 Kasım 2012 Pazar

Inquiry Demonstration

Subject Area-Grade Level: Physics – 9th Grade
Concepts: Electrostatic
Name of Demonstration: Bending Water with a PVC Pipe – What happens when an electrically charged object is brought near a stream of water?
1.    A piece of PVC pipe
2.    A plastic cup that has a smaal hole at the bottom of it
3.    Water
1.    One of the tester hold the cup.
2.    Other tester fill the cup with water.
3.    Charge the pipe with hair.
4.    Bring the pipe close to the stream of water.
1.    Why the tester charge the pipe with hair?
2.    What happened to water stream? Why?
The PVC pipe is made of molecules that have electrons floating around them. Electrons have negative charge. When the PVC pipe charged with hair, it collects electrons from the individual strands of hair to itself. The molecules in the water stream are neutral. When tester bring the pipe close to the water stream, electrons that are closer to the pipe are being repelled away. Therefore, the molecules that are closer to the PVC pipe become positive and away from the pipe, there is more negative charge.
Any possible harm-risk(if exists): This demonstartion does not have any harm to students.
Application: Photocopiers use static electricity to copy documents. The thing you want to copy is copied in static electricity inside the copier, where it is sprayed with toner. The toner only sticks to the charged part of the paper.
Shakhashiri, B. Z. (2010). A handbook for teachers of chemistry. Retrieved November  2012, from Home experiments: http://scifun.chem.wisc.edu/homeexpts/BENDWATER.html
[Online document]. Retrieved from http://www.sciencemadesimple.co.uk/page30g.html 

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