PBL Task 5
Topic: Van de Graff Generator
Interview
...because i want someone who is knowledgeable about my topic to explain it very well and to be able to answer any questions I have about the topic. I actually know a girl that did this same topic last year and i am thinking of interviewing her and maybe Mr. Ekinci too.
INTERVIEW
-Me: In your own words, describe the Van de Graaff Generator.
-Ekinci: It is a static electric generator which generates high amounts of electricity on the metal globe.
-Me: Do you know when the Van de Graaff Generator was invented?
-Ekinci: Yes. It was invented in 1929 by the physicist Robert J. Van de Graaff
-Me: How does the generator work?
-Ekinci: The Van de Graaff Generator builds up static electricity of very high voltages by transferring charge through a synthetic conveyor belt to the top into a hollow metal globe. It continuously redeposits the charge where it accumulates
-Me: Why does start to stand when we touch the Generator?
-Ekinci: Both hair and the Van de Graaff Generator are negatively charged and like charges repel each other and make our hair stand on end!
-Me: Do you think that we can safely touch the globe?
-Ekinci: Not if you're on the ground! I do not suggest touching it when you are on the ground, unless you enjoy getting shocked.
-Me: Why do we need to be off of the ground to prevent shocking?
-Ekinci: Well, the ground is neutral so if we stand on it, the only insulator we would have is our shoes which is not enough. The electrons would go through us and to the floor which therefore shocks us; but when we have a platform to stand on that insulates properly, the electrons gathers on us and we then become the conductors of electricity. It is really cool!
-Me: Why do we need to neutralize the Van de Graaff Generator before touching it?
-Ekinci: Because the electrons are still there on the globe and they can jump if you get close. The air is a good insulator too so that gives the electrons something to grab on to and jump even further. And then you will get shocked which is not fun at all so neutralize!
-Me: happens if we touch it with a rubber glove?
-Ekinci: Rubber--believe it or not--actually stops electricity form glowing so you will not get shocked. Rubber is an insulator and there is no path for electricity to flow through you with rubber.
-Me: How many volts does the Van de Graaff carry?
-Ekinci: Wow, a lot! A battery has only 1.5 V, a socket has only 120 V but the Van de Graaff has so much more. It has 200,000 which is so much more than we can handle. That much electricity can kill someone.
-Me: How does the Van de Graaff Generator use a moving belt to accumulate very high voltages on a hollow metal globe on the top of the stand?
-Ekinci: The Generator uses a spinning belt to carry a charge picked up from a brush at the bottom of a long tube to another brush at the top where the charge is distributed onto a metal sphere
PBL Task 7
I have chosen to focus on the Van de Graff Generator for my Science PBL Project. For my ELA connection, i will conduct an interview (option 5). I will present this interview by adding it as a document under my PBL website.