charge

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Pre Reqs: electric potential, electric field, work-energy To start, remember that for a constant electric field the change in electric potential energy would be: WARNING: that is only for a constant electric field. I know you will be tempted later to use this for a different electric field, but DON’T DO IT. But if not…

Basics: Electric Potential

Pre Reqs: Electric Field, Work-Energy, Potential Energy If you are already familiar with the topics listed in the pre-reqs above, this will be uber-simple. Potential energy – short version The work-energy principle basically says: In this most basic form, the energy is just kinetic energy (if you are not going near the speed of light).…

Basics: The electric field

Suppose I take a 1 kg ball and hold it near the surface of the Earth. What would be the gravitational force the Earth exerts on this ball? And I could say “g” is: The magnitude of this force would then be 9.8 Newtons. And, if I replaced the ball with a 10 kg ball,…

Pre Reqs: vectors, forces This is typically the first topic in the second semester of introductory physics – the interaction between objects with electric charge. There are 4 fundamental forces that physics typically looks at: Gravity – an interaction between objects with mass – wow, I don’t have a post on the universal law of…

Lab: The Charge of an Electron

Not really. Here are the details (and some data) for the Millikan Oil Drop Experiment without the oil drop that I talked about previously (originally from The Physics Teacher – lucky you, it was a featured article so it should still be available (pdf)). The basic idea that Lowell McCann and Earl Blodgett from U…

What kind of electricity is lightning?

Someone complained about a teacher using this question and the answer was disputed. After some time, the teacher claimed that the answer was that lightning is static electricity because she looked it up on the internet. So, I decided to look also, here is what I found searching for “what kind of electricity is lightning?”…