Course Reports

Category archives for Course Reports

Last week, we looked at the resistance of a voltage sensor by using the discharge of a capacitor, getting a value that was a bit high, but not wildly out of line with the specs. This time out, we’re going to look at the resistance of a current meter, because some students asked about it…

For the latest in our ongoing series of post where I overthink simple questions, I’d like to present the longest single continuous experiment in Uncertain Principles history, which took six and a half hours yesterday. All to answer the question in the post title. This may seem like a waste, given that I could download…

In the previous post about simulating the attraction between sticky tapes using VPython, I ended with a teaser mentioning that there was a discrepancy between the simulation and the theoretical solution from directly solving the equations. The problem is kind of subtle, but clearly visible in this graph from that post: In this, we see…

Physics Hangout in Need of Better Title

What with the umpteen zillion articles declaring the Death of the Blog, I’ve been toying with the idea of doing something podcast-ish for a while. Rhett Allain from Dot Physics was game, too, and suggested using Google+ to do a video hangout, so here we are talking about our classes this term: The video quality…

Simulated Tape and Universal Behavior

Having spent a lot of time solving equations related to sticky tape models, including trying to work solutions in my head while driving to Grandma and Grandpa’s with the kids, and making some measurements of real tapes, there was only one thing left to do: try simulating this problem in VPython. Because I’m a physics…

Atomic Physics with Sticky Tape

In addition to making a toy model to show the tipping-point behavior of charged pieces of sticky tape, I spent some time on Tuesday trying to do something quantitative with this. Of course, Tuesday is the one day of the week that I don’t teach, and I didn’t want to go to campus to do…

One of the labs we do in the introductory E&M class I’m teaching this term involves investigating charged particles with sticky tape. If you haven’t seen it before, “invisible” tape picks up an electric charge when it’s peeled off a surface quickly, and with a little care, you can create both positively and negatively charged…

Replacing Gravity

I’m teaching introductory E&M this term, so it’s kind of fun to play around with silly applications of Coulomb’s Law. For example, let’s imagine that gravity suddenly switched off, but we wanted to keep the Earth in its orbit. How much charge would we need to move from the Earth to the Sun for the…

Classes for the Winter term start today, and I’m totally prepared for this. Yep. Uh-huh. Losing a bunch of prep time to snow and ice last week hasn’t thrown anything into disarray. Anyway, for a variety of reasons, I’ve ended up departing from my plan to not do any new preps while I’m stuck being…

Over at Unqualified Offerings, Thoreau has a bit of a rant about what students perceive as grading on a “curve”: Moreover, many students have only the foggiest idea of what a curve is. Many (though probably not all) of their high schools had fixed grading scales with fixed percentages for each letter grade. The A/A-…