I am VERY sorry to be out again with a flu-like illness, but here are some things we can still accomplish.
Periods 3-4: Tension problems are notorious for their detail, but with some practice and thinking about them systematically, are quite doable. Check out this video and take notes to get a technique down that we will use for just about any more complex, multi-object system we encounter, so we can find 'internal forces' of the system.
Periods 1-2, 8-9: We mentioned that the key quantity for everything in E&M is electric charge. All charges, whether a single particle or a charged balloon, produce TWO physical quantities: electric fields and electric potential (better known as voltage; this is not the same as potential energy!). Fields are vectors, and potential is a scalar. Check out this video for an introduction for finding total voltage and net electric fields from a system of point charges. Take notes, and see if you can work through the practice problems.
Everyone can also find a science article of interest and provide a summary - we do this every so often so you can have a chance to check out some current, cutting edge topics and get a sense of some very cool things going on out in the world! It can be from a Scientific American (please return at some point!) or online, and can be from any discipline.
Have a Happy Friday and weekend, and see you Monday. :-)