MITx Homework 1 and Lab 1 are finished. Whew.

his weekend I finished both the first homework and the first lab, and I received perfect scores on both. This was not without a lot of work, and several late nights while I scoured the textbook, scribbled circuits and formulas all over sheets of paper, and checked the discussion forum for hints on ways to solve the more difficult problems. Just an hour from the deadline, I am starting to see posts from people who want others to post answers in the discussion forum. In response, the staff or other users with enough karma points are closing those threads or reminding people that homework answers cannot be posted in the discussion forum.

Just a reminder: in MITx, the homeworks are online. When you solve a problem, you type the answer into a box, press the "check" button, and--if you're correct--you see a green checkmark beside the field. Some problems are so hard that I do small dances whenever I can get that green checkmark to show up. Most of the time I get the red X, which means, "Try again." The problems have several parts, so you need to get that first answer correct so that it can be plugged into another equation and then your answers fall like dominoes (well, like slowly falling dominoes).

I am grateful, most of all, that the course (so far) has not required any math that is more complicated than algebra. If anything, the problems are hard because you develop a lot of independent equations for different variables (voltage, resistance, current) that you can solve for by a process of substitution. The homework took me a long time--at least 5-10 hours over several days, I think. A lot of my learning seems to happen in the constant process of trial and error--coming up with equations, solving for values, trying out the result.

I have learned that one weakness in the system is that I have gotten several answers by just changing the sign of the value I entered in the box. For this reason, I am still pretty weak on identifying whether currents associated with voltage sources are positive or negative. I have changed x to -x and gone from wrong to right, but I still don't know why I was wrong the first time.

I find that I do get many of the equations or heuristics for solving circuits from the lectures or reading, but the discussion forums contain nuggets of information that I need for solving questions. I look for posts that contain a possible way of thinking about a problem without actually solving the problem. That is hard because part of me just wants the answer.

I am holding my breath that I can continue to succeed despite not having the prereq--I fear that Coulomb's law and electric fields are stalking me in the magnetosphere. But the assumptions of the lumped matter discipline have created a "playground," as the professor calls it, that make things simple (though not easy).

When I checked my grade, I saw that I have earned 3% of the final grade. That 3% is going to be polished and put in a case.