Student "edition" found at {csi dot journalspace dot com}.

Maybe I shouldn't have started this blog now, not with everything that's been going on.

In the first meeting of my Engineering Materials Science for the eighth week of the first term we had some practice problems for the weight, atomic and volume percentages of elements in alloys, the last part of chapter 4 (Imperfections in Solids) that we started on the previous meeting.

Some of the examples were direct substitutions of the formulas I introduced previously, while the others were obviously making use of system of equations for two or three variables or unknowns, a computational method they are most familiar with from several previous subjects.

One of the questions was if it was possible for the weight percent of an element in an alloy to be in the nineties range, but its atomic percentage is one digit.

Using the equations that were given, we substituted and got an atomic weight for the first element to be zero, so our conclusion was that it was not possible.

But after the class, another approach in the computation showed that it was possible, if the atomic weight of the first element is half of the second. That will have to be brought up in a future session before the next chapter.

In the first meeting of my Introduction to Electricity and Magnetism lecture class for that week, we discussed the first four checkpoints for the chapter on potential, which were more or less theoretical questions using the given equations but not using any numerical substitutions.

Since this also applied their previous knowledge of potential energy and work (given as the product of force and distance – or displacement) they had to recall when work is considered positive and negative.

We were able to finish all the checkpoints (up to learning that equal-potential lines are perpendicular to electric field lines and electric fields are in the direction of decreasing equal potential lines) except the last one – relatively the most difficult, since it asked them to analyze whether an electron in an electric field between two charged sheets is accelerating or not – which I gave as an assignment.

Session 1211 has no notes. Class dismissed.