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

Concluding my mechanics lecture last Monday, I enumerated for the students certain specific forces that we would be using from then on, particularly in two-dimensional motion.

These are weight (mass times acceleration due to gravity), normal force, frictional force and tension (on a taut rope).

I will be probably using weight and tension in some side view examples, and tension again in some top view examples, but friction and normal force, which go hand in hand, is a whole new topic for another day (and a complete experiment in itself in the lab).

In my Mathematical Methods class last Tuesday I taught them about three part inequalities in one variable in one degree, and two-sided inequalities in one variable of degree two (or quadratic).

The first topic was easy enough, just being an extension of the previous day’s topic and easy to visualize with the number line.

The second topic, where the zero factor property is used in a different way that it was before, extending to find two expressions to the negative of the two roots, confused the students a bit because of the positive and negative signs that were placed on top of the number line.

It took them some time to determine what that meant when it was just the two factors whose resultant sign is all we were looking for.

If the original inequality said that the quadratic expression is less than zero, then the range between the two roots that produced a negative number was their answer. Otherwise, their answer is the region less than and greater than that range.

After several examples, we were able to conclude that the negative values are always to the left of the positive values.

In my mechanics labs yesterday, we started with the first experiment on Uniform Acceleration.

The first hitch happened when some of the students (even in the afternoon class, who had time to consult with their classmates in the lecture from the morning class) were surprised with the experiment we were going to perform that day.

They had read up in the Composition of Concurrent Forces, which was the first experiment in the manual. I told them that I had posted the leader, secretary and individual report assignments last week before our activity, which meant that it also included the sequence of experiments we were going to follow.

Besides, in the lecture, we took up uniform acceleration first before we had concurrent forces, which I have only discussed in theory last Monday but for which I had not yet given examples.

I also reminded them about the written report and the format file I had, because up till then I had not yet received any diskettes from those who were to submit the report next week.

I’ll continue the discussion on this tomorrow. The class is dismissed for today.