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 my most recent general science requirement mechanics lecture class, which is the last lesson before their second exam, I started the discussion with the students on two dimensional motion as seen from the side view, which means that it already will have acceleration due to gravity applied on the vertical motion.

I told the students that we will start with the easiest case, which is the one that doesn’t have any forces, and is in fact their third experiment: projectile motion.

I started with the simplest case, which is when the initial velocity and the initial angle are both given.

From just these two values, they can already get several other values that could fill a table, such as the vertical and horizontal displacement and time at each point along the trajectory, the new values of the vertical and resultant velocity, and the new angles to be computed using the right-triangle formulas.

They should have had an easy time remembering how to get the components of the initial velocity along the x and y, and that motion along x is governed by constant velocity (and therefore the x component of each velocity is always the same) and that the motion along y is governed by laws of freefall.

Thus they had to recall the previous lessons we had on one dimensional motion and apply them together.

At this point hopefully those who had to answer their problem set would appreciate the practice in mastering that topic, since it is not abandoned and is still fundamentally used.

We also discussed the two special points along the trajectory, which are when the object is at its maximum height, and therefore minimum velocity, and when the object returns to its original height. I didn’t tell them though about the special formula for that – yet. There’s always next lecture.

In preparation for the exam I told them that those who did not give any exam booklets last time will have to give two this time, and that those who gave one before will only have to give one for the second exam. I didn’t tell them that those who submitted test booklets early will get bonuses, but I will if there are still people who don’t submit test booklets before the exam day itself.

Yes, reward giving is one way to modify students' behavior, as it doesn’t take anything away from the teacher and makes him or her look generous.

Session 1523 will obey for points. Class dismissed.