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 general science requirement mechanics lecture class, in the most recent discussion I was surprised to see that my discussion about how to solve for the unknown time in cases of uniform acceleration by using the quadratic formula* took less than thirty minutes.

I still gave them the option that if they found themselves wanting to avoid using this formula, then they could go the way as their classmates did during our earlier board work, which was to solve for another quantity first, then use that to get the value of the time using a less complicated formula with no exponent.

But that, I said, is the risk they have to decide on taking, which could be made worthwhile by extensive checking of their intermediate results to be used later.

I certainly wasn’t prepared to give them recitation and board work in preparation for their upcoming exam, and seeing as the other class (which in our recent School of Arts and Sciences meeting we discussed having departmental exams) is already up to free fall, I dove into the next topic out of the blue for both me and the students.

I first gave some of the standard changes we have to make, such as x to y in the equations, using -9.8 meters per second squared as the acceleration, and allowing for negative velocity, which was not allowed for horizontal motion.

Then I started with the first of the three scenarios usually used, which when an object is dropped and the initial velocity is zero. This also didn’t take long to teach. I did give several examples where each of the other quantities was the unknown one.

From here I went to the second scenario, which is when an object is given an initial velocity straight downwards, a rare occurrence, since it only happens when a kid is extremely hyperactive or an adult is physically angry.

Fortunately I could stop there since there wasn’t enough time, and the third scenario is the most complicated where an object is given an initial velocity upwards, and it has two directions of motion – reserved for the next lecture.

Session 1495 was falling. Class dismissed.

*One senior student expressed an expletive of surprise seeing this equation, since it has been a long time since he last encountered it – years probably.

Yet another instance when the bad influence of the more lax older students should be removed from the impressionable first year college enrollees.