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

On the third day of finals week, I had my make up exams in mechanics lecture.

I was expecting nine students to take the exams, for two different occasions that they individually missed out.

For those who missed the exam on tension in one and two dimensions (with a smattering of projectile motion and forces in two dimensions), I had to make a new exam for them.

Again I had to use a different reference from the textbook that I announced in class because one of the students borrowed it and did not return it in time. Maybe next time I’ll institute a policy of not lending out my copy of the book because the reason it was made into our main reference in the first place is because it is readily available, and will contribute to their grade greatly if they take the time out to buy it.

Not that I profit anything from that either.

The first problem had two forces acting on the same object resulting in a third force, obviously. But this third force has the same magnitude as the first one, but at a perpendicular direction. So they had to get the value and the direction of the second force. Not so difficult if they just thought about it.

The second problem was projectile motion, which the book coyly starts describing as “a mechanics professor, displaying daredevil tendencies, jumps a ravine…” The various dimensions of the ravine are given, including the angle of the ramp, so that they only needed to get the initial velocity.

The first of the two problems on tension in one dimension had two blocks attached to each other and lifted up. The acceleration of the system was asked as well as the tension on the rope.

In the fourth problem, two blocks hang from opposite ends of a rope through a pulley. The pulley is hung from a chain to the ceiling. The tensions on the rope and the chain are asked for.

The first of two problems on two-dimensional tension had the same set up as the third problem, except that now the two blocks are on an inclined plane and attached to the wall. Again the tensions on the ropes were asked.

The last problem had a hammock with a given weight supported hanging from two trees. The angles of the ropes were given, and they had to get the tension again.

I didn’t give any illustrations for these problems (there was no more time) and the Koreans were the ones who again had a difficult time in comprehending the set ups, so I had to tell them whether their diagrams were correct or wrong.

As for the two students taking an exam on earlier topics, they were below average scorers, so I determined that if they were able to get the previous questions from their classmates, answer them and remember them for the make up exam which had the same questions then they deserved to pass.

I’ll continue this next time though. For now, class dismissed.