## 20121028

### Online reading assignment: forces and rotations

Physics 205A, fall semester 2012
Cuesta College, San Luis Obispo, CA

Students have a weekly online reading assignment (hosted by SurveyMonkey.com), where they answer questions based on reading their textbook, material covered in previous lectures, opinion questions, and/or asking (anonymous) questions or making (anonymous) comments. Full credit is given for completing the online reading assignment before next week's lecture, regardless if whether their answers are correct/incorrect. Selected results/questions/comments are addressed by the instructor at the start of the following lecture.

The following questions were asked on reading textbook chapters and previewing a presentation on forces and rotations.

Selected/edited responses are given below.

Describe something you found interesting from the assigned textbook reading or presentation preview, and explain why this was personally interesting for you.
"Torque and energy use the same SI units, but only one of them can be measured in joules."

"As an aspiring physical therapist, it is interesting to see how these concepts apply to biomechanics."

"How several different forces acting on an object each produce torque, and therefore adding them together you find the overall (net) torque on the object."

"It's possible for the net force acting to be zero while the net torque is nonzero."

"I feel that by the end of this class, I'll know the whole Greek alphabet."

"Nothing really, I am taking statics and this stuff about forces and moments (torques) is familiar to me."
Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"This whole lever arm thing--I didn't get it in statics and I don't understand it in physics."

"Nothing seemed to be confusing. However I did feel that the static equilibrium chapter wasn't the easiest section to read."

"The sign of the torque not being determined by the sign of the angular velocity, but determined by the sign of the angular acceleration."
Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"I came to your office hours before the last quiz and it didn't help me at all. If anything I would say I was thrown off. I would say that nearly half of what was talked about wasn't even on the quiz. What can we do about this?" (It's not my intent to mislead you in office hours, but I can only answer your questions and others' questions as time allows. Let me know what you yourself specifically need via e-mail, after class on Wednesdays, as well as office hours when they are less crowded.)

"How do you find all these awesome videos?" (I am online way too much for my own good. But if you have any cool physics video recommendations, let me know.)

"I am confused how the lab scores work. The syllabus says there is a possible 100 points for lab, but with the number of labs we at 5 points each we can't earn 100 points by the end of the semester." (In addition to the lab report points, each week there are two points from completing the online pre-lab and post-lab assignments, for a total of 13 labs × 7 points = 91 points, which do not include additional points for early report submission, and challenge activity points.)