## 20140827

Physics 205A, fall semester 2014
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 the reading textbook chapters and previewing a flipped class presentation on (constant acceleration) motion.

Selected/edited responses are given below.

Describe what you understand from the assigned textbook reading or presentation preview. Your description (2-3 sentences) should specifically demonstrate your level of understanding.
"Velocity is related to displacement, and acceleration indicates a change in velocity. Acceleration does not just mean 'speeding up.' It really means a change in velocity, which can be speeding up or slowing down in any direction."

"What velocity, displacement and magnitude are. I also understand how to calculate all of these terms."

"The section about velocity and instantaneous velocity. Being that I came straight out of calculus its pretty similar to the derivatives we did."

"Average velocity and instantaneous velocity are different. Also average speed and average velocity are different."

Describe what you found confusing from the assigned textbook reading or presentation preview. Your description (2-3 sentences) should specifically identify the concept(s) that you do not understand.
"Each of the graphs for acceleration, position, and velocity."

"The calculus graphs, areas under the curves, chords, and tangent lines. Basically, I find it hard to look at a graph and understand what exactly it represents."

"The textbook was very confusing when presenting graphical examples and explaining what the terms represented on the graphs. I also don't fully understand when and how to manipulate some of the formulas for constant acceleration."

Mark the level of your expertise in algebraically solving multiple equations for multiple unknowns.
 None at all. ** [2] Slight. ***** [5] Some. ******************** [20] A fair amount. ********************* [21] A lot. **************** [16]

Mark the level of your exposure to (basic calculus) concepts of derivatives/integrals.
 None at all. ***************** [17] Slight. ************** [14] Some. *********** [11] A fair amount. ******** [8] A lot. ************** [14]

Briefly describe the difference(s) between a chord slope and a tangent slope on a graph.
"A chord slope is the slope of the line connecting two points. Tangent slope is that line at an instantaneous point."

"Chord slopes are used to find average velocity or average acceleration. Tangent slopes are used to find instantaneous velocity or instantaneous acceleration."

"I am not sure what the difference is between these two slopes, and I could really use a good explanation in the next class."

The __________ gives the displacement of an object.
 chord slope of an x(t) graph. ******* [7] tangent slope of an x(t) graph. ** [2] chord slope of a vx(t) graph. ** [2] tangent slope of a vx(t) graph. ** [2] area under a vx(t) graph. ********************************* [33] area under an ax(t) graph. * [1] (None of the above choices.) ** [2] (Unsure/guessing/lost/help!) *************** [15]

The chord slope of a vx(t) graph gives the __________ of an object.
 displacement. ** [2] position. [0] change in (instantaneous) velocity. [0] (instantaneous) velocity. ***** [5] average velocity. ******************************* [31] (instantaneous) acceleration ** [2] average acceleration. ************* [13] (None of the above choices.) [0] (Unsure/guessing/lost/help!) *********** [11]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"Maybe we could review a little bit more on how to read a position, velocity and acceleration graph during class."

"Can you go over notation and graphs from this section?"

"Can we do examples in class using each of the five formulas for constant acceleration so we can take notes on when the appropriate times to use each is?"
(Sure, as time allows.)

"When will the problems given as homework be due?" (They're assigned, but not collected. You are expected to keep up at your own pace, and the online homework reports are meant to track your progress (or lack thereof).)

"Please clarify what you mean by chord and tangent slopes, and if we need to know what these are. Also any equations we need to memorize for the tests." (You do need to know the difference between chord and tangent slopes. You do not need to memorize the constant acceleration motion equations, as they'll be provided to you on the quiz and midterm.)

"Every time I see this box I don't know what to write in it." (You just did.)