Online reading assignment: constant acceleration equations of motion

Physics 205A, fall semester 2019
Cuesta College, San Luis Obispo, CA

Students have a bi-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 reviewing 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.

"I am starting to understand the 'chain of pain' much more now, especially after the practice we had in lecture last week."

"Position-time graphs and velocity-time graphs are becoming easier to read and understand with the help of the 'chain of pain.' The more I look at the chain of pain and the graphs, that more they appear logic-based."

"I have a much better understanding of chord and tangent slopes. A chord slope touches two different points on a graph, and therefore represents an average; whereas a tangent slope only touches one point on the graph, providing instantaneous information."

"I understand the how and why of the 'chain of pain,' though I have yet to memorize it."

"We can solve one-dimensional motion problems using kinematic equations by determining the known and unknown variables and then selecting the appropriate equation(s) to solve for the unknowns. These equations only apply when acceleration is constant."

"There are four equations we need to know regarding time, velocity, acceleration, and position. We need to know three variables per equation in order to solve for the fourth introduced variable or else it isn't solvable."

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.

"I am still confused about the 'chain of pain' chart. I am not sure what the arrows lead to and how to figure out how to solve a problem using it."

"After attending the class last Wednesday, the 'chain of pain' was not as confusing as it was earlier. The hardest part is just memorizing each process and how to get to each piece of the chart."

"The kinematic graphs are still confusing to me; I need to memorize the 'chain of pain' and how to find chord and tangent slope."

"The constant acceleration equations. I am unsure of when they are supposed to be used during certain equations."

"I am struggling with deciding which constant acceleration equation to use for these problems. It's difficult for me to confirm which quantities are given, especially with the UAV example."

"I am still a bit unsure of how to extract what the problem gives and then plug that information into the equations. I am also still a bit confused on picking the best kinematic equation. I know you pick based off of what information is given, but extracting the information proves to be a bit difficult for me."

"Not much at all. You just have to pay attention to what the problems are asking for."

Mark the level of your expertise in algebraically solving multiple equations for multiple unknowns.

None at all.	* [1]
Slight.	* [1]
Some.	************* [14]
A fair amount.	********************** [22]
A lot.	****** [6]

"2012 Chrysler 300 - First Drive"
NRMA Motoring and Services
flic.kr/p/d1bozj

"The braking distance for a 2012 Chrysler 300C to slow down from 31 m/s to a complete stop is 50.3 m. Assume that the acceleration is constant as the car slows down to a stop, and always points in the opposite direction as its velocity."

From the statement of this problem, determine whether the values of these kinematic quantities are known/given or are unknown/undetermined (without solving the problem numerically).
(Only correct responses shown.)

Final horizontal position x (initial horizontal position x₀ assumed to be 0): known/given. [86%]
Initial horizontal velocity v_0x: known/given. [89%]
Final horizontal velocity v_x: known/given. [82%]
Horizontal acceleration a_x: unknown/undetermined. [75%]
Final time t (initial time t₀ assumed to be 0): unknown/undetermined. [75%]

For the Chrysler 300C, the horizontal distance traveled is __________ the magnitude of the horizontal displacement.

less than.	** [2]
equal to.	******************************** [32]
greater than.	******** [8]
(Unsure/guessing/lost/help!)	** [2]

"Leichtathletik WM 2009 Berlin"
André Zehetbauer
flic.kr/p/6RmNQn

"Jamaican sprinter Usain Bolt holds the world record for the 100 m sprint, covering that (straight-line) distance in 9.58 s in Berlin, 2009. Assume that his acceleration starting from rest to when he crosses the finish line is constant, and always points in the same direction as its velocity."

From the statement of this problem, determine whether the values of these kinematic quantities are known/given or are unknown/undetermined (without solving the problem numerically).
(Only correct responses shown.)

Final horizontal position x (initial horizontal position x₀ assumed to be 0): known/given. [95%]
Initial horizontal velocity v_0x: known/given. [52%]
Final horizontal velocity v_x: unknown/undetermined. [52%]
Horizontal acceleration a_x: unknown/undetermined. [77%]
Final time t (initial time t₀ assumed to be 0): known/given. [95%]

For Usain Bolt, the horizontal distance traveled is __________ the magnitude of the horizontal displacement.

less than.	*** [3]
equal to.	**************************** [28]
greater than.	*********** [11]
(Unsure/guessing/lost/help!)	** [2]

"6 kJ Portable Pneumatic Catapult"
UAV Factory
uavfactory.com/product/21

"A portable pneumatic catapult is able to launch a Penguin B unmanned aerial vehicle (UAV) from rest to a final speed of 23 m/s along a 4.0 m rail. Assume that the rail is horizontal, and that acceleration of the UAV starting from rest to when it is launched is constant, and always points in the same direction as its velocity."

From the statement of this problem, determine whether the values of these kinematic quantities are known/given or are unknown/undetermined (without solving the problem numerically).
(Only correct responses shown.)

Final horizontal position x (initial horizontal position x₀ assumed to be 0): known/given. [61%]
Initial horizontal velocity v_0x: known/given. [82%]
Final horizontal velocity v_x: known/given. [89%]
Horizontal acceleration a_x: unknown/undetermined. [61%]
Final time t (initial time t₀ assumed to be 0): unknown/undetermined. [84%]

For the UAV, the horizontal distance traveled is __________ the magnitude of the horizontal displacement.

less than.	**** [4]
equal to.	************************ [24]
greater than.	******** [8]
(Unsure/guessing/lost/help!)	******** [8]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.

"I am still a little unsure of the difference between horizontal distance and the magnitude of the horizontal displacement? I believe they are the same as long as the object is moving in one direction but not confident." (You are correct.)

"For the Usain Bolt 100-m sprint question, are we assuming that he's running on a straight or curved track? If it's curved, wouldn't that make the displacement magnitude smaller than the total distance traveled?" (If the sprint were along a curved track, then yes, the displacement magnitude smaller than the total distance traveled. However, a 100-m sprint is usually along a straight section of track, in which case the displacement magnitude would be equal to the total distance traveled.)

"When a problem says to assume acceleration is constant, does that mean it is 0?" (Not necessarily. When acceleration is zero, it is constant. But acceleration can be a constant non-zero value as well.)

"This is very basic stuff, but it is very important in order to do well in any type of physics."

"Can you please go over one of these questions including kinematic quantities in class." (We will.)

"Will Quiz 2 be structured in roughly the same way as the 'chain of pain' worksheet done in class last Wednesday?" (Yes, for several questions, the rest will be on kinematic equations and on free fall, which we will cover this week.)

"What is the best way to study for your tests?" (Study questions from old quizzes and midterms. Which is every example done in class, the majority of homework problems, and also the practice quizzes from last semester.)

Online reading assignment: motion

Physics 205A, fall semester 2019
Cuesta College, San Luis Obispo, CA

Students have a bi-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.

"Using derivatives and integrals to move left or right on the chain of pain, respectively."

"From what I was able to deduce, the reading is about the relationship between acceleration, velocity, and motion. When you follow the charts given they show their relationship by tangents and chords (and areas)."

"The concept of acceleration--how it correlates to what we've already learned with velocity and displacement. With a positive acceleration headed in the same direction as the velocity, the velocity increases, resulting in the object moving faster. However with a negative acceleration pointed in the opposite direction, the object slows down resulting in a smaller velocity."

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.

"I think the kinematic equations were a lot to process. It made sense, but I need to get more familiarized with them."

"I don't understand how chord slopes work and what information it is telling me. I also don't get what number would be the chord slope."

"The graphical relations are confusing at the moment but will hopefully be clarified once I see some of these graphical relations in action. When I'll need to use what equation will take some studying."

"I don't fully understand the operations that are embedded in our non-calculus 'chain of pain.' I'm confused on how they all connect."

"Memorizing all the equations. I have little practice or interactions with these equations and the key to learning it would be to have a visual connected with every part of the equation so I can learn by logic and not memorization. Also lost on the slopes."

Briefly describe the difference(s) between a chord slope and a tangent slope on a graph.

"A chord slope is a straight line that connects two points on a curve. A tangent slope touches the line at only one point."

"A tangent line is slope of a line from a single point on a curved line and a chord slope is the line between two points on the curve."

"Chord slopes are for average values and tangent slopes are for instantanious."

"I honestly don't understand these concepts enough to explain."

Mark the level of your exposure to (basic calculus) concepts of derivatives/integrals.

None at all.	********** [12]
Slight.	******* [7]
Some.	******** [8]
A fair amount.	************* [13]
A lot.	*** [3]

Indicate how each of these quantities are determined from kinematic graphs.
(Only correct responses shown.)

Displacement ∆x: area under a v_x(t) graph. [58%]
Position x: (None of these choices.) [40%]
Change in (instantaneous) velocity ∆v_x: area under an a_x(t) graph. [51%]
(Instantaneous) velocity v_x: tangent slope of an x(t) graph. [65%]
Average velocity v_x,av: chord slope of an x(t) graph. [60%]
(Instantaneous) acceleration a_x: tangent slope of a v_x(t) graph. [56%]
Average acceleration a_x,av: chord slope of a v_x(t) graph. [58%]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.

"What is the most important thing to understand from this homework?" (Knowing what to do with a graph, and how to do it (calculating areas, chord slopes, or tangent slopes, i.e. the "chain of pain").)

"I'm a little confused on when to use m/s and m/s². Is m/s used only with velocity and m/s² only with acceleration?" (Yes.)

"Why have a chart that sounds and looks torturous?"

"The chain of pain is so daunting at first but if you stare at it long enough it kind of starts to make sense, as long as you can see the system and you know the variables."

"I am finding the 'chain of pain' very confusing. Can you please lecture on this in class."

"I'm confused by 'v_av,x.' Is that the average velocity based off of the displacement value of x?" (Yes, it is the average horizontal velocity.)

"Will we be making or looking at graphs during the next lab?" (Yes, next lab will be an introduction to graphs in general (using Excel), and the following two labs will have you generating velocity versus time graphs generated from video tracking software, or from ultrasound motion detectors.)

"Do we have to memorize all these formulas and the kinematic graphs?" (All of the equations will be given to you. However, the relationships between the graphs (areas, chord slopes, and tangent slopes, i.e. the "chain of pain") is something you have to memorize yourself.)

"How do you solve kinematics equations that have more than one missing variable? Would you use substitution?" (Yes. You would need as many equations as you have missing variables.)

"This class is beginning to concern me."

"Hopelessly lost :("

Online reading assignment: constant acceleration equations of motion

Physics 205A, fall semester 2018
Cuesta College, San Luis Obispo, CA

Students have a bi-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 reviewing 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.

"Some of the basic differences between instantaneous velocity vs average velocity (same with acceleration). Average velocity puts into consideration the whole time scope from t₀ = 0 s to the finish, whereas instantaneous uses small snippets of time and examines each small vector (hopefully I am explaining this correctly. Also the slopes and how to read/understand the graphs more this time around, and what the graph reflects about an object's movement. I realize that 'magnitude' reflects absolute value of a quantity."

"How to find velocity, acceleration and displacement through the use of calculus concepts pretty well. I took calculus in high school and a lot of the material is coming back to me which is great."

"That you have to choose which equation you use carefully to determine the correct unknown variable. I understand the correlations for the 'Chain of Pain,' and which operations should be used to calculate what is trying to be found."

"I'm beginning to understand the relationship between velocity, speed, displacement, and distance traveled a lot more than before. Although displacement and distance traveled can be the same, they can also be different if the movement of the object is not along a straight line. I'm also beginning to see that average speed connects to distance traveled whereas average velocity connects to displacement. Finding these connections among the variables has helped with my ability to problem solve and my overall understanding of the equations."

"I understand that when doing problems with kinematics, it is essential to write down the given information and work step by step in order to avoid errors. I also understand the four kinematic variables (x, v_x, a_x, and t) and their meaning."

"This was the same reading assignment as last time, which helped because I did not really understand the "chain of pain" until reading this chapter again. However, I have seemed to have a better grasp on the concept. I understand that you can find the distance traveled from a velocity graph by finding the are of the graph because the displacement is the same as distance traveled if the distance is all in one direction. I know you can find the average acceleration from a velocity graph by finding the chord slope."

"That in order to solve a problem, we should be able to determine which information is given to us and which isn't first. Then, figure out what equations to use, but actually using it in practice is confusing to me."

"That picking a random physics equation and trying to use it won't end well. I understand that in this class we will need to remember what equations to use and when to use them."

"I took a closer look at what all the variables stand for and it was a bit easier to read the equations."

"How to read the position versus time and the velocity versus time graphs. I think its a little bit easier to solve those problems actually instead of just when information is given."

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.

"Chords, tangents, and areas."

"I would like to go over how to use the chain of pain little bit more and brief overview the stuff is probable good for me."

"The differences between acceleration and velocity. Especially on which variables are used to calculate each one."

"Everything so far makes sense. The 'Chain of Pain' is becoming much clearer now as I spend more time with it and understand its components better."

"Honestly, the textbook is pretty confusing. The chapters assigned just confused me even further. Their use of examples to define something doesn't help explain what something is in the first place if you don't know what it is. How do you decide what equation to use?"

"The 'Chain of Pain' graphical relations flowchart makes sense when I am looking at it but it is very hard to remember/memorize. Hopefully more work with these types of problems will make me more efficient."

"Understanding graphs. Sometimes I get confused on which equations to use when given a graph to analyze. For instance, when to use the area below the curve versus a different type of equation. This confusion may have to do with the need for some more practice with graphs. I am however beginning to understand the equations themselves more which will probably slowly help with understanding the graphs."

"I do mostly understand the 'Chain of Pain' graph however, the symbols are still a bit confusing."

"Figuring out how to use the equations and knowing which one to use in a certain problem. I think during class it could be beneficial to learn how to analyze problems and figure out what information we already have and expand on the process of how to get what we want. I know we've already done this, but I have a hard time doing this with our assigned homework problems and problems from the book."

"Still not familiar with the equations used for finding values, especially what each variable represents. I need to review the definitions more."

"How to determine which equation you choose to determine the variable that is being asked to solve for."

"I think I'm okay."

Mark the level of your expertise in algebraically solving multiple equations for multiple unknowns.

None at all.	**** [4]
Slight.	****** [6]
Some.	************** [14]
A fair amount.	***************** [17]
A lot.	********* [9]

"2012 Chrysler 300 - First Drive"
NRMA Motoring and Services
flic.kr/p/d1bozj

"The braking distance for a 2012 Chrysler 300C to slow down from 31 m/s to a complete stop is 50.3 m. Assume that the acceleration is constant as the car slows down to a stop."

From the statement of this problem, determine whether the values of these kinematic quantities are known/given or are unknown/undetermined (without solving the problem numerically).
(Only correct responses shown.)

Final horizontal position x (initial horizontal position x₀ assumed to be 0): known/given. [88%]
Initial horizontal velocity v_x: known/given. [82%]
Final horizontal velocity v_0x: known/given. [84%]
Horizontal acceleration a_x: unknown/undetermined. [72%]
Final time t (initial time t₀ assumed to be 0): unknown/undetermined. [74%]

For the Chrysler 300C, the horizontal distance traveled is __________ the magnitude of the horizontal displacement.

less than.	*** [3]
equal to.	********************************* [33]
greater than.	****** [6]
(Unsure/guessing/lost/help!)	******** [8]

"Leichtathletik WM 2009 Berlin"
André Zehetbauer
flic.kr/p/6RmNQn

"Jamaican sprinter Usain Bolt holds the world record for the 100 m sprint, covering that distance in 9.58 s in Berlin, 2009. Assume that his acceleration starting from rest to when he crosses the finish line is constant."

From the statement of this problem, determine whether the values of these kinematic quantities are known/given or are unknown/undetermined (without solving the problem numerically).
(Only correct responses shown.)

Final horizontal position x (initial horizontal position x₀ assumed to be 0): known/given. [94%]
Initial horizontal velocity v_x: known/given. [50%]
Final horizontal velocity v_0x: unknown/undetermined. [56%]
Horizontal acceleration a_x: unknown/undetermined. [74%]
Final time t (initial time t₀ assumed to be 0): known/given. [96%]

For Usain Bolt, the horizontal distance traveled is __________ the magnitude of the horizontal displacement.

less than.	[0]
equal to.	************************************** [38]
greater than.	***** [5]
(Unsure/guessing/lost/help!)	******* [7]

"6 kJ Portable Pneumatic Catapult"
UAV Factory
uavfactory.com/product/21

"A portable pneumatic catapult is able to launch a Penguin B unmanned aerial vehicle (UAV) from rest to a final speed of 23 m/s along a 4.0 m rail. Assume that the rail is horizontal, and that acceleration of the UAV starting from rest to when it is launched is constant."

From the statement of this problem, determine whether the values of these kinematic quantities are known/given or are unknown/undetermined (without solving the problem numerically).
(Only correct responses shown.)

Final horizontal position x (initial horizontal position x₀ assumed to be 0): known/given. [74%]
Initial horizontal velocity v_x: known/given. [82%]
Final horizontal velocity v_0x: known/given. [82%]
Horizontal acceleration a_x: unknown/undetermined. [70%]
Final time t (initial time t₀ assumed to be 0): unknown/undetermined. [76%]

For the UAV, the horizontal distance traveled is __________ the magnitude of the horizontal displacement.

less than.	*** [3]
equal to.	****************************** [30]
greater than.	***** [5]
(Unsure/guessing/lost/help!)	************ [12]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.

"Can we go over displacement vs distance again using the three examples you gave us for homework?"

"If something is traveling in a straight line and does not go backwards or turn right or left, is displacement equal to distance?" (Yes.)

"Can we use the kinematic equations to solve for distance traveled on a velocity versus time graph, or would you prefer we show how we found the area by using squares and triangles?" (Whichever method works best for you. I'll teach you both methods, but ultimately how you get your answer is your call.)

"Will you give kinematic equations to us on quizzes and exams, or do we need to memorize them?" (You are always given those equations, so don't memorize them. Instead concentrate on how they are to be used.)

"How do you decide which kinematic equation to use? And will you give these to us on tests/quizzes or do we need to memorize them?" (The "most useful" kinematic equation to use will depend on the information that you are given, and what you are being asked to solve for, which will be different for every particular problem.)

"Could we go through one of these problems in class?" (We will. Then you'll go through one of these problems on your own for problem-solving today, and then more for homework later.)

"I think I just need a bit more practice with identifying all the different variables in the problems, also being able to calculate the different variables as well."

"No comment or question today. Class is going well!"

Online reading assignment: motion

Physics 205A, fall semester 2018
Cuesta College, San Luis Obispo, CA

Students have a bi-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.

"I have a better understanding about displacement and how it represents the objects initial starting point to the ending point. I understand how the magnitude of displacement is the shortest distance between the initial and ending point. I also will memorize the chart and the acceleration formula."

"The sections in the book confused me. However, what I took from this lesson is that average speed and average velocity magnitude can in fact be equal if your are driving a straight path. By definition average speed = (distance traveled)/(time elapsed), where as average velocity = (displacement magnitude)/(time elapsed). So if you're driving in a straight line then your (displacement magnitude)/(time elapsed) would not differ from distance traveled)/(time elapsed)."

"To go from position, to velocity, to acceleration you take the derivative. If you do the exact opposite, taking the integral, you can go from acceleration, to velocity, to position."

"The graphical relations to get to average velocity and acceleration from position and instantaneous velocity respectively. Also how to move from position to instantaneous velocity to instantaneous acceleration using tangent slopes."

"The calculus relations chart--calculus is not a new subject for me, so the concept of integrating to go one way and deriving to go the other was familiar and almost comforting to see."

"I think I understand the 'Chain of Pain' and how you get an answer by following the flow chart. Conceptually I don't think I'm there yet but hopefully will be soon."

"I was intimidated by this (and still am), but from what I understand, we are utilizing derivatives to calculate position, acceleration, and velocity. I think that the lecture will help clear a lot of things up for me."

"The thing I most found confusing was when the graphical relations were mentioned. The tangent slopes and chord slopes were the most confusing in this reading. How you get from position, average velocity and average acceleration using chord slopes or tangent slopes confuses me."

"The last sentence in the preview made the most sense. I wish it was the first: 'The most important part of solving physics problems will be reading through and picking out the known/given/inferred quantities, identifying the remaining unknown quantities, so then this will help you determine just equation(s) you should be using for a particular situation.' I finally understood something."

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.

"While I am great with calculus, the 'Chain of Pain' chart is very confusing. I am not really sure what a chord slope is and I am just lost on the equations with all the different symbols."

"Calculus has never been my strong suit, but I love physics, so I think that once I have a lecture on the material and see some examples done in class and do some more on paper, I will have a much clearer understanding of it."

"Something that I feel I could use a better explanation of is the 'Chain of Pain.' I'm not sure exactly how you want us to follow it."

"The difference between chords and tangents."

"The 'Chain of Pain?' What was that all about? Chord slope? Tangent slope? Didn't make sense to me. Also what was the calculus relations chart about?"

Briefly describe the difference(s) between a chord slope and a tangent slope on a graph.

"A tangent line touches the graph at only one point while a chord touches two points on the graph. "

"A chord slope connects two points on a graph, and it can be used to find the average slope of the graph between the two points. A tangent line touches a point on a graph and can be used to calculate the slope of the curve at that point."

"Chord slopes and tangent slopes have two different types of velocities and accelerations (average and instantaneous)."

"The chord slope connects two different points on the graph, and if those points get closer and closer to a single point to find the slope, it becomes a tangent slope set a single given point."

"I know that a tangent slope touches the graph in one spot--that's about all I remember... :["

Mark the level of your exposure to (basic calculus) concepts of derivatives/integrals.

None at all.	************ [12]
Slight.	******* [7]
Some.	******* [7]
A fair amount.	************* [13]
A lot.	***** [5]

Indicate how each of these quantities are determined from kinematic graphs.
(Only correct responses shown.)

Displacement ∆x: area under a v_x(t) graph. [39%]
Position x: (None of these choices.) [25%]
Change in (instantaneous) velocity ∆v_x: area under an a_x(t) graph. [43%]
(Instantaneous) velocity v_x: tangent slope of an x(t) graph. [43%]
Average velocity v_x,av: chord slope of an x(t) graph. [41%]
(Instantaneous) acceleration a_x: tangent slope of a v_x(t) graph. [48%]
Average acceleration a_x,av: chord slope of a v_x(t) graph. [52%]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.

"All of this graphing and the equations are just jumbled up for me, is there a better way to approach or understand them? i really need help with the the 'Chain of Pain.'"

"How the heck do I read the 'Chain of Pain chart?' Where/how do the arrows start/stop?"

"Please go over the graphs in regards to tangents and chords and how they relate to the equations and graphs."

"We need to go over this in class. I have not done calculus since senior year of high school!"

"Just hoping that the lecture notes and practice problems in class will help clear this section up for me a bit!"

"I wasn't able to get my hands on the textbook for this reading assignment; and I did not find the presentation to be helpful for this assignment."

"When is the latest that students should acquire their textbooks?" (Right around now, especially since the presentation slides only just summarize the details that are explained more fully in the textbook. There is a reserve copy of the textbook available at the library.)

Online reading assignment: constant acceleration equations of motion

Physics 205A, fall semester 2017
Cuesta College, San Luis Obispo, CA

Students have a bi-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 reviewing 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.

"The chain of pain. I am starting to get how to use it when I am given certain information."

"Re-reading these sections helped me gain some understanding on these topics overall. It definitely gave me a greater understanding of applying the equations of kinematics but I still feel I could use some equations in class to go over."

"Acceleration is negative when it goes against the direction of velocity. Tangent lines touch the graph on one point."

"Since the velocity is a vector and the formula for the acceleration is the velocity over change in time, then Acceleration has also a magnitude and direction. Instantaneous acceleration will be a tangent line and average acceleration will be a chord line on a velocity versus time graph."

"There are four kinematic equations with multiple variables to make it possible to find a missing variable that we are interested in. If we are given all but one of the variables we can solve for the missing piece of the equation."

"When it comes to displacement it can be equal to distance traveled if there are no changes in the direction of motion. "

"Utilizing the given information/variables to select the best equation in determining an unknown variable."

"The different slopes are something that i understand. It makes sense to me that if it is between two point it is a chord slope and if it touches at one spot then it is a tangent slope."

"After re-reading the assignment, I was able to understand more about motion and the calculus equations. From the reading and online presentation, I was able to really focus on using constant acceleration equations."

"Moving around the chain of pain is straightforward, which is good seeing as there is a quiz soon."

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.

"Something that I'm still struggling with is figuring out what part of the chain of pain to use when I'm given information in a different format or wording than I'm used to. I think it would just take practice and a little more review during class."

"The thing I feel I'm not fully grasping is using the values of velocity or acceleration and applying them to a graph. I can understand how to read the graph usually but to come away with the desired value is difficult for me."

"Need some clarifications on the constant acceleration equations and how to use them."

"Because of the emphasis on memorization, this presentation wasn't too difficult to get the hang of."

"Although I understand the concept of the chart much more, I still get some confusion on applying the area. I just need a very quick explanation on when and how to use it. Is it always base×height?"

"I didn't find any of the information confusing. I did notice that finding the correct equation to use can be somewhat challenging, but writing-out all of the given variables and what you need to find helps immensely."

"Being able to pick out the variables in a word problem. However, that will probably get easier with more practice."

"How/when a chord can be a tangent line when a chord has to hit two points."

"The biggest concepts that I feel still confused by are when to use each kinematic equation for constant acceleration. It could totally just be that I really need to try to memorize it more, but I do understand you want to use the quantities that are given and find the equation that best suits it to find the missing/desired quantity. Maybe I am just overthinking it? Also, I still need to review the chain of pain better and follow the examples given in class. "

"Though I am confused by when to use the chain of pain and the kinematic equations for constant acceleration. I do understand the mathematics/rearranging of quantities to find the undetermined quantity."

"To be fully honest, I read the chapter two more times on top of the previous times a read it and I still do not understand it."

"How to solve for multiple unknown quantities, and would benefit from further explanation."

"I did not find anything confusing but appreciate the review."

"Not too confused about anything."

Mark the level of your expertise in algebraically solving multiple equations for multiple unknowns.

None at all.	[0]
Slight.	***** [5]
Some.	************** [14]
A fair amount.	****************** [18]
A lot.	********* [9]

"2012 Chrysler 300 - First Drive"
NRMA Motoring and Services
flic.kr/p/d1bozj

"The braking distance for a 2012 Chrysler 300C to slow down from 31 m/s to a complete stop is 50.3 m. Assume that the acceleration is constant as the car slows down to a stop."

From the statement of this problem, determine whether the values of these kinematic quantities are known/given or are unknown/undetermined (without solving the problem numerically).
(Only correct responses shown.)

Final horizontal position x (initial horizontal position x₀ assumed to be 0): known/given. [72%]
Initial horizontal velocity v_x: known/given. [89%]
Final horizontal velocity v_0x: known/given. [85%]
Horizontal acceleration a_x: unknown/undetermined. [70%]
Final time t (initial time t₀ assumed to be 0): unknown/undetermined. [74%]

For the Chrysler 300C, the horizontal distance traveled is __________ the magnitude of the horizontal displacement.

less than.	** [2]
equal to.	*************************************** [39]
greater than.	** [2]
(Unsure/guessing/lost/help!)	*** [3]

"Leichtathletik WM 2009 Berlin"
André Zehetbauer
flic.kr/p/6RmNQn

"Jamaican sprinter Usain Bolt holds the world record for the 100 m sprint, covering that distance in 9.58 s in Berlin, 2009. Assume that his acceleration starting from rest to when he crosses the finish line is constant."

From the statement of this problem, determine whether the values of these kinematic quantities are known/given or are unknown/undetermined (without solving the problem numerically).
(Only correct responses shown.)

Final horizontal position x (initial horizontal position x₀ assumed to be 0): known/given. [87%]
Initial horizontal velocity v_x: known/given. [41%]
Final horizontal velocity v_0x: unknown/undetermined. [46%]
Horizontal acceleration a_x: unknown/undetermined. [74%]
Final time t (initial time t₀ assumed to be 0): known/given. [93%]

For Usain Bolt, the horizontal distance traveled is __________ the magnitude of the horizontal displacement.

less than.	* [1]
equal to.	******************************** [32]
greater than.	********** [10]
(Unsure/guessing/lost/help!)	*** [3]

"6 kJ Portable Pneumatic Catapult"
UAV Factory
uavfactory.com/product/21

"A portable pneumatic catapult is able to launch a Penguin B unmanned aerial vehicle (UAV) from rest to a final speed of 23 m/s along a 4.0 m rail. Assume that the rail is horizontal, and that acceleration of the UAV starting from rest to when it is launched is constant."

From the statement of this problem, determine whether the values of these kinematic quantities are known/given or are unknown/undetermined (without solving the problem numerically).
(Only correct responses shown.)

Final horizontal position x (initial horizontal position x₀ assumed to be 0): known/given. [76%]
Initial horizontal velocity v_x: known/given. [76%]
Final horizontal velocity v_0x: known/given. [85%]
Horizontal acceleration a_x: unknown/undetermined. [63%]
Final time t (initial time t₀ assumed to be 0): unknown/undetermined. [80%]

For the UAV, the horizontal distance traveled is __________ the magnitude of the horizontal displacement.

less than.	***** [5]
equal to.	******************************* [31]
greater than.	***** [5]
(Unsure/guessing/lost/help!)	***** [5]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.

"I think I understand how to calculate the differences between horizontal distance traveled and magnitude of the horizontal displacement, but not sure if I am exactly doing it correct/using the right numbers."

"Do you recommend just memorizing the chain of pain or not?" (If that works for you. If you have a different system, then by all means go for it.)

"How can we calculate for an object that does not move with constant acceleration?" (If acceleration is not constant, but its derivative ("jerk") is, then you would use a different set of constant jerk equations, say, where:

x = x₀ + v_x0⋅t + (1/2)⋅a_x0⋅t² + (1/6)⋅j⋅t³,

and so on. #wut)

"Is there any difference between finding the area of the triangle below or above the slope?" (If the line is above the time axis, find the area "below the slope," down to the time axis. But if the line is below the time axis, then find the area "above the slope," up to the time axis.)

"How similar will these questions be to quiz/exam questions?" (My intent is to be very similar, as these were actual quiz questions from previous semesters.)

"I would benefit from further explanation on the selected topics. I do not learn well by self teaching from book material."

"The flipped class is confusing me."

"I do not understand this, I can't teach myself physics." (That's okay, as long as you're giving me a heads-up on specifically what you find confusing, so we can address this in class--even if it's everything.)

"For all three cases above I believe the distance is equal to the magnitude of horizontal displacement. They all seem to be going in a single direction without any turns or back tracks. It's weird to put 'equal to' three times in a row though so I am second-guessing myself." (Don't psych yourself out. Sometimes it is what it is.)

"Putting equations into other equations is a little confusing. Is there a simpler, or different, way to solve these equations?" (That's the way algebra works. #itiswhatitis)

"No comment." (You just did.)

"What's the best kind of musubi?" (SPAM musubi, of course.)