Rhino’s Big Adventures – 23 February 2009
The next installment in the ongoing adventures our favorite virtual pachyderm.
Last night my physics I lecture was about work and energy. I usually start a new chapter with a bit of introductory improvisation with whatever comes to my mind about the topic. In this case, the main point I made was that our working definition of “energy” would be the ability to do work. In addition to setting the stage for establishing the equivalence of energy and work, I was attempting to set the stage for explaining how energy “flows” between potential energy and kinetic energy in some systems, ultimately leading to the idea of Conservation of Energy.
As usual, the students we showing all of the signs of discomfort from the beginning, ranging from extreme boredom to comatose to signs of significant physical pain each time I uttered a syllable. I’m getting used to that, but I still notice it. For those who are unfamiliar with the style I’m developing, I tend to favor a Socratic Method as much as possible wherein I ask questions of students in order to get them to put the pieces of the puzzle together themselves as well as to verify that at least some of them are “getting it.” Some classes respond better than others.
Toward the end of the evening, I was explaining how springs store potential energy when they are deformed. I had a power point slide on the board showing an undeformed spring, one that is deformed with a ball in front of it, and then ultimately the ball being propelled by the spring as it returned to its undeformed length. The equation for the potential energy was prominently displayed (elastic PE = ½∙k∙x2). I decided it was time for a “question” and a little reality check in the room.
I looked around. I saw two or three pair of clear eyes, and the rest ranging from drowsy to some unholy cross between pain and constipation. Typically I will ask a student about whose comprehension I am concerned (usually with good reason). I knew I was losing them, so I decided to make it as simple as I could. It went a little something like this:
“Remember that our definition of energy is the ability to do work. If the spring is compressed and has stored a certain amount of potential energy, how much work can it do?” Looking around the room, I see a suitable vict . . . er . . . candidate. I restated, posing the question to them directly.
Response: “I dunno. I don’t get it.”
Okay, no big deal. It happens. I’ll try someone else, right?
Next response: “No clue.”
Third response: “I don’t understand the question.”
Fourth response: “Huh?”
Keep in mind that each and every time I addressed a student; I rephrased the question, hoping to trigger some remnant of electrical activity in their cerebellums. Each time I included, “Keeping in mind our definition that energy is the ability to do work . . .”
Nothing. Nada.
I went through at least 15 people (not exaggerating), sometimes asking (begging) one of the better students to help us. At one point, I considered asking for help from Jesus, since I’ve heard that God protects children and fools and I was obviously a fool for taking that job. I decided against it because I wanted to save any divine favors for later.
So there we were. I’m asking an incredibly simple and leading question in which I give the answer while asking the question and no one in the room can or will answer with anything remotely correct. I was even rolling around on my chair making eye contact and trying to telepathically beam the answer into their minds so that my own skull would not explode. No dice.
And then it happened. Two guys in the back row attracted my attention because between the two of them, they had deciphered the complex, Sphynxian riddle of the ages with a solution delivered unto them by some serendipitous convergence of whatever the hell it was that happened.
“It’s the same as the amount of energy stored in the spring.”
That’s when something else happened. Not unlike the spring in the example, the increasing stress of the unending inability (or refusal) to connect two adjacent dots had built to a crescendo of frustration in my tiny mind. I’m not sure what words I used, but I do recall that whatever I said was, well, kind of . . . loud.
I got excited. Apparently I started screaming about how they were right because the emotional potential energy I had stored was doing a little work of the verbal communication kind. All at once. Did I mention I was a little loud and excited?
Naturally, my outburst caused a bit of surprise in the room. On the bright side, I think it awakened those on the brink of dreamland. On the other hand, something else happened.
A security guard rushed into the room, asking “Is everything all right in here? I heard someone yelling!” She thought I was angry or dressing down a student and thought there might be trouble.
That’s when the laughter started.
I regained what composure I could and tried to explain to her that it was all right, no one was angry and that I was just a little bit excited that someone was finally able to answer my question.
She accepted my explanation, but made sure to close the door as she was leaving.
Did I mention that the security office is nowhere near the room I was in? Yeah, those who have spent time with me in public are probably not surprised because they know how loud I get in a restaurant, typically with no regard for those around me (and no regard for the topic discussed). In this case, we seemed to have moved past nominal rhino decibel level to somewhere between an AC/DC concert and the business end of the turbojet engine on a 747.
More laughter ensued.
I’m hoping that maybe a few others “got it” and now understand the relationship between energy and work. I’m naïve though, because that would presuppose they cared enough to want to know.
What I did know was that I had their attention. The next power point slide (prepared by the author of the book, not me!) showed the conservation of mechanical energy for elastic potential energy and kinetic energy. There was also a strobe/multiple exposure photo of a pole vaulter doing a jump, so I seized what I perceived to be a “teachable moment.”
The idea was that I would discuss the flow of energy among kinetic, gravitational potential energy, and elastic potential energy, and how ultimately the pole vaulter used conservation of mechanical energy to complete the jump. The reality was, as soon as I started talking about “pole” and appropriate adjectives describing the physical properties that made it a spring, the snickering started. So I had to continue my discussion by substituting “pole vaulting device,” which only partially solved the problem. Eventually I just called it a “spring,” but then half of them lost that I was referring to the pole as the spring.
Sigh.
Hopefully the pole vaulting example made it into some of their pointy heads before I lost them again. At the very least, they seemed to be awake as I was talking, but that was probably just residual epinephrine from when I sent security into high alert just a few minutes before.
Finally I asked something I ask at least 30 times each evening: are there any questions? Is there anyone who does not understand?”
Question! A question! Someone had a question! It’s just possible someone wanted to know more about work and energy!
“Will the midterm be multiple choice”?
I slapped my forehead.
“How many questions will be on the midterm?”
I put my head in a vice.
“Will there be a review session for the midterm”
Slowly I turned the handle on the vice . . .
The next installment in the ongoing adventures our favorite virtual pachyderm.
Last night my physics I lecture was about work and energy. I usually start a new chapter with a bit of introductory improvisation with whatever comes to my mind about the topic. In this case, the main point I made was that our working definition of “energy” would be the ability to do work. In addition to setting the stage for establishing the equivalence of energy and work, I was attempting to set the stage for explaining how energy “flows” between potential energy and kinetic energy in some systems, ultimately leading to the idea of Conservation of Energy.
As usual, the students we showing all of the signs of discomfort from the beginning, ranging from extreme boredom to comatose to signs of significant physical pain each time I uttered a syllable. I’m getting used to that, but I still notice it. For those who are unfamiliar with the style I’m developing, I tend to favor a Socratic Method as much as possible wherein I ask questions of students in order to get them to put the pieces of the puzzle together themselves as well as to verify that at least some of them are “getting it.” Some classes respond better than others.
Toward the end of the evening, I was explaining how springs store potential energy when they are deformed. I had a power point slide on the board showing an undeformed spring, one that is deformed with a ball in front of it, and then ultimately the ball being propelled by the spring as it returned to its undeformed length. The equation for the potential energy was prominently displayed (elastic PE = ½∙k∙x2). I decided it was time for a “question” and a little reality check in the room.
I looked around. I saw two or three pair of clear eyes, and the rest ranging from drowsy to some unholy cross between pain and constipation. Typically I will ask a student about whose comprehension I am concerned (usually with good reason). I knew I was losing them, so I decided to make it as simple as I could. It went a little something like this:
“Remember that our definition of energy is the ability to do work. If the spring is compressed and has stored a certain amount of potential energy, how much work can it do?” Looking around the room, I see a suitable vict . . . er . . . candidate. I restated, posing the question to them directly.
Response: “I dunno. I don’t get it.”
Okay, no big deal. It happens. I’ll try someone else, right?
Next response: “No clue.”
Third response: “I don’t understand the question.”
Fourth response: “Huh?”
Keep in mind that each and every time I addressed a student; I rephrased the question, hoping to trigger some remnant of electrical activity in their cerebellums. Each time I included, “Keeping in mind our definition that energy is the ability to do work . . .”
Nothing. Nada.
I went through at least 15 people (not exaggerating), sometimes asking (begging) one of the better students to help us. At one point, I considered asking for help from Jesus, since I’ve heard that God protects children and fools and I was obviously a fool for taking that job. I decided against it because I wanted to save any divine favors for later.
So there we were. I’m asking an incredibly simple and leading question in which I give the answer while asking the question and no one in the room can or will answer with anything remotely correct. I was even rolling around on my chair making eye contact and trying to telepathically beam the answer into their minds so that my own skull would not explode. No dice.
And then it happened. Two guys in the back row attracted my attention because between the two of them, they had deciphered the complex, Sphynxian riddle of the ages with a solution delivered unto them by some serendipitous convergence of whatever the hell it was that happened.
“It’s the same as the amount of energy stored in the spring.”
That’s when something else happened. Not unlike the spring in the example, the increasing stress of the unending inability (or refusal) to connect two adjacent dots had built to a crescendo of frustration in my tiny mind. I’m not sure what words I used, but I do recall that whatever I said was, well, kind of . . . loud.
I got excited. Apparently I started screaming about how they were right because the emotional potential energy I had stored was doing a little work of the verbal communication kind. All at once. Did I mention I was a little loud and excited?
Naturally, my outburst caused a bit of surprise in the room. On the bright side, I think it awakened those on the brink of dreamland. On the other hand, something else happened.
A security guard rushed into the room, asking “Is everything all right in here? I heard someone yelling!” She thought I was angry or dressing down a student and thought there might be trouble.
That’s when the laughter started.
I regained what composure I could and tried to explain to her that it was all right, no one was angry and that I was just a little bit excited that someone was finally able to answer my question.
She accepted my explanation, but made sure to close the door as she was leaving.
Did I mention that the security office is nowhere near the room I was in? Yeah, those who have spent time with me in public are probably not surprised because they know how loud I get in a restaurant, typically with no regard for those around me (and no regard for the topic discussed). In this case, we seemed to have moved past nominal rhino decibel level to somewhere between an AC/DC concert and the business end of the turbojet engine on a 747.
More laughter ensued.
I’m hoping that maybe a few others “got it” and now understand the relationship between energy and work. I’m naïve though, because that would presuppose they cared enough to want to know.
What I did know was that I had their attention. The next power point slide (prepared by the author of the book, not me!) showed the conservation of mechanical energy for elastic potential energy and kinetic energy. There was also a strobe/multiple exposure photo of a pole vaulter doing a jump, so I seized what I perceived to be a “teachable moment.”
The idea was that I would discuss the flow of energy among kinetic, gravitational potential energy, and elastic potential energy, and how ultimately the pole vaulter used conservation of mechanical energy to complete the jump. The reality was, as soon as I started talking about “pole” and appropriate adjectives describing the physical properties that made it a spring, the snickering started. So I had to continue my discussion by substituting “pole vaulting device,” which only partially solved the problem. Eventually I just called it a “spring,” but then half of them lost that I was referring to the pole as the spring.
Sigh.
Hopefully the pole vaulting example made it into some of their pointy heads before I lost them again. At the very least, they seemed to be awake as I was talking, but that was probably just residual epinephrine from when I sent security into high alert just a few minutes before.
Finally I asked something I ask at least 30 times each evening: are there any questions? Is there anyone who does not understand?”
Question! A question! Someone had a question! It’s just possible someone wanted to know more about work and energy!
“Will the midterm be multiple choice”?
I slapped my forehead.
“How many questions will be on the midterm?”
I put my head in a vice.
“Will there be a review session for the midterm”
Slowly I turned the handle on the vice . . .
