tag:blogger.com,1999:blog-31189917.post918003567660728131..comments2024-03-11T04:40:23.756-07:00Comments on The Blog of Phyz: Why are you spending so much time on kinematics? (The NGSS Edition)Dean Bairdhttp://www.blogger.com/profile/17681829220589441713noreply@blogger.comBlogger8125tag:blogger.com,1999:blog-31189917.post-16126644792606623122013-09-01T17:51:09.628-07:002013-09-01T17:51:09.628-07:00I've fought with this each of the 9 years I...I've fought with this each of the 9 years I've taught, and I've tried dealing with it differently each time. Last year it was teaching electric circuits first to build cars whose motion we analyzed. This year I started with programming on day 1, having students model first data that they are familiar with ( loops that output a bank balance with interest compounding, number of particles with radioactive decay, etc.) to get the expected exponential relationships, then using VPython they'll make things move in different ways and we'll model that data. Finally we'll compare that to data for real motion using Tracker, CBRs etc. It might not save time, but it will keep us from getting mired in kinematic equations, and will give students some extra skills. And it's fun.Marc Bradenhttps://www.blogger.com/profile/10236578974886719295noreply@blogger.comtag:blogger.com,1999:blog-31189917.post-71287246731667342822013-08-22T06:58:42.192-07:002013-08-22T06:58:42.192-07:00My experience as an AP Physics teacher has informe...My experience as an AP Physics teacher has informed me that too much time in kinematics results in students keen to use the equations of Uniform Accelerated Motion to solve problems in Simple Harmonic Motion.<br /><br />Their mastery of UAM makes it they're go-to solution when they're otherwise unsure how to solve a problem.<br /><br />It would be better if they fell back on energy conservation when lost.Dean Bairdhttps://www.blogger.com/profile/17681829220589441713noreply@blogger.comtag:blogger.com,1999:blog-31189917.post-37155493527495707632013-08-21T17:53:24.286-07:002013-08-21T17:53:24.286-07:00Given that the human mind wrestled with the concep...Given that the human mind wrestled with the concept of acceleration for more than 2000 years before mastering it, teaching the concept in introductory physics presents an open-ended blank check if you let it.<br /><br />When I say, "Done", I mean I'm going to demonstrate the concepts, discuss the definitions, engage the students in some lab experiences, and move on.<br /><br />Will they construct a master's understanding of acceleration? No. Will they understand motion enough to proceed into new territory where the concepts will be reinforced and built upon? Absolutely.<br /><br />I don't think it's reasonable to expect intro learners to go from zero to master in our first-year classes.<br /><br />Acceleration will occupy as much of the curriculum as you allow it to and still many students will not deeply get it. <br /><br />Accept that the deep understanding does not come about upon initial introduction and move on. Flawed or incomplete conceptions do not prevent what we called "advanced" performance on state-mandated testing.<br /><br />As instructors, we well up with pride if a student can correctly interpret the meaning of the slope on a transposed-axes motion graph.<br /><br />But I think it's nice if they can explain why the sky is blue to their grandmother, too. When I have to pick, I'll take the latter over the former every time.Dean Bairdhttps://www.blogger.com/profile/17681829220589441713noreply@blogger.comtag:blogger.com,1999:blog-31189917.post-66118640313670852172013-08-21T11:23:22.580-07:002013-08-21T11:23:22.580-07:00Dean, I agree with you almost completely. I'm ...Dean, I agree with you almost completely. I'm not one of those folks spending six weeks on quadratics. Like you, I find the algebra to be a great time suck (and not that great at teaching acceleration). Like you, I emphasize recognizing the concept of acceleration. <br /><br />The disagreement comes when you say "Done." I 'm sure you realize the concept is not that simple.<br /><br />I find it's one thing to get the kids to say back those three kinds of acceleration. It's another, more involved thing to get students to actually look at a motion or a representation of it and then identify whether it's accelerating, and be able to say why.<br /><br />I don't want people underestimating how much effort (and time) it takes to really get that concept. <br /><br />My bottom line: Don't spend *so much* time trying to do all of kinematics. Instead, spend quality time on the kinematics that is important to your purpose.Anonymoushttps://www.blogger.com/profile/01544481241309759909noreply@blogger.comtag:blogger.com,1999:blog-31189917.post-91032321756832113092013-08-21T09:49:49.702-07:002013-08-21T09:49:49.702-07:00Paul,
How deep an understanding of acceleration d...Paul,<br /><br />How deep an understanding of acceleration do you think students need to gain an introductory-level understanding of Newton's Second Law?<br /><br />"Change in velocity." "Speeding up, slowing down, or changing direction." <br /><br />Done.<br /><br />Coaxing "a" out of v^2 = v0^2 + 2ax? Appreciating that a concave-down plot on an x vs. t graph indicates negative acceleration while not necessarily revealing whether a body is speeding up or slowing down?<br /><br />Too much!Dean Bairdhttps://www.blogger.com/profile/17681829220589441713noreply@blogger.comtag:blogger.com,1999:blog-31189917.post-49682148825410792222013-08-21T09:15:39.500-07:002013-08-21T09:15:39.500-07:00Even as I post this, I am working to reduce the ki...Even as I post this, I am working to reduce the kinematics footprint in my academic year.<br /><br />I tend to use kinematics as the playground in which students learn that equations are more than just formulas for computing answers. You can't find anything more concrete that does so much to connect seemingly lifeless algebra to things going on right in front of you. <br /><br />And, ideally, they learn to see equations as variable relationships. If they carry it forward to future lessons, it means I can communicate tons of information just by showing them an equation that relates other variables, such as potential curves for universal gravitation.<br /><br />At the best moments, we barely have to start into learning something before students are deriving relationships and inferring the next steps. As I said, I am applying your advice right now. But don't give short shrift to the benefits of bringing equations to life.<br /><br />I am also biased by my experience as an AP teacher. It always seemed that time spent in foundational kinematics paid off for students' scores, whereas other areas didn't translate as well. So working on a broad analytical view of the amazing world around us sometimes took a backseat to perfecting projectile motion.cskeslerhttps://www.blogger.com/profile/10859993453570661007noreply@blogger.comtag:blogger.com,1999:blog-31189917.post-40619303872549126832013-08-21T05:14:35.150-07:002013-08-21T05:14:35.150-07:00My question is, how does one really learn Newton&#...My question is, how does one really learn Newton's second law without kinematics? If students lack an understanding of acceleration, then F = m a is merely senseless plug and chug.Anonymoushttps://www.blogger.com/profile/01544481241309759909noreply@blogger.comtag:blogger.com,1999:blog-31189917.post-71437151526345900072013-08-21T05:08:01.026-07:002013-08-21T05:08:01.026-07:00This hit me right where I've been thinking for...This hit me right where I've been thinking for a while. I posted recently about how no "physicist" does kinematics (meaning check the journals, etc) but that it's just one of our many very successful models. I love what you're thinking about doing here, and I'm getting even more excited about the NGSS.Andy Rundquisthttps://www.blogger.com/profile/04900696452285397726noreply@blogger.com