Chapter+1+Reflections

Chapter 1: Driving the Roads

 * One dimensional motion**. Topics include speed, average speed, instantaneous speed, velocity, vector/scalar, acceleration, negative acceleration, centripetal force

Overall:

 * //Sections 1 - 2://** Chapter 1 begins with two sections that introduce the set-up of the curriculum and the lab procedures that will be followed for the remainder of the year. Of the two, 1.1 on reaction time is the more engaging and accessible lesson. The investigation itself is easy to accomplish, the students generally understand the purpose of the investigation and it allows students to practice creating a useful and meaningful lab notebook. Section 2 is on precision and accuracy, but this section can (and should) be skipped in the interest of time - the ideas of measurement error, precision, and accuracy can be embedded throughout any/all investigations.


 * //Section 3 - 5//** deal with speed, velocity, acceleration. They are important to lay the foundation for future work although it is important to realize that ALL of the topics in these sections are covered again in Chapter 2. Students do not have to be perfect in their understandings at this point, but should start developing at least a conceptual understanding.


 * //Section 6//** is a difficult section to cover - the Investigation is not particularly engaging, it is heavy in math and calculations. Skip it.


 * //Section 7//** does a slight departure from straight-line motion and introduces centripetal force/acceleration. If running behind, this section can be skipped or re-introduced in Chapter 2.3 when Newton’s 2nd law comes back around.


 * Must-Dos: 1, 3 - 5**

**Section 1: Reaction Time**

 * learning outcomes:**
 * every one has a reaction time and it can be measured
 * reaction time plays an important role in driving an automobile safely
 * there are factors that can affect reaction time

the stopwatches will confuse a portion of your students - they will let the watches run for say, 20 seconds and then report their reaction time as 20.1 seconds - in other words, they don’t understand what “take the difference” between the two stopwatch times means - they don’t understand the significance
 * pitfalls:**

On the rulers, kids will get pretty jazzed and competitive - make them put their hand on the edge of the table to keep the measurements accurate and the competition “fair.”

students have a difficult time understanding that a speeding car doesn’t change their reaction time - they may miss that the reason speed is an issue when talking about reaction time is that the car will travel a greater distance. Don’t get bogged down with the speed formula yet, but keep this in mind because the relationship between speed, distance, and time is a big one. You will get a chance to revisit the relationship between a speeding car and reaction time/reaction distance in 1.3
 * misconceptions//://**


 * Section 3: Average Speed **
 * learning outcomes:**
 * compare/contrast instantaneous and average speed
 * use different models of speed (strobe, graphing, calculations) to describe motion
 * develop a strategy for relating distance traveled to velocity traveled (teacher note: might be extrapolating on a graph, might be a table, might be a calculation)

set up the motion detectors/netbooks ahead of time; expect kids to play a little bit - perhaps even build in 5-10 minutes of “explore time” with the motion detectors to help mitigate off-task behavior going forward there is a LOT for students to write in their lab books for this investigation - be sure to remind students to do ALL “pencil prompts” fully and completely
 * pitfalls:**

because this section uses the lens of following distance to talk about models of motion, some students may confuse strobe models for cars following each other - instead of one car having its picture taken at equal time intervals - I down-play the “following distance” aspect of this investigation until we get to the end of the lab portion. That said, this is the section where students should be able to make sense - at least conceptually - of the relationship between velocity and distance traveled.
 * misconceptions:**


 * Section 4: Graphing Motion **
 * learning outcomes:**
 * describe acceleration with words, and equation, and a graph
 * calculate acceleration, velocity, and time using acceleration formula
 * interpret d-t and v-t graphs for no motion, constant velocity, acceleration, motion in the opposite direction


 * pitfalls:**
 * t**he lab is a difficult one to use to meet the learning outcomes because the ramp is so small - the graph created using the motion detector has a barely perceptible curve - a better alternative is the Moving Man lab using the PhET simulation

it’s easy to get bogged down in this section: particularly #10 - 12 of the investigation

It’s not really a misconception, but students without a strong math background may struggle a bit at forst with graphing motion on anything other than a position-time graph; they also want to say things like, “the line is straight” when they actually mean the line has no slope. It will help down the road if students can begin to make the connection between what is happening on the y axis when a line has a slope v. when it doesn’t. One way to show students the importance of the y axis is to show the same motion on corresponding d-t and v-t graphs.
 * misconceptions:**

relate velocity to braking distance graphically and mathematically
 * Section 5: Negative Acceleration **
 * learning outcomes:**

students will want to put “time” on their x axis graph because that’s what they usually do students will relate ramp height to braking distance instead of velocity to braking distance the quadratic relationship can be difficult for weaker math students to “see” Try giving students perfect, small numbers to help them make the connection and see the pattern. It helps to make a table with “X times velocity is increased” and “x times braking distance is increased” so that they can see the square relationship more readily.
 * pitfalls:**

to a person, students will expect the relationship between velocity and braking distance to be linear - it takes multiple examples (graphically, mathematically) to convince them otherwise
 * misconceptions:**