Yesterday the students took a formative assessment on kinematic graphs. I used that to put together some teams that the students worked in as we checked the predictions for the 7 different situations involving the motion of a phan cart (OK… a dynamics cart with a fan assembly). Here are this handout with the situations.Physics Phan Cart Phun.
The fan assembly I use is from Pasco and I have the pulse assembly. This allows the length of time the fan is on or a delay before it starts to be used.
There are two main objectives for this activity. The obvious one is to gain more practice thinking about a situation involving accelerated motion and to accurately predict the kinematic graphs. The second one (and REALLY IMPORTANT) is to use it as an introduction to solving constant acceleration problems using a v-t graph. This is a truly powerful problem solving approach that I want my students to master. So, after we check the graphs, I ask an extra question or two… “Use the v-t graph to determine the acceleration”, ” Use the v-t graph to determine the change in position during this time interval”.
We are almost finished with our optics unit. All we have to determine a mathematical method (equation) that can be used to predict image characteristics. We saw the types of images formed by converging lenses is the same converging mirrors, and likewise for diverging lenses and mirrors.
The transition was great for this because one student asked “Does this mean the Thin Lens equation is really the Thin Lens/Mirror Equation?”. Well, let’s find out.
The plan for today was to use the Thin Lens Applet to gather data for a converging or diverging mirror and test to see if the thin lens equation hold true for mirrors also. BUT the computers I have would not run the Java so… Logger Pro to the rescue. I quickly generated six different data sets (object distance and a calculated column for image distance). Each student worked independently and tomorrow will team up to compare how they made it linear (by trying/making the same modification we did with the thin lens) and whiteboarding.