College-Prep Physics: Today was the Colliding Buggies lab practical. Bringing life to the traditional problem ”One train leaves NY, another leaves LA. Where will they meet?”
(Video shot at 1/4 speed)
AP Physics C: Here’s the results from this year’s toilet paper roll drop. We had a bit of an issue dropping it though. On the first attempt, the student holding the end of the unrolling roll let go, thereby causing the roll to fall rather than unroll. On the second attempt, the falling roll hit the measuring tape near the ceiling. Then several days passed before the third attempt — success!
ICYMI, here are the videos from previous years:
College Prep Physics: In previous years, I introduced the concepts of distance and displacement by giving students the definitions first and then looking at a few examples. Here’s a screenshot from last year’s handout with notes:
This year, I started by giving students this question first:
The dialogue and debate among the students was great.
Now we had a purpose for the words distance and displacement because sometimes “how far” is just too vague. Plus, the students came up with the definitions on their own first, and later we can attach the formal scientific terms to those definitions.
I am on the lookout for more examples like this!
College-Prep Physics: Introduced the motion detector and position-time graphs today. Students used the mini-whiteboards to predict the graph shapes for various fast/slow buggy scenarios.
Also great discussion about how the slopes on forwards and backwards buggies compare. Typical predictions included inverse, negative, and negative reciprocal.
College-Prep Physics: Today I started using rubber stamps to help expedite grading of lab notebooks. During lab, as students finished a section in their notebooks, I looked it over to make sure it was OK. If so, I stamped the section. If not, I gave verbal feedback in the moment, (not days/weeks later) and the student hadto go and correct any errors/omissions right then and there. Now when notebooks are due, the only section I’ll need to look at is the conclusion.
College-Prep Physics: We’ve been looking at how objects interact when they are at rest. But how about when they are moving? Do interacting objects still exert equal force on each other? I’ve posted about this demo before, but the quality of the video was lacking. So I’ve got better camera and a better table. Enjoy!
UPDATE: I’ve gotten requests for access to the raw videos for video analysis purposes. You can access all the videos here: http://bit.ly/collidingcarts2014
Some useful data for video analysis:
- Frame rate = 220 fps
- Length of table = 1.825 m
- Length of cart = 0.223 m
- Mass of cart = 0.786 kg
- Mass of green College Physics textbook = 2.251 kg
- Mass of Matter and Interactions textbook = 2.303 kg