# Elevators!

89 (Yeah, missed a few days. Last week was “Quarterly Assessment” week and was not very photogenic.) Today the conceptual classes are applying Newton’s 2nd Law to the motion of elevators. Since I don’t want any student to feel obligated to reveal their weight to their classmates, I am the one who gets to stand on the bathroom scale. We use the differences in the scale reading when starting to move and when coming to a stop (compared to standing still) to determine the acceleration of the elevator at different points in its motion. I’m wearing my favorite brown boots in this photo, and they are pretty heavy. ðŸ˜‰

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Posted in forces, Uncategorized

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# Paper Tower

84Â (Apologies for being out of focus – sometimes the phone camera does that. This is for last Friday, the 18th.) We did a teambuilding exercise in the AP class today: the paper tower activity. The class was divided into five groups of five, and each group had two pieces of paper, two pairs of scissors, two rulers, and two 2-decimeter pieces of tape. Then they had about 25 minutes of SILENT time to work as a team with the goal of building the tallest tower based on the floor and not attached to anything but the floor. The winning team planned in advance by writing things down, measured before they cut, and worked well together to build a tower 140 cm tall. The second-place team finished quicker but built to only 135 cm high. Two teams did not complete a tower that could stand up on its own.

Posted in AP

# Scores

83 This is another histogram of my AP class’s multiple-choice scores on a test. I posted a picture of one of these before. This test had 26 multiple-choice questions and on the AP Physics C exam 50% of the points will get you a 4 or a 5 (depending on how the scores work out). 20 students scored higher than 50% on the multiple choice! Overall the kids are doing pretty well! Plus, I like making histograms. ðŸ˜€

Posted in AP, assessment

# Inversely Proportional

82 We are nearly finished analyzing the data from the Newton’s 2nd Law lab. This is the first time this year that the conceptual students have had to deal with an inverse proportion, so that is new. The shapes of the graphs look nice, but we haven’t checked to see how the slope values match up with what they should be. We are not quite there yet.

This post is actually for today. Today is the 82nd day of school. ðŸ˜‰

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Posted in forces, graphing

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# Brilliant

81 I love Brilliant.org and I wish I had time to sit and solve all the problems! They posted a problem last week about a simple pendulum and the fraction of time it spends at angles greater than the maximum angle divided by three. I gave the problem to my AP class since they have a test on oscillation this week. Several of them solved it handily, and here is one student’s graphical explanation.

I was out with a virus Wednesday through Friday last week and I forgot to take a photo Monday, so this post is for yesterday.

Posted in AP

# Chickyboom

76 With the new year, my students have to prove their physics knowledge in order to use the hall pass. They have to remove a piece from the balance board, and if the board does not fall down they are allowed to go. This game was a gift from my sister-in-law and is available on Amazon.

(posted today for last Tuesday because last Tuesday I was coming down with a nasty virus)

Posted in equilibrium

# N2 Lab

75 It is time for the conceptual classes to learn about the relationship between acceleration, force, and mass. We’re doing modified Atwood’s, varying total system mass first. As you can see, we are not a single-vendor school. I don’t even know where those little hanging mass sets come from, but I like them!

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Posted in acceleration, forces, lab

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# 0.01

74 My 5th period class had some great results from their practicum with the coffee filters. One group got a time only 0.04 seconds off their “given” time, and another group (shown above) got only 0.01 second off their “given” time! Wow!

# Equilibrium Practical

73 (I fell asleep before posting yesterday) The AP class is making mobiles. It is a tradition! I require that each must have a theme and students vote on the best theme. Really we are finished with equilibrium and are on Newtonian Gravitation, but we HAVE to do the mobiles!

Posted in AP, equilibrium, Fun

# Coffee Filters

72 Starting off the new year with a lab. This is a coffee filter drop lab, in which students model the motion of a coffee filter from data they take in class, then they predict how high they would have to drop it from in order for the filter to take a given amount of time to hit the floor. The tricky bit is the room is less than 3 meters tall, and invariably they calculate a height greater than 3 meters (I’m sneaky about how I pick the “given” times). We have to go out to one of the stairwells to test the prediction. A good model results in a drop time within 0.1 s of the given time.