Thursday, 11 May 2017
Broke out the photo gates for the first time this year.
I’m not a fan of photo gates in my labs because I think the setup time is too expensive for the results. Instead, I have students use video analysis whenever possible. Conservation of Momentum is one of the rare times the photo gates are a good choice. Video analysis would be time-consuming for the number of collisions we need to run.
Monday, 8 May 2017
This kid wanted to launch a rocket with multiple engines. I said ok. It wasn’t until he went to hook up the launchers that he realized this wasn’t going to work.
Wednesday, 3 May 2017
The purpose of the rocket project is to see a use for impulse. Model rocket engines like the A8 from Estes are specified for their impulse. We launch, measure the altitude using right triangles, then compare to the prediction.
This project has a ton of error, though — and that’s something I want to tackle before using the project again.
Friday, 28 April 2017
We took the entire 9th grade class to Six Flags. There was a new ride in the kids area that went in circles but you have control over this rudder/sail thing. My friend and colleague Henrik brought along a Bluetooth force probe and physics-ed the heck out of it.
This is the Wonder Woman ride at Six Flags.
Yes, my colleague brought his computer to the park.
Thursday, 20 April 2017
This one kid asked about the Monkey and Gun demo because his father remembered it from his days as a student. Did we have a way to set it up? Of course we do! So, in the last few minutes of class, I found the apparatus and they set it up. Here’s the slo-mo money shot:
The apparatus is I have is made by Pasco but I cannot find the exact electromagnet monkey-dropper available online, though this is a similar product.
Wednesday, 12 April 2017
While two of my classes took a unit test today, the third got sent outside to throw things in the air — for projectile motion. I asked them to show evidence as to whether or not the sportsball they chose was in equilibrium while flying through the air, considering horizontal and vertical equilibrium separately. Here they are filming their throws:
and here’s one group’s graph:
After 15 minutes of throwing, filming, and video-analyzing, we circled up and discussed. The evidence went something like this: See this position-time graph above? Because the vertical motion (in blue) shows changing velocity, it must have non-zero net force. And because the horizontal motion (in red) shows constant velocity, it must have zero net force.
Side note: I default to video analysis whenever possible, so my kids are good at it by now. We did this entire activity in about 20 minutes, including the discussion.
Tuesday, 11 April 2017
My colleagues ordered new carts and we used our PLC time this morning to see how we like them. These connect to a computer over Bluetooth and have an integrated 3-axis accelerometer and a force sensor. Pasco makes these carts.
One of the features of the software (Capstone) I liked was that to show data on a graph, you have to choose what to show. I think that step makes the student think about what they want to see rather than have the choices made for them.
image source: Pasco