Wed. March 26, 2014
Physics students were given the task of analyzing several similar but different unbalanced force situations. I had two of these types of problems so I decided to split my large class into just two halves. This left 2 groups of 8-9 students each. I gave the groups the assignment of coming up with 1 whiteboard for the group that every one in the group agreed on. For a task like this that takes some thinking and debate the large groups worked really well to encourage discourse among the students without my interaction. It was like having two small board meetings going on at the same time and I wasn’t involved in either one!
Tues. Mar 25, 2014
After groups made observations from the Sticky Tape Lab they shared their data with me and the class using a Google Form that looked like this: (Link)
The class data then gets dumped into a Spreadsheet: (Link)
And finally as a class we look at all the groups data in displayed as one nice summary format generated by Google: (Link)
This works as a great way to quickly, easily, and without too much debate, agree on what we should be seeing. Because in this particular lab I’m not looking for a lot of debating discussion about what the data is. We are able to spend our time analyzing the patterns in the data the way each group should be seeing it. (Trying to have students draw conclusions from one set of wrong data doesn’t work too well, I’ve found that this fixes that.)
Mon. Mar 24, 2014
Classic Modeling Chemistry! My chem students began exploring electrical interactions (granted we didn’t call them that yet.) We used the traditional Scotch tape lab to statically charge the items and test their attraction and repulsion to each other. This lab sets the table for creating a particle model that contains charge. This will lead us into reasoning how compounds are bonded together.
Last week at the WSST (Wisconsin Society of Science Teachers) conference there was lots of talk about the Claim, Evidence, and Reasoning format for summarizing lab results. I’ve always kind of tried to get students to write conclusions in this format, but never really had the simple defining model to aid them in their writing. Today physics groups were creating whiteboards summarizing their results from the Unbalanced Force Lab, so I figured I would give it a try. We’ll see how it goes.
Thurs. Mar 20, 2014
This is one of my favorite yet simplistic labs we do. Using a small plane mirror students place a whiteboard marker in front of the mirror. Because the markers are taller than the mirrors I have the students place a second marker at the location the image appears to be at. Once they have it placed they measure the position of the “image marker” relative to the mirror, both x and y components.
The View in the Mirror:
Wed. Mar 19, 2014
Yesterday Physics was brainstorming ideas about how to change the amount of unbalanced force on a system and then measure how that effects acceleration. One group really wanted to “funnel” down the wind from a blowing fan cart. Yesterday’s design looked good but ultimately didn’t help us. The funnel didn’t allow enough air to pass through, most of the air just rebounded off the funnel and back towards the fan. A couple of crude paper funnels worked a little bit, but they found having a funnel really didn’t change anything in terms of the force the cart was experiencing. They scrapped the idea and simplified their approach.
What most groups ended up with was something like this:
Some decided to alter the mass of the cart and keep the fan speed the same. Others are holding the mass constant and altering the speed of the fans. To do this I have the fortune of having these sweet Fan Carts from Pasco:
Tues. Mar 18, 2014
Today we brainstormed variables that might affect the acceleration of an object that is experiencing an unbalanced force. One group wondered what would happen if we were able to “funnel” the wind being blown from the cart down. They hypothesized that the faster moving air at the end of the funnel would provide more “push” on the cart. However, one of the group members saw a problem with the fact the air is pushing in a smaller area. They began by trying to create a paper funnel without too much luck. One found this nice plastic funnel in my chem equipment drawers.
They had a few problems with this set up. Do you know what they were? They are thinking of doing some modification to the design, so I’ll wait to share tomorrow what they come up with.