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Month: March, 2013

Algodoo

Well, this was interesting.

For the qualitative testing experiment I made a pretty simple pendulum testing model. I have 3 pendulums with bobs of different masses but the same length, and then two pendulums with bobs of the same mass but different length. This is meant to qualitatively test the hypothesis  that the period of a pendulum is proportional to the length of the string/wire/linear-non-stretchable-object. If this hypothesis is true, then the 3 pendulums should oscillate together without collisions. This is true for small amplitudes, but for larger ones the relation clearly does not hold. File can be found here.

For the quantitative experiment, I again went with something oscillatory, this time with a mass/spring cart system. Students can measure the position vs time, and from that graph ascertain the period of the oscillation. By pausing and adding or taking away mass, students can determine how exactly period of a spring is dependent on the mass and spring constant. File can be found here.

For fun, I made something called Beware The Rainbow. All of us are well aware that Lord Unicorn Pegasus, enemy of the Robotic Republic, is a vicious creature that demands sacrifice once every thousand years as tribute for protecting our universe from invasion of synthetic life. Seeing as the last sacrificial ceremony in honor our lord and savior was 500 years ago, I created a short simulation…for posterity. Simulation of our future can be found here.

 

 

Geogebra 2

For the second geogebra, I wanted to do something cool, but quickly found myself limited by my experience with the program. I wanted to create a situation where students could see how Fraunhofer Single Slit Diffraction depended on slit width, wavelength, and distance to the screen, but ended up with a raw simulation only dependent on wavelength and distance to the screen. Ideally I would have added a wave function for the intensity as well, but that was beyond the scope of my abilities given my time constraints this week.

Instead I used a ray model, with a slit width of one micrometer. The distance varies between 1 and 2 meters, and the wavelengths vary from either edge of the optical spectrum. It serves the purpose of allowing students to get a qualitative feel for how maxima and minima vary based on what kind of light is shining through and how far away the screen is, but I really would have liked to add intensity. 

I couldn’t figure out how to rotate the sine function (rotate object about point didn’t seem to work), but in the future I suppose I could feasibly just rotate my canvas and laser instead. 

Obviously this would work well for a class on optics, with the goal of having students feel their way through how light diffracts. PUM did not have a module laid out for optics, so this one was a bit of a solo project.

Here’s the link

Geogebra 1

It took me a while to think of something do simulate, and eventually I settled on making a variable force diagram for a pendulum. About 20 minutes into this, I decided that this was a terrible idea and set out to create a more interesting variable simulation. I stuck with the pendulum idea, but instead made a bar chart in geogebra.

This is modeled after the Energy Module in Pum, Lesson 3.4 specifically. Students are asked to reason as to how bar charts would change given different points in a bar charts motion. This simulation allows students to instantly check their reasoning.

Making the simulation was straightforward enough, from the get go I knew exactly what I wanted to accomplish. The hard part (unsurprisingly) was figuring out how to get geogebra to do what it was that I wanted it to do. You’ll have to forgive my work, as it is a bit messy, but lo and behold I accomplished my task.

A few notes: I made sure the pendulum bob was bound to the arc length cut out by my pivot point and two anchors, but for some reason it keeps going to a height of 1.01 instead of .98 on the right hand side. Because of this, the Kinetic Energy shows as (slightly) negative on that side. I’m not entirely sure why geogebra is allowing the bob to exceed it bounds on the right hand side, but seeing as this doesn’t really take away from the main point I’m not too worried about it. In addition, the simulation is not mobile, it is bound to the x-axis (technically it is mobile, but I wasn’t clever enough to design it such that all measurements are relative). For fun, I added two sliders: one for the mass of the bob and one for the value of the constant “g”. I imagine students will be able to have fun checking to see how messing with these values will affect the graphs.

 

Here’s the link.

Mail Merge 2

For the second mail merge, I decided to contrive an electrostatics quiz. The challenge here was deciding what values would lead to realistic results for the students. I really went all out and have large variations in all of the different value fields, so I don’t think any two quizzes are exactly the same. For the question that asks students to solve for conditions of a new acceleration, I decided to just take the answer to the previous question and add two onto that magnitude. I will be able to quickly tell whether or not students got the correct answer that way.

On one of the quizzes the sum of forces is 0. I purposely left this in, as I do not think it is too much to ask students to use their critical reasoning abilities to realize that when the sum of forces is 0, acceleration is 0 and the mass of the object of interest is completely irrelevant.

This quiz is similar to to Electrostatics Quiz 3 CP, question two.

MailMerge2 – Quiz Setup

MailMerge2MERGED – Merged Quizzes

SMITH_MM_project – Value fields listed under “Mail Merge 2”

Mail Merge 1

For the first mail merge project I decided to to keep a similar format to the example quiz we did in class, but I wanted to see just how much I could vary the conditions of the problem using “if”statements and separate conditions in excel. I decided that given the amount of students in each period, I would need at least 7 different quizzes so that no more than 4 students in a period could have the same quiz. I imagine that for points recovery most students in high school will sit down with their friends (either in the same class or other classes) and try to figure out what went wrong, and given the variety of quizzes I think the probability of them having the same quiz is relatively low. I hope the variety will facilitate healthy scientific discussion.

This quiz is similar to the HS Momentum Assessment for Lesson 2.

MailMerge1 – Quiz Setup

MailMerge1MERGED – Merged Quizzes

SMITH_MM_project – Excel Spreadsheet (under mailmerge 1)