# Day 4

We started the class by taking the safety quiz. It is a 10 question multiple choice quiz.  I always use our Senteo Student Response system so the students can learn how to use them (although most students are now familiar with them because more of our teachers have started to use them.)

Following the safety quiz, we started out first lab.  I use the modeling method, so the experiment started with a demonstration and making some observations.

SIDEBAR:  Our first unit is called Essential Skills.  It is everything we want the students to know how to do. It also allows us to let the students experience modeling style physics experiments… ones with no handouts. This unit includes reviewing how to write the EOL (equation of the line) for linear graphs, using Logger Pro to create graphs, linearizing non-linear graphs.  Or first experiment is one that will give a linear data set.

The first experiment uses an inertia balance, but I do not call it that right away.  At this point it is known as a Physics Wiggler… it wiggles back and forth.  This name leads to a definition of period (and frequency).  We notice that we can change the period by adding mass to the wiggler.  This leads to a discussion and decision about independent and dependent variables.  Usually the class ends up with two experiments:  Period vs. Amplitude (with constant mass) and Period vs. Mass Added.  After just a few different amplitudes, the students see there is no effect on the period, so they don’t worry about amplitude with the mass added data set.  We write the purpose, make our hypotheses, but really don’t talk too much about the procedure.  I emphasis that we want to be as accurate as possible and to think about how we can make this happen as we gather data.

With the General classes, we guide them a bit more… we demonstrate how do gather data for the period (time ten cycles, the divide by ten) by looking at the amplitude relationship.  This makes the data gathering a bit shorter for them.

Monday will be all data gathering.