Earth Science Class Day 5

Below are my reflections and suggestions for teaching students how to measure distance by gaining an understanding of what the Magnus effect is.

You can find the student reading and discussion about the Magnus effect here.

At about day 5 I introduce the International System of Units or SI to the class.  I discuss distance first and students know that we measure distance in meters.  I then discuss the difference between mass and weight, giving examples about how mass stays the same no matter where you are in the universe but weight does matter.  We discuss that mass is a quantity of "stuff" found in an object and is measured in grams and weight is measured in Newtons because it depends on the gravity's pull.  I then do some Karaoke with Mr. Edmonds who sings about the difference between mass and weight.  I do my best to get the class to at least do the "ba, ba, baum," down.  This year kids pulled out their phones shining light as we went, that was pretty fun and funny.

Next I introduce gravity by talking about how everybody is attractive and that the more massive they are the more attractive they get because of the they have more gravity.  This lightens the mood a little and sometimes I get that big buff football player excited that he is the most attractive student in class.  We discuss as well that it gravity is measured in Newtons and is a force.

Next we talk about volume and how it is calculated and measured.  After volume we talk about density and that it is the mass divided by the volume of an object.  I use density cubes to demonstrate that even though all the cubes are the same size they have different densities.

At this point I let the students know that we are going do three labs that will help us measure all of the SI units above.  We started off by talking about the Magnus effect and show the video that YouTube sensation Veritassium did on the Magnus effect.  You need to show this to your classes because it is fascinating.  In a little bit students will use their understanding of the Magnus effect and fly "bic" pens through the air by spinning them backwards.

I move all the tables/desks to the side so that we can fly the pens down the middle of the classroom.  Down the middle I have the tape with the metric side up.  I teach students how to use the meter tape.  Believe it or not this is actually tough for some kids.  Some have never read a meter tape yet.

There are two ways to do this lab.  Method one is to demonstrate to the students how to fly a pen using the Magnus Effect.  Tape a meter tape down the middle of your classroom with all the desks moved out of the way. Give every student a sticky note and have them write their names on it.  I collect the sticky notes.  These sticky notes are used to mark their distances.  As I call a student up in the order that I received the sticky notes, I give them three empty "bic" pens.  They get three tries to fly the pen the furthest they can.  I place their sticky note next to my estimated distance.  Because I don't like bending over all day long, I sit in a rolling chair with a long poking stick and mark their spots as the pen first hits, not where it spins off to.  After a students has launch his pen the third time I have him/her come up to where I marked the tape and they have to read the distance out to the class in millimeters. I let students know that we are using millimeters because it is more precise than centimeters and way more precise than meters. An extension of this activity is to have the student's group record his/her distance onto a spreadsheet that calculates the average and keeps track of the distance.  You can find the extension activity on SI Unit page on EarthScience.xyz.    Anyway back to the competition.  After every students has read the tape and recorded their distances, I collect all the sticky notes starting with the furthest flight placing it on the bottom of the stack as I collect them.  When I collect half of the sticky notes, I throw the others away.  The half of the class that went the farthest, get another chance.  If you are doing the extension activity, those students who lost, have to put zeros in the columns of flights in which they didn't get to fly.  This gives me an opportunity to explain how zeros can lower averages, by a lot.  I have seen students who fly a pen 7 meters on their first try, but don't go anywhere on their second try so even though they did great the first time, the zeros horribly dropped the average.  I compare this to how zeros affect grade averages as well.  I have the winners fly the pens again, read and record the tape again, and then trash the shorter distance half again.  I continue doing this for four rounds.  The last round usually only has 2-4 students left and this allows me to get a first, second, and third place winner.  I do join the competition by the way and after 10 years of doing this I have never won the game.  Sometimes I can get third place.  

Notes:  If you do the spreadsheet extension you teach them how to make calculations so that it calculates the averages as they type in their distances.  This Google Spreadsheet tutorial will demonstrate how to create calculations for this assignment.

Awards:  I give awards for the following winners:  Group with the highest average, Individual with the highest average, Furthest in the class, Furthest in all classes..

Even though the Magnus effect is not part of the Earth Science curriculum, the ability to measure distance is, and so I find that this activity is fantastic for practicing reading meter tapes.