Its Electric...Boogie Woogie Woogie!

Two weeks ago I conducted the "make your own electromagnet" lesson for my class.  I did this about 5 years ago as part of a state science inquiry writing assessment.  I have to be honest, when you've taught a long long time - there really isn't that many new classroom descrepant events that you can do that you haven't already seen.  That is both a good and bad thing.  Good because you can plan well and know what you will need for your students.  You've seen many possibilities and know what the outcome is so there is no surprises.  Bad because it is boring and hard to get really excited and enthusiastic for your students.  If they see you enthusiastic, then they pick up on it and get excited too....
I also did the "how to keep your cup warm" experiment.  I tried cloth, styrofoam peanuts, cardboard enclosure, and newspaper.  When you are doing stuff that is rote...you sometimes loose the obvious.  You get so bored you don't think...I thought the peanuts would do the job, but the cardboard really kicked butt.  Then my 11 year old son came in and said something to the fact...Duh Mom, Starbucks solved that one a long time ago!  Sometimes, stupidity AND bordom is not a good combination.  I wonder how many of my students would get the obvious as well.  Knowing the students I have this year?  probably a lot - which will make me feel really stupid!

Skateboarding anyone? Exploring the Physical World~

Skateboarding is a common activity amongst middle school students. When there is a skate park across the street from a school, it is a community built laboratory for physics. The students are well aware of the behaviors of their boards but rarely do they know the physics behind the play. To teach how different surfaces affect the momentum of an object, relating it to their skill set is the best way to make science “real” for them.

            After carting the marbles down to the park and letting them go off of the various ramps, I could see that there were some issues with using the park with my students. The cement was not conducive to rolling small objects such as marbles, especially if they were of a material that bounces readily. If I rolled more than two, it was difficult to track where each went. Positioning on the ramps was just as important. A few marbles rolled up adjoining ramps. It was impossible to judge the effect of a double roll on the ramp materials. I know my students would not know how to differentiate the effect.

            If I were to do this with my students, I would use larger, heavier balls, such as bowling balls or shot puts. Another option would be the use of skateboards (without the accompanying rider). I could offer students a variety of surface treatments they could use such as remnant carpets of varying piles and cardboard sheets (old refrigerator boxes). I would offer rolling guides (1”x1” wooden strips taped to the cement) on the ramps to keep the objects from rolling astray. I would also have a strip of wood to place in front of the objects as a lift release for each the rolling event. This would eliminate the variable of an accidental (or not) push.

            The simple idea of a marble rolling down a hill can involve many physics concepts such as Potential and Kinetic energy, momentum, friction, speed, velocity, force, and gravity. I had thought that constructing a ramp in the hallway or the class would be interesting; but the skate park offers a connection that relates directly to something they enjoy. Addressing those concepts in the context of using the park and marbles or skateboards as instructional tools seems ideal and fun. I think that when they apply these concepts in this setting, they will forever change how they view their sport. Maybe inspire them to create a skate park that challenges them with different surfaces. Now that would be interesting!

Exploring Heat Transfer

           Often my students ask why learning a particular concept is important. What they want is real-life examples of the concept in action. A simple way to demonstrate one common scientific concept is to have students apply it and look for real-life applications. One example is the concept of heat transfer. We see the applications of isolative properties of matter around us. For our students to see them, we have to wrap a discovery around the concept.

            In presenting this to my students, I would discuss what keeps them warm and why that particular item keeps them warm. We would discuss what properties that the item has and why those properties work in the way they do. We would talk about how other things in their lives have to be kept warm and what is used to insulate those products. To explore this concept, I experimented with different products to keep a cup of water warm for thirty minutes.

            For my experiment, I chose to use various materials to keep water warm in an ordinary coffee cup. I had chosen four identical cups and positioned them on the counter out of drafts. I will fill each with ¾ cup of water at 200° Fahrenheit. I will cover them with various materials to test their isolative properties. The materials I choose to cover the cups were a towel, a plastic bag of foam peanuts, doubled cardboard sleeve with cap, and a cake plate cover. I labeled them Cup A (towel), Cup B (foam peanuts), Cup C (doubled cardboard), Cup D (metal cake plate cover). I believe that the bag of Styrofoam peanuts will have the best isolative properties. Being that refrigerators and ice chests are encased Styrofoam, their primary function is to insulate.

            I attached temperature strip thermometers to the same position in each cup instead of the thermometer included in the materials from the course. The thermometer would not be accurate from cup to cup because recalibration time for the thermometer to cool between each cup would affect the data collection time and temperatures of the remaining cups. I poured the 200° water into the cups. The materials are placed over the cups and left undisturbed for a period of 30 minutes.

            After 30 minutes, I checked the temperature strips in each cup. Cup A (towel) had dropped in temperature to 127°. Cup B (foam peanuts) had dropped to 113° Fahrenheit. Cup C (doubled cardboard) had dropped in temperature to 146° Fahrenheit. Cup D (cake plate) had dropped to 88° Fahrenheit, which, was still above the room temperature of 69° Fahrenheit. After recording my data, I poured out the water, rinsed the cups with cold water to reset the thermometers and repeated the experiment two more times. The results were close to the same with only a + 3° Fahrenheit temperature difference which is not enough to skew the data to another conclusion.

            I was wrong about my assessment of the Styrofoam peanuts being the most effective insulator. I did not account for the spaces between the peanuts being a heat loss factor. The towel was very effective. I believe that the air spaces in the fabric were large enough to trap air but not so large to cause as great a heat loss as the large spaces amongst the peanuts. The cake plate cover was a dismal failure. The large space under the cover was not isolative enough to retain any heat. Being metal it actually served as a heat conductor.

            It was surprising to find that the doubled cardboard did the best job at keeping the liquid in the cups hot. It was not until my son walked in to the kitchen and said, “Mom, doesn’t Starbucks use cardboard sleeves?” that I realized that this concept had been explored quite extensively by engineers of a leading corporation (Sorensen 1995). It was one of those fore-head slapping moments. I had not realized that the chambers in the cardboard make excellent heat insulators. The cardboard being a wood product that has isolative properties added to its success in keeping the liquid hot. It was also slightly waxed. Sometimes the obvious just is not quite so observable. I suppose that an old dog can be taught new tricks after all.

References

Sorensen, J. (1995-06-20). International Patent No. A47G23/02; B65D25/28;B65D3/28; B65D81/38;(IPC1-7): B65D3/22. Washington, DC: U.S.A.

2.14.2011

Moved from Edmodo 2.14.2011

Well, another Inquiry lesson done. I structured this one for the State Science Inquiry Writing assessment. Why not kill 2 birds with one stone! The only thing is that it wasn't just one lesson, it was a week's worth. Day 1: review background info, lab procedures and safety, Day 2: present scenario, problem and hypothesis, Day 3: Procedures and materials lists, Day 4 Lab, Day 5: conclusion. Its very indepth. They were so excited to use the test tubes and acids. We did an acid/base lab and evaluated the effectiveness of various antacids on the market, I even included Pepto Bismol (which isn't an antacid at all!) - just wait till the discussion on Monday when they realize that the pink stuff is actually fake mucus - we will use the word "snot". I can just hear them groan!!! I've attached a pdf of the work samples, scenario/lab booklet (for the sped kids), and the scoring guide for our state. I also am posting the lessons - have fun there is a lot there....

Jan. 23. 2011

Discussion from Edmodo on Jan.23.2011
What happens if the polar ice caps melt?
This is such a broad question. Are we talking about the coastal influence, effect on ocean currents, influence on weather patterns, wildlife effects, atmospheric changes, etc? What are the effects in different parts of the world? What are the long range effects?
With all that in mind, one can start with the following points for student discussion. Given that you have time to depart the background knowledge needed for the students to understand the magnitude of the problem.
Coastal influence: destruction of habitat
– mainly estuary (marine nursery) destruction which leads to imbalance of
marine populations. Flooding and backwashing of saline into freshwater
environs.
Ocean currents – Gulf Stream is fed by cold freshwater influence off of
Greenland. The cold water mass dropping below the warm Gulf Stream
creates an “engine” driving the Gulf Stream. Without this influence, the major
Atlantic current will cease to flow. This influence will stop the moderating
affect on the weather in Northern and Central Europe. This will create an ice
age in Europe. http://www.blogger.com/link?url=http%3A%2F%2Fen.wikipedia.org%2Fwiki%2FThermohaline_circulation
Weather – notwithstanding the dropping of temps in Europe, the warm water
will stagnate at the equator creating higher temperatures. Rise in water temps
are a major contributor to the severity of tropical storms.
http://www.blogger.com/link?url=http%3A%2F%2Fwww.civilboard.org%2Ffiles%2Fpdf%2Fhurricane%2FModels_and_Simulation%2FModel_for_Severity_of_Hurricanes_in_Gulf_of_Mexico.pdf

What other questions do you have about this Science Inquiry Experience?

Some of the questions seem too wide open to present to an elementary classroom. It is so much more than coastal flooding - even that would entail enough information to take several days of discussion. How does one decide what direction to go with the discussion – we as teachers sometimes have to make decisions as to how in-depth and board we want to go on a particular subject. I think I would narrow it down into the different components and have different groups do research to find out and report back to the group – if there is time in our curriculum to do so and if the computers are available in the lab. State testing uses several months of our tech resources and the library material is outdated (lacks $ for keeping printed resources up to date) so using that resource is unlikely. Time is usually the determining factor.
---another thing, in a middle school classroom, watching ice melt? Seriously? that would be “BORING!!” no matter what you were demonstrating with it.
Also, allowing time for a chunk of ice to melt in a glass introduces several variables.
How warm is the classroom?
How much time do you have to monitor the melting process?
In a middle school classroom you have about 45-55 minutes – not nearly enough
time to notice any real volume of melting that would show a large rise in fluids –
Is the water free of impurities?
Is the ice at the poles free of impurities?
Does that have an effect on melt rate?
Can the students extrapolate melt time to ice cap melting?
If a single cube chunk takes x amount of time and considering how much ice is at the
poles, the students may get an unrealistic view of the melt time for the polar caps?
Does the rate of melt at the poles actually accelerates with time or is it a regular metered
rate?
The younger the students, the more you have to compensate for variables – as a teacher, it
is important for us to represent Good Science. Not just Science.