Sunday, July 24, 2011

Inquiry Activity - Heat Transfer

The Heat Is On!!!!


I recently completed an inquiry activity that investigated the transfer of heat through various materials.  For my experiment, I used waxed paper, aluminum foil, plastic wrap, and a dryer sheet.






To time the activity, I used http://www.online-stopwatch.com/.


My hypothesis was that the aluminum foil would be the best insulator, followed by the waxed paper, the plastic wrap, and, finally, the dryer sheet.  As time progressed, I noticed bits of condensation underneath the waxed paper and the plastic wrap.  Also, there was a scent being given off by the dryer sheet.  At the end of the thirty minutes, I measured the temperature of each cup.  To my surprise, the plastic wrap and the waxed paper, at a tie, beat out the aluminum foil.  The dryer sheet, as I suspected, at the worst time.




If I had to repeat the experiment, I would change several variables.
  • Instead of ceramic coffee mugs, I would use plastic cups or Styrofoam cups.
  • Instead of hot water, use cold water to investigate the amount of heat transfer INTO the water.
  • Broaden the variables used to cover the cups (newspaper, fabric, sandpaper, etc.)
Procedural changes are as follows.
  • Use individual thermometers for each cup/container so that there is no lapsed time between readings.
  • Shorten the time between readings, and make more readings (three to five).  This allows for more accurate data so that students can graph the energy transfer.
  • Have students complete the activity in small groups, between two to three students.
  • Use digital cameras to record the activity.  Pictures can be used for PowerPoints and social networking sites, such as blogs.
To incorporate this into STEM, I found an engineering related guided inquiry activity from "Save the Penguins: Teaching the science of heat transfer through engineering design."  This article,written by
Christine Schnittka, Randy Bell, and Larry Richards, explores how students can engineer a habitat for penguin shaped ice cubes.  To do this, students expand upon their knowledge of insulating materials and how heat energy moves through conduction, convection, and radiation.  (This journal article can be found at the Walden University Research Database.) 

Sunday, July 10, 2011

Guided Inquiry - Swinging Pendulums

As part of the Second Application, we were asked to create a guided inquiry activity based on a question.  The question that I choose was

Which pendulum will come to rest more quickly – a lighter pendulum or heavier pendulum?



So, how did I answer this question.  Here's the process -

1.  Research - I investigated the washers that I was using.  By investigating, I mean I weighed and measured them.  I assigned them with labels - Washer A (2g), Washer B (20g), and Washer C (35g). 

2.  Hypothesize - I created a hypothesis, which states that the heavier washer, Washer C (35g) would take longer to come to rest, as compared to the other two washers, Washer A (2g) and Washer B (20g).

3.  Design and Carry Out the Experiment - To swing the washers and create a pendulum, I found an elevated flat surface.  I taped a pointer (long cylindrical tube) to the top of the flat surface.  I looped a string through Washer A.  Then I hung the washer from the tube.  I pulled the washer ninety degrees (level to the surface).  Then I dropped the washer, which began to swing.  I timed the washer using an online stopwatch.  I repeated the process for the other two washers.

4.  Record and Analyze - I recorded the data on a table.  I used the information to analyze the results.  Only parts of my hypothesis was correct.  From the information, I determined that part of the experiment is flawed.  (The larger the object, the longer it should swing.)

5.  Communicate the Results - I am communicating the results.  :)  Also, I am attaching a copy of my data sheet with the information from my experiment.  I am hoping to attach small videos of the process as soon as possible.

To modify the results, I could change the length of the string, as well as use more sizes of washers.  Also, I could use a pole that is shaped differently (as opposed to a cylinder).

My students could participate in a modified version of this guided inquiry activity based on my state's standards.  They are always interested in experimenting.  My greatest challenge will be to actively engage the students in the process before and after the experiment. 

This activity leads into discussion about momentum.  This also includes the momentum and inertia of moving vehicles.  My students are in the process of studying for their driver's licenses.  The activity creates an opportunity for students to learn about the impact of mass and velocity on momentum, such as the momentum of a moving vehicle.