Engaging in Guided Inquiry: As the Pendulum Swings

With the passing of every week I find myself diving deeper into the inquiry of science, the disciplines they encompasses and then quickly realize how the world is changing…with the passing of each day.

The guided inquiry question I selected was which pendulum will come to rest more quickly—a lighter pendulum or heavier pendulum. The materials I utilized from Walden’s science kit during this inquiry were a nylon string (one meter in length; 39.37 inches) and three different masses of steel washers (with diameters of 0.5, 1.0, and 1.5 inches). I created a data table to record findings and used a stopwatch to determine the period of time for each pendulum. Initially many thoughts came to mind as I prepared this inquiry specifically relating to the variables involved (length of string and masses of the steel washers). I enhanced this inquiry with an extension activity to create a means of differentiating instruction for student’s ability levels. Groups would not only explore the masses of the pendulum, but how the length of the pendulum affects its swing as well. This additional variable would provide students with a means to extend the exploration of this concept.

My exploration began by constructing the first pendulum with the one meter nylon string. I attached it first to the large, steel washer (1.5 inches in diameter). I tied one end to the washer and taped the second end of the string to a pencil. I then attached the pencil to a table with tape which would allow the pendulum to freely swing. Pulling back on the string I allowed the pendulum 20 seconds of falling time (with a timer), counting the amount of swings. I determined each time the pendulum returned to the position it began would be one full swing. I logged this information on my data sheet. I continued the same process with the remaining steel washers (1.0 inches and 0.5 inches in diameter), logging this information as well.



Although the point I am about to make references the extension activity, I would like to note my reasoning for beginning with the larger washer. Observation has taught me the majority of my students this year consider beginning with smaller manipulatives and continuing with larger ones. I also believed this to be one variable my students might consider as well. Scientifically, investigations must be written in a way to reproduce the original inquiry. To tie an end of the string to each washer required more string for the larger one. Beginning with the larger washer would allow me to consider the amount of string to use for all three washers. Tying the nylon string to the larger washer used two and one half inches of string. To balance out the amount of string utilized on both ends, I measured and used two and one half inches of string when tying it to the pencil; a total of five inches. The pendulum was now 34.37 inches in length.

The results from each of the three inquiries were identical. In a twenty second period of time, each steel washer completed 11 periods. The masses of each were different, the release point, time allotted, and length of the pendulum remained constant, 34.37 inches. As I observed each pendulum after the 20 second period of time, it was the lightest pendulum which came to rest first, followed by the middle weight and concluded with the heaviest pendulum. What I discovered is it takes less opposing forces to slow a lighter pendulum even though the three pendulums had the same oscillation periods.

This inquiry was quite engaging and did assist in my understanding of this concept. All aspects of the inquiry went well. Continuing with the extension activity and the ability to manipulate more than one variable, granted me greater knowledge into how friction and gravity affect objects in motion. My initial challenges focused on accurately tying the exact amount of string to each washer. Tying the washer itself would pose a challenge to many of my students whose fine motor skills are still developing. Determining the release height and how to release the pendulum came into consideration as well during this inquiry.

This guided inquiry would greatly benefit students and tap into their learning styles and interest levels. Students could describe the motions of each pendulum, compare and contrast and graph their results. I believe this would be an excellent means to review historical perspectives and educate students on Galileo’s views and findings of the pendulum; measuring falling time by using his pulse will certainly captivate them.

Continuing with this inquiry I realized how easily integrating yo-yo’s as a pendulum would engage students as an extension activity. The Science NetLinks web site offers a very detailed extension where students design and create their own yo-yo’s. “The engineering component of STEM education puts emphasis on the process and design of solutions” (Lantz, 2009) and allow for greater understanding of concepts. This lesson offers a myriad of ideas to assist students in their knowledge of force and motion, change of speed, comparing masses, and the effect of gravity through exploring a yo-yo. “When students gain experience with problem solving, they have the potential to invent new ways of doing things.” (Capobianco & Tyrie, 2009).

After completing this inquiry I was motivated in so many ways. I created a 5E instructional lesson plan (Hammerman, 2006) incorporating force and motion, the pendulum, and the yo-yo. Although this school year is coming to a close, I will implement this inquiry next year.

References:

Capobianco, B. M., & Tyrie, N. (2009). Problem solving by design. Science & Children, 47(2), 38–41.

Hammerman, E. (2006). Modified five Es lesson plan format. In Becoming a Better Science Teacher (pp. 81–87). Thousand Oaks, CA: Corwin Press.

Lantz, H. B. (2009). What should be the function of a K–12 STEM education? SEEN Magazine, 11(3).

Yo-Yo Motion. (2006, August 16.). Science NetLinks. Retrieved May 14, 2010, from http://www.scienclinks.com/lessons_printable.php?DocId=456.