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STEM Education Innovation: Using Water Rockets and Data-Collection Technology to Teach Physics

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We’re always excited when educators share the ways they use Vernier products in their STEM classes—and we’re always so impressed by their ingenuity. We will be showcasing at least one example of STEM education innovation in each edition of The Caliper.

During the 20-plus years that Pat Counts has been teaching at Wyoming High School in Wyoming, Ohio, data-collection technology has been an essential component of his physics and Advanced Placement (AP) Physics classes.

“My school purchased a lab set of the Vernier Universal Lab Interface the first year I was hired,” Counts said. “Since the very beginning, data-collection technology has been an important part of my instruction—and I’m always looking for new ways to integrate technology into my labs to help students make real-world connections as they learn about physics concepts.”

Getting Started

A major theme for Wyoming High School’s AP Physics C course is the connection between force and motion, so Counts implemented a yearlong water rocket project to teach students about this concept.

In the fall, as an introduction to force and motion, students build their rockets from two-liter bottles, add water and compressed air, launch the vessels, and evaluate the launch performance by measuring maximum height and time aloft. 

Students build rockets to explore force and motion in Pat Counts’ AP Physics C class.
Students build rockets to explore force and motion in Pat Counts’ AP Physics C class.

“It’s too early in the year for students to use complex physics to inform their design, so they just build their rockets as they see fit,” Counts said. “This gives us a common baseline experience we can talk about and draw from as we dive deeper into physics throughout the year.”

As the months progress, students begin to write Python® programs to model the motion of the rockets, with a focus on thrust force and gravitational force.

Mastering Motion Concepts

After studying rotational dynamics, students revisit their rockets and adjust the fins for stability. Then they are ready to delve into a phenomenon they have been ignoring up to that point: the force of air resistance or drag.

“The water rocket project helps students really develop a fuller understanding of drag force while having them go through the engineering design process,” Counts said. “While many students know an object moving through air feels a resistive force and that the force depends on how fast the object is moving, air resistance isn’t the only example of drag force.”

During this time, students examine motion through a viscous fluid by observing ball bearings falling through corn syrup. Students record video of this phenomenon taking place and use the Vernier Video Analysis® app to collect and analyze position versus time data. They also use Logger Pro® to graph drag force versus speed and to determine the relationship between the variables. 

“Students are able to see that drag force in corn syrup is directly proportional to speed,” Counts said. “Without going through the video analysis process, students would have a much harder time finding this out.”

Students observe ball bearings in corn syrup to model drag force.
Vernier Video Analysis
Then students use Vernier Video Analysis to analyze the data.

To further understand drag force, students drop stacks of coffee filters over a Vernier Motion Detector and then speculate how a skydiver moves. Students analyze the position, velocity, and acceleration during various trials and compare them to their predictions.

“We are able to discuss the meaning of the slope of the best-fit line that Logger Pro applied to our drag force versus speed data,” Counts said. “This time, they see that drag force through air is proportional to speed squared.”

Preparing for Launch

As part of one of the final units in the project, students use what they have learned about drag force to revise their Python programs to simulate the motion of the two-liter bottle water rockets, including adding code to account for air resistance.

Then, after AP exams are completed, students use their programs to optimize and rebuild their rockets before launching them as part of a fun end-of-course activity.

Bottle Rocket Launch
Students record motion data from each rocket launch.

“My students really enjoy launching their rockets—it’s a spectacle!” Counts said. “Students cheer when the launch goes as planned, and they laugh and learn from the unexpected surprises. I am always so impressed and fascinated because they come up with design ideas I would never have thought of.” 

Pat Counts has taught physics at Wyoming High School for more than 20 years. Check out his experiments by following him on Twitter at @Misterfizzx.

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