Instead of your typical test, Heart Mountain Academy students had a more exciting math and science final last week.
The students created their own trebuchets and tested them by launching water balloons at HMA principal Beth Blatt.
“It was a really fun project and the most fun final I’ve ever done,” sophomore Cody Downer said.
A trebuchet is a type of catapult that uses a swinging arm to throw a projectile.
Science teacher Ben Larsen gave the students a small model to build so they could study the physics of the devices.
“First we built the small versions and timed those by three to get all the dimensions (for the larger ones),” junior Abby Schuster said. “Then we had to figure out the right weight for it.”
Trebuchets work by using the energy of a falling counterweight to launch the projectile.
The students needed to earn STEM (Science, Technology, Engineering and Math) dollars to build their larger trebuchets, which they did in business math.
“This was a practical way to apply the concepts learned in the classroom,” math teacher Stephanie Gabriel said. “They needed to earn money, write checks to the bank, balance their savings accounts, as well as invest their earnings. We alternated weeks between ‘learning’ weeks and ‘challenge’ weeks.”
Once they’d earned enough for their materials, the students spent about two weeks constructing their contraptions.
Rainy weather forced them to test the trebuchets inside the Stock Activities Center using tennis balls.
“We didn’t know if they would work, but they shot the ball and worked great,” Larsen said. “In the Stock they got it dialed in to where they were hitting a garbage can almost every time.”
Schuster said the two contraptions both had different strengths.
“One had a lot of accuracy and the other had the best distance,” she said.
When they moved the trebuchets outside for the final May 29, the students faced a new problem, as the machines were dialed in for tennis balls and not water balloons.
“The water balloons were heavier,” Downer said.
Both groups had to add more weight to the trebuchets to launch the water balloons. Blatt sat on a chair between the two groups as “the castle.” The groups moved their machines to try and get a direct hit. After several close calls one balloon fell directly into her lap.
“The crazy thing was the accuracy with the tennis ball versus the water balloons,” Larsen said. “The balls are lighter and round but there are so many variables due to the balloons’ weight and shape.”
Gavin Strope also tested a smaller catapult and launched a balloon that Blatt caught in her hands.
“There was another lesson,” Larsen said. “The catapult could be reloaded quicker and launched faster but the trebuchets allowed them to move back and shoot from farther away.”
At the end of the tests, the students snuck up behind Blatt and pelted her with the remaining water balloons.
This is the second big STEM project HMA has taken on this year. In the winter they designed floatable shoes to walk on water at the Rec Center. Larsen said they plan more STEM projects next year.
“Our students were highly engaged throughout this project,” Gabriel added. “By developing challenges throughout they invested in their learning.”