Halloween is a special time at Windham High School in New Hampshire. Students get to pelt their teachers with water balloons—using machines the teens built themselves! The yearly tradition is known as Trebuchet Day.
During the Middle Ages, European military forces used trebuchets [treh-byuh-SHAYS] to attack castles. These weapons could launch a projectile, like a boulder or pot of flaming material, hundreds of yards. Inspired by these ancient machines, physics teacher Pat Kaplo challenges his students to explore projectile motion by designing water-balloon-launching trebuchets. Teams have about a month to build them. “Mr. Kaplo gives some tips, but mainly we’re figuring it out as we go,” says student Ethan. “You might go through many versions of your design,” adds Nick, another student. “At first it’s not going to work the way you think.”
On Halloween morning, “you see trebuchets strapped onto cars and trucks driving to school,” says classmate Aliya. Teams wear themed costumes. Students and community members gather to watch the fun.
Teams arrange their machines in a circle 35 meters (115 feet) from a plywood “castle” at the center. Students earn points for distance and accuracy—including striking the castle, landing within the walls, or hitting the teacher inside. Teams can improve their score after the event by doing calculations to analyze the trajectory, or path, of their balloons.
“When a balloon comes close, the crowd gasps,” says Kaplo, who attends in costume as a medieval knight. “When I get hit, the squeals of joy are fantastic!”
Halloween is a special time at Windham High School in New Hampshire. Students use machines to pelt their teachers with water balloons. And the teens built the machines themselves! The yearly tradition is known as Trebuchet Day.
During the Middle Ages, European military forces attacked castles with trebuchets [treh-byuh-SHAYS]. These weapons launched projectiles. They could send a boulder or pot of flaming material hundreds of yards. Physics teacher Pat Kaplo got an idea from these ancient machines. He wants his students to learn about projectile motion. So he challenges them to design water-balloon-launching trebuchets. Teams have about a month to build them. “Mr. Kaplo gives some tips, but mainly we’re figuring it out as we go,” says student Ethan. “You might go through many versions of your design,” adds Nick, another student. “At first it’s not going to work the way you think.”
Halloween morning arrives. Then “you see trebuchets strapped onto cars and trucks driving to school,” says classmate Aliya. Teams wear themed costumes. Students and community members watch the fun.
Teams arrange their machines in a circle. They’re 35 meters (115 feet) from a plywood “castle” at the center. Students earn points for distance and accuracy. That includes striking the castle, landing within the walls, or hitting the teacher inside. After the event, teams can improve their score by doing calculations. They analyze their balloons’ trajectory, or path.
Kaplo attends in a medieval knight costume. “When a balloon comes close, the crowd gasps,” he says. “When I get hit, the squeals of joy are fantastic!”