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Hack 'N Hurl Catapult Challenge

There is perhaps no STEAM* project at Calhoun that is more popular than the annual Hack 'n Hurl Catapult Challenge.

Students test catapult

Formerly known as the Punkin' Chunkin' competition, this seventh grade physics unit couples the students' understanding of force, potential and stored energy with mathematical precision, combined with  woodshop skills and artistic flair for the design of the catapult. Add to that the creativity points given for thematic presentation (music and costumes), and it's no wonder that the Hack 'n Hurl challenge requires complete (S)team collaboration!

Students are deeply engaged in the engineering design process as they plan, test, redesign and retest their creations. As they work, they continuously problem solve and take on a solution-oriented mindset, inspiring even their teachers. But the joy is not reserved just for the students and teachers involved. The culminating event has become an annual Calhoun tradition attended by an enthusiastic crowd of Lower and Middle School students, faculty and parents, who cheer on their favorite teams as they attempt to hurl hacky sacks across the gym.

The Objective
The objective of the catapult is to demonstrate the principles behind the use of stored energy: students are asked to hurl a projectile with a simple machine, using primary energy storing mechanisms like tension, torsion and gravity.

The project also provides students with an exciting, practical demonstration of force and motion while challenging them to deal with budgetary restraints and deadlines—much like they would have to do in real life situations.

Advance Research
Before the hands-on work begins, the students research and learn about different simple machines – in this case, mangonel catapults – and find out the history of medieval devices of war and siege. Combining the knowledge of catapults and including the study of potential energy and stored energy, the students start to create, test and modify their own catapults.

The Process
The students are organized into teams that are required to simulate the process that would take a company through the development of a commercial product, from proposal to design and building of the catapult, through multiple testings and final launch. The teams are judged on overall effectiveness of the catapult (distance the projectile is hurled); the company’s ability to stay within budget and on schedule; and theme design and presentation (involving the design of the catapult, costumes for team members, and accompanying musical score).

Students test their catapult during the catapult challenge

The teams make decisions as a unit, but each team member has a designated job title and task:

  • Project Manager – Works to keep the team within the eight-day schedule for the project by documenting the process and sticking to the company goals. The demonstration day is the deadline, and it is up to the Project Manager to make sure things go according to plan. Not working efficiently during class time results in “daily fees” against the budget.
  • Budget Director – Oversees the team’s $100,000 budget. The student in this position writes checks and keep records of expenditures. Wasted materials add to the cost, which ultimately affects the overall team score, so the Budget Director has to keep this in line. Construction supplies (tape, glue, etc.) are a big part of the budget.
  • Building Director – Each team invests in an 11-piece “kit” to build their catapult. The kits, pre-made by MS woodshop teacher Mike Zurkuhlen ’06, are all the same, but how the catapults are built and modified is up to the Building Director and team members. Using the knowledge of potential energy, force and energy, the building director modifies the catapult for what s/he believes will result in the best launching mechanism.
  • Launch Director – Throughout the eight-day schedule, the Launch Director is in charge of testing and perfecting the launch. Through research and further calculations –and making sure to stay within budget—last minute changes during testing days can result in a better performance during the demonstration day.
  • Design Director – The Design Director comes up with a company theme, decorative flair and costumes. Music and presentation—along with the creative theme—add to the overall score during demonstration day. It wouldn’t be a STEAM project without artistic expression and creativity!

*Science, Technology, Engineering, Art, Math


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