Science and siege machines

Posted on: May 24, 2018

Science and siege machines

What’s a sure-fire way to engage students in a ninth-grade physical science class when discussing simple machines and energy? Introduce flying projectiles, of course.
 
Earlier this spring students in Stephen Schaack’s class set up trebuchets in the high school commons and cafeteria area, then set about launching balls at varying heights and distances.
 
For those unfamiliar with medieval siege machinery, a trebuchet is a type of catapult that uses a counterweight to power a throwing arm, which holds a projectile in a sling.
 
“Working with trebuchets gives the kids a specific hands-on way to see how the potential energy of a falling mass can be converted into the kinetic energy of a launched projectile,” said Schaack.
 
“Also, students can see how the range (firing distance) of the trebuchet depends on how much falling mass there is and what angle the projectile leaves the machine at. Overall, it serves as a common reference point for the teachers to use in class. For instance, when we talk about different types of levers, we can cite the trebuchet as an example.”
 
A side benefit of the project, which has been a highlight for the past dozen years, is that students are often required to troubleshoot problems with the trebuchets.
 
“So the students get the positive experience of figuring out how to make something work, and then apply that knowledge and skill in a competitive and exciting manner,” he said. “Most of them think it’s a lot of fun.”
 
See more photos at bit.ly/2KQTXJT.