Modern-day high school students will tackle centuries-old technology during the seventh annual "Physics Day" at Hope College on Thursday, May 3.

In anticipation of the event, teams of students from 13 Michigan high schools are constructing miniature trebuchets--catapult-like siege engines used during the Middle Ages. Their mission: build a working model that will be able to hurl a projectile at a target accurately.

Trebuchets work something like a misbalanced see-saw board. The projectile is placed on the long end, which is held low to the ground. A weight is attached to the short end, which is raised in the air. When the long end is released, the weighted short end drops, pulling the long end up and forward fast. The projectile goes with it, and then keeps going.

To keep the challenge even, every four-member team has been sent an "official" contest projectile to hurl.  Among other criteria, the trebuchets can't be more than about half a meter (19 inches) on any given side; the trebuchet can't weigh more than five kilograms (about 11 pounds); some sort of trigger has to be built in (even if only a pull-string with a latch); and all of the energy for throwing the ball must come from "gravitational energy."

The contest will be held in the gymnasium of the college's Dow Center. The contestants haven't been told what range to shoot for--only that it won't exceed 25 meters (about 82 feet). The most accurate throw will win.

The contest is one of three events in which the four-member teams will compete. Later in the morning, they will have a chance to solve a physics problem presented to them at the time, using only their wits and materials provided. Following lunch, each team will solve a set of physics problems.

The event is coordinated by the college's department of physics. The two teams that earn the highest scores through the three events will receive a monetary prize to support the teaching of science at their respective high schools.

The schools participating this year include:  Bangor High School, Battle Creek Area Math and Science Center, Fennville High School, Grand Ledge High School, Hackett High School, Holland Christian High School, Holland High School, Howardville Christian High School, Kalamazoo Central High School, Lansing Catholic Central High School, Morrice High School, St. Joseph High School and West Ottawa High School.