“If you build it right, it will float.”
Okay, okay, that’s not exactly how Archimedes, the ancient Greek mathematician, would have described his principle of “mass equals buoyancy.”
But it does sum up what three grade eight science classes at Robert Moore School learned about cardboard boats last week.
Under the direction of teacher Cathy Baron, the students lugged 15 huge homemade cardboard boats to the Fort Frances Sportsplex last Friday morning to test whether they would float across the width of the pool carrying two occupants.
“We learned how dense your boat has to be to float and what type of boat you have to have,” said Dan Yatchuk, 13, one of a group of five teens who worked together to build a boat.
“You have to have a medium-sized boat—not too big, not too small—with an air pocket in the bottom,” he added, noting his group’s boat made it across without sinking.
“We made it airtight,” he said.
“We made it just about three-quarters of the way across the pool,” noted Megan Canfield, 14, of another boat-building group. “We learned about buoyancy . . . our boat was less dense than the water.”
“It was a project to demonstrate Archimedes’ principle [and] the students did very well. They did a lot better than I expected,” Baron said Monday, noting only four of the 15 sunk.
Archimedes’ principle is the law that a body totally or partially immersed in a fluid is subject to an upward force equal in magnitude to the weight of fluid it displaces.
Archimedes died in 212 B.C.
Baron, who discovered the unique project on the Internet, gave her students two weeks to build their boats. Done during class time only, they first had to draw blueprints of their creation and follow strict building codes.
“They could only put in a maximum of two thickness’ of corrugated cardboard and only one and a half inches of tape on either side of a seam,” noted Baron.
“It could be a maximum of eight feet long and had to hold two people,” she added.
“What they discovered was that large flat boats with v-fronts and a dead air space pocket were the best [and] it was the ones who didn’t reinforce the bottoms of their boats that sunk,” she said.
Students were given a maximum of 25 points for size requirements, 25 points for their taping job, and a maximum of 100 points if they successfully crossed the width of the pool.
Baron also noted the project reinforced the philosophy of co-operative teamwork, with students doing peer evaluations on how well they worked together.
“Next year, I’m going to change the requirements and we’re going to build race boats and race them down the length of the pool,” she enthused.