The Foil Boat Challenge

Mr. Adeyemi held up a single square of kitchen foil. "Engineers," he said, "your challenge is to build a boat that can carry the most marbles without sinking. Each team gets one sheet of foil. That's all."

Tomas, Grace and Ravi huddled at their table. "We need tall sides," said Tomas, "so water can't get in."

Grace wasn't so sure, but they built it his way: a tiny, deep boat like a cup, with high walls.

At the test tub, Mr. Adeyemi set their boat on the water. It floated. Ravi added marbles, one at a time, counting aloud. "One, two, three, four, five, six." On the seventh marble the cup tipped over and sank to the bottom with a sad little glug.

"Seven marbles," said Mr. Adeyemi, writing it on the board. Another team had made a pointy boat like a canoe. It held nine. A team with a raft-shaped boat got fourteen.

Tomas frowned. "How did a flat raft beat a boat with walls?"

"Here's a clue," said Mr. Adeyemi. "When you put something in water, it pushes some water out of the way. If it can push away water that weighs as much as it does, it floats."

Grace's eyes lit up. "So a bigger bottom pushes away more water!"

"And the marbles were all in a pile in our cup," said Ravi. "That's why it tipped."

Mr. Adeyemi handed out fresh sheets of foil. "Round two," he said.

This time the team made a plan before they started. They drew three designs and voted. They chose a wide, flat boat, like a tray, with low walls just tall enough to keep the water out.

Then Tomas had another idea. "When we add the marbles, let's spread them out, so one side isn't heavier."

They tested it in the sink first. A corner leaked. Grace pinched it tighter. They tested again. No leaks.

Back at the test tub, the class gathered round. Ravi added marbles, one at a time, spreading them across the bottom. "Ten. Eleven. Twelve." The boat sank lower, but it stayed level.

"Eighteen. Nineteen. Twenty." Water was nearly at the top of the walls. Everyone held their breath.

"Twenty-three," whispered Ravi. The twenty-fourth marble made a tiny wave slosh over the edge, and the boat slowly sank.

"Twenty-three!" cheered the class. It was the most so far.

Tomas grinned at Grace. "Your idea was better than mine."

"No," said Grace. "Our first boat taught us what didn't work. That was part of it too."

Mr. Adeyemi wrote one word on the board, in big letters: Improve. "That," he said, "is what engineers do."

⭐ The End ⭐