The Perpetual Motion Club by Sue Lange Read Free Book Online Page A

could no longer hold out against Mr. Brown’s wit. They laughed while their teacher stood with his hands on his hips as though thinking about whipping the poor girl for her stupidity.
    Elsa could stand it no longer. It wasn’t so bad to tease Cyndy Newman or Gerald Davidson, but Julie Danforth? That was just macabre.
    “But she’s right,” Elsa said from the cheap seats.
    The crowd hushed immediately and turned to the back of the room. Their laughing faces turned into those of surprise and maybe awe. The initiates up front smirked at what they thought was someone finally putting Brown in his place.
    “Ah!” Mr. Brown said, leaping forward to shake the hand of the answerer. Elsa shrank back in her seat, annoyed that she had inserted herself into the drama.
    Mr. Brown pulled her to her feet. Elsa looked sheepishly at Mr. Brown. “I mean, rotational inertia, anyway.”
    “Yes! Yes!” Mr. Brown screamed. “Rotational inertia! The inertia of a rotating body. The measure of resistance of an object to changes in its rotation. It increases with the distance from the center as the something rotates. Think about a figure skater, kids. What happens when she does her Hamill Camel?”
    Mr. Brown ran to the front and assumed the pose of a figure skater mid-Hamill Camel. “She spins lazily with her leg sticking out and then when she leans down, reaches her hands to her feet, what happens?”
    Elsa sat down. Let someone else answer.
    Ms. Danforth mumbled up front. Mr. Sun spoke out loud. Mr. Davidson and Ms. Newman fairly shouted. The entire room of people, even May, said it: “She goes faster!”
    “Yes!” Mr. Brown jumped up and sang out. She goes faster!” With the class laughter egging him on, he spun around, positively giddy that a correct answer had been produced and the trial was almost over.
    Suddenly he came to a stop and whispered forcefully: “She goes faster.”
    He straightened. “When her extremities come in to the center of the spin she speeds up. The rotational inertia, in this case Dorothy Hamill, is greater when she is spread out, radiating out, so to say. But when she pulls in, her rotational inertia is smaller because the radii of all the little bits that make up her body are smaller. She speeds up.”
    He raced to his wheel contraption. “Although there is a momentary increase of torque on the side going down when the lead globs at the top slam over, the rotational inertia for that lead glob is at the same time greater because its distance from the center is greater.” Mr. Brown spun the contraption. “You’ve got torque and inertia fighting each other. The torque wants to speed it up and the inertia wants to slow it down. The thing stops moving.” The thing stopped moving.
    He picked up his Georgia Pacific pointing stick and indicated the lead weight sitting at the bottom of the wheel. At its resting place it had the greatest distance from the center.
    “Here we have the greatest torque because it’s farther away from the center, but we also have the greatest rotational inertia to overcome to get it back up to the top. They cancel each other out. This pig won’t root!”
    Triumphantly he leaned his stick against the whiteboard, picked up a marker and scribbled “Q.E.D.” on the board.
    “Quadratic Equation Done,” one of the juniors said. Everyone including Mr. Brown laughed. Even Ms. Danforth the hero of the day, smiled a little. The normal color in her face had by now returned.
    Having come to the final conclusion so elegantly, the initiates became full-fledged members of the Northawken Science Society. They donned ceremonial robes and wore them for the rest of the evening over their ads for ibooks and Xplore. They drank a ceremonial Morton salt solution to symbolize the imbibing of scientific knowledge. The president gave each a Print•Write laminated card with the TSS (Twenty Standard Subroutines used in universal applications) and a list of the websites of the biggest software