Posted: 10/16/03

by Elyse Kaner, Staff writer

Velocity. Slope of linearization. Y is proportional to the square of X.

The words rolled from the tongues of Michael Crofton’s 11th and 12th-grade physics students with ease.

Students in Crofton’s classes at Spring Lake Park High School last week learned how to determine the relationship of the position and time of a disc rolling down a ramp.

But this wasn’t the old learn-by-textbook approach. Instead, they learned by modeling – a method in which students are assigned ground rules and then develop the procedures themselves, rather than being handed the equation in a textbook.

“I try to get them to have a conceptual idea before we sit down and start doing the math problems,”

Crofton said.

Working in small groups, students immersed themselves in the trial experiments.

One student carefully rolled a disc down a ramp, another timed the disc’s descent, while a third marked where the disc was at certain times of the experiment.

After three trials, they entered the data in a computer, the computer spit out a curved graph which

students then converted into a linearized graph.

“Are we measuring in centimeters?” a student asked.

“Yes, please,” Crofton said.

Junior Kelsey Hokenson enrolled in physics to satisfy a college requirement.

“I like to see why things work, and this is another way of exploring it,” said Hokenson, who plans to go into acting or teaching history.

Jennifer Anthenat said she learned “how velocity changes when gravity is an object.”

In the last unit, students moved model cars across the floor. The object of the lesson was to study the speed of objects that run at a constant speed.

As a followup, students examined speed changes and the velocity of objects that slow down and move in different directions.

Next, Crofton plans to have students roll a ball from a table and they must decide where the ball will land on the floor.

“They’ll have to figure out how fast it’s leaving the table top,” Crofton said. “Once they figure that out, they can figure out where it lands.”

Physics teaches students how to organize patterns and to solve problems that can be useful in other

situations. It teaches students to learn in teams and present their findings – two important skills necessary in the workplace, Crofton said.

For the last five years, Crofton has taught by a modeling, hands-on style. He has used computers, but prefers a “low-tech” lab, in which students have the opportunity to watch objects speed up – the disc rolling down the ramp, for example.

“I like the aesthetics better, too,” Crofton said.

Crofton has written a text and study guide for his physics class and has trained teachers on the modeling method at Arizona State University during the last two summers. The method is based on the teaching of deceased Phoenix, Ariz., physics teacher Malcolm Wells.

The physics modeling method, began in the late 1980s, gained national momentum in 1992, Crofton said.

Although the method of study takes longer, Crofton said, his students seem to enjoy physics more.

“They’re able to answer more complex questions with more accuracy,” he said.

Ninety-three percent of Crofton’s students do well enough to earn college credit by qualifying for an advanced placement test, Crofton said.

Elyse Kaner is at elyse.kaner@ecm-inc.com

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