University of South Carolina

moment of inertia
Changing the moment of inertia while revolving on a turntable can cause startling increases in the rate of spin.

Hands-on physics at the fair

By Steven Powell,, 803-777-1923

Enthusiastic middle and high school students from around the state crowded around physics demonstrations at Tuesday’s R. L. Childers Midway Physics Day at the South Carolina State Fair. A bubbling flask of liquid nitrogen froze flexible cloth into solid. A solid rod of metal was made to “sing” through hand-induced vibrations.

“The kids just love it,” said Debra Evans, a teacher at Columbia middle school W.A. Perry School of Aerospace. Her 28 students were “really excited about all the activities.”

“But it’s not just about fun, it’s about learning,” said University of South Carolina physics professor Jeff Wilson, who has organized the event since 2008. “The better you can engage the students in an activity, the more likely they are to retain what you’re trying to teach them,”

More than 40,000 students have taken part in USC’s annual Midway Physics Day since it was first held in 1997.

“We have teachers come up and tell us, ‘Our kids love this – and they really remember the stuff when they get back,’” he said.

At one station, students climbed onto a turntable to feel how the conservation of angular momentum could make them spin much faster when outstretched arms were pulled to one’s side. Physics professor Yordanka Ilieva of USC’s College of Arts and Sciences handed out weights for the students to hold, which heightened the effect.

“At first, they are shocked by how much more quickly they spin,” said Ilieva. “‘Why does it happen?’ they ask. Some of them wonder if the weights have to do with magnetism.”

“And then we can answer the questions. We talk about the conservation of angular momentum, which is one of the fundamental conservation laws, and we do it in a way that they can understand.”

The activities have become highly interactive by design, Wilson said. “We used to do a more traditional stage show, but about five years ago we started with small-group demonstrations, and the kids really responded to them.”

“It’s much more engaging for the students, and it gets the teachers more involved as well.” Ten USC students volunteered to help put on demonstrations this year, he said.

“It’s a really good experience for the USC students,” Wilson said. “Having to explain what’s going on andanswering questions is a learning experience for them, too.  We really appreciate the support the fair gives us to enable us to offer this event every year.”

After taking part in the series of demonstrations under the WLTX tent, the students ventured out to the rest of the fair, carrying packets of materials with which they could conduct further experiments.

“We’re going to use angles and distances on the ground to figure out the height of some of the rides,” said Jordan Kennedy of Northwood Academy in North Charleston. Other students had instruments to measure the forces they experienced on rides.

“I came back this year after doing it last year,” said A.C. Flora High School junior Salley Reamer, who’s interested in engineering. “It’s cool.”

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Posted: 10/17/12 @ 6:45 PM | Updated: 10/17/12 @ 7:00 PM | Permalink



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