Judson L. Berkey, of Manassas, is a high school varsity baseball player who began looking into the physics of a spinning baseball. Ramana Sadananda, of Springfield, undertook to investigate cardiac rhythms because her grandmother had heart trouble.

That personal motivation, hard work and a love of science brought them worldly recognition this week: They and three other Washington area students were among 40 finalists in the annual Westinghouse Science Talent Search, chosen from 1,573 students from 686 schools who entered research projects. The finalists -- 23 male, 17 female -- come from 18 states.

They will compete for $205,000 in scholarship prizes, to be awarded March 4 in Washington. This is the 50th year of the nation's most prestigious science competition for high school seniors.

Three of the local winners -- Berkey, Sadananda and Daniel M. Skovronsky, of Vienna, all of whom are 17 -- attend Thomas Jefferson High School for Science and Technology in Fairfax County. Berkey and Sadananda used the school's access to supercomputers, won in two nationwide competitions, for their projects.

Virginia's other winner, Tatiana T. Schnur, 16, of Burke, attends Robinson Secondary School in Fairfax County. The area's fifth finalist, Joel E. Moore, 17, of Chevy Chase, attends St. Albans School in the District.

Berkey's mother, Judith, said yesterday that her son began looking into the physics of baseball last spring. At one point, he read a paper by researchers at Tulane University concluding that although a baseball slows after it is pitched, its spin doesn't slow.

"It didn't make sense from his own experience," Judith Berkey said. She said her son's project, which involved sophisticated computer simulations, proved that his hunch was true. It also has potential applications in missile technology and other uses.

Sadananda said her project employed a new type of math known as nonlinear dynamics to help understand what is happening during a heart attack. She developed a computer simulation of the onset of an attack to establish conditions under which the heartbeat becomes chaotic.

Sadananda said the supercomputer performed quick calculations that could have taken hours on a conventional computer and produced graphics that would have been impossible otherwise.

Skovronsky's research idea stemmed from long hours in the library and laboratory finding a project to work on with his teacher, John Lieberman. He investigated the behavior of a class of chemical compounds using techniques such as ultraviolet spectroscopy and nuclear magnetic spectroscopy.

The research would not have been possible without the expensive equipment at Jefferson, but "those opportunities aren't the biggest opportunities," Skovronsky said. "It's having the teachers who are willing to take the time to help you."

Schnur's project, which investigated how the human brain decides what an ambiguous word means, will add to what is only a small amount of knowledge about what is going on in the brain when people talk. She did her project with a computer at the Naval Research Laboratory.

Her interest in linguistics derives partly from her mother's career as a psycholinguist. Sara Lee Schnur said her daughter also was inspired by travel and study in France.

Moore's project created a computer simulation of a technique for growing thin semiconductor films used in microelectronic circuitry. His research was done in part through a summer program at the University of California at San Diego.

"It's amusing that he wins an all-expense trip to Washington," said his mother, Janet Moore. "We said maybe we could let him take a cab."