Sweet swing of success.

Tiger Woods is on course to become a golf legend. Find out the science scoop on what makes him so good.

Scores of teens dream of sports stardom. But California Eldrick "Tiger" Woods doesn't have to. This 17-year-old is already one of the world's best-known golfers. Magazines from Sports Illustrated to People to Ebony have all run stories about him. And wherever Tiger goes, throngs of adoring fans follow. "He's the only amateur player that people want to talk about," says U.S. Golf Association official Rich Skyzinsky.

Tiger's claims to fame are talent beyond his years and a picture-perfect swing. With a club in his hand, Tiger is as smooth and graceful as a dancer. "When I grow up," quips 52-year-old golf legend Jack Nicklaus, "I want to have a swing as pretty as his."

But make no mistake, that swing packs a wallop. Tiger can smack a ball more than 340 yards--farther than many pros hit.

THE ENERGIZER

The secret to Tiger's swing: speed. "By the time it reaches the ball, his club is moving frighteningly fast," says golf pro Jeff Mowrer. That speed sends the ball sailing.

To get the ball moving in the first place, Tiger has to give it energy--specifically kinetic energy, the energy of motion. That energy comes from his muscles. They transfer energy to the club, which, on impact, passes it along to the ball.

Just how much energy the club has when it collides with the ball depends on two things: the mass of the club and its speed in a particular direction, or velocity.

Scientists express this relationship as an equation: Kinetic Energy = 1/2 mass x [velocity.sup.2]. From the equation, you can see that the faster a club moves, the more kinetic energy it will have. During a typical Tiger swing, the club reaches 200mph. On impact, the ball just flies... Fore!

If you're really on your toes, you might be wondering if Tiger could produce even more kinetic energy with a heavier, more massive club. Well, take another look at the equation. The benefit he'd get by increasing the club's mass (which gets divided by two) is minuscule compared with the benefit of increasing his velocity (which gets squared).

Besides, Tiger knows that the heavier a club is, the harder it is to swing. Light clubs, by contrast, are easier to swing and build more speed. Result: They transfer more kinetic energy to the ball. No surprise, then, that Tiger's long-distance drivers are the lightest clubs in his bag.

JOIN THE CLUBS

So what does Tiger do with all those other clubs? They're for hitting shorter shots. After all, it takes a combination of long and short shots to actually put the ball in the hole. To make these crucial short shots, Tiger must slow down his club. Otherwise, it would transfer too much kinetic energy, and the ball would sail past the mark.

To decrease his club speed, Tiger could alter his swing. But why mess with perfection? Instead, he selects a club designed to propel the ball the distance he wants.

For those 340-yard megablasts, Tiger uses a 43-inch driver. But when he needs to tap the ball a scant 60 yards or so, he goes with a club whose shaft is only 35 inches. In general, the shorter the club, the less speed it will build up.

If that sounds a little odd to you, try this: Lie on a carpet with one arm straight up over your head. Now move your straightened arm along the carpet in an arc down to your side. Measure the trail that your hand leaves using a tape measure.

Now try it again, this time holding a ruler to extend your arm and make a bigger arc in the carpet. Measure again.

It took your arm the same amount of time to make both arcs, but the tip of the ruler traveled farther -- right? That means it must also have traveled faster. Rate = Distance * Time, remember? Same goes for golf clubs. The longer the club, the faster the head will move through the swing.

Still, there are parts of Tiger's game that clubs cannot control. His nerves, for example. During a tournament last spring, he confesses, "I was so tense I had a tough time holding the club."

So Tiger is taking it one step at a time. Before hitting the pro ranks, he plans to go to college, play golf, and study accounting. Good plan. With a swing like his, Tiger's future is in the bank.