![]() ![]() To create the interactive training Web site 's concise, 105-second How to Throw a Curveball video, the site teamed up with Marc McDonnell, from AllStar Dugout, a baseball and softball instructional facility. This short, straightforward tutorial, " Thrown for a Curve," comes from the Exploratorium, San Francisco's splendid self-described "museum of science, art, and human perception." It even suggests how to make such activity classroom safe (almost): "We've found that it's much easier to throw these pitches and observe the results by throwing a Styrofoam ball." Here, to get you started, is a selection of Web sites and videos guaranteed to bring physics to your classroom in ways that will be both fun and fascinating. A good way to overcome resistance is to show students the direct role physics plays in their lives and interests, and the rich resources on the Internet makes doing so easy. Physics is fun for physicists, but some students, to say the least, don't immediately warm to the subject. In fact, motorcyclesare excellent examples of just how well physics works." Physics, Fun? Oh, Yes! "Speaking on behalf of physicists everywhere," Falco declares,"nothing that ever happens on a motorcycle breaks the laws of physics. ![]() There is a very fine line between optimum corneringand crashing, where outward, downward, and forward forces balance precisely.But rules are rules. Successful race riding is a lot like paying taxes: You want to push the rules as faras you can without breaking them. Some of this heat is transferred to the hydraulic-brake fluid, which cancause brakes to lose stopping power, with potentially disastrous consequences.Engineers use space age ceramic materials to avoid this problem, and riders becomeskilled at getting on and off the brakes quickly. "All that excess energy has to be dissipated by the brakesin the form of heat," Falco says, thus bringing up the law of conservation of matterand energy. Friction on the brakes (primarily the frontbrakes) makes this possible. On some tracks, grand prix motorcycles approaching tight turns must slow frommore than 200 mph to around 40 mph. "This will happen until the rider runsout of track, or other forces become nonnegligible, such as wind resistance," says Falco. To explain why the machine moves at all, Falco invokes Newton's second law of motion:A force applied to an object will cause it to accelerate. ![]() Thelean angle of the motorcycle shifts the center of gravity to the side, causing the biketo turn, while the weight redistribution lets the machine stay slightly more upright.At the point of maximum lean required to get through a turn at the highest possiblespeed, centrifugal force wants to pull the bike machine off the track, and the rideruses traction, gravity, and momentum to stay in the game. Because the wheels act as gyroscopes, this countersteeringleans the bike in the opposite direction (into the turn), which puts the tires at an angle,narrowing what engineers call the contact patch and making the bike easier to turn.Īt the same time, the rider moves off the bike in the direction of the turn. First, a rider pushes the handlebars slightly awayfrom the direction of the turn. To a rider, this means that the faster a motorcycle isgoing, the less it wants to turn.Ĭonverting a bike's kinetic energy from straight ahead to turning requires a negotiationwith physics in a couple of ways. Friction: A special compound in these rounded tires allows traction on asphalt even at lean angles of 60 degrees and more.Īccording to Charles Falco, the University of Arizona's chair of condensed-matterphysics and co-curator of the Guggenheim Museum's The Art of the Motorcycle exhibition, the initial physics lesson to be learned watching a racing bike hurtle into a tight turnis Newton's first law of motion: "Every object persists in its state of rest or uniformmotion in a straight line unless it is compelled to change that state by forcesimpressed on it," explains Falco. Centrifugal Force: In fast turns, lean angle and forward motion counteract the powerful pull toward the outer edge of the track.Ħ. Thermodynamics: Slowing the motorcycle from high speed for tight turns causes heat buildup in its brakes and can diminish effectiveness.ĥ. ![]() First Law of Motion: Newton stated that a body in motion persists in a straight line unless compelled to change.Ĥ. Kinetic Energy: At speed on a straightaway, a motorcycle’s energy is directed forward.ģ. ![]()
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