Extreme rollers: physics helps two adventurous skaters pull off amazing stunts.When daredevils Jean-Yves Blondeau and Dirk Auer strap on their inline skates, they plan on more than just a leisurely glide in the park. For one, Blondeau doesn't attach wheels just to his feet: He lashes 28 of them to his whole body. "I have wheels on my belly, back, elbows, knees, hands, and feet," he says. Blondeau spent years researching and designing his "Buggy Rollin" suit. Now, he can cruise the roads lying on his back or even facedown on his stomach with his nose less than l0 centimeters (4 inches) from the ground. "Just standing on skates wasn't enough fun for me," he says. Unlike Blondeau, Auer limits his wheels to his feet. Still, his skating stunts are far from ordinary. With the help of an engineer, he designed a device to fasten his skates to the rails of a roller coaster. Then, supported by a safety crew, Auer skated a 520 meter (1,706 feet)-long coaster. "I was a human roller-coaster car," he says. "Nobody had ever come up with such an insane idea before!" They may be extreme, but these high-tech rollers use simple laws of physics--plus a watchful eye from trained safety experts--to pull off extraordinary stunts. GOING DOWN? Whether standing on roller-coaster rails or lying facedown, Auer and Blondeau both strive to maximize speed. Normally, skaters build forward velocity (speed in one direction) by exerting a force (push or pull) on the road. According to according to prep. 1. As stated or indicated by; on the authority of: according to historians. 2. In keeping with: according to instructions. 3. Newton's third law of motion Noun 1. Newton's third law of motion - action and reaction are equal and opposite law of action and reaction, Newton's third law, third law of motion law of motion, Newton's law, Newton's law of motion - one of three basic laws of classical mechanics : When a skater pushes off with one leg, the ground reacts-pushing the skate forward with an equal but opposite force. With each backward leg pump, the skater's forward velocity increases. To max out his forward velocity, however, Buggy Rollin' Blondeau rests his legs. Instead, he lies facedown at the top of a hill. There, his body holds gravitational grav·i·ta·tion n. 1. Physics a. The natural phenomenon of attraction between physical objects with mass or energy. b. The act or process of moving under the influence of this attraction. 2. potential energy (stored energy due to height). With a safety team nearby, he drops headfirst head·first also head·fore·most adv. 1. With the head leading; headlong: went headfirst down the stairs. 2. Impetuously; brashly. downhill. His stored potential energy converts to kinetic energy kinetic energy: see energy. kinetic energy Form of energy that an object has by reason of its motion. The kind of motion may be translation (motion along a path from one place to another), rotation about an axis, vibration, or any combination of (energy of motion), and he torpedoes down the slope. "My record speed was 98 kilometers (61 miles) per hour on a steep downhill road in Italy," he says. Auer uses the same physics to cruise the roller-coaster rails. "I began at the starting ramp--at a breathtaking height of 27 m (89 ft)," he says. The kinetic energy he gained while rolling along e ramp helped him rocket down the coaster's mils. "I did the whole run in 58 seconds at a top speed of 65 km (40 mi) per hour," he says. WHAT A DRAG Racing downhill, both extreme rollers feel the air whoosh whoosh also woosh n. 1. A sibilant sound: the whoosh of the high-speed elevator. 2. A swift movement or flow; a rush or spurt. intr.v. in their faces. While the wind can be thrilling, it also slows the skaters' rides. "As [their bodies] move through the air, they have to literally shove air molecules out of the way," says Steven Manly, a physicist at the University of Rochester The University of Rochester (UR) is a private, coeducational and nonsectarian research university located in Rochester, New York. The university is one of 62 elected members of the Association of American Universities. . That causes air resistance, a slowing force. And thanks to Newton's third law Noun 1. Newton's third law - action and reaction are equal and opposite law of action and reaction, Newton's third law of motion, third law of motion law of motion, Newton's law, Newton's law of motion - one of three basic laws of classical mechanics , "as you push the air forward, it pushes you backward equally hard," says Louis Bloomfield, a physicist at the University of Virginia. One way to reduce air resistance: Shrink the surface area exposed to the wind. Then, the skaters push fewer air molecules out of the way. That's why Blondeau's favorite position is flat on his stomach, a move he dubbed the "torpedo torpedo, in naval warfare torpedo, in naval warfare, a self-propelled submarine projectile loaded with explosives, used for the destruction of enemy ships. Although there were attempts at subsurface warfare in the 16th and 17th cent. ." Instead of smashing into air molecules with his entire body, only the top of his head and shoulders collide with them. Similarly, to slash air resistance while rolling on the rails, Auer tucks his body and bends his knees. He also wears a special helmet. "It's pointy point·y adj. point·i·er, point·i·est Having an end tapering to a point. [in the front], so it helps him spread air molecules sideways and out of the way without slowing him down as much," says Manly. TIGHT TURN A streamlined helmet helped Auer hit the straightaways Straightaways is the second release of the band Son Volt. Release Date: April 22 1997 Track listing
The inward force required to keep a particle or an object moving in a circular path. It can be shown that a particle moving in a circular path has an acceleration toward the center of the circle along a radius. (force that causes an object to move in a circle) on his legs. Meanwhile, thanks to Newton's first law of motion Noun 1. Newton's first law of motion - a body remains at rest or in motion with a constant velocity unless acted upon by an external force first law of motion, Newton's first law (see Nuts & Bolts, below), his body tried to continue on a straight path. That made him feel as if his body was being smashed sideways. "It's the same feeling you have in a car when you go around a tight curve," says Manly. "You feel like you're being thrown against the car door." The centripetal force was stronger when Auer rolled faster. "You need to have a lot of experience to balance," he says. To keep from crashing, he leaned into the turns. "That way his weight feels like it is directly over his feet," says Bloomfield. At the end of the run, Auer says his legs trembled from trying to hold himself up: "I couldn't stand the forces for one second longer." Nuts & Bolts Newton's first law of motion states that an object has inertia: It resists change in its motion. So an object at rest remains at rest, and a body moving at a particular velocity continues at that velocity unless a force acts Force Acts Series of four acts passed by the U.S. Congress (1870–75) to protect the rights guaranteed to blacks by the 14th and 15th Amendments to the Constitution of the United States. on it. This inertia keeps Auer's body moving in a straight line when he hits the coaster's curves. To turn him, the rails exert a force on his body. DID YOU KNOW? * Inventor John Joseph Merlin Jean-Joseph Merlin, born on September 17th, 1735 Huy and died on May 4th, 1803 London was an inventor, noted for the invention of roller skates. He also improved musical instruments and manufactured automats, as Cox's timepiece. is thought to be the first creator of roller skates roller skates npl → patines mpl de rueda roller skates roll npl → patins mpl à roulettes roller skates roll npl . He designed the skates which had in-line wheels--in the mid-1700s. Unfortunately, he wasn't a good skater. He wore them to a party in London, England. Unable to stop rolling, he crashed into a mirror and seriously injured himself. * Riding a roller coaster isn't the only stunt Dirk Auer has mastered on skates. He has been pulled by a motorcycle at over 290 kilometers (180 miles) per hour on a closed section of a highway in Germany. CRITICAL THINKING. * After reading the story, have students discuss how wind resistance and Newton's laws of motion Newton's laws of motion: see motion. Newton's laws of motion Relations between the forces acting on a body and the motion of the body, formulated by Isaac Newton. influence other sports. CROSS-CURRICULAR CONNECTIONS: HISTORY/ART: Research the history of roller skates. Then, create an illustrated time line, highlighting significant events related to the invention. RESOURCES * Grolier search terms: Issac Newton, wind resistance * To find out about the physics behind many everyday objects and activities, see: http://howthingswork.virginia.edu/ * For more on overcoming air resistance, check out: www.exploratorium.edu/cycling/aerodynamics1.html CHECK FOR UNDERSTANDING Name: -- DIRECTIONS: Match the word(s) in the left column with the correct phrase in the right column.
--1. velocity a. energy of motion
--2. force b. resistance to change in motion
--3. gravitational potential energy c. push or pull
--4. kinetic energy d. slowing force due to air
molecules
--5. centripetal force e. speed in one direction
--6. inertia f. force that causes an object
to move in a circle
--7. air resistance g. stored energy due to height
1.e 2. c 3. g 4. a 5. f 6. b 7. d ANSWERS 1. b 2. a 3. d |
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