Speed

Speed LEVELED READER • RA Reading A–Z Level R Leveled Reader Word Count: 1,511 Visit www.readinga-z.com Written by Bruce D. Cooperfor thousands of books and materials. www.readinga-z.com

Photo Credits: Front cover: © Sebastien Starr/Getty Images; back cover, page 8: © PhotoDisc; title page, page 7: © Pascal Lauener/Reuters/TimePix; page 4: Joe McDonald/Visuals Unlimited; page 5: © Richard Hermann/Visuals Unlimited; page 6, 11: © Bettmann/Corbis; page 9, 10, 12, 13, 16, 17, 19, 20, 21, 23: © Getty Images; page 14, 15: © NASA; page 18: © Associated Press; page 22: Louise Ann Noeth/TimePix; page 24: © Malcolm Fife/Getty Images.Written by Bruce D. Cooper Speed Correlation Level R Leveled Reader LEVEL R www.readinga-z.com © 2002 Learning Page, Inc. Revised October 2003 Fountas & Pinnell O Written by Bruce D. Cooper Reading Recovery 22 ReadingA–ZTM DRA 34 © Learning Page, Inc. All rights reserved. Learning Page 1630 E. River Road #121 Tucson, AZ 85718 www.readinga-z.com

Contents The fastest living thing, a peregrine falconIntroduction ...............................................4Who Is Fastest?..........................................7 IntroductionBicycles .....................................................10Boats ..........................................................12 What is speed? Speed is the time it takesTrains.........................................................14 to go a certain distance. For most things,Automobiles.............................................16 speed is measured in kilometers or miles perAircraft......................................................19 hour. For example, a speed of 16 kilometersConclusion ...............................................23 (10 mi.) per hour means that something is moving fast enough to travel 16 kilometers 3 in one hour. This speed is recorded as 16 kph. Speed can also be measured in other units of time and distance. It can be measured in meters per second or meters per minute. It can be measured in centimeters or inches per second, minute, or hour. 4

Faster objects are usually measured in People have always seemed to belarger units of distance and shorter units of fascinated by speed. We seem to love thingstime. Slower things, on the other hand, are that move fast. It doesn’t matter if it is ausually measured in smaller units of distance cheetah chasing a gazelle, a horse gallopingand larger units of time. For example, a snail’s around a track, or human runners dashingspeed might be measured in centimeters per toward a finish line. We simply think thathour. The movement of a glacier might be fast things are cool. Perhaps that is whymeasured in meters per month. Light—the some of the most popular Olympic events,fastest thing in the universe—moves at from the first games on, have been contests299,338 kilometers per second (186,000 mps.). involving speed.The marlin (pictured here) and sailfish are among the fastest Footrace in early Greek Olympic gamesfish in the world. 6 5

Female sprinters competing in the 100-meter dash A cheetah Who Is Fastest? Speed is important for the survival of When we watch a track meet or other most living things. The cheetah, which runssporting event, we cheer for the fastest at speeds of up to 113 kilometers per hourrunners. But compared with other living (70 mph), is the fastest living thing on land.things, humans are not all that fast. In fact, The cheetah depends on its speed to capturethe very fastest humans run at speeds of food. For many animals, survival oftenonly about 35.4 kilometers per hour (22 mph.) depends on being faster than the animal that is chasing you. 7 8

Fish swim much faster than humans due A man riding the “Accelerator,” an early bicycle (1819). It couldto their more streamlined bodies. The fastest travel uphill at the same speed as a man walking. Downhillfish is the sailfish. It zips through the water it could travel as fast as a galloping horse.at speeds of up to 113 kilometers per hour(70 mph). Bicycles The fastest living thing moves through Humans are the only animals that buildthe air. It is the peregrine falcon. This falcon mechanical things. We keep inventing newreaches speeds of 435 kilometers per hour ways to go faster and faster. Long ago we(270 mph) as it dives to capture other birds found that by building and riding bicycles,in flight. Even sailfish and cheetahs are slow we could go faster than riding a walkingcompared to the falcon. or trotting horse. A bicycle didn’t take up as much space as a horse. We didn’t need But humans are not limited by our to feed and water it, and we didn’t havebodies in order to move from place to place. messes to clean up.We use our brains to come up with ways totravel faster. Let’s look at some of these ways. 10A lithograph of Maud S, the fastest trotter in the world, in 1874 9

When we ride a bicycle, the air in front A 1794 ship showing sails puffed up by the windof us seems to push back. This is called airresistance. As we ride faster, the air seems Boatsto push back harder. In 1899, a bicycle racernamed Charles Murphy had the idea of When humans first started using boats,reducing air resistance by riding his bicycle speed was governed by how fast the riverbehind a train. By riding behind a train, flowed, how quickly and hard we paddled,Murphy was able to go 98.5 kilometers per and how hard the wind blew. By using sails,hour (60 mph). The land speed record for we were able to go faster than paddling.bicycles is now 244.6 kilometers per hour Because of drag (pull) of the water on the(152 mph). This record was set by a bicyclist boat, sailors were limited in their speed.riding behind a race car. As boat designs improved, sailors were able to go faster, but never faster than the speedCharles Murphy riding behind a train to reduce air resistance of the wind and the current.and go faster 12 11

The invention of the steam engine brought The drag of the water on the bottom ofabout huge changes in travel. When the steam the boat slows it down. Modern racing boatsengine began to be used to power ships, are designed to barely touch the water aspeople could go even faster. They were able they skim over the surface. This is calledto go faster than the wind and water. They hydroplaning. A hydroplane boat can gocould travel into the wind and against the as fast as 354 kilometers per hour (220 mph).current of the water. The fastest boat in the world is a jet-powered hydroplane. It has gone 510.2 kilometers per hour (317 mph).The SS United States, powered by a steam engine, was the The hydroplane Miss Madison on the Ohio Riverfastest ocean liner ever. It crossed the Atlantic Ocean at anaverage speed of 35 knots (65 kph, or 41 mph). Its top speedwas 44 knots (80.5 kph, or 50 mph).13 14

An early steam locomotive For years, train speed was limited by the train’s wheels rolling over steel rails. Trains This problem was solved when magnetic trains were invented. Magnetic trains ride The steam engine was first used to power on a thin cushion of air.boats and tractors. When the train wasinvented, the steam engine was used to Modern trains, called bullet trains, withpower it, too. These trains carried people and new powerful engines, now travel at speedsproducts faster than boats or wagons could. of nearly 320 kilometers per hour (200 mph). There are plans for even faster trains. These Early trains reached speeds of up to trains will travel through tubes at over 80065 kilometers per hour (40 mph). Some kilometers per hour (500 mph).passengers, used to much slower horse-drawn carriages, fainted when traveling A high-speed train in Japanat these speeds. 16 15

Some early cars also had steam or electric power. The first recognized land-speed record for an automobile was set in 1898. An automobile powered by an electric motor went 63.13 kilometers per hour (39.24 mph). Imagine going down a bumpy dirt road in a golf cart at almost 64.4 kilometers per hour (40 mph). The driver must have had quite a thrilling ride!An early automobile, the Daimler car, in 1886 Automobiles An early automobile race, 1900 When automobiles were first invented, 18they were very slow and fragile. The first carwas not much more than a small horse buggyrolling on bicycle wheels, with a small, noisyengine powering it. It was kind of like a golfcart with a lawn mower engine. Can youimagine a golf cart as your family car? 17

Sir Malcolm Campbell in one of his Bluebird cars trying to set a The land speed record for wheelednew world land speed record on Daytona Beach, Florida, 1934 vehicles is held by a jet car that is powered by two jet fighter engines. In October of 1997, As engineers, designers, and builders Andy Green became the first human to goimproved cars, the cars went faster and faster. faster than the speed of sound in a landIn the early 1900s, there were no paved vehicle. He went 1,228 kilometers per hourroads to drive fast on. People found that (763.035 mph) in a jet car called the Thrustthey could drive on the hard-packed sand SSC. It went from a complete stop to 965.6on ocean beaches at low tide. For many years, kph in 16 seconds.the fastest speed records were set on beaches.People discovered that they also could drive Andy Green driving his Thrust SSC at 1,228 kph (763 mph)fast on dry lake beds in the desert. Placeslike the Bonneville Salt Flats in Utah and 20the Black Rock Desert in Nevada are flat,open areas extending for miles. Vehiclesare safely driven at high speeds over thesedry lake beds. 19

The Lockheed SR-71 is the fastest jet airplane in the world. The Saturn V launching an Apollo mission to the Moon Aircraft If you want to move really fast, become an astronaut. In order to escape the gravitational Humans have always wanted to fly like pull of the earth, rockets must go over 45,062birds. Over the centuries, inventors have tried kilometers per hour (28,000 mph).many different ways to fly. The first airplanesused engines that drove propellers. About 2240 years later, the jet engine was invented,and the speed of aircraft really increased.The speed record now for aircraft is 3,367kilometers per hour (2,193 mph). Can youimagine flying all the way across the UnitedStates in one hour and 15 minutes? An averagejet airliner now takes about five and a halfhours to make the trip. 21

At one time, humans wanted to travel at the speed of sound. Eventually, we found ways to make planes that traveled faster than sound. Today, rockets blasting off for space travel several times greater than the speed of sound. No doubt, humans will continue to find ways to go faster over land and water and through the air. Humans probably will not be satisfied until we are traveling at the speed of light. At that speed, we could circle the globe more than 7 times in a single second. It is hard to imagine moving at such an incredibly fast speed. Conclusion 24 It is unlikely that, in the future, cheetahswill run faster or sailfish will swim faster.Nor is it likely that falcons will fly faster.Even humans are not likely to run muchfaster than they do now. But that won’t stophumans from finding other ways to go faster. 23