My Science School

There used to be a dangerous trend in America for racing at night through the streets in souped-up road cars, nicknamed ‘hotrods’. The official sport of hotrod racing was founded to put an end to racing on the road.

Is it true? Racing cars are not allowed to race in cities any more.

No. Several Grands Prix are still run on public roads. The event at Monte Carlo has been held on almost exactly the same circuit since 1929. The Australian Grand Prix in Melbourne is another example. The streets are cleared of public traffic in advance and crash barriers are set up. Dozens of classic car rallies also run from town to town.

Amazing! In July 1924, Ernest Eldridge broke the World Land Speed Record on a French public road. He was driving a specially built 1907 Fiat called Mephistopheles and reached 234 kph!

What were café racers?

Cafe racers were specially modified bikes, which were raced to and from roadside cafes. This craze started in England in the 1960s. Not surprisingly, cafe racing on public roads is against the law!

Who wears a yellow shirt if he’s winning?

The overall leader in the exhausting Tour de France bicycle race wears a bright yellow shirt. Recently some stages of the race have been run in southern England, Spain and Belgium, as well as France.

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Race officials aren’t allowed to talk with drivers during a race, so they communicate with flags. Different flags warn of danger, problems, or may order a driver off the track. The chequered flag is waved in front of the winning car.

Who wears fireproof underwear?

Underneath their overalls, racing drivers must wear fire-resistant ‘Nomex’ underwear, made up of a long sleeved vest, full length pants, socks and a balaclava. These protect the driver against a blaze of 700° C for twelve seconds.

Amazing! In dry conditions, bald tyres provide better grip than tyres with grooves. In the rain, cars switch to tyres with deep slots, to disperse as much water as possible and prevent skids. Each tyre can disperse 26 litres of water from the road per second!

Is it true? Racing cars could race across the ceiling.

Yes. The air pressure pushing a speeding racing car on to the track is so great that they could race upside down.

Who works in the pit?

About 20 mechanics work in the pits, where they make quick repairs and adjustments during a race. They can change a wheel in under five seconds!

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Riders in motorbike Grands Prix take corners verb quickly by leaning sharply into bends, scraping their knee against the track. This is called the ‘knee down’ position. For protection, they have tough nylon knee pads sewn into their leathers.

Which motorbike racers have three wheels?

Sidecar racing bikes have three wheels. The sidecar isn’t powered, but the second rider provides vital balance. On corners, the sidecar rider leans out, for extra roadholding, and the driver hardly has to reduce speed.

Amazing! Some bikes have tyres with metal spikes sticking from them, for riding on ice. The spikes pierce the icy surface and stop the bike from skidding. Without them, both bike and rider would go flying!

Which motorbikes don’t have brakes?

Speedway racing bikes don’t have brakes. Instead, the bike slows to an almost instant halt, as soon as the throttle is released. Riders wear extra sturdy steel boots, which they grind into the dirt, to bring the bike to a final standstill.

Is it true? Motorbike races last only one hour.

No. Different races have different lengths. The famous Le Mans race in France, for example, lasts for an exhausting 24 hours, while speedway races are often run over just four laps (1200 metres) and last for about a minute!

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There are very strict formulas or rules about how racing cars are built. Formula One cars’ size, shape and petrol tank are all governed by rules, so that every race is fair.

Amazing! Although go-carts are much smaller than other racing cars, they can reach speeds of up to 250 kph! Carting is very popular among young drivers, and many Formula One stars, like Michael Schumacher, used to race carts.

Is it true? Modern racing cars have wings.

Yes. They are at the front and back of the car. A racing car’s wings are carefully designed to stop the car from taking off. As air passes over the wing, it pulls the car down on to the track. This gives the driver better control and roadholding.

What’s an Indycar?

Indycar racing takes place at the Indianapolis Motor Speedway in America. They have powerful engines and huge fins.

Which cars race for 24 hours?

Sports cars race around the Le Mans circuit in France for 24 hours. Two or three drivers take turns at the wheel to drive the car as far as possible.

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In 1970, American Gary Gabelich drove his rocket-powered car, The Blue Flame, at 1,016 kph through the Bonneville Salt Flats, and it’s still the world’s fastest rocket car. When he wasn’t breaking records, Gary also raced dragsters and worked as a test astronaut.

Who put a rocket on a bike?

Richard ‘Rocketman’ Brown started building The Challenger in 1996. It has three rocket engines, which produce about 12,200 horsepower per tonne, taking it to 530 kph!

Is it true? Some cars need parachutes.

Yes. Some cars are so fast that brakes alone aren’t powerful enough to stop them. Parachutes drag these cars back to lower speeds when they’re travelling very quickly. Thrust SSC has four parachutes to bring it back below the sound barrier.

Who went faster than the speed of sound in a car?

Briton Andy Green set a world record in 1997, when he drove the jet-powered Thrust SSC at 1,227.985 kph through the Nevada desert.

Amazing! As early as 1904, some cars could travel at more than 160 kph! Louis Rigolly was the first person to reach this speed in his enormous 100 horsepower Gobron-Brillie car, during the July Speed Trials in Ostend, Belgium. Luckily he didn’t crash. Seatbelts hadn’t been invented and Rigolly only wore a cloth cap to protect his head!

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In 1825, George Stephenson raced his engine Locomotion against a team of horses, and won. For the first time ever, he showed that a mechanical vehicle could travel more quickly than a horse-drawn carriage.

Amazing! Racing machines have been around for a very long time. The Romans used to race horse-drawn chariots more than 2000 years ago. Their chariots had two wheels which were connected by a wooden axle. It must have been a bumpy ride. The drivers used to stand up to drive, for balance. The more horses, the faster the chariot went.

Is it true? In 1897, a cyclist beat a motorbike in a race.

Yes. A man called W.J. Stocks pedalled over 43 kilometres on his bicycle in one hour, and beat a motorbike by 270 metres. The rider of the motorbike was not happy. He said that the crowd was too noisy and had put him off!

Who first raced in cars?

The first ever race was in 1894 between Paris and Rouen in France. The Count de Dion won in a steam-powered car, which could only manage 18 kph. Early motor races showed people that cars were as fast and reliable as horses.

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INSIDE AN AIRLINER

Seated at the controls on the flight deck are the pilot and co-pilot. For much of the journey, the controls are switched to an automatic control system, or autopilot. This uses computers to sense outside conditions, such as wind speed, and to manipulate the controls accordingly to travel along a pre-set route. All the crews have to do is to keep an eye on the monitors to check that all systems are functioning correctly.

For safety reasons, a Boeing 747 is equipped with a voice recorder and a flight recorder, sometimes known as the “black box” (although it is actually a bright orange colour).These instruments record every manoeuvre the aircraft makes. In the event of an incident or a crash, the recordings can be played back and provide evidence for what went wrong.

Six display screens - three for each pilot - give all the information needed to fly the plane. The Primary Flight Display shows the aero-plane’s attitude - the angle at which it is flying in relation to the Earth. It also indicates the plane’s course, its speed and the height of the plane above the land or sea. The Navigation Display plots the plane’s position on a map of the route. The Engine Indication and Crew Alerting System (EICAS) gives information about the operation of the aero-plane’s systems and engines.

Air pressure, which keeps oxygen supplied to our lungs, is much lower at cruising altitudes (about 10,000 metres). Air is pumped into the pressurized passenger cabin to keep it at comfortable levels.

In a jet engine, air is drawn in, compressed by spinning blades, mixed with kerosene fuel and burned in a combustion chamber. The hot exhaust gas escapes at speed through the rear of the engine, turning a turbine (which drives the compressor) as it spurts past. The backward-flowing air provides a forward thrust, like the kick of a rifle after a bullet is fired.

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JET ENGINES

There are four engines on a Boeing 747, two on each wing, contained within engine cowlings (casings) attached to the wing undersides. The front entrance to the engine, known as the intake, is so large a person could stand in it.

The 747 engine is a type of jet engine called a turbofan. All jets work in the same way: hot, compressed air is expelled from the back of the engine, driving it forwards. In a turbofan, air is sucked into the engine by a whirling fan in front of the compressor. It is driven by another turbine at the rear of the engine. Some of the inflowing air is ducted around the combustion chamber to join the exhaust gas. Besides being much more powerful than other types, the engine is cooler and quieter, and more economical in its use of fuel.

Turbofan engines are equipped with thrust reversers. When in use, the jet of hot exhaust gases is deflected forwards instead of backwards, producing a force which rapidly slows down the plane landing on the runway.

Besides driving the plane through the air, the engines supply the power needed for the electricity used on board. Air is also diverted from the engine compressor to pressurize the cabin.

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BOEING 747

All Modern aeroplanes have similar features, although those of airliners such as the Boeing 747 are larger and more complex than those of smaller aeroplanes. The fuselage is a strong tube inside which the passengers, crew and their baggage travel. Wings support the aeroplane in the air by creating a force called lift. Engines provide a forward force called thrust, which pushes the aeroplane forwards against the resistance of the air (which is called drag). The fin and tail-plane keep the plane flying straight and level. Hinged sections called control surfaces (the rudder, elevators, and ailerons) steer the aircraft through the air.

The 747 is 70.7 m long. Its wingspan is 64.3 m. Take-off weight is 400 tonnes, including 150 tonnes of fuel, stored in tanks in the wings.

The Boeing 747-400 is the latest model of the world’s largest airliner, known as the “Jumbo Jet”. It can carry up to 569 passengers (but normally carries 420 in first, business and economy cabins), and cruises at up to 985 kilometres per hour, at an altitude of 10 kilometres. Its maximum range is 14,100 kilometres - more than a third of the way round the world.

As an aeroplane moves forwards through the air, air hitting the leading edge of the wing separates above and below the wing. Because of the curved shape of a wing, called an aerofoil, the air that flows over it is faster than that flowing underneath. This creates higher air pressure under the wing than above it. The difference in pressure pushes the wing upwards with a force called lift.

CONTROLLING LIFT

The amount of lift from a wing increases with the aero-plane’s speed and also with the angle of attack, the angle at which the wing hits the air. At lower speeds, the pilot maintains lift by raising the nose of the plane to increase the angle of attack. But if the angle becomes too great, air cannot flow smoothly over the top of the wing and lift is lost. This is called a stall.

At low speed during take-off and landing, flaps extend from the trailing (rear) edge of the wing. On the 747, each set of flaps has three sections. There are also small flaps on the leading edge of the wing. Flaps increase the size of the wing, and so create extra lift. For take-off, flaps are partly extended. For landing they are fully extended. Spoilers flip up from the upper surface of the wing. They break the flow of air over the wing, reducing lift.

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JET AIRCRAFT

The jet engine was developed in the late 1930s, both by Hans von Ohain in Germany and Frank Whittle in Britain. The first jet aircraft flew in 1939. Jet engines powered new jet fighters with swept-back wings, such as the MiG-15 and later the Mirage, and a new generation of airliners. Rocket-powered aircraft such as the X-15 were built for research into high-speed flight. The X-15 still holds the world speed record of 7274 kilometres per hour.

The introduction of long-range, economical, jet-powered airliners, such as the De Havilland Comet and the Boeing 707, the first “big jet”, led to a huge boom in airline travel. The first (and so far the only) supersonic airliner, the Concorde, was introduced in 1969, and the first wide-bodied airliner, the Boeing 747, came into operation in 1970.

The latest airliners, fighters such as the Eurofighter, and bombers such as the Northrop B-2, have sophisticated control systems, such as “fly-by-wire”. In an aircraft with a fly-by-wire system, the pilot controls where the aircraft goes, but a computer actually does the flying. In an airliner, fly-by-wire can prevent the pilot making mistakes such as stalling. In a fighter, it allows the pilot to make manoeuvres that would be impossible if he or she were using a standard mechanical control system.

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STORY OF FLIGHT II

The first passenger airlines were formed in 1919, just after the end of World War I. Their airliners were converted wartime bombers, such as the Farman Goliath, which had seats for 11 passengers. Flying in them was cold and bumpy, and there was noise and vibration from the piston engines. In the 1920s and 1930s aviation engineers began building in metal instead of wood, creating aircraft with strong tubular fuselages and monoplane wings, such as the Martin B-10 bomber.

The first modern-style airliners, such as the Douglas DC-3, appeared in the mid-1930s. During World War II pilots needed heavy bombers, such as the B-24 Liberator, and fast fighters, such as the Ilyushin II-2.

In 1926 a prize of $25,000 was offered to the first pilot who could fly non-stop from New York to Paris. American airmail pilot Charles Lindbergh took up the challenge. He had a new, all-metal monoplane, the Spirit of St. Louis, built especially for the journey, and decided to fly on his own. Lindbergh took off from New York on 19th May 1927. Navigating virtually by guesswork, flying low to avoid fog and fighting sleep, Lindbergh reached Paris 33 hours and 30 minutes later, to achieve the first solo Atlantic crossing.

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HELICOPTERS

The idea of a flying machine lifted by a spinning rotor is centuries’ old. The Italian painter and scientist Leonardo da Vinci designed a simple helicopter in about 1500, but he did not have an engine to power it. In 1907 Frenchman Paul Cornu rose 30 centimetres into the air in a twin-rotor helicopter, but he had no controls.

The Focke-Achgelis Fa-61 of 1936, the first successful helicopter, and the Sikorsky VS-300, the first single-rotor helicopter.

The first successful helicopters, built in the 1930s, had two rotors for lift and a propeller for propulsion. The single-rotor helicopter was developed by Russian-born American engineer Igor Sikorsky. The main rotor provided lift and propulsion, and the tail rotor prevented the fuselage (body of the aircraft) spinning in the opposite direction to the main rotor. Helicopters were soon being used by navies and for passenger services. The development of the jet engine in the 1950s made larger, faster helicopters possible.

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STORY OF FLIGHT I

For thousands of years, people must have watched birds flying around them and dreamed of copying them. Many actually tried it. These “birdmen” strapped on wings and leapt from towers, trying to flap their arms. Most were killed.

The first manned flight took place in Paris in 1783, in a hot-air balloon built by the French brothers Joseph and Etienne Montgolfier. Aviators also began to develop airships - balloons with a streamlined shape, pushed through the air by an engine. Balloons and airships are described as lighter-than-air aircraft because they float upwards in the heavier air around them.

The first heavier-than-air aircraft were gliders, built and flown in the nineteenth century by pioneers such as the German Otto Lilienthal. In the USA, two brothers, Orville and Wilbur Wright, were experimenting with kites and gliders. They made thousands of test flights in their gliders, gradually perfecting their controls. In 1903 they finally built an aeroplane, called Flyer 1, with a petrol engine. It made the first-ever powered, controlled aeroplane flight, which lasted just 12 seconds.

The Montgolfiers’ balloon carried the first pilot and passenger on a 25-minute flight. The air in the balloon was heated by straw burning on the ground. In 1852 Frenchman Henry Giffard took off in his steam-powered airship. The envelope was filled with lighter-than-air hydrogen gas rather than hot air. Airships such as the 245-metre-long Graf Zeppelin II had a steel skeleton covered in fabric. The gas was contained in huge bags inside.

In the decade after the Wright brothers’ historic flight, aviation became a popular sport. Race meetings and airshows were held, and pilots made historic long-distance flights. Aircraft technology steadily improved. Aviators began to understand how to build stronger aircraft structures without increasing weight, wings which gave better lift and created less drag, and controls that made life easier for the pilot. The standard aircraft shape, with a tail section supporting a fin and tailplane, began to become popular. More efficient and powerful engines and propellers gave aircraft greater speed, endurance and reliability. By 1913 the speed record was 203 kilometres per hour, and the distance record 1021 kilometres.

Armies began ordering aircraft from manufacturers such as Glenn Curtiss in the USA and Louis Bleriot in France. During World War I, aircraft became specialized for certain jobs, such as fast, maneuverable fighters and large, long-distance bombers. Large, flat decks were added to some battleships where aircraft could take off to attack enemy ships with torpedoes.

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BICYCLE

A bicycle is a human-powered vehicle with two wheels. The first bicycles, called “hobby horses”, were built about 200 years ago. The rider moved along by pushing his or her feet against the ground. The first pedal-powered bicycle was made by Scottish blacksmith Kirkpatrick Macmillan in 1839. In 1861 in Paris, Pierre Michaux built a bicycle on which the pedals turned the front wheels. It was known as the “boneshaker” and was the first popular bicycle. The modern bicycle, with a diamond-shaped frame and chain-driven back wheel, was designed in 1885 by Englishman John Starley.

MOTORCYCLES

Early motorcycles were simply bicycles with a small steam engine attached, but they were not practical machines. The first modern-style motorcycles, with a metal frame, two air-filled tyres and a lightweight petrol engine, appeared around 1900. Modern motorcycles have similar features to cars, but have much greater acceleration.

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HISTORY OF CARS

People had used carts pulled by horses, oxen or other large animals for more than 5000 years before the first self-propelled vehicle was built. This was a clumsy steam-powered carriage designed to pull artillery guns, built by Frenchman Nicolas Cugnot in 1769. Steam-powered vehicles called traction engines took the place of horses on farms from the 1850s. Cars driven by small steam engines were popular in the USA in the 1890s.  

Nicolas Cugnot’s steam carriage could manage just 5 km/h. Karl Benz’s three-wheeled car, which had a single-cylinder petrol engine, reached speeds of 15 km/h.

The age of the car really started with the development of the internal combustion engine. This development began in the 1850s, but it was not until the 1880s that small, lightweight, petrol-driven engines were perfected, first of all by Gottlieb Daimler in Germany. The first petrol-driven car was built by German engineer Karl Benz in 1885.

INTERNAL COMBUSTION ENGINE

The job of the internal combustion engine is to convert the energy stored in its fuel into movement. Inside the heavy engine block are cylinders (normally four in a car engine). Pistons fit snugly inside the cylinders. When the engine is running, the pistons move up and down, turning a crankshaft (which turns the wheels) via connecting rods.

Most internal combustion engines work on a four-stroke cycle which is repeated again and again as the pistons move up and down. On the first stroke, as the piston moves down, the inlet valve opens to allow a mixture of fuel and air to be sucked into the cylinder. On the second stroke, as the piston moves up, the air and fuel is squeezed into the top of the cylinder. Now a spark is created electrically by the spark plug, igniting the fuel, which forces the cylinder down. This is the third stroke. On the fourth stroke, the exhaust valve opens to let waste gases be forced out as the piston moves up again.

THE MOTOR AGE BEGINS

Benz and Daimler started selling cars in the late 1890s. In 1891 the first car with a front engine and rear-wheel drive appeared. Early cars were tricky to operate, slow and hand-built, which made them expensive. In 1908 motoring was opened up to ordinary people with the introduction in the USA of the Model-T Ford. This small car was built on a production line, making it cheap to make and so cheap to buy.

Meanwhile, motor sports were becoming popular, with cars taking part in races and rallies, and car builders competing to build the world’s fastest car. The land-speed record was first set in 1898, at 63 kilometres per hour.

Early land-speed record-holders:

(1) Jeantaud (1899, 93.7 km/h),

(2) La Jamais Contente (1899, 105.9 km/h),

(3) Serpollet (1902, 120.8 km/h)

(4) Mors (1902, 124.1 km/h).

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