TedTest

From the Ted Talk by Asaf Bar-Yosef: An athlete uses physics to shatter world records

Unscramble the Blue Letters

In the early 1960s, Dick Fosbury tried his hand at almost every sport, but never execlled at anything, until, at the age of 16, he trnued to the high jump. But when he couldn't compete against the strong athletes at his college using the standard high jump techniques of the time, frsbouy tried to jump a different way: backwards. Instead of jnmipug with his face towards the bar, bringing each leg over in the traditional straddle method, he jumped with his back towards the bar. Fosbury improved his record by over half a foot, and left his coaches amazed by this strange new slyte of high jumping. During the next few yares, Fosbury perfected his high jump style, won the U.S. National trials, and assured his place in the 1968 omiclpys in Mexico. In the Olympic Games, Fosbury amazed the wlrod with his new technique, winning a gold metal with an Olympic record leap of 2.24 meters. By the next omiylpc gmeas, almost all of the competing of high jumpers had adopted what came to be known as the Fosbury Flop. What's the secret behind the technique? It lies in a physics concept claeld the center of mass. For every object, we can lcoate the average position of all of its mass by taking into acocunt how the mass is spread around the object. For itancsne, the center of mass of a flat, rectangular object of uniform density will be in the intersection of both diagonals, in equal distance from each corner. We can find the center of mass for other objects by similar calculations, or by finding the object's balancing point, which lies right underneath its center of mass. Try balancing a broom by hlindog it and sollwy bnirnigg your hdans together until they meet. This balcaning point lies right underneath the broom's center of mass. We humans also have a center of mass. When most people stand up, their center of mass is around the blley, but what happens to your center of mass when you lift your hands in the air? Your center of mass moves upwards. It moves all the time as you move through the day, based on how your body is positioned. It can even move outside of your body. When you bend forward, your center of mass is located below your bent belly in a place where there is no mass at all. Weird to think about, but that's the average position of all your mass. Many objects' center of mass are outside their bodies. Think of doughnuts or boomerangs. Now look at the Fosbury Flop, and follow the position of the center of mass of the jumper. The jmpuer runs very fast, so he can divert his horizontal vticoely to vertical velocity, and jumps. Wait for it...there. Look at the jumper's center of mass as his body bends backward. It's below the bar. That is the secret behind the jump. With the old, pre-Fosbury techniques, the jumper had to apply enough focre to lift his center of mass above the bar by a few ihnces in order to clear it. The Fosbury Flopper doesn't have to do that. The genius of the Fosbury Flop is that the jumper can apply the same amount of force, but raise his body much higher than before. That means he can rsaie the bar so high that even when his cneter of mass can't go any hihger, his arching body can. Fosbury's technique brought the high jump to new hgteihs by splitting the jumper's body away from his center of mass, giving it that much more room to claer higher and higher bars. So the Fosbury Flop may be srotps history's only garet leap forward, that is also a great leap backward.

Open Cloze

In the early 1960s, Dick Fosbury tried his hand at almost every sport, but never ________ at anything, until, at the age of 16, he ______ to the high jump. But when he couldn't compete against the strong athletes at his college using the standard high jump techniques of the time, _______ tried to jump a different way: backwards. Instead of _______ with his face towards the bar, bringing each leg over in the traditional straddle method, he jumped with his back towards the bar. Fosbury improved his record by over half a foot, and left his coaches amazed by this strange new _____ of high jumping. During the next few _____, Fosbury perfected his high jump style, won the U.S. National trials, and assured his place in the 1968 ________ in Mexico. In the Olympic Games, Fosbury amazed the _____ with his new technique, winning a gold metal with an Olympic record leap of 2.24 meters. By the next _______ _____, almost all of the competing of high jumpers had adopted what came to be known as the Fosbury Flop. What's the secret behind the technique? It lies in a physics concept ______ the center of mass. For every object, we can ______ the average position of all of its mass by taking into _______ how the mass is spread around the object. For ________, the center of mass of a flat, rectangular object of uniform density will be in the intersection of both diagonals, in equal distance from each corner. We can find the center of mass for other objects by similar calculations, or by finding the object's balancing point, which lies right underneath its center of mass. Try balancing a broom by _______ it and ______ ________ your _____ together until they meet. This _________ point lies right underneath the broom's center of mass. We humans also have a center of mass. When most people stand up, their center of mass is around the _____, but what happens to your center of mass when you lift your hands in the air? Your center of mass moves upwards. It moves all the time as you move through the day, based on how your body is positioned. It can even move outside of your body. When you bend forward, your center of mass is located below your bent belly in a place where there is no mass at all. Weird to think about, but that's the average position of all your mass. Many objects' center of mass are outside their bodies. Think of doughnuts or boomerangs. Now look at the Fosbury Flop, and follow the position of the center of mass of the jumper. The ______ runs very fast, so he can divert his horizontal ________ to vertical velocity, and jumps. Wait for it...there. Look at the jumper's center of mass as his body bends backward. It's below the bar. That is the secret behind the jump. With the old, pre-Fosbury techniques, the jumper had to apply enough _____ to lift his center of mass above the bar by a few ______ in order to clear it. The Fosbury Flopper doesn't have to do that. The genius of the Fosbury Flop is that the jumper can apply the same amount of force, but raise his body much higher than before. That means he can _____ the bar so high that even when his ______ of mass can't go any ______, his arching body can. Fosbury's technique brought the high jump to new _______ by splitting the jumper's body away from his center of mass, giving it that much more room to _____ higher and higher bars. So the Fosbury Flop may be ______ history's only _____ leap forward, that is also a great leap backward.

Solution

olympics
years
balancing
higher
jumping
heights
called
excelled
slowly
clear
turned
center
account
velocity
fosbury
raise
force
world
olympic
sports
locate
style
great
inches
holding
jumper
instance
games
bringing
hands
belly

Original Text

In the early 1960s, Dick Fosbury tried his hand at almost every sport, but never excelled at anything, until, at the age of 16, he turned to the high jump. But when he couldn't compete against the strong athletes at his college using the standard high jump techniques of the time, Fosbury tried to jump a different way: backwards. Instead of jumping with his face towards the bar, bringing each leg over in the traditional straddle method, he jumped with his back towards the bar. Fosbury improved his record by over half a foot, and left his coaches amazed by this strange new style of high jumping. During the next few years, Fosbury perfected his high jump style, won the U.S. National trials, and assured his place in the 1968 Olympics in Mexico. In the Olympic Games, Fosbury amazed the world with his new technique, winning a gold metal with an Olympic record leap of 2.24 meters. By the next Olympic Games, almost all of the competing of high jumpers had adopted what came to be known as the Fosbury Flop. What's the secret behind the technique? It lies in a physics concept called the center of mass. For every object, we can locate the average position of all of its mass by taking into account how the mass is spread around the object. For instance, the center of mass of a flat, rectangular object of uniform density will be in the intersection of both diagonals, in equal distance from each corner. We can find the center of mass for other objects by similar calculations, or by finding the object's balancing point, which lies right underneath its center of mass. Try balancing a broom by holding it and slowly bringing your hands together until they meet. This balancing point lies right underneath the broom's center of mass. We humans also have a center of mass. When most people stand up, their center of mass is around the belly, but what happens to your center of mass when you lift your hands in the air? Your center of mass moves upwards. It moves all the time as you move through the day, based on how your body is positioned. It can even move outside of your body. When you bend forward, your center of mass is located below your bent belly in a place where there is no mass at all. Weird to think about, but that's the average position of all your mass. Many objects' center of mass are outside their bodies. Think of doughnuts or boomerangs. Now look at the Fosbury Flop, and follow the position of the center of mass of the jumper. The jumper runs very fast, so he can divert his horizontal velocity to vertical velocity, and jumps. Wait for it...there. Look at the jumper's center of mass as his body bends backward. It's below the bar. That is the secret behind the jump. With the old, pre-Fosbury techniques, the jumper had to apply enough force to lift his center of mass above the bar by a few inches in order to clear it. The Fosbury Flopper doesn't have to do that. The genius of the Fosbury Flop is that the jumper can apply the same amount of force, but raise his body much higher than before. That means he can raise the bar so high that even when his center of mass can't go any higher, his arching body can. Fosbury's technique brought the high jump to new heights by splitting the jumper's body away from his center of mass, giving it that much more room to clear higher and higher bars. So the Fosbury Flop may be sports history's only great leap forward, that is also a great leap backward.

Frequently Occurring Word Combinations

ngrams of length 2

collocation	frequency
high jump	4
fosbury flop	3
average position	2
great leap	2

Important Words

account
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age
air
amazed
amount
apply
arching
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