full transcript
#### From the Ted Talk by Arleen Sugano: The physics of the "hardest move" in ballet

## Unscramble the Blue Letters

The other option is for the dancer to bring her arms or leg in closer to her body once she returns to pointe. Why does this work? Like every other turn in ballet, the fouetté is governed by aalngur mmtneoum, which is equal to the dancer's angular vtcieoly tmeis her rotational inertia. And except for what's lost to fiorictn, that angular momentum has to stay constant while the daecnr is on pointe. That's called coeriovtsnan of angular momentum. Now, rotational iinrtea can be thought of as a body's resistance to rotational motion. It increases when more mass is distributed further from the axis of rotation, and decreases when the mass is distributed closer to the axis of rotation. So as she brings her arms closer to her body, her raiottanol inertia shrinks. In oedrr to conserve angular momentum, her angular velocity, the speed of her turn, has to increase, allowing the same amount of stored momentum to crary her through mtpiulle turns. You've probably seen ice skaters do the same thing, spinning faster and faster by drawing in their arms and legs.
## Open Cloze

The other option is for the dancer to bring her arms or leg in closer to her body once she returns to pointe. Why does this work? Like every other turn in ballet, the fouetté is governed by **_______** **________**, which is equal to the dancer's angular **________** **_____** her rotational inertia. And except for what's lost to **________**, that angular momentum has to stay constant while the **______** is on pointe. That's called **____________** of angular momentum. Now, rotational **_______** can be thought of as a body's resistance to rotational motion. It increases when more mass is distributed further from the axis of rotation, and decreases when the mass is distributed closer to the axis of rotation. So as she brings her arms closer to her body, her **__________** inertia shrinks. In **_____** to conserve angular momentum, her angular velocity, the speed of her turn, has to increase, allowing the same amount of stored momentum to **_____** her through **________** turns. You've probably seen ice skaters do the same thing, spinning faster and faster by drawing in their arms and legs.
## Solution

- times
- velocity
- dancer
- momentum
- multiple
- angular
- rotational
- friction
- order
- conservation
- carry
- inertia

## Original Text

The other option is for the dancer to bring her arms or leg in closer to her body once she returns to pointe. Why does this work? Like every other turn in ballet, the fouetté is governed by angular momentum, which is equal to the dancer's angular velocity times her rotational inertia. And except for what's lost to friction, that angular momentum has to stay constant while the dancer is on pointe. That's called conservation of angular momentum. Now, rotational inertia can be thought of as a body's resistance to rotational motion. It increases when more mass is distributed further from the axis of rotation, and decreases when the mass is distributed closer to the axis of rotation. So as she brings her arms closer to her body, her rotational inertia shrinks. In order to conserve angular momentum, her angular velocity, the speed of her turn, has to increase, allowing the same amount of stored momentum to carry her through multiple turns. You've probably seen ice skaters do the same thing, spinning faster and faster by drawing in their arms and legs.
## Frequently Occurring Word Combinations

### ngrams of length 2

collocation |
frequency |

angular momentum |
3 |

rotational inertia |
3 |

black swan |
2 |

stored momentum |
2 |

## Important Words

- allowing
- amount
- angular
- arms
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- conservation
- conserve
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- dancer
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- fouetté
- friction
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- ice
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- inertia
- leg
- legs
- lost
- mass
- momentum
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- multiple
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- order
- pointe
- resistance
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- rotation
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- shrinks
- skaters
- speed
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- stored
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- times
- turn
- turns
- velocity
- work