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 gnorveed 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 dncaer is on pointe. That's called covsriaotenn of angluar 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 decarsees 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 oredr to conserve angular momentum, her angular velocity, the speed of her turn, has to increase, allowing the same amount of setrod moenmtum to crary her through multiple turns. You've probably seen ice skaters do the same thing, snnipnig 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 ________ 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 ______ is on pointe. That's called ____________ of _______ 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 _________ 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 _____ to conserve angular momentum, her angular velocity, the speed of her turn, has to increase, allowing the same amount of ______ ________ to _____ her through multiple turns. You've probably seen ice skaters do the same thing, ________ faster and faster by drawing in their arms and legs.

Solution

  1. momentum
  2. dancer
  3. conservation
  4. stored
  5. order
  6. spinning
  7. angular
  8. governed
  9. decreases
  10. carry

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

  1. allowing
  2. amount
  3. angular
  4. arms
  5. axis
  6. ballet
  7. body
  8. bring
  9. brings
  10. called
  11. carry
  12. closer
  13. conservation
  14. conserve
  15. constant
  16. dancer
  17. decreases
  18. distributed
  19. drawing
  20. equal
  21. faster
  22. fouetté
  23. friction
  24. governed
  25. ice
  26. increase
  27. increases
  28. inertia
  29. leg
  30. legs
  31. lost
  32. mass
  33. momentum
  34. motion
  35. multiple
  36. option
  37. order
  38. pointe
  39. resistance
  40. returns
  41. rotation
  42. rotational
  43. shrinks
  44. skaters
  45. speed
  46. spinning
  47. stay
  48. stored
  49. thought
  50. times
  51. turn
  52. turns
  53. velocity
  54. work