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Pairs figure skaters

One discipline within figure skating involves a pair of skaters, one male and one female. The most spectacular move is a "throw jump", in which the male skater throws the female into the air so that she spins several times before landing on a single blade. The top pairs in the world (such as Zhang Dan and Zhang Hao of China, shown below) can send the female skater a horizontal distance L = 7 meters across the ice, and raise her center of mass h = 1.2 meters high.

It helps to have a big, strong fellow and a petite partner. Zhang Hao, for example, is about 5' 11" tall and weighs 159 pounds, while Zhang Dan is only about 5' 4" and weighs only 106 pounds.

  1. How long is the female skater in the air?
  2. What is her initial velocity (speed and direction)?
  3. What is her maximum gravitational potential energy above the ice?
  4. What is her maximum kinetic energy?
  5. Estimate Zhang Dan's angular velocity as she is spinning in the air.
  6. Suppose that the moment of inertia around the center of her body is I = 0.9 kg*m^2 while her arms and legs are tucked in. What is her rotational kinetic energy? How does it compare to her translational kinetic energy?

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Creative Commons License Copyright © Michael Richmond. This work is licensed under a Creative Commons License.