The Physics of the "Death Spiral"

 When I was younger my mom would absolutely love to watch figure skating during the Olympics and given that we have been discussing skating in class, I wanted to dive deeper.  I wanted to analyze the rotational motion of a specific move called the “death spiral.”  A picture of this move is shown here, it looks incredibly difficult!   In this move the male skater pulls his female partner around in a circle while she is hovering above the ground. 

 In the case of the figure skater, there is no outside force causing his body to rotate after he starts to spin, so to spin faster he has to pull together his arms and legs, which reduces his radius and inertia (I) and his rotational speed increases as a result.The male skater must plant the front tip of his blade firmly in the ice as he pulls his partner around in a circle. This is due to the centripetal acceleration that both the male skater and his partner experience during the rotation. Shown below are the equations asking the question: how much force does the male skater have to exert on the ice to maintain his center of rotation, and not drop his partner?

As seen in the equation, we get FP = 1040 N. This is equal to about 105 kg of force that the male skater must exert on the ice. This is about 25 kg more than his body weight. This is why he must crouch down low, since that gives him enough leverage to maintain his position as he rotates while not dropping his partner. And with his other skate he maintains his balance by laying the blade sideways on the ice as he goes around.

Reference: https://www.livescience.com/6120-physics-figure-skating.html#:~:text=A%20fundamental%20law%20of%20physics,turn%2C%20she%20spins%20more%20quickly.