Why is figure skating always a "Beauty and the Beast" combination?

The Beijing Winter Olympics is about to begin! There are so many events in the Winter Olympics that people don't understand or have never heard of, such as curling, skeleton, biathlon, and freestyle skiing. What are the rules of these events? Speed ​​skating and short track speed skating, alpine skiing and cross-country skiing, big jump and freestyle skiing big jump are all confusing. What are the differences between them? What are the physical principles behind them?

Figure skating is a sport that brings thrills and beauty to the extreme, and jumps and spins are the most exciting moments in figure skating. Do you know what physics knowledge is hidden here?

First, the athlete stretches out his arms and lifts one leg to start spinning. Then he pulls his arms and leg in, and the spin speed increases because of the physics principle of conservation of angular momentum.

The conservation of angular momentum states that for a rotating object, when there is no external torque, the product of the moment of inertia and the angular velocity is constant. The moment of inertia describes the relationship between the mass of each part and the distance from the axis of rotation. The greater the mass of the object, the farther the mass distribution is from the axis of rotation, the greater the moment of inertia. The angular velocity describes the speed of rotation. The greater the angular velocity, the faster the rotation.

At first, the athlete stretched out his arms and legs, the mass distribution was far away from the axis of rotation, and the moment of inertia was large, so the angular velocity was slow; later, the athlete retracted his arms and legs, the mass distribution was close to the axis of rotation, and the moment of inertia was small, so the angular velocity was fast.

Moreover, if you look closely at the figure skating blades, you will find that there are serrations on the front of the blades. These serrations are very particular! When the skater rotates, he is actually skating backwards, with the front half of the blade touching the ice. The serrations on the front can play a very good stabilizing role, so that the skater will not fall. Moreover, when the skater flies into the air and then falls back to the ice, the serrations on the front are the first to touch the ice and dig deep into the ice, so that the skater can quickly stabilize.

Of course, the most beautiful thing in figure skating is the throw jump between male and female pairs. Before the throw jump, the male athlete will stretch his arms and pull the female athlete hard, reducing his own speed while the female athlete's speed increases, transferring his own speed to the female athlete, which is called conservation of momentum in physics. When "throwing", the male athlete treats the female athlete as a "stick" just like playing with a bamboo dragonfly when he was a child, and "spins it out" horizontally. The female athlete gains a torque like a spinning top, making herself spin.

At the same time, the female skater will use the blade to push the ice hard to complete the "jump" action. In this way, they can gain upward speed. Only when the male skater rubs hard enough and the female skater pushes hard enough can they jump higher and turn faster. The male skater is strong and the female skater is light, so they can throw high and turn fast. Therefore, many figure skating combinations are nicknamed "Beauty and the Beast".

At the 2010 Vancouver Winter Olympics, Chinese skaters Shen Xue and Zhao Hongbo finally won the gold medal in pairs skating after five Winter Olympics. This "couple on ice" achieved a "zero breakthrough" for my country in this event. After that, Sui Wenjing and Han Cong successfully won the silver medal at the Pyeongchang Winter Olympics. Han Cong's "passionate kiss" after the game has become a classic scene in Olympic history forever. We look forward to this year's Beijing Winter Olympics, where Chinese figure skaters can achieve even better results!

Source: Mr. Li Yongle