Japanese Martial Arts: Kusarigama / Mr. Denjiro’s Happy Energy! скачать в хорошем качестве

Japanese Martial Arts: Kusarigama / Mr. Denjiro’s Happy Energy!

DENJIRO: Perhaps you've seen this weapon in a Japanese movie before? It's called a "kusarigama." This an old weapon consisting of a sickle and a weight are connected by a chain. Let me show you how it's used. You can entangle the opponent's weapon with the weight or throw the weight directly at them. When we watch the weight wrap around the sword, it looks like it's speeding up. In reality, it only appears that way—the weight isn't actually moving faster. Let's perform an experiment. A metal ball is attached to a wooden pole with string. Let me roll the ball. It wrapped around the pole as it moved in circles. Let's place a dot on the ball's path every 0.2 seconds. When we compare the first lap and when the length of the string is halved, we see that the distance between the dots is the same. Since no energy is applied to the ball, it doesn't accelerate. Now, we're going to pull the string through a hole to it shorten it as the ball moves. This time, the ball accelerates. That's because energy is applied to the ball when the string is pulled down. But the angular momentum stays the same, so when the length of the string is halved, we know that the speed of the ball doubles. The same principle applies when a figure skater tucks in their arms to spin faster. Let me show you! ON-SCREEN TEXT: Bringing in the arms is the same as applying energy, so he rotates faster. I hope energy will bring you all happiness. Our magic word is "Happy Energy!"