In fact, in China, "wooden stick" has multiple meanings: an aquatic plant; A Changbai Mountain ginseng; One metaphor is that the human brain is too stupid; The other one mentioned in this article is a washing tool! Many friends have seen this scene in movies, TV plays or remote villages. Rural women in the village wash clothes by the river in twos and threes. They soaked the dirty clothes in the river, put them on the slate and beat them hard with sticks and mallets. Every time they fight, they splash water first, then wash in the river, and then fight. Many times, again and again. Until the clothes are washed.
Many friends must be very strange. Can you knock the dirty things off your clothes with a hammer? Can I really wash clothes with a hammer? Will you ruin all your clothes? Due to the popularity of washing machines, this kind of scene is less and less common, and even the mallets in some places have become antiques. Therefore, for many friends, it is understandable to have the above questions. Then, can you explain the physical phenomenon that hammering can clean clothes?
It turns out that the reason for washing clothes with a hammer is that the moisture in wet clothes is forced to be ejected from the gaps between the clothes fibers at high speed, and the dust is washed away by the high-speed water flow. "What is the physical principle? It seems that only kinematics, mechanical knowledge and energy can explain it. That is to say, due to the rapid impact of the mallet, the water between the fibers splashes at high speed, which generates great kinetic energy when moving at high speed, so that the dust between the fibers of the clothes is strongly pushed and then splashed out with the water.
In other words, you can beat clothes with a mallet to wash clothes. But not all clothes fit. Some clothes will break if you knock like this. Physics is both interesting and useful. Now you know why!