Bipolar feet are often used in festivals, weddings, celebrations and other occasions. The principle is that the reaction force generated by the impact of bottom powder on the ground is relieved;
Its powder is divided into two layers by cement or soil. The "back door" at the bottom is not tightly blocked, and the airflow generated by the lower gunpowder explosion "pinged" through the back door and sprayed downward. The downward jet of air generates upward thrust, pushing firecrackers into the air.
At this time, the fuse just ignited the gunpowder sealed at the upper end, and it quickly burned-exploded, and the second kick blossomed in mid-air. Fireworks also rely on the rapid combustion of gunpowder-the thrust generated by the explosion.
Extended data:
safe
It is dangerous to let it out, big or small. Inferior skirting boards are prone to air leakage and moisture, which will lead to two explosions on the ground, or only one. When purchasing, you should choose a regular manufacturer.
In short, kicking two feet is to wrap gunpowder in dense paper, use the expansion generated by gunpowder explosion to fry paper and make noise to entertain the masses. Because there are two sounds, it is called two kicks.
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