If you are suspended, your height will drop. I haven't. Here's the theory. His liftoff is the thrust provided by the explosion of gunpowder, which reacts with the expansion of gas. This force is pushed around, which is a spherical magnifying force field. The ground is equivalent to cutting the ball in half, leaving only the upper hemisphere, but the original strength has not changed, and the lower part cannot be broken, and it can only be concentrated in the upper hemisphere. Of course, the distribution is not uniform in the upper hemisphere. It should be a gradual weakening superposition along the ground, that is to say, in the absence of the ground, the force along the ground may increase to 1.5 times, while the force in the direction of kicking the second leg will increase to1.65,438+0 times, (all are not measured, and the figures are only for your understanding). This effect is more obvious when you kick the second leg with a gun rack, because the gun rack is usually made of iron pipes and steel pipes. The opening at the bottom is more obvious, and the power of spherical expansion is limited to two breakthroughs, one is the opening at the lower ignition point, and the other is the opening in the direction of kicking away. The power of these two points will become much greater. Why does the gun have a tube? That's it. When all the forces are forced out in the direction of the muzzle, the air resistance of the shell passing through the barrel is much greater than that in the open space. The faster the speed, the greater the resistance. Therefore, the length of the barrel is also precisely calculated to ensure that the force is greater than the resistance, and there can be no deceleration in the barrel, only acceleration. Gas expansion has a process of acceleration and deceleration. When the powder starts to burn, the gas expands and accelerates, pushing the projectile and reaching the maximum value after combustion. When the projectile leaves, the space in the gun bore also releases a certain pressure. When the projectile leaves the gun barrel, all the pressure flows out along the gun bore. Therefore, the length of the barrel of a sniper rifle is usually longer than that of an ordinary rifle, which requires a higher muzzle velocity to reach a farther killing range, and the matching ammunition is also very different. I can't figure these out. It's difficult, but you should understand what I said. Similarly, you should be able to understand things like seaplanes and ground effect planes.