Now let's simply think about it at this level. The problem means that the speed of flying forward horizontally does not consider the speed of falling.

Generally throwing things, many images are parabolas (some are upside down), so just choose parabolas directly, which may be difficult in high school.

By the way, the physical principle, in this process, energy is conserved, because it will consume a certain amount of energy when encountering resistance (so the general trend of the image is downward). When the inertia is not enough to maintain horizontal motion, the accumulated gravitational potential energy is released and begins to fall. When falling, the faster the falling speed, the slower the horizontal flying speed.