Elementary school math problem: the volume of conical volume is 16 liter, and some water has been filled in the container. The water level is exactly half the height of the cone. How much water is in the container? This problem can be divided into two cases: the results of irrigation in the positive and negative directions of the cone will be different, that is, 2 or 14.

First of all, we should know that when the height of the water surface is half of the total height of the cone, the water surface divides the cone into a small cone. The radius of the bottom of this small cone is half that of the big cone, and the height is also half that of the big cone, which is similar to a triangle.

Let the radius of the cone bottom area be r and the height be h.

16=π*R*R*H/3

π*R*R*H=48

The radius of the small cone is r=R/2 and the height is h=H/2.

The volume of water =16-π * r * r * h/3 =16-π * r * h/8 =16-48/24 =14 liter.

Here's the cone. That's it.

When the cone is downward, it is 16- 14=2 liters.