Solution: v = π rrh = 3.14× 4×1.2 = 60.288m?
After 150 minutes, the inflow V = 0.314×150 = 47.1m?
At this time, the rising height of the water surface is h = 47.1÷ (3.14× 4) = 0.9375 m.
The following questions are similar, just talking about ideas.
2. Idea: Calculate the area of the bottom surface according to the perimeter of the bottom surface, and then calculate the volume by using the volume formula of the cone. The volume of this pile of sand remains unchanged after leveling, and the final result can be obtained by the cuboid volume formula.
3. Idea: Equal perimeter of the bottom surface means equal radius of the bottom surface, that is, equal area of the bottom surface, so the volume ratio of two cylinders is also a high ratio.
4. Thinking: This problem is actually to find the volume of the 1/4 cone wheat pile, but there seems to be one condition missing.
5. Idea: To make the surface area the most natural, there should be more exposed cubes, and the surface area is naturally larger when tiled than when stacked. Think for yourself. . .