(1) According to the problem of injecting water from cylinder A to cylinder B, we can get the dotted line ABC, which is the relationship between the water depth of cylinder B and the injection time. The practical significance indicated by point B is that the liquid level in tank B is just flush with the top of the cylindrical iron block;

(2) The functional relationship between Y and X in the two water tanks is obtained respectively, so that the time when the water levels are equal can be obtained by making Y equal;

(3) The volume of iron can be obtained by subtracting the volume of water in the water tank from the volume of water in the water tank;

Solution: solution: (1) b; a； The height of iron block in cylinder B is14cm; ;

(2) Let the analytical expressions of line segments AB and DE be: y 1=k 1x+b 1, y2=k2x+b2, ∫AB crossing points (0,2) and (4, 14), and DE crossing points.

4k 1+b 1= 14, and the solution is k 1=3 b 1=2.

b2= 12

6k2+b2=0, and the solution is: k2=-2b2= 12.

The analytical formulas are y=3x+2 and y=-2x+ 12. Let 3x+2=-2x+ 12 and the solution is x=2.

After 2 minutes, the water levels of the two water tanks are the same.

(3) According to the image, the water level rises 12cm in 4 minutes when there is no iron in the cylinder, that is, 1 minute rises by 3cm, and rises by 5cm in 2 minutes when there is no iron in the cylinder, that is, 1 minute rises by 2.5cm. If the bottom area of iron is acm2, the volumes of iron in tank B are 2.5 respectively.

(4) 60 cm2。 ∵ The volume of iron block is 1 12cm3, the bottom area of iron block is112 ∵14 = 8cm2, and the bottom area of tank A can be set to m and tank B to n.

5n=4m

Solution: m=60cm2.

Hope to adopt, thank you _!