Analysis: According to the stem, when the water surface is 8 cm, the volume of falling water is equal to the volume of a cylinder with a radius of 5 cm and a height of 8 cm. It can be concluded that the volume of water falling 4 cm is 5×5×3. 14×8=628 cubic centimeters, and the bottom area of the water tank is 628 ÷ 4 = 628 cubic centimeters according to the volume formula of the cylinder. The volume of steel is equal to the volume of 9 cm after water is completely put into water, so157× 9 =1413 cubic centimeter.

Answer:

Solution: bottom area of water tank: 5×5×3. 14×8÷4, =628÷4,

= 157 (square centimeter),

The volume of steel is:157× 9 =1413 (cubic centimeter).

A: The volume of steel is 14 13 cubic centimeters.

Comments: The bottom area of the water tank can be obtained according to the area of the falling part of the water surface when it is pulled out 8 cm, and the problem can be solved by grasping the relationship between the rising volume of water and the volume of steel.

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