1, its radius must be found first, so 12.56÷3. 14÷2=2cm. The radius is 2cm, so 150.72÷3. 14÷2? = 12 cm.

A: Its height is 12 cm.

2. We know that the formula for calculating the volume of a cylinder is: bottom area × height, so first find its radius, which is 15.7÷3. 14÷2=2.5m, and then calculate the volume: 2.5? ×3. 14× 1.2=23.55m？ . A cubic meter of corn weighs 0.75 tons, so 23.55 cubic meters will weigh: 23.55×0.75= 17.6625(T).

A: This pile of corn weighs 17.6625 tons.

3. We know that the length of the cylinder after expansion is the circumference of the bottom and the width is the height. So this is an unfolded square, and its height is the circumference of the bottom. Because the sides of a square are all the same. It is known that the perimeter of the bottom surface is 6.28cm and the radius is 6.28÷3. 14÷2= 1cm. The radius is 1 cm and the two cardinal numbers are 1? ×3. 14×2=6.28cm？ . Lateral area's formula is: bottom circumference × height, and the bottom circumference is diameter × 3. 14, so the diameter is twice the radius. Lateral area:1× 2× 3.14× 6.28 = 39.4384cm? . Two plus one is 39.4384+6.28=45.7 184cm? .

A: Its surface area is 45.7 184 square centimeters.

4. First calculate the volume of the cylindrical container: (10÷2)? ×3. 14× 18 = 14 13cm？ . 0.3 14L=3 14ml, so the height of water is 3 14÷5? ÷ 3.14 = 4cm. Put a big thing into the water, and the water will definitely rise. The rising part of water is the volume of iron filings. Find the rising height of water: 628÷3. 14÷5? =8cm, and the height of the poured water is 4 cm, which is 8+4= 12 cm, and a * * * is 18 cm. 18 > 12, so it will not overflow.

A: The water will not overflow.

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