I can't do two practical problems, 1: Cut a cylinder with a height of 10cm into two parts along the diameter, and increase the surface area by 120 m2. What is the volume of the original cylinder? 2: A piece of rectangular paper with a length of 6.28m and a width of 3.14m is rolled horizontally into a cylinder, and Xiaofang is rolled vertically into a cylinder. Which cylinder is filled with sand? How much more?

1. The surface area is increased by 120c ^, that is, 2 diameters are multiplied by height. Radius = 120 ^ 2 ^ 10 ^ 2 = 3M, Volume V = sh = 3.14 * 3 * 3 * 10 = 282.6cm & sup2; 2. The sheet is rolled horizontally into a cylinder, radius is 6.28 ^ 2 ^ 3.14 = 1m, volume is 3.14 * 1 * 3.14 = 9.8596m3

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