2. The original lateral area =2πRh= 10πh, and the increased lateral area = 2πR(h+2) = 10π(h+2).
Therefore, the lateral area increases =10 π (h+2)-10 π h = 20 π (square centimeter).
3. because v = Sh/3, h = 3v/S =3v/ 15 =v/5 (cm).
4. A. Equal (This is the same as the first question! The reason is that the volume of the cone is multiplied by 1/3).
5, cut into three sections, then the surface area increases by four bottom areas = 12.56 square centimeters.
Therefore, the bottom area of the original cylinder = 3. 14 cm2.
Volume = Sh = 3. 14×6= 18.84 cubic centimeters.
m = 18.84×7.8 = 146.952g = 0. 146952kg。
Are you sure you want to keep the integer?
That's 0!
Either what you ask is wrong!
Maybe what people want is "How many grams does the steel pipe weigh?"
Maybe it is the height of the steel pipe. You didn't give it right?
It should be "6 meters"?