As shown in Figure A, it is the exterior of Rudong Wind Farm in Jiangsu, which is the largest wind power base in Asia at present. After Xiaoming visited the wind farm,

(1) Blades of different materials will affect the output power of the generator. For example, the lighter the material of the blade, the easier it is to rotate. At the same time, if the blade surface area is different, the energy obtained by the blade is also different, which will also affect the output power.

So the answer is: the material (or surface area) of the blade.

(2) Since the lifting height should be the same, we can know from h=Vt, lifting speed from lifting time, and output power from P=Wt=mght=mgV, so we can know the power by comparing lifting time.

So the answer is: the time to upgrade the hook code to point A.

(3) By analyzing the data in table 1, it can be seen that the higher the wind speed, the shorter the time for the hook code to rise to point A, and the greater the output power of the windmill.

So the answer is: the greater the wind speed, the greater the output power of the windmill.

(4) Wind energy is a clean and renewable energy, with abundant resources and no pollution; Wind power converts wind energy into electric energy, and generators generate electric energy through movement, that is, using the principle of electromagnetic induction.

So, the answer is: renewable; Electromagnetic induction.

(5) By analyzing Table 2 and Table 3, it can be seen that the energy obtained by the windmill increases with the increase of wind speed in the range of 5 m/s to 15 m/s, so the energy obtained by the windmill is directly proportional to the cubic power of wind speed.

So the answer is: the energy obtained by windmills is directly proportional to the cubic wind speed.

(6) When the wind speed is 10m/s, the output power of the windmill is 720kw.

Power generation of windmill operation 1h:

W power =720kw× 1h=720kw? h，

(1) energy can be used in the classroom 10 lights marked "220V 40W" work at the same time;

T=W electricity p total = 720kwh 0.04kw×10 =1800h.

(2) Coal with complete combustion quality is required to generate these energies:

m = Qq = 720×3.6× 106 J3× 107j/kg = 86.4kg

So the answer is:1800; 86.4.

(7) When the wind speed is 10m/s, the energy obtained in 1s is 120× 104J,

Energy obtained by windmill operation 1h;

W total =120×104j× 3600s = 4.32×109j,

Power generated by windmill operation 1h:

W power =720kw× 1h=720kw? h=2.592× 109J，

Efficiency of windmill power generation:

η=W total power w×100% = 2.592×109j4.32×109j×100% = 60%.

So the answer is 60%.

(8) In order to prevent the blade from being damaged due to the excessive wind energy obtained per second, the stress area of the blade can be appropriately reduced, or the blade can be made of flexible materials.

So the answer is: appropriately reduce the stress area of the blade (or the blade is made of flexible material).