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If each inner angle of a polygon is equal to 150 degrees, the sum of the inner angles of the polygon is______ Degree
∵ every inner angle of a polygon is equal to 150 °, every outer angle of a polygon is equal to 180 ° - 150 ° = 30 °, the number of sides is n = 360 ° / 30 ° = 12, ∵ the sum of the inner angles of the polygon is (12-2) × 180 ° = 1800 °. So the answer is: 1800
y1=X+3 y2=2-x
When x is Y 1 = y 2?
When x is Y 1 greater than y 2 by 5?
When x is - 1 / 2, Y1 = Y2
When x is 2, Y1 is 5 greater than Y2
In the experiment, the resistance value to be measured is between 20 and 30 ohm, and the power supply is four dry batteries connected in series
A. 0-0.6 a, 0-3 V B. 0-0.6 a, 0-15 V C. 0-3 a, 0-3 V D. 0-3 a, 0-15 V
The voltage of the power supply composed of four dry batteries in series is 1.5V × 4 = 6V; therefore, the range of voltmeter is 0-15v; the minimum value of resistance to be measured is 20 Ω, then the maximum current in the circuit is I = ur = 6v20 Ω = 0.3A; therefore, the range of ammeter can be 0-0.6a, if 0-3A is selected, the pointer deflection angle will be too small to read correctly
In the chemical equation 2h2 + O2 = combustion, what is the mass ratio of H2 to O2? Why
2H2+O2==2H2O
4g 32g
Theoretically, there are four h reactions, i.e. 4G and two o reactions, i.e. 32g
So the reaction is 4:32 = 1:8
The following statement is correct ()
A. Resistance refers to the resistance of the conductor to the current. When there is no current passing through the conductor, the conductor has no resistance. B. the smaller the current passing through the conductor, the greater the resistance of the conductor. C. The greater the voltage at both ends of the conductor, the greater the resistance of the conductor. D. the filament resistance of an incandescent bulb is higher when it normally emits light than when it does not emit light
ABC, conductor resistance depends on the length, material and cross-sectional area of the conductor, but has nothing to do with the voltage at both ends of the conductor and the current passing through it, so ABC is wrong; D, when the filament of an incandescent bulb normally emits light, the temperature is high and the resistance is large; when it does not emit light, the temperature is low and the resistance is small, so D is correct
If there is only one common point between the line L and the hyperbola 4x2-9y2 = 36, then such a line has ()
A. 1 B. 2 C. 3 d. 4
Let the straight line L: y = K (x-3) be substituted into the hyperbolic equation to simplify it to (4-9k2) x2 + 54k2x-81k2-36 = 0. In order to make L and hyperbola have only one common point, only one or two real roots of the above equation must be equal, 〈 4-9k2 = 0, or △ = 0 (not tenable). The solution is k = ± 23. When the slope of the straight line does not exist, there is only one common point between the straight line x = 3 and the hyperbola 4x2-9y2 = 36
What is the resistance of copper wire with diameter of 0.5mm and 1m
Resistance coefficient of copper: 0.0178 ohm square millimeter / meter at 20 ℃
The cross-sectional area of copper wire with diameter of 0.5mm is 0.196 square mm and 0.091 ohm / m
（1）、x²-|2|=0 （2）、（x-2）²=100 （3）、25（2y-3)²-64=0
(1) , X & # 178; - | 2 | = 0x & # 178; = 2x = ± √ 2 (2), (X-2) & # 178; = 100 (X-2) & # 178; = 100x-2 = ± 10x1 = 12 x2 = - 8 (3), 25 (2y-3) & # 178; = 64 / 252y-3 = ± 8 / 52y = 23 / 5 or 2Y = 7 / 5y1 = 23 / 10, y2 = 7 / 10
How much electricity does a 2500W electric appliance consume per hour? How to calculate it?
There are six projects in an engineering team that need to be completed separately. Project B can only be carried out after project a is completed, project C can only be carried out after project B is completed, and project D can only be carried out immediately after project C is completed______ (answer with numbers)
According to the meaning of the question, B must be behind a, C must be behind B, C and D must be adjacent, and D must be behind C. just insert the remaining two projects in turn between the four projects of a, B, C and d. There are four kinds of insertion in the first one, and five empty in the second one. There are five methods. There are five × 4 = 20 different arrangements
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