If the image of function y = KX passes through point P (3, - 1), then the value of K is () A. 3B. -3C. 13D. -13

If the image of function y = KX passes through point P (3, - 1), then the value of K is () A. 3B. -3C. 13D. -13

The image of ∵ function y = KX passes through points P (3, - 1), ∵ 3K = - 1, ∵ k = - 13

What is the resistance of the national standard wire

It depends on the size of your wire
The conductor resistance of 0.75 square millimeter stranded copper conductor at 20 ℃ is 26 ohm / km
1.0 19.5
1.5 13.3
2.5 7.98

To solve the monastic equation: {2x + y + 4Y + W = 3 4x + 2y-2z-w = 12 x-3y + Z + W = - 13 x + 4y-z-w = 19
It's solving the equation of degree four. Wrong number.

2x+y+4y+w=3 ①
4x+2y-2z-w=12 ②
x-3y+z+w=-13 ③
x+4y-z-w=19 ④
According to the meaning of the title: ① + ②, ② + ③, ③ + ④
6x+7y-2z=15 ⑤
5x-y-z=-1 ⑥
2x+y=5
⑤ - 2x 6
-4x+9y=17
It is combined with 2x + y = 5 to form binary linear equations
2x+5y=5
-4x+9y=17
The results are as follows
x=14/11
y=27/11
Taking X and Y into the original equations, we get
W=-130/11
z=54/11
Verification: by substituting x, y, W, Z for ③, we get two equations with equal sides, so the solution of the original equations is as follows:
x=14/11
y=27/11
w=-130/11
z=54/11

What is the relationship among current, voltage and power?
What is the inevitable relationship among RT, and how do they influence each other?
Is it voltage or current? Let's take the electricity It's very high. When the electricity reaches the person, it's over
thank you!

Total power of any circuit (P) = voltage applied at both ends of the circuit (U) * total current in the circuit (I)
This is the definition of electric power, so it must exist for any circuit
The actual cause of death is electric current. In winter, the voltage of electric spark can reach thousands of volts when you take off your sweater. However, because the generated electric power is very small, the electric current of people is very small and there is no danger

Is (1 / M) * (X-Y) a fraction
Please answer the question,

Yes

A 100W household bulb, know the rated voltage of 220 V, rated current how much a, then how to calculate 100W?
If the resistance of a 20W bulb is relatively high and the resistance also consumes electricity, is the efficiency low?

The so-called 100W bulb means that under the designed rated voltage of 220V, its power is 100W. This power should also be called rated power. Because the resistance of the filament under different voltages is different, so the power is naturally different. The rated current is I = P / v = 0.455a resistance R = u / I = 500 ohm resistance

Given 1 / A-1 / b = 3, find the fraction 2ab-a + B / 5ab + 3a-3b

It is known that 1 / A-1 / b = 3
(b-a)/ab=3
That is, A-B = - 3AB
So the fraction, (2ab-a + b) / (5ab + 3a-3b)
=(2ab+3ab)/(5ab-9ab)
=-5ab/4ab
=-5/4.

An electric appliance is connected in series with a 24 ohm resistor and connected to both ends of the power supply. The actual power of the electric appliance is 1 / 9 of its rated power after power on, and the circuit is stable
A consumer is connected in series with a 24 ohm resistor and connected to both ends of the power supply. After power on, the actual power of the consumer is 1 / 9 of its rated power, and the current on the circuit is 1 A. if the resistor is removed, the consumer will be directly connected to both ends of the original power supply. At this time, the actual power of the consumer is just equal to its rated power. What is the rated voltage and rated power of the consumer?

The actual power of the equipment is PW
The actual power of the appliance is 1 / 9 of its rated power and the current on the circuit is 1 A. at this time, the voltage of the appliance is v = P / 9 and the resistance is r = P / 9. At this time, the total resistance is (P / 9 + 24) Ω and the total voltage is (P / 9 + 24) v
P=(P/9+24)^2/(P/9)
The solution is p = 108W
The total voltage is: (P / 9 + 24) v = 108 / 9 + 24 = 36V
The rated voltage of this appliance is 36V and the rated power is 108W

Xiaoming slides from the 8m long straight slide from top to bottom to the ground. The slope angle of the slide is known to be 40 ° and the height of the slide is calculated. (accurate to 0.1M)

Let the height of slide be XM
Then x / 8 = sin40 degree
x=sin40°*8
Look up the table
x=0.64*8
x=5.12

How to calculate the power consumption of household appliances

There is a "rated input power" index in the manual or chrome plate of household appliances. If it is 100W, it means 1 kwh in 10 hours. If it is 500W, it means 1 kwh in 2 hours, 1000W, 1 kwh in 1 hour, 2000W, 1 kwh in 0.5 hours