Use English symbols to represent numbers one, two One denotes I, two denotes II, and then how?

Use English symbols to represent numbers one, two One denotes I, two denotes II, and then how?

This is the Roman number
[group number rule]
We should pay attention to several points;
(1) Any one of the basic numbers I, x, C can not be more than three by itself, or by placing it on the right side of the large number; only one can be used on the left side of the large number
(2) We can't put any one of the basic numbers V, l, D as a decimal on the left side of the large number and use subtraction to form the number; on the right side of the large number, we use addition to form the number and only one can be used
(3) The small numbers to the left of V and X can only be used as I
(4) The small numbers to the left of L and C can only be used as ×
(5) The small numbers to the left of D and M can only be c
(6) Add a bar to the number to indicate 1000 times the number
[edit this paragraph] [contrast example]
·Single digit example
I,1 】II,2】 III,3】 IV,4 】V,5 】VI,6】 VII,7】 VIII,8 】IX,9
·Ten digit example
X,10】 XI,11 】XII,12】 XIII,13】 XIV,14】 XV,15 】XVI,16 】XVII,17 】XVIII,18】 XIX,19】 XX,20】 XXI,21 】XXII,22 】XXIX,29】 XXX,30】 XXXIV,34】 XXXV,35 】XXXIX,39】 XL,40】 L,50 】LI,51】 LV,55】 LX,60】 LXV,65】 LXXX,80】 XC,90 】XCIII,93】 XCV,95 】XCVIII,98】 XCIX,99 】
·Examples of hundreds
C,100】 CC,200 】CCC,300 】CD,400】 D,500 】DC,600 】DCC,700】 DCCC,800 】CM,900】 CMXCIX,999】
·Thousand digit example
M,1000】 MC,1100 】MCD,1400 】MD,1500 】MDC,1600 】MDCLXVI,1666】 MDCCCLXXXVIII,1888 】MDCCCXCIX,1899 】MCM,1900 】MCMLXXVI,1976】 MCMLXXXIV,1984】 MCMXC,1990 】MM,2000 】MMMCMXCIX,3999】
·Examples above thousand digits
-----
CLXXX MMMDCL,183650】
====== -----
CXXXIV CMXLV DLXXXIV,134945584】

Life is wonderful because of

I have provided two articles for you. Life is wonderful because of setbacks. Being defeated and captured is a kind of frustration. It is also a kind of frustration when encountering failure and suffering from illness. It is inevitable to encounter setbacks in one's life. It is just like a bunch of thorns suddenly sticking out on a flat road and stabbing us all over. Because of this, our life is more wonderful! Yes

What is the maximum capacity of 630kVA transformer

It depends on the power factor of the load, which is 630 * 0.8 = 504kw according to the average calculation of 0.8. In addition, if it is a dry-type transformer, it can be overloaded and its capacity can be expanded by adding a cooling fan. The key depends on the insulation grade of the transformer, and the internal temperature of the transformer should not exceed the standard

Calculate (a-2b) (a ^ 2-3ab + B ^ 2)?

Original formula = a (a ^ 2-3ab + B ^ 2) - 2b (a ^ 2-3ab + B ^ 2)
=a³-3a²b+ab²-2a²b+6ab²-2b³
=a³-5a²b+7ab²-2b³

A classmate did the experiment of measuring the electric power of small light bulb by volt ampere method. He used small light bulb (the rated voltage is 3.3V, the rated current is one of 0.32A or 0.28a), sliding rheostat marked with 2A or 20 ohm, voltmeter, key and other equipment. After connecting the circuit, the classmate followed the correct experimental steps. When he just closed the key, the voltage was 4V, and then when he moved the slide, When the voltmeter gets smaller and the ammeter gets bigger, the student knows that he has made a mistake in connecting the circuit, but he continues to move the slide. When the small lamp lights normally, he finds that the slide of the rheostat is near the midpoint of the rheostat. The student reconnects the circuit correctly. According to the correct experimental steps, when the key is just closed, the voltage expression is 2V, and he calculates the rated power of the small lamp according to these conditions
1. What was the student's mistake at the beginning
2. How did the student judge that the small lamp was working normally at the beginning
3. Calculate the rated power of the small lamp
Please note that he judged that the small lamp was normally on at the wrong time. At this time, there was no 2V
After a long time, I can't do it,
On the third floor, how did you know 2V at the beginning? He judged it when he was wrong. At this time, he didn't know that the result was 2V

I guess the first one is that the ammeter is connected in parallel with the sliding rheostat
But I can't get the right result according to this way of thinking. I'm also a junior high school student
Ah, I mean the voltmeter measures the voltage of the rheostat
According to the formula of voltage division, when they are connected in series, when the resistance of transformer decreases, the voltage they distribute also decreases

Xiao Ming's height is 1.70 meters. He walked 4 meters forward under the street lamp and found his shadow is 2 meters. He asked for the height of the street lamp

Let the light Height x / (4 + 2) = 1.7/2 and solve X

The meaning of "meat"
Resistivity r = "meat" times L (length) divided by s (area)
The "meat" symbol is a curved P. what does it mean? Is it a cross-sectional area?

Material representing resistance
The definition is that the resistivity is related to the material, length and cross-sectional area of the conductor
The determinant is that the resistivity is numerically equal to the ratio of voltage to current

The mass of a spring oscillator is 20g, and the stiffness coefficient is k = 50N / m
The mass of a spring vibrator is 20g, and the stiffness coefficient is k = 50N / m. now pull the vibrator 10cm away from the balance position, and calculate the stiffness coefficient of the spring vibrator
Amplitude A
Vibration period T
Vibration frequency f
Vibration energy E
Maximum acceleration a
The mass of a spring vibrator is 20g, and the stiffness coefficient is k = 50N / m. now pull the vibrator 10cm away from the balance position, and calculate the following: (1) amplitude A (2) vibration period T (3) vibration frequency f (4) vibration energy E (5) maximum acceleration a (6) maximum velocity v

Forget to calculate the acceleration, QAQ
A = f / M = (- k * x) / M = (- 50 * 0.1) / 0.02 = - 250 & nbsp; m / S ^ 2 & nbsp; = = I don't know why it is so big

A capacitor, a resistor and a voltage source are connected in series to form a circuit. How to calculate the voltage at both ends of the capacitor?

At the moment when the circuit is connected, the voltage on the capacitor rises gradually from zero (charging process) and finally becomes the power supply voltage (charging completion)
The charging (discharging) process of capacitor is called transient process

On a circular arc horizontal curve with radius of 28m, it is known that the maximum static friction of the curved road facing the automobile tire is equal to 0.70 times of the vehicle weight. What is the maximum speed of the automobile turning without sideslip?

When a car turns a corner, it relies on static friction to provide centripetal force. When the static friction reaches the maximum, the speed is the maximum. According to Newton's second law: & nbsp; & nbsp; 0.7mg = mv2r, then VM = 0.7 × 10 × 28 = 14m / s. A: the maximum speed when a car turns a corner is 14m / s