What kind of thoughts and feelings does "San Gu Mao Lu" express in the romance of the Three Kingdoms

We can see three points: 1. Liu Bei is thirsty for talents; 2. Zhuge Liang is cautious in choosing the right person; 3. If this is a real event in history rather than a story made up by the author, the author only plays a role of record restoration, which can not reflect the author's thoughts and feelings

What kind of story does Sangu Maolu tell in the romance of the Three Kingdoms, and what kind of emotion does the author express

Liu Bei and his brother waited and waited for each other. As a result, they did. When Mr. Zhuge learned that Liu Bei had been waiting so long, he was moved to go with him
Emotion. It shows that Liu Bei loves talent and is patient. It also paves the way for Mr. Zhuge to be loyal to his family

Measuring the resistance of small light bulb
1. The experimental principle of measuring the resistance of small bulb is as follows:____ The physical quantity to be measured during the experiment is_ And___ .
2. When connecting the circuit, the switch should be closed The sliding rheostat should be set to_ Its function is_ In this way, we can test more groups And_ The corresponding values are calculated respectively The measurement should pass the___ Adjust the voltage to the normal working voltage of the small bulb, and then gradually increase from the voltage_ To obtain several sets of data
3. In the experiment of measuring resistance by volt ampere method, if the circuit connection is correct, the switch is closed, the light is not on, the ammeter has a reading, and the voltmeter has no reading, the reason is ()
A. The power supply has no output voltage
B. Poor contact of switch
C. Short circuit at both ends of small bulb
D. Poor contact due to loose terminals of voltmeter
4. In the experiment of measuring unknown resistance RX with ammeter and voltmeter, the power supply voltage is 3V, and the resistance of Rx is about 5 Ω. There are two sliding rheostat, the rules are "0.2A 50 Ω" and "1A 20 Ω", one ammeter (range 0 ~ 0.6A and 0 ~ 3A), and one voltmeter (range 0 ~ 3V and 0 ~ 15V)__ The ammeter should be selected Range: voltmeter should be selected Range
5. The experimental table is equipped with an ammeter (range 0 ~ 0.6A and 0 ~ 3a), a voltmeter (range 0 ~ 3V and 0 ~ 15V), a sliding rheostat (1a, 18 Ω) and a power supply (6V)
(1) In order to form the experimental circuit, in addition to the above equipment, it also needs one_ At least Root
(2) The current variation range of the circuit is about 0__ .
(3) It is required that the ammeter pointer should not exceed the range in the experiment, and the ammeter pointer should be deflected over the center line of the dial in several measured data_ Range, voltmeter should be selected____ Range

1. The experimental principle of measuring the resistance of small bulb is as follows:_ Ohm's law_ The physical quantity to be measured during the experiment is_ Voltage_ And_ Current_ . 2. When connecting the circuit, the switch should be closed_ Open_ The sliding rheostat should be set to_ Maximum resistance_ Its function is_ Protection circuit_ In this way, we can test more groups_ Voltage_ And_ Current_ Value, respectively

When an object moves in a straight line, the velocity of the first segment is 6m / s, the velocity of the second segment is 9m / s, and the average velocity of the whole process is 8m / s
Then the displacement ratio of the front and back ends is

Let X be the front segment and y be the back segment
Total time t = x / 6 + Y / 9
Displacement S = x + y
Average velocity = s / T = (x + y) / (x / 6 + Y / 9) = 8
x+y=8x/6+8y/9
x/3=y/9
x:y=1:3

Complete set of Physics Formulas in junior middle school
The conventional formula of junior high school physics

Summary of junior high school physics concepts
Physical quantity name physical quantity symbol unit name unit symbol formula
Mass m kg m = ρ V
Temperature T ° C ° C
Velocity v m / S M / S v = s / T
Density p kg / M & sup3; kg / M & sup3; P = m / V
Force (gravity) f Newton (cow) n g = mg
Pressure P Pascal PA P = f / S
Work w Joule (joule) J W = FS
Power P watt W P = w / T
Current I a (a) a i = u / R
Voltage U V U = IR
Resistance R ohm (Ω) r = u / I
Electric work w Joule (joule) J W = UI t
Electric power P watt (watt) W P = w / T = UI
Heat Q Joule (joule) J Q = cm △ t
Specific heat C coke per kilogram degree centigrade J / (kg &; ° C) C = q / m △ t
Common data:
The speed of light in vacuum is 3 × 10 ^ 8 m / s
G 9.8 N / kg
Sound speed 340m / s in air at 15 ° C
The safety voltage is not higher than 36 v
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Basic concepts of junior high school physics
1、 Measurement
1. Length L: main unit: meter; measuring tool: scale; when measuring, it should be estimated to the next digit of the minimum scale; light year is the unit of length
2. Time t: main unit: second; measuring tool: clock; stopwatch in laboratory. 1 hour = 3600 seconds, 1 second = 1000 milliseconds
3. Mass m: the amount of material contained in the object is called mass. Main unit: kilogram; measuring tool: scale; pallet balance for laboratory
2、 Mechanical movement
1. Mechanical movement: movement in which the position of an object changes
Reference: to judge the motion of an object, another object must be selected as the standard
2. Uniform linear motion:
① Two ways to compare the speed of movement: a compare the distance traveled in the same time
B compare the time required to travel an equal distance
② Formula: v = s / T
③ Unit conversion: 1 m / S = 3.6 km / h
3、 Strength
1. Force F: force is the action of objects on objects. The action of forces between objects is always mutual
Unit of force: Newton (n). Instrument for measuring force: dynamometer. Spring scale is used in laboratory
The effect of force: to deform or change the state of motion of an object
The change of object motion state refers to the change of object velocity or motion direction
The three elements of force: the size, direction and action point of force are called the three elements of force
The diagram of force should be scaled; the diagram of force should not be scaled
Gravity g: the force exerted on an object due to the attraction of the earth
Relationship between gravity and mass: g = mg m = g / g
G = 9.8n/kg. Reading method: 9.8n/kg, which means the gravity of an object with a mass of 1kg is 9.8n/kg
Center of gravity: the point of action of gravity is called the center of gravity of an object. The center of gravity of a regular object is at the geometric center of the object
4. Balance condition of two forces: acting on the same object; equal magnitude of two forces; opposite direction
Under the balance of the two forces, a body can be stationary or move in a straight line at a constant speed
The equilibrium state of a body means that the body is in a state of static or uniform linear motion. The resultant force of the external force on the body in equilibrium state is zero
5. The combination of two forces on the same line: the direction is the same: the resultant force F = F1 + F2; the resultant force direction is the same as that of F1 and F2;
The direction is opposite: F = f 1 - F 2; the direction of the resultant force is the same as that of the larger force
Under the same conditions, the rolling friction is much smaller than the sliding friction
Sliding friction is related to normal pressure, material properties and roughness of contact surface
7. Newton's first law is also known as the law of inertia. Its content is: when all objects are not affected by external forces, they always keep static or uniform linear motion
Inertia: an object has the property of keeping the original static or uniform linear motion state, which is called inertia
4、 Density
1. Density ρ: the mass per unit volume of a substance. Density is a property of a substance
Formula: M = ρ V, international unit: kg / M & sup3;, common unit: g / cm & sup3;,
Unit conversion: 1g / cm & sup3; = 1 × 10 & sup3; kg / M & sup3;; ρ water = 1 × 10 & sup3; kg / M & sup3;;
Reading: 10 & sup 3; kg / m3, which means the mass of 1 cubic meter of water is 10 & sup 3; kg
2. Density measurement: mass measurement with pallet balance and volume measurement of solid or liquid with measuring cylinder
Area unit conversion:
1cm & sup2; = 1 × 10 ^ - 4m & sup2;,
1 mm & sup2; = 1 × 10 ^ - 6 M & sup2
5、 Pressure
Pressure P: the pressure on the unit area of an object is called pressure
Pressure F: force acting vertically on the surface of an object, unit: n
The effect of pressure is expressed by pressure, which is related to pressure and area
Pressure unit: n / M & sup2;; special name: Pascal (PA)
Formula: F = PS [S: the area under force, the common part of two objects in contact; unit: M & sup2;.]
Methods to change the pressure: ① reduce the pressure or increase the stress area, can reduce the pressure; ② increase the pressure or reduce the stress area, can increase the pressure
2. Internal pressure of liquid: [measurement of internal pressure of liquid: use liquid manometer (U-tube manometer)]
Causes: due to the gravity of the liquid, pressure is produced on the bottom of the container; due to the fluidity of the liquid, pressure is produced on the wall of the container
Laws: 1. At the same depth, the pressure in each direction is equal
② The greater the depth, the greater the pressure
③ At the same depth of different liquids, the liquid with higher density also has higher pressure
The formula is: P = ρ G H: unit: m; ρ: kg / M & sup 3;; g = 9.8 N / kg
3. Atmospheric pressure: the atmospheric pressure is produced by the action of gravity. It is the madeburg hemispheric experiment that proves the existence of atmospheric pressure, and it is Torricelli (Italian scientist) who determines the value of atmospheric pressure
The height of mercury column remains unchanged and the length of mercury column becomes longer after the torrix tube is tilted
1 standard atmospheric pressure = 76cm mercury column height = 1.01 × 10 ^ 5pa = 10.336m water column height
Instruments for measuring atmospheric pressure: Barometer (mercury barometer, box barometer)
Atmospheric pressure changes with altitude: the higher the altitude, the lower the atmospheric pressure, that is, the higher the altitude, the lower the boiling point
6、 Buoyancy
1. Buoyancy and its cause: an object immersed in liquid (or gas) is supported upward by liquid (or gas), which is called buoyancy. Direction: vertical upward; cause: pressure difference between liquid and object
2. Archimedes principle: objects immersed in liquid are subject to upward buoyancy, and the buoyancy is equal to the gravity of objects expelling liquid
That is, f floating = g liquid discharge = ρ liquid GV discharge
3. Buoyancy calculation formula: F floating = G-T = ρ liquid GV discharge = f upper and lower pressure difference
4. When the object floats: F floats = g and ρ g and ρ 2F

As shown in the figure, the mass of the tripod resting on the horizontal plane is m, and a small ball with mass m is connected with two light springs in the middle. When the small ball vibrates up and down and the pressure of the tripod on the horizontal plane is zero, the acceleration of the small ball is 0 , direction ．

Take M as the research object, M is supported by gravity and the ground, and the spring force on M upward. F: according to the balance equation, we get: n + F = mg, when the pressure of the square frame on the horizontal plane is zero, that is, n = 0, f = mg. Take M as the research object, according to Newton's second law: Ma = Mg + F = Mg + Mg, so: small ball acceleration a = Mg + MGM, the direction is vertical downward, so the answer is: Mg + MGM; vertical direction Next

Ampere's molecular ring current hypothesis can not be used to explain ()
A. The magnet loses its magnetism at high temperature. B. the magnetism of the magnet will be weakened after knocking. C. ferromagnetic materials have magnetism after being put into the magnetic field. D. There is a magnetic field around the electrified wire

Ampere's molecular ring current hypothesis is that the electrons outside the nucleus move in a circle around the nucleus, so Ampere's molecular ring current hypothesis can explain the phenomenon of magnetization and demagnetization. A. the arrangement of molecular current inside the magnet is roughly the same, so each molecular current has the same effect

What kind of thoughts and feelings does "San Gu Mao Lu" express in the romance of the Three Kingdoms