Knowledge of physics, what is the knowledge of physics

Physics is a basic discipline in the natural sciences, which mainly studies the phenomena and laws of the motion, energy, mechanics, electromagnetism, optics, heat, and atomic nuclei of matter. Here are some of the basics of physics:

1.Mechanics: It mainly studies the laws of motion of objects, the action of forces and the motion state of objects.

2.Electromagnetism: mainly studies phenomena such as electric charge and electric field, current and magnetic field, and electromagnetic waves. Dust.

3.Thermal: Mainly studies the heat transfer process, thermodynamic laws, etc.

4.Optics: Mainly studies the generation and propagation of light phenomena, including reflection, refraction, interference, diffraction and other phenomena of light.

5.Quantum mechanics: It mainly studies the behavior of matter and energy in the microscopic world or the positive Zen domain, and studies the structure, properties and interactions of atoms, molecules, and elementary particles.

6.Theory of Relativity: It mainly studies the physical laws and motion states of objects in high-speed motion, including special relativity and general relativity. Clearing.

7.Nuclear Physics: Mainly studies the structure of atomic nuclei, nuclear reactions and the utilization of nuclear energy.

8.Cosmology: It mainly studies the origin, evolution and structure of the universe.

Physics is an important foundation of modern science and technology, and its research results have a wide range of applications in various fields, from energy development, material science to medical diagnosis and so on, are inseparable from the knowledge and technology of physics.

1.The following statement is true:

The DA switch must be connected between the positive pole of the power supply and the consumer to control the consumer.

bAll power sources are devices that convert chemical energy into electrical energy.

c. Do not connect the voltmeter directly to both ends of the power supply.

d. Do not connect the ammeter in parallel with the current to be measured.

2.The following statements are true about the magnitude of the resistance of a certain conductor:

The voltage at both ends of the conductor is increased by a factor of two, and the resistance of the conductor is also increased by a factor of two.

b.If the current through the conductor is reduced by half, the resistance of the conductor is increased by a factor of two.

c.When the voltage across the conductor and the current through the conductor are zero, the resistance of the conductor is zero.

d.A property of resistive conductors themselves, independent of voltage and current.

3.The current through the conductor is 1A when the voltage at both ends of a certain conductor is 4V, and if the voltage at both ends of the conductor is reduced to 2V, the current through the conductor is.

4.Regarding current, voltage, and resistance, the following statements are true:

da.As long as a conductor is connected to a circuit, there is an electric current in the circuit.

b.The greater the current passing through a conductor, the less resistance it has.

c.A small bulb through which an electric current passes does not necessarily have voltage at both ends.

d.The greater the voltage across the conductor, the greater the current passing through that conductor.

5.When a voltage of 20V is applied to both ends of a conductor with constant resistance, the current passing through it is 1V, and now the voltage at both ends of the conductor is changed to 5V, then the current through the conductor and its resistance are respectively

20 ohms. Ohm Ohm.

Ohm. 6.The resistance inside the ammeter or voltmeter is called the internal resistance, and the internal resistance of an ammeter is ohms, and the maximum current allowed to pass through is 3A, and this ammeter is ---

Can't--(fill in "can" or "can't") directly connected to the power supply with voltage, this is because the current through the ammeter is too large, which will burn out the ammeter.

The internal energy is related to temperature, volume, mass, state.

The sum of the kinetic and potential energy of all the molecules inside the object.

Wherein: 1. The average kinetic energy of the molecule is related to temperature. The higher the temperature, the more intense the thermal movement and the greater the average kinetic energy of the molecules.

2. The average potential energy of the molecule is related to the volume of the object. When the distance between molecules changes, the average potential energy of the molecules also changes (similar to a spring); When the volume of the object changes macroscopically (the distance between molecules changes), the potential energy of the object usually changes.

3. In addition, it is related to the phase state (solid, liquid, gaseous) presented by the object. Because the forces between molecules of the same object in different phases are not the same. For example:

Ideal gases, because the distance between the gas molecules is relatively large, the intermolecular effect is so small that it can be ignored; Then between the molecules of the gas, we can consider that there is no molecular potential energy. However, when it is in liquid or solid state, the intermolecular forces cannot be ignored and the molecular potential energy should be considered.

To sum up, we generally believe that:

1. The internal energy of a gaseous object is related to the temperature of the object and the amount of gaseous substance.

2. The internal energy of solid and liquid objects is related to the temperature, volume and quantity of the object.

q amp = qmq is the calorific value of the fuel m is the mass of the fuel.

t=w/ q1=( q1-q2) /q1=1- q2/ q1。

Factors influencing internal energy: temperature (molecular kinetic energy), volume (molecular potential energy), mass (number of molecules).

The formula for calculating the heat emitted by fuel combustion is: q=mq

What is the knowledge of physics in life?

RT is recommended by the questioner.

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1) "Sweating" from the beer bottle in the refrigerator in summer: the water vapor liquefies into small droplets that adhere to the bottle when it is cold.

2) Freezing flowers on windows in winter: water vapor condensation.

3) Wake up in the morning and see fog: the phenomenon of liquefaction of water vapor in the air.

4) Clothes that are frozen in winter will dry out: the sublimation of ice.

5) The boiling point of water is different at different times and places: the difference in atmospheric pressure.

6) Water can only cook dumplings to white, while oil can fry dumplings yellow: the boiling point of oil is higher than that of water.

7) Mirage phenomenon: Light is deflected due to encountering an uneven atmosphere.

8) Small holes into inverted images: light propagates in a straight line.

9) Plane mirror imaging: reflection of light.

10) The chopsticks that are inserted into the water are bent: the light is obliquely reflected into another medium and the refraction occurs.

11) Sunlight is refracted by a prism into seven colors: the dispersion of light.

12) Solar eclipse phenomenon: the linear propagation of light.

13) Convex lens can image: refraction of light.

14) There is no sound on the Moon: Sound propagation requires a medium.

15) See lightning first, then thunder: Light travels much faster on Earth than sound travels on Earth.

16) We can measure the weight of an object with an ordinary rod scale: the principle of levers (17) "Drink" soda with a straw: the extrusion of atmospheric pressure.

18) Put the vegetables in the pan and fry them to cook: the phenomenon of heat conduction.

19) People and vehicles can walk on the ground: friction between objects (20) Human muscle movement: the principle of leverage.

It looks a little fuzzy, not very clear, but from the ** can still be vaguely seen that the hand is still relatively slender, and the fingers are still more symmetrical and slender, so it is a pair of good-looking hands. Look.