高中物理必背知识点实用口诀

高中物理必背知识点实用口诀(TXT手机版)（Practical tips forhigh school physics (TXT)）1. Description of movement1. Object model with particle size, ignore shape and size; The earth turns to be a particle, the earth's rotation is about the size. The change of the object position, accurate description with displacement, speed S movement than t, with Δv and t than a.2. Using general formula, average velocity is simple method, intermediate time velocity method, initial velocity zero ratio method, and geometric image method, to solve the method of motion. The free fall is an instance, the initial velocity is zero a, etc. The speed of the center moment is equal to the average velocity; Acceleration has a good side, ΔS a T square, etc.3. The velocity determines the motion of the object, in the direction of the acceleration of the velocity, the same direction is accelerated backward, and the vertical turning is the same.Second, the force1. Force analysis is the key to solve mechanical problems; Analyze the force of force and deal with it according to the effect.2. The analysis force should be careful, quantitativecalculation of seven forces; The force of gravity is determined by the force of gravity. There is elasticity and friction, relative motion is the basis; The force of gravity is definite in all things. Lorenz force, the essence is unity; Vertical force is the largest, parallel inability to remember.3. The calculation result is only "quantity" in the same direction. The two forces are small and large, two forces are q-angle clip, parallelogram method; The resultant force size varies with q, only in the maximum minimum, and the force of the force is combined to the other side.The multi-force problem state, orthogonal decomposition to solve, trigonometric functions can be resolved.4. Multiple methods of mechanical problems, integral isolation and hypothesis; All you need to do is look at the external force and solve the internal force isolation. The state is the same as the whole, otherwise it is much more isolated; Even if the state is different, the whole cow ii can be done; Suppose that some force is or is not, and is determined according to the calculation; The limit method grabs the critical state, the procedural law is done in order; Orthogonal decomposition coordinates, the axial vector is as much as possible.Newton's laws of motion1. F and other ma, Newton two law, produce acceleration, because of force.So the net force is going in the same direction as a, so thevelocity variable is going to be equal to a, so it's going to be a smaller, but it's going to be greater than u, so it's going to be equal to u.2. The force of N and T depends on the weight, and the mg product is the real weight. Heavy weight loss is regarded as heavy, and the invariant is real weight; Acceleration is overweight, deceleration is also overweight; Weightlessness is determined by adding and decreasing, completely losing attention to zeroFour, curve motion, gravitation1. The motion trajectory is the curve, the centripetal force exists as the condition, the curve is changing, the direction is the tangent line.2. The circular motion centripetal force, the supply and demand relation in the heart, the radial force provides the foot, needs mu squared over R, MRW square also needs, the supply and demand balance is not disoriented.Gravitation is born of mass and exists in all of the world. Satellites orbit the celestial body, and the fast and slow motion of the satellite is determined by distance, the closer it is, the faster it goes, the farther it goes, the slower it goes, the speed of the synchronous satellite is fixed, and the satellite is traveling over the equator.Mechanical energy and energy1. Determine the state for kinetic energy,The analysis process looks for the force work, plus the positive and negative work together, the kinetic energy increment is the same as that.It's clear that the two state mechanical energy, the process force is doing work, the "gravity" is zero, the initial state energy is the same.3. Determine the state to find the amount of energy, and then look at the process force to do work. So there's a change in energy, and the initial state energy is the same.6. Electric field1. Coulomb's law charge force, gravitational attraction force, as if it is the twin brother, kQq and r squared ratio.2. There is an electric field around the charge, and F is stronger than q. KQ is more than r2, and U is equal to the electric field.The intensity of the electric field is the vector, the force of the positive charge is fixed. Description of the use of electric field, the density of weak and strong.The field energy is electric potential and the field line is decreasing. The work of field force is qU, the kinetic energy theorem cannot be forgotten.4. The electric field has equipotential surface, which isperpendicular to the field line. The direction is low with high direction, and the surface density is characteristic.7, constant current is optional 3-1When the charge is moving, the current is equal to q over t. The free charge is the internal cause, and the voltage on both ends is the condition.The positive load flow direction is determined, and the flow meter is measured. The external current of the power supply is negative, from negative to serious.2. Three factors of resistance law, the temperature is constant, the control variable is discussed, r l ratio s and other resistance.The current is doing the work U I t, the electrothermal I squared R t. Electric power, W ratio t, voltage times current is also.3. Basic electric path linking and separating pressure shunt. Complex circuits use the brain, the equivalent circuit is the key.4. Partial circuit of closed circuit, external circuit and internal circuit, followed by ohm.Pressure drop in the terminal voltage, and the electromotive force, except the total resistance current is8, 3-1There is a magnetic field around the magnet, and the force of the N is determined. There is a magnetic field around the current, and ampere set the direction.2. F ratio I l is the field intensity, phi and other B S magnetic flux, magnetic flux density phi ratio S, the name of magnetic field strength is different.3. BIL ampere force, perpendicular to each other.Lorentz force, the force of the force to the left.9. Electromagnetic induction (3-2)1. Electromagnetic induction magnetic induction, flux variation is a condition. The circuit closes with a current, and the circuit breaker is the power supply.The induction electromotive force size, the flux rate of flux is known.2. The direction of lenz's law is the key to prevent change. Conductors cut the magnetic line, and the right hand rule is more convenient.3. Lenz's law is abstract, which really understands from the three parties, hinders the increase and decrease of the magnetic flux, and the relative motion is resisted, theself-inductance current wants to stop, the energy conservation should be. You look at the magnetic field in the first place,where the induced magnetic field is going to go up, and all the magnetic flux increases or decreases, and the ampere set is known to the I.10. Alternating current (3-2)1. The uniform magnetic field has coils, rotating to generate alternating current. The current voltage electromotive force, the change rule is the string.The neutral surface time is sine, parallel time is cosine.2. NBS omega is the maximum value and the effective value is calculated with heat.3.Transformer for ac use, constant current cannot be used.Ideal transformer, primary U I value, secondary U I value, equality is principle.Ratio of voltage to ratio of turns; The ratio of the current to the ratio of turns.Apply the ratio of variable-pressure ratio, if you want to find the number of turns, turn it into the turns.Far away from the power transmission, the voltage drop is sent, otherwise the user will lower the pressure.11. Gaseous equation: 3-3Study the quality of the gas and determine the status of the parameters. The absolute temperature is the volume of T, volume is volume.Pressure analysis, Newton's law for you. The state parameter must be found, PV is equal to T.12. Laws of thermodynamicsThe first law of thermodynamics, the conservation of energy. How much internal energy change, how much heat you can do.Positive and negative signs need to be accurate, income expenditure to understand. The internal energy and heat absorption are positive. External work and heat release can reduce negative values.2. Second law of thermodynamics, heat transfer is irreversible, heat transfer and heat transfer work, with directivity.13, mechanical vibrations 3-4The simple harmonic vibration should keep in mind that O is the displacement of the starting point, the direction of the recovery force, always in the equilibrium position,The magnitude is proportional to the displacement, and the equilibrium position is u.2. O point symmetry don't forget, vibration strength is the amplitude of vibration speed is a cycle, the cycle, 4 a walk pendulum cycle than l g, n-th root by 2 p, again place cycle for 2 seconds seconds, set about length of 1 meter long.To the center of the center of mass, the pendulum has equal time.3. The direction of the vibration image is traced from the bottom to the top, from top to bottom; The displacement of the vibration image, the great displacement of the base point, the positive and negative sign direction.14. Mechanical wave (3-4)1. On the left, on the right and on the right. The peak point has no direction.2. Follow the direction of communication, from the valley to the peak of the climb, the bottom of the foot must push down, up and down to move.3. The images of different time, four points Δt one or three, particle movement doubts, S and v t sent to use.15. Optics for elective 3-41. Self-luminescence is the source of light source and the same straight line. If you encounter obstacles, the path of transmission will change.The law of refraction is the key point of reflection. The lightmedium has refractive index, (its) definition is sinusoidal ratio, it can also be used with velocity ratio, and the wavelength ratio is also caused.2. Total reflection, keep in mind that incoming light is in the light. The Angle of incidence is greater than the critical Angle and the refractive light is nowhere to be found.Physical opticsLight is an electromagnetic wave that produces interference and diffraction. Diffraction has a single slit and a small hole, and the interference has a double slit and a membrane. Single slit diffraction is the middle width and interference (fringe) is similar. Aperture diffraction occulting ring, film interference is more useful. It can be used to measure the workpiece and can be made into a membrane. Poisson bright spot is diffraction, interference formula should be grasped. Elective 3-42. Light metal can produce electricity and the incoming light has a limit. Photoelectric kinetic energy and small,It's related to the photon frequency. The number of photoelectrons is more and less, which is closely related to the light intensity. The photoelectric effect can occur instantaneously, the limit frequency depends on the work. I'm going to take 3-5.17. Momentum1. Determine the state to find the momentum, analyze the process to find the impulse, and the same linear direction, the calculation result is just "quantity". If the direction of a certain amount is uncertain, the calculation result will be specified.2. Determine the status of the momentum, analyze the process to find the impulse, the external force impulse is zero, and the initial state momentum is the same.18 atomic nuclei1. Nucleus, central station, electron layering around it; To the external transition to excitation, the radiation photons are moving inward; The photon energy, hn, can be calculated by the differential.2. Nuclei, can change, alpha beta decay. Α is helium nuclei, electron flow is beta.Gamma photons not only occur, but also occur with decay. Uranium is divided into fission, and neutron impact is the condition.Fission can build an atomic bomb, and it can be used to generate electricity. The light core polymerization is fusion, and the temperature is extremely high.Change can be hydrogen bomb, or solar energy source; The peaceful use of the future is good, but it has not been realized.。