What do the letters of the physics formula of the second year of junior high represent 40

The ultimate physics formula, e=mc

Energy = speed of light *m

p pressure f force g gravity m mass g gravity constant f friction w work j joules i sophomore.

Force. 1. Pressure: p=f s

p represents pressure, the unit pascal (abbreviated as pa, symbol pa) f represents pressure, unit newton (n) s represents the area of force, unit square meter.

2. Liquid pressure and buoyancy: f = meat gh

3. Density = m v

Density, m for mass, and v for volume.

4. Gravity g=mg

5. Velocity v=s t

6. Work w=fs (w represents work, f represents work).

7. Power p=w t fv

8. Mechanical efficiency w useful w total gh fs=g fn (n is the number of strands of the pulley group).

9. Thermal energy q cm t

10. Calorific value q=mq

11. Sliding friction f= n (f is sliding friction, n is positive pressure, and friction factor is unitless).

The formulas and letter meanings that must be mastered in junior high school physics are as follows.

1. Formulas that must be mastered

First of all, Niu Yan's second law f=ma, which means that the force is equal to the mass multiplied by the acceleration; The second is the work w=f s, which represents that the work done by the force in the direction of displacement is equal to the force multiplied by the displacement; Then there is the kinetic energy theorem e k=1 2mv 2, which represents that the kinetic energy of an object is equal to half of its mass proportional to the square of the velocity; Finally, there is the wavelength formula = v f, which means that the wavelength is equal to the speed of the wave divided by the frequency.

2. The meaning of letters and common units

f stands for force and the unit is bull (n); m stands for mass and is measured in kilograms (kg); a stands for acceleration in meters per second squared (m s); w stands for work, and the unit is joules (j); s stands for cover brigade displacement in meters (m); e k stands for kinetic energy and the unit is joules (j).

v stands for velocity, measured in meters per second (m s); represents the wavelength in meters (m); v stands for wave velocity in meters per second (m s); f stands for frequency, and the unit is hertz (Hz).

3. Practical application

Physics formulas for junior high school are widely used. For example, in mechanics, Newton's second law can be used to calculate the acceleration and force experienced by an object; In terms of energy, the kinetic energy theorem can solve the kinetic energy problem and the energy conversion problem of objects; In optics, the wavelength formula helps us calculate wavelength and frequency. These formulas are not only of great significance in study and examinations, but also widely used in production and practical life.

4. Learn skills

The mastery of physics formulas in junior high school requires constant practice and summarization. You can do more examples, exercises and mock tests, and at the same time pay attention to classification and memorization and induction. In addition, it is also necessary to pay attention to the meaning of letters and the conversion of units, and be familiar with common units and prefixes.

5. Summary

Physics formulas are the foundation of physics learning, which not only has a profound impact on physics learning in high school and college, but also has a great role in practical application. Therefore, when learning junior high school physics, it is necessary to grasp the formulas and units carefully, and at the same time, it is necessary to pay attention to the connection with reality, positive thinking and flexible application.

n Newton, the unit of force.

fOptics denotes the focal point and mechanics denotes the physical force.

Optics indicates focal length and mechanics indicates friction.

g Gravity. g constant g=

m for mass.

v volume v denotes velocity.

For each physical quantity, there is a corresponding letter. According to the order of the textbooks taught by junior high school people, the letters and meanings that appear in turn are as follows.

Bottom: M, Mi Quan.

s, min, minute.

h, hour. m s, meters per second.

f, which indicates the frequency.

Hz, hertz, unit of frequency; Celsius.

t, which indicates time or temperature.

f, the focal length of the lens, in m

f, the focal point of the lens, the density, in kg m3 or g cm3

m, mass, in kg, t (tons) or g

n, the unit of force in Newton, can also denote a supporting force or pressure.

f, which denotes force.

p, power. p, pressure.

g Gravity. g, which means efficiency.

w, the unit of work or power in watts.

q, heat. j, joules, a unit of energy and heat.

kw, kilowatts.

Each of the auspicious physical quantities.

all have corresponding letters. According to the order of the textbooks taught by junior high school people, the letters and meanings that appear in order are as follows:

m, m. s, seconds.

min, minutes.

h, hour. m s, meters per second.

f, which indicates the frequency.

Hz, Hertz.

the unit of frequency; Celsius.

t, which indicates time or temperature.

f, the focal length of the lens, in m

f, the focal point of the lens, the density, the unit is kg m3 or g cm3m, the mass, the single tansen bit is kg, t (t) or g

n, the unit of force that gives the mountain acres of newtons.

It can also indicate support or pressure.

f, which denotes force.

p, power. p, pressure.

g Gravity. g, which means efficiency.

w, the unit of work or power in watts.

q, heat. J, Joule.

A unit of energy, heat.

kw, kilowatts.

g=mg: g stands for gravitational force, m-mass, g-gravitational acceleration.

f=ma:f-force (Newton.

force), m mass, a acceleration;

f=gmm r 2: gravitational force formula.

f=qe: electric field force = charge electric field strength.

w=qu: electric potential energy = electric charge potential;

v=at:velocity=acceleration time;

s=a*t 2: distance = acceleration time squared;

ep=mgh: ep gravitational potential energy;

ek=:ek kinetic energy;

p=fv: power=force, velocity;

w=pt=fs: work = power time = force displacement;