Deformation of Remarks Formula of Physical Quantity (Unit) Formula
Speed V(m/S) v= S: distance /t: time.
Gravity G (N) G=mg m: mass g: 9.8n/kg or 10N/kg.
Density ρ (kg/m3) ρ=m/V m: mass v: volume.
The resultant force f and (n) are in the same direction: f and =F 1+F2.
Opposite direction: f = f1-when F2 is opposite, f1> Second generation
Buoyancy f float
(N) F float =G object-G sight G sight: the gravity of an object in a liquid.
Buoyancy f float
(n) The formula f float = g object is only applicable.
Objects float or suspend.
Buoyancy f float
(n) f float = g row = m row g = ρ liquid gv row: the gravity of the liquid shifts.
Line m: mass of displacement liquid.
ρ liquid: density of liquid
The fifth line: the volume of liquid discharged.
(i.e. the volume immersed in liquid)
Lever balance condition f1L 1 = f2l2f1:power l1:power arm.
F2: resistance L2: resistance arm
Crown block F=G object
S=h F: tension at the free end of the rope.
G object: the gravity of the object.
S: the distance that the free end of the rope moves.
H: the distance the object rises.
Moving pulley F= (G object +G wheel)
S=2 h G object: the gravity of the object
G wheel: the gravity of the moving pulley.
Pulley block F= (G object +G wheel)
S=n h n: the number of rope segments passing through the moving pulley.
Mechanical work w
(J) W=Fs F: force
S: distance moved in the direction of force.
effective work
Total work w total w has =G substance h
W total =Fs is suitable for the case that the pulley block is placed vertically.
Mechanical efficiency η= × 100%
Power supply p
(w) P=
Woman: Work.
T: time
Pressure p
(Pa) P=
pressure
stressed zone
Liquid pressure p
(pa) p = rhogh rho: liquid density.
H: depth (from liquid level to required point)
Vertical distance)
Heat q
(J) Q=cm△t c: specific heat capacity m: mass.
△t: change value of temperature
Fuel combustion emission
Q(J) Q=mq m: quality
Q: calorific value
Common physical formulas and important knowledge points
I. Physical formula
Unit) Formula Remarks Formula Deformation
series circuit
Current I (a) I = I 1 = I2 = ... Current is equal everywhere.
series circuit
The voltage u (v) u = u 1+U2+ ... from the series circuit.
Partial pressure action
series circuit
The resistance r (ω) r = r 1+R2+ ...
parallel circuit
Current I (a) I = i 1+I2+ ... The main currents are equal.
Sum of branch currents (shunt)
parallel circuit
Voltage u (v) u = u 1 = U2 = ...
parallel circuit
Resistance r (ω) =++ ...
Ohm's law I=
Current and voltage in the circuit
Directly and inversely proportional to the resistance.
Current definition I=
Q: Charge (Coulomb)
time
Electrical engineering w
(J) W=UIt=Pt U: Voltage I: Current
T: time p: electricity
Electric power P=UI=I2R=U2/R U: voltage I: current.
R: resistance
Electromagnetic wave velocity and wave
The relationship between length and frequency C=λν C:
Physical quantity unit formula
Name symbol name symbol
Mass m kg kg m=pv
Temperature t celsius c
Speed v m/sec m/sec v = sec/sec
Density p kg/m3kg/m3 p = m/v.
Force (gravity) f Newton (cattle) N G=mg
Pressure p Pascal (Pa) Pa P=F/S
Work w joule (coke) J W=Fs
Power p watt (watt) w P=W/t
Current I Ampere (A) A I = U/R.
Voltage u volts (volts) V U=IR.
Resistance r ohm (ohm) r = u/i.
Electric power watt Joule (joule) watt =UIt
Electric power p watt (W) w P=W/t=UI.
Heat q joule (coke) j q = cm (t-t)
Specific heat c coke/(kg c) j/ (kg c)
The speed of light in vacuum is 3x108m/s.
9.8 N/kg
15 C the speed of sound in the air is 340 m/s.
Compilation of junior high school physics formula
Mechanics division
1, speed: V=S/t
2. Gravity: G=mg
3. Density: ρ=m/V
4. pressure: p=F/S
5. Liquid pressure: p=ρgh
6. Buoyancy:
(1), f float = f'-f (pressure difference)
(2), f float = g-f (apparent gravity)
(3), f float = G (float, pause)
(4) Archimedes principle: F float =G row = ρ liquid gV row.
7. Lever balance condition: F 1L 1 = F2L2.
8. ideal slope: f/g = h/l
9. Ideal pulley: F=G/n
10, actual pulley: f = (g+g movement) /n (vertical direction)
1 1, work: W = FS = GH (lifting an object very high)
12, power: p = w/t = Fv.
13, working principle: w hand = W machine.
14, actual machinery: w total = w plus +w extra.
15, mechanical efficiency: η = w /W total.
16, pulley block efficiency:
(1), η = g/nf (vertical direction)
(2), η = g/(g+g motion) (excluding vertical friction)
(3), η = f/nf (horizontal direction)
Branch of thermology
1, endothermic: q endothermic = cm (t-t0) = cm δ t.
2. heat release: q = cm (t0-t) = cm δ t.
3. calorific value: q = q/m
4. Efficiency of furnace and heat engine: η = q effective utilization rate /Q fuel.
5. thermal balance equation: q- discharge = q- suction.
6. Thermodynamic temperature: t = t+273 K.
Department of electricity
1, current intensity: I = Q power /t
2. Resistance: R=ρL/S
3. ohm's law: I = u/r
4, Joule's law:
(1), q = i2rt general formula)
(2), Q = UIT = PT = UQ power = U2t/r (pure resistance formula)
5, series circuit:
( 1)、I=I 1=I2
(2)、U=U 1+U2
(3)、R=R 1+R2
(4)u 1/U2 = r 1/R2 (partial pressure formula)
(5)、P 1/P2=R 1/R2
6, parallel circuit:
( 1)、I=I 1+I2
(2)、U=U 1=U2
(3)、 1/R = 1/R 1+ 1/R2[R = R 1r 2/(R 1+R2)]
(4)I 1/I2 = R2/r 1 (shunt formula)
(5)、P 1/P2=R2/R 1
7 Fixed value resistance:
( 1)、I 1/I2=U 1/U2
(2)、P 1/P2=I 12/I22
(3)、P 1/P2=U 12/U22
8 electricity:
(1), w = UIT = PT = UQ (general formula)
(2), w = i2rt = u2t/r (pure resistance formula)
9 electricity:
(1), p = w/t = ui (general formula)
(2), P = I2r = U2/r (pure resistance formula)
Common physical quantities
1, speed of light: c = 3×108m/s (in vacuum)
2. Sound speed: V = 340m m/s (15℃)
3. Ear discrimination echo: ≥ 0. 1s
4. Gravity acceleration: g = 9.8n/kg ≈ 10n/kg.
5. Standard atmospheric pressure value:
Height of 760mm mercury column =1.01×105pa.
6. Density of water: ρ = 1.0× 103kg/m3.
7. Freezing point of water: 0℃
8. Boiling point of water: 100℃
9. Specific heat capacity of water:
C=4.2× 103J/(kg？ ℃)
10, elementary charge: e =1.6×10-19c.
1 1. The voltage of one dry cell:1.5v.
12. Voltage of lead battery: 2V.
13. safe voltage of human body: ≤36V (not higher than 36V).
14. voltage of power supply circuit: 380v.
15, household circuit voltage: 220V.
16, unit conversion:
(1), 1 m/s = 3.6 km/h.
(2)、 1g/cm3 = 103kg/m3
(3)、 1kw？ h=3.6× 106J
Compilation of junior high school physics formula
Mechanics division
1, speed: V=S/t
2. Gravity: G=mg
3. Density: ρ=m/V
4. pressure: p=F/S
5. Liquid pressure: p=ρgh
6. Buoyancy:
(1), f float = f'-f (pressure difference)
(2), f float = g-f (apparent gravity)
(3), f float = G (float, pause)
(4) Archimedes principle: F float =G row = ρ liquid gV row.
7. Lever balance condition: F 1L 1 = F2L2.
8. ideal slope: f/g = h/l
9. Ideal pulley: F=G/n
10, actual pulley: f = (g+g movement) /n (vertical direction)
1 1, work: W = FS = GH (lifting an object very high)
12, power: p = w/t = Fv.
13, working principle: w hand = W machine.
14, actual machinery: w total = w plus +w extra.
15, mechanical efficiency: η = w /W total.
16, pulley block efficiency:
(1), η = g/nf (vertical direction)
(2), η = g/(g+g motion) (excluding vertical friction)
(3), η = f/nf (horizontal direction)
Branch of thermology
1, endothermic: q endothermic = cm (t-t0) = cm δ t.
2. heat release: q = cm (t0-t) = cm δ t.
3. calorific value: q = q/m
4. Efficiency of furnace and heat engine: η = q effective utilization rate /Q fuel.
5. thermal balance equation: q- discharge = q- suction.
6. Thermodynamic temperature: t = t+273 K.
Department of electricity
1, current intensity: I = Q power /t
2. Resistance: R=ρL/S
3. ohm's law: I = u/r
4, Joule's law:
(1), q = i2rt general formula)
(2), Q = UIT = PT = UQ power = U2t/r (pure resistance formula)
5, series circuit:
( 1)、I=I 1=I2
(2)、U=U 1+U2
(3)、R=R 1+R2
(4)u 1/U2 = r 1/R2 (partial pressure formula)
(5)、P 1/P2=R 1/R2
6, parallel circuit:
( 1)、I=I 1+I2
(2)、U=U 1=U2
(3)、 1/R = 1/R 1+ 1/R2[R = R 1r 2/(R 1+R2)]
(4)I 1/I2 = R2/r 1 (shunt formula)
(5)、P 1/P2=R2/R 1
7 Fixed value resistance:
( 1)、I 1/I2=U 1/U2
(2)、P 1/P2=I 12/I22
(3)、P 1/P2=U 12/U22
8 electricity:
(1), w = UIT = PT = UQ (general formula)
(2), w = i2rt = u2t/r (pure resistance formula)
9 electricity:
(1), p = w/t = ui (general formula)
(2), P = I2r = U2/r (pure resistance formula)
Common physical quantities
1, speed of light: c = 3×108m/s (in vacuum)
2. Sound speed: V = 340m m/s (15℃)
3. Ear discrimination echo: ≥ 0. 1s
4. Gravity acceleration: g = 9.8n/kg ≈ 10n/kg.
5. Standard atmospheric pressure value:
Height of 760mm mercury column =1.01×105pa.
6. Density of water: ρ = 1.0× 103kg/m3.
7. Freezing point of water: 0℃
8. Boiling point of water: 100℃
9. Specific heat capacity of water:
C=4.2× 103J/(kg？ ℃)
10, elementary charge: e =1.6×10-19c.
1 1. The voltage of one dry cell:1.5v.
12. Voltage of lead battery: 2V.
13. safe voltage of human body: ≤36V (not higher than 36V).
14. voltage of power supply circuit: 380v.
15, household circuit voltage: 220V.
16, unit conversion:
(1), 1 m/s = 3.6 km/h.
(2), 1 g/cm3 =10 3 kg/m 3
Element 0 1: hydrogen [chemical symbol ]H, pronounced "light"
Element 02: Helium [chemical symbol ]He, pronounced "Hai"
Element 03: Li (chemical symbol), pronounced "Li"
Element 04: Be[ chemical symbol], pronounced "skin"
Element 05: boron [chemical symbol ]B, pronounced "Peng"
Element No.06: carbon [chemical symbol ]C, pronounced "carbon"
Element 07: nitrogen [chemical symbol ]N, pronounced "light"
Element 08: oxygen [chemical symbol ]O, pronounced "nourishing"
Element No.09: fluorine [chemical symbol ]F, pronounced "Fu"
Element 10: neon [chemical symbol ]Ne, pronounced "nai"
Element number 1 1:Na[ chemical symbol], pronounced "Na"
Element 12: magnesium [chemical symbol] Mg, pronounced "beauty"
Element 13: aluminum [chemical symbol ]Al, pronounced "Lu"
Element 14:Si[ chemical symbol ]Si, pronounced "Gui"
Element 15: phosphorus [chemical symbol ]P, pronounced "adjacent"
Element 16: sulfur [chemical symbol ]S, pronounced "flowing"
Element 17: chlorine [chemical symbol ]Cl, pronounced "green"
Element number 18: argon [chemical symbol ]Ar, a, pronounced "Ya"
Element 19: potassium [chemical symbol ]K, pronounced "a"
Element 20: calcium [chemical symbol ]Ca, pronounced "beggar"
Element number 2 1: Scandium [chemical symbol ]Sc, pronounced "Kang"
Element No.22: titanium [chemical symbol ]Ti, pronounced "Tai"
Element 23: Vanadium [chemical symbol ]V, pronounced "Fan"
Element No.24: chromium [chemical symbol ]Cr, pronounced "each"
Element No.25: Mn[ chemical symbol ]Mn, pronounced "Meng"
Element No.26: Iron [chemical symbol ]Fe, pronounced "iron"
Element No.27: Cobalt (chemical symbol) Co, pronounced "ancient"
Element 28: Ni [chemical symbol ]Ni, pronounced "Jing"
Element No.29: copper [chemical symbol ]Cu, pronounced "copper"
Element 30: zinc [chemical symbol ]Zn, pronounced "Xin"
Element number 3 1: Gallium [chemical symbol] ga, pronounced "home"
Element 32: Germanium [chemical symbol ]Ge, pronounced "Zhejiang"
Element 33: arsenic [chemical symbol ]As, pronounced "Shen"
Element 34: Selenium [chemical symbol ]Se, pronounced "West"
Element 35: bromine [chemical symbol ]Br, pronounced "xiu"
Element 36: krypton [chemical symbol ]Kr, pronounced "gram"
Element 37: rubidium [chemical symbol ]Rb, pronounced "Ru"
Element 38: Sr[ chemical symbol], pronounced "Si"
Element No.39: Y[ chemical symbol], pronounced "B"
Element 40: Zr[ chemical symbol ]Zr, pronounced "high"
Element No.41:niobium [chemical symbol ]Nb, pronounced "Ni"
Element 42: Mo[ chemical symbol ]Mo, pronounced "mu"
Element 43: Blocking [chemical symbol ]Tc, pronounced "De"
Element No.44: ruthenium [chemical symbol ]Ru, pronounced "le"
Element 45: rhodium (chemical symbol) Rh, pronounced "old"
Element 46: palladium [chemical symbol ]Pd, pronounced "ba"
Element 47: silver (chemical symbol) Ag, pronounced "silver"
Element 48: cadmium [chemical symbol ]Cd, pronounced "ge"
Element 49: indium [chemical symbol ]In, pronounced as "cause"
Element No.50: Tin [chemical symbol ]Sn, pronounced "West"
Element number 5 1:Sb[ chemical symbol], pronounced "step"
Element No.52: Te[ chemical symbol], pronounced "Di"
Element 53: iodine [chemical symbol ]I, pronounced "iodine"
Element 54: Xenon [chemical symbol ]Xe, pronounced "fairy"
Element 55: cesium [chemical symbol ]Cs, pronounced "color"
Element 56: Ba [chemical symbol] Ba, pronounced "Bei"
Element No.57: lanthanum [chemical symbol ]La, pronounced "blue"
Element 58: cerium [chemical symbol ]Ce, pronounced "city"
Element No.59: Praseodymium [chemical symbol ]Pr, pronounced "Pu"
Element 60: neodymium [chemical symbol ]Nd, pronounced "mother"
Element number 6 1: promethium [chemical symbol ]Pm, pronounced "Po"
Element 62: Sm[ chemical symbol], pronounced "shirt"
Element 63: europium [chemical symbol ]Eu, pronounced "you"
Element 64: gadolinium [chemical symbol ]Gd, pronounced "rolling"
Element No.65: Terbium [chemical symbol ]Tb, pronounced "Te"
Element 66: Dy[ chemical symbol], pronounced "Didi"
Element 67: Ho[ chemical symbol], pronounced "fire"
Element 68: Er[ chemical symbol], pronounced "ear"
Element 69: thulium [chemical symbol ]Tm, pronounced "lost"
Element 70: Ytterbium [chemical symbol ]Yb, pronounced as "meaning"
Element number 7 1: lutetium [chemical symbol] Lu, pronounced "Lu"
Element 72: Hafnium [chemical symbol ]Hf, pronounced "ha"
Element No.73: Tantalum [chemical symbol ]Ta, pronounced "Tan"
Element 74: tungsten [chemical symbol ]W, pronounced "Wu"
Element 75:Re[ chemical symbol ]Re, pronounced "Lai"
Element 77: Iridium [chemical symbol ]Ir, pronounced "clothes"
Element 78: platinum [chemical symbol ]Pt, pronounced "Bo"
Element 79: Gold [chemical symbol ]Au, pronounced "today"
Element 80: mercury [chemical symbol ]Hg, pronounced "arch"
Element number 8 1: thallium [cHemical symbol ]Tl, pronounced "he"
Element 82: lead [chemical symbol ]Pb, pronounced "money"
Element 83: Bismuth [chemical symbol ]Bi, pronounced "must"
Element 84: polonium [chemical symbol ]Po, pronounced "splash"
Element 85: at [chemical symbol], it is pronounced as "Ai".
Element 86: radon [chemical symbol ]Rn, pronounced "winter"
Element 87: francium [chemical symbol ]Fr, pronounced "Fang"
Element 88: Radium [chemical symbol ]Ra, pronounced "thunder"
Element 89: actinide [chemical symbol ]Ac, pronounced "A"
Element 90: thorium [chemical symbol ]Th, pronounced "earth"
Element number 9 1: praseodymium [chemical symbol ]Pa, pronounced "servant"
Element 92: uranium [chemical symbol ]U, pronounced "by"
Element 93: neptunium [chemical symbol ]Np, pronounced "take"
Element 94: Plutonium [chemical symbol ]Pu, pronounced "No"
Element 95:Am[ chemical symbol], pronounced "eyebrows"
Element 96: curium [chemical symbol ]Cm, pronounced "bureau"
Element 97: thulium [chemical symbol ]Bk, pronounced "accompanied"
Element 98: californium [chemical symbol ]Cf, prOnounced "on"
Element 99: polonium [chemical symbol ]Es, pronounced "mourning"
Element 100: americium [chemical symbol ]Fm, pronounced "Fei"
Element number 10 1:Mo[ chemical symbol ]Md, pronounced "door"
Element number 102: actinide [chemical symbol] No, pronounced as "Nuo"
Element 103: technetium [chemical symbol ]Lw, pronounced "Lao"
Element 104:RF[ chemical symbol], pronounced "Lu"
Element number 105: Degree [chemical symbol] Db, pronounced "degree"
Element 106: Xi[ chemical symbol ]Sg, pronounced "Xi"
Element 107: Cheng Bo [chemical symbol ]Bh, pronounced as "wave"
Element 108: black [chemical symbol ]Hs, pronounced "black"
Element 109: wheat [chemical symbol ]Mt, pronounced "wheat"
Element 1 10: tantalum [chemical symbol ]Ds, pronounced "Da"
Element number 1 1 1: Lun [chemical symbol] Rg, pronounced "Lun".
Element112: uub (112)
Element113: UUT (113)
Element114: uuq (114)
Element115: UUP (115)
Element116: uuh (116)