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What is the publicity of mathematics?
List of things in junior high school

The main unit of the main principle of physical quantities

Length (L) (1) Measure (2) the distance moved in the direction of force (3) with a ruler: s= (4) arm of force = (5) the depth of liquid.

(6) the thickness of the object h= a=

Kilometers, meters, decimeters, centimeters, millimeters, etc.

1 km =1000m

1m= 100cm

Area (s) (1) area formula S = AB S = A2 S = π R2 = π D2.

(2) Volume formula (3) Pressure formula

1 m2 = 102 m2

1dm2= 102cm2

1cm2= 102mm2

Volume (V) (1) Mathematical formula V positive =a3 V length =Sh=abh V column = =Sh V ball = π R3 (2) Density formula (3) V = V2-V 1 (4) V = V row = F floating/ρ liquid G is partially exposed when submerged by Archimedes principle.

1dm3= 103cm3

1cm3= 103mm3

Time (t) (1) Definition of speed (2) Power (3) Measured by clocks.

1h = 60 minutes

1 min = 60 seconds

Speed ()

( 1) (2)

1 m/s = 3.6 km/h

Mass (m) (1) Gravity formula (2) Work formula

(3) Measure the density with a balance formula (4).

1t= 1000kg

1 kg =1000g

1 g = 1000 mg

Density (ρ) (1) has (2) pressure formula (3) Archimedes principle F floating = ρ liquid gV discharged and then ρ liquid =

1 g/cm3 = 1000

Kg/m3

The resultant force (f) (1) in the same direction f = f 1+F2 (2) in the opposite direction f = f1-F2 (f1> F2) n.

Pressure (p) (1) (applicable to all solids and liquids) (2) Applicable to all liquids and solids (cuboids, cubes and cylinders) whose sides are perpendicular to the bottom (1pa = 1n/m2).

Buoyancy (F float) (1) Weighing method F float = G-F means (2) Pressure difference method F float = F up -F down.

(3) Archimedes principle method F floating = ρ liquid gV row (4) floating or floating method F floating = g.

Strength and resistance

Just be the same as the unit.

Work (w) (1) definition W=Fs gravity work W=Gh=mgh friction work W=fs.

(2) Total work W =F total moving s W = w usage +w quantity.

Useful work = ghw has = w total-w amount

(3)η= W Yes =ηW Total w Total = (4) W=Pt

1J= 1N.m

= 1w.s

Mechanical efficiency (η) (1) η = =

(2) η= =

(3) For pulley block η= (n is the number of strands on the moving pulley)

(4) η= =

Since useful work is always less than total work, η is always less than 1.

When the pulling force (f) (1) does not include the weight and friction of the moving pulley and rope, f = (2) does not include the weight and friction of the rope, (3) generally uses (n is the number of rope strands on the moving pulley) (4) the object moves at a uniform speed, generally f = F= (2 f is generally friction).

Power (P) (1) P = (2) P = = (3) read from the nameplate of the machine.

1w= 1J/s

= 1 nm/sec

Specific heat (c) (1) q absorption = cm (t-t0) q discharge = cm (t0-t) can be unified as q = cm △ t.

rule

(2) q amplifier = QM (q is J/kg m, unit is kg)

(3) q amplifier = qv (q is m3 to J/ m3 V)

(4)Q- absorption = Q- emission without heat loss (heat balance equation)

The unit of c is

J/(Kg。 The specific heat capacity of water is 4.2× 103J/(Kg. The physical meaning is 1kg. The heat absorbed by water is 4.2× 103J.

The charge amount (Q) (1) is defined as Q = IT (2) W = UIT = UQ, and Q = (Q is the charge amount).

The unit of q is C.

Definition of current (I) (1) (Q is the amount of charge) (2)

(3) w = uite rule

(4) P = UI, then (P is electric power)

(5) Joule's law Q = I2RT is

(6) If the pure resistance circuit w = UIT = I2RT, then

(7) p = ui = i2r, then

(8) series connection: I = i 1 = I2 parallel connection: I = i 1+I2 (9) read from the ammeter 1A = 1000ma.

Voltage (U) (1) (Q is the amount of charge) (2) U = IR (3) (4)

(5) Joule's Law (Q is the heat generated) Then (6) Series connection: U = U 1+U2 Parallel connection: U = U 1 = U2.

(7) Read 1 kV = 1000 V from the voltmeter,

1V= 1000mV. The household circuit is 220V, and the safe voltage to human body is not more than 36 V.

Resistance (R) (1) (principle of measuring resistance by voltammetry) (2) W = UIT = I2RT =

(3)

(4) Joule's Law Q = I2RT (Q is the heat generated)

(5) Series connection: r = r 1+r2, then r 1 = r-r2r2 = r-r 1.

(6) Parallel connection: (7) Read the words "10Ω1a" on the sliding rheostat from the ohmmeter or nameplate. 1ω= 1V/A

1mω= 106ω

1kω= 103ω

Electric work (w) (1) w = UIT = uq (q is the amount of charge) (2) w = q =

(3) P = W = (4) W = Q = when there is no heat loss.

(5) Read out from the electric energy meter (unit: Kwh). The international unit is J, and the commonly used unit on electric energy meters is kW.h.

1KW.h=3.6× 106J

Power (P) (1) (2) P = (3) read from electrical appliances.

1Kw= 1000w

1 HP = =735w W。

When electric heating (q) (1) does not calculate heat loss, q = w =

(2) heat balance equation q absorption = q let its unit be j.

Electrification time (t) (1) (Q is the amount of charge) (2) w = UIT, then

(3) p = then (4) q = then

You'd better give me your qq mailbox so that I can send you the documents.