Unit conversion in junior high school physics. 5

Unit conversion is to exchange all units for the international system.

1l = 1000ml = 1000 cubic centimeters.

1 cubic meter = 1,000,000 cubic centimeters.

Common unit conversion in junior high school physics: length units: length units are kilometers (km), meters (m), decimeters (dm), centimeters (cm), millimeters (mm), microns (m), nanometers (nm).

where the meter (m) is the international basic unit, and the conversion between units is as follows.

For fractions of integers, there is a "carat premium" phenomenon between the ** of diamonds, and even if there is only a difference of 1 point, 99 points is far from the price of 1 carat.

Carat: In 1907, it was internationally agreed that the carat of the seeds of a carob tree should be used as a unit of measurement for gemstones such as pearls and diamonds. Because this carat weight is surprisingly consistent, the weight is mostly about 200 mg, and it is stipulated that 1 carat diamond is fixed equal to grams, and 1 carat can be divided into 100 points, so 1 carat = g = 200 mg = 100 points, and 30 points diamond is naturally a gram.

The weight of the diamond of the domestic testing agency is usually kept to three decimal places, that is, if the weight of a diamond is. In the international diamond market, there are usually two decimal places, and the third digit is rounded to nine instead of rounding, and the monogram on the international certificate is usually priced in tenths: 20-29 points, 50-59 points.

1. Conversion of length units: 1 km = 1000 meters, 1 meter = 10 decimeters = 100 cm, 1 cm = 10 mm, 1 mm = 1000 microns.

2. Time unit conversion: 1 year = 365 days, 1 day = 24h, 1h = 60min, 1min = 60s

3. Velocity unit conversion: 1m s=

4. Mass unit conversion: 1 kg = 1000 grams 1 ton = 1000 kg, 1 gram = 1000 mg.

5. Volume unit conversion: 1 cubic meter = 1000 cubic decimeters, 1 cubic decimeter = 1000 cubic centimeters.

6. Density unit conversion: 1g cm3 = 1000kg m3

7. Area unit conversion: 1 square meter = 100 square decimeters 1 square decimeter = 100 square centimeters.

1 square centimeter = 100 square millimeters.

8. Power unit conversion: 1kw=1000w

9. Current unit conversion: 1a=1000mA, 1mA=1000 microamperes.

10. Voltage unit conversion: 1kv=1000v, 1v=1000kv

11. Resistance unit conversion: 1 trillion ohms = 106 ohms, 1 thousand ohms = 1000 ohms.

12. Conversion of electric work units: 1 kWh = 3600000J

13. Frequency unit conversion: 1 MHz = 106 Hz, 1 kHz = 1000 Hz.

In the physics of Juexian junior high school, many of the units to be used are to be converted.

1.Conversion of length units. Commonly used conversions are: and shooting.

1 km 100 m.

The following adjacent units are tenfold relationships.

1m 10 dm, 1 dm 10 cm.

2.Area Unit Conversion. The following adjacent units have a 100-fold relationship with each other.

1 square meter is 100 square decimeters, 1 square decimeter is 100 square centimeters.

3.Conversion relationship between volume units: 1000 times relationship between adjacent units.

1 cubic meter 1000 cubic decimeters, 1 cubic decimeter, 1000 cubic centimeters.

1 liter 1 cubic decimeter 1000 ml 1000 cubic centimeters.

4.Density Spike Unit Conversion Relationship:

1 gram cubic centimeter 1000 kilogram cubic meter.

5.Speed Unit Conversion Relationship:

1 m/s kmh.

A negative exponent is equal to the inverse of the opposite (i.e., a positive number) of the silver wither.

Let's take an analogy.

x to the power -a is equal to the reciprocal front of x to the power a.

The -2 power of 2 is equal to 1 (the 2nd power of the 2).

1 Units of length and conversion:

Kilometers (km), meters (m), decimeters (dm), centimeters (cm), millimeters (mm), microns (m), nanometers (nm).

1 kilometer (km) = 1000 meters (m), 1 meter (m) = 10 decimeters (dm), 1 meter (m) = 100 centimeters (cm), 1 meter (m) = 1000 millimeters (mm), 1 meter (m) = 106 micrometers (m), 1 meter (m) = 109 nanometers (nm).

2 Time Units and Conversions:

Hours (h), minutes (min), seconds (s).

1 hour (h) = 60 minutes (min) = 3600 seconds (s).

3 Speed Units and Conversions:

Kilometers (km h), meter seconds (m s) 1m s = km h

The speed of light in a vacuum is 3 108 m/s, and the speed of sound in air is 340 m/s at 15°C.

4 Units of Mass and Conversion:

Tons (t), kilograms (kg), grams (g), 1 ton (t) = 1000 kilograms (kg), 1 kilogram (kg) = 1000 grams (g).

5 Density Units and Conversions:

Kilogram m3 (kg m3 ) g cm3 (g cm3) kg dm3 (kg dm3).

1 g cm3 = 1 kg dm3 = 103 kg m3

6。Force (Gravitational) Units:

Newton (Newton) n g=mg g= Newton kilograms.

7。Pressure unit: Pascal (Pa) Pa

8。Work unit: Joule (joule) j

9 Power unit: watts (watts) w

10 Current Unit: Ampere (Ampere) a

11 Voltage Unit: Volts (volts) V safety voltage not higher than 36 volts.

12 Resistance Unit: Ohm (ohm).

13 Units of electrical work: joules (joules) j degrees (kWh).

1 degree (kWh) = focal (j).

14。Electrical power unit: Watts (watts) w

15。Calorific unit: Joules (joules) J

16 Specific heat capacity unit: joule (kg°C) j (kg°C).

17。Temperature unit: Celsius °

Good luck in your studies and excellent results in your exams.

1. Length unit conversion: 1 km = 1000 meters 1 meter = 10 decimeters = 100 cm 1 cm = 10 mm 1 mm = 1000 microns m - m dm - decimeter cm - cm mm - mm 2, time unit conversion: 1 year = 365 days, 1 day = 24h, 1h = 60min, 1min = 60s3, speed unit conversion:

1m s = mass unit conversion.

Common Unit Conversions in Junior High School Physics:

1. Units of length: The units of length are kilometers (km), meters (m), decimeters (dm), centimeters (cm), millimeters (mm), microns (m), and nanometers (nm). where the meter (m) is the international basic unit, and the conversion between units is as follows.

1km=10³m、1m=10dm=10²cm=10³mm

1mm=10³μm、1μm=10³nm、1nm=10-9m

2. Time units: time units (h), minutes (min), seconds (s), milliseconds (ms), microseconds (m), nanoseconds (ns). where the second(s) is the international basic unit, and the conversion between units is as follows.

1h=60min、1min=60s、1s=10³ms

1ms=10³μm、1μm=10³ns

3. Volume units: The volume units are cubic meters (m), cubic decimeters (dm), liters (l), cubic centimeters (cm), milliliters (ml), and the conversion between units is as follows.

1m³=10³dm
dm³=1l、1cm³=1ml

1dm³=10³cm
l=10³ml

1m3=103dm3=106cm3

4. Conversion of mass units:

1t=10³kg
kg=10³g 1g=10³mg

5. Area unit conversion:

1m2=102dm2=104cm2

Common Unit Conversions for Exams:

1. Current: 10 mA 1A 106 A

2. Voltage: 1kV 10 V MV 1V

3. Resistance: 1k m 106

4. Electric energy (electric work): 1 degree (electricity) = 1kw·h =

5. Electric power: 1kw 10 w

6. Mass: 10 g 1kg, 10 mg 1g mg 1kg t=10 kg

7. Volume: 1L(L) 1DM

8. Density: 1000kg m3=1g cm39, speed: 1m s

10. Length: 1km 1000m=10 m dm=

1mm
nm=1m

12. Area: 1dm 10-2m, 1cm 10-4 m, 1mm 10-6m

13. Volume: 1dm 10-3m cm3 10-6m mm3 10-9m3

14. Pressure: 1Pa=1N m

1. Length (l) 1m=10dm=100cm=1000mm

2. Area (s) 1m2 = 100dm2 = 10000cm2

3. Volume (v) m3 = 1000dm3 = 1000l = 1000000cm3 = 1000000ml 1dm3 = 1000ml

4.The unit of velocity (v) is m s, and the common unit is km (v=s t).

5. Mass (m=g g) unit kg, common unit t, g, mg

1t=103kg 1kg=103g 1g=103mg

5.Density ( kg m3 common unit g cm3 (m v).

1g/cm3=103kg/m3 1kg/m3=

6.Pressure (P) is commonly used in mmHg, standard atmospheric pressure (P=F S).

1pa = 1n m2 1 standard atmosphere = 760 mmHg =

7.The unit n of force (f).

8.The unit of work (w) is J, 1J= (W=FS).

9. The unit of power (P=W T) is W(1W=1JS) The common unit is KW 1KW=103W

Calorifics. 1.Temperature (t) unit: Common unit Kelvin (k) t=(t+273).

2.Specific heat capacity (C) unit: J kg Q = cmδt

3.Calorific value (Q) unit: J kg Q=mq

Electricity. 1.Current (i) unit a, commonly used unit ma, a (i=u r).

1a=100ma 1ma=100μa

2.Voltage (U) unit V, common unit KV, MV, V (U=IR).

1kv=1000v 1v=100mv 1mv=100μv

3.Resistance (R) unit, commonly used unit k, m (r=u i).

1mω=1000kω 1kω=1000ω

4.The unit of electrical energy (W) is J, and the common unit is kWh (W=PT=UIT).

1kwh=5.Electrical power (P) unit W, common unit kW, 1KW=103W (P=W T=UI).

6.Electrothermal (Q) unit j (Q=I2RT).

A few values to keep in mind:

1. The propagation velocity of sound in the air is 340m s 2. The propagation velocity of light in a vacuum or air is 3 108m s; 3. Density of water; 4 Specific heat capacity of water; The melting point of ice is 0; The boiling point of water is 100