How do you solve the conversion between physical units?

Conversion of units, decimal system conversion, unit system conversion, and definition conversion;

Base conversion: e.g. 1km=1000m; 1m 1000mm, etc. (1km 1000m, 1m 1000mm).

Unit system conversion: e.g. 1 horsepower watt.

Definition conversion: e.g. 1m s 1n kg; 1 per second per second meter 1 per kilogram newton; 1 kg Newton.

It is easier to convert to base, with large units becoming small units multiplied by base system, and small units changing to large units divided by base system.

The unit system conversion can be understood and memorized as a special base system, and the conversion method is the same as the base system.

Definition conversions are to memorize the definition of units and the physical meaning of each quantity.

For example: volts ohms amps;

Tip 1: Use definition conversion to check whether the answer is correct, for example.

Meter Seconds Meter Seconds Meter Seconds;

Volts Ohm Volts Ampere Watts.

In the process of calculation, if the units of each physical quantity cannot be obtained by the unit of the result, it means that there may be an error in the solution process.

Tip 2: Using definition conversion can help you memorize the definitions of various physical quantities and help you understand the physical meaning. Like what.

Newton, Coulomb, Volt, meter (electrostatic charge force);

Newton kilogram coulomb volt meter kilogram meter second (acceleration of electric charge in an electric field).

Tip 3: Use definition conversion to help solve the problem column.

For example, the gravitational force of 4 kilograms of matter on the surface of a planet is 80 Newtons, and the gravitational acceleration of the planet's surface is calculated.

Definition conversion: Newton kilogram meter second;

Fill in the count: 80 Newtons 4 kg 20 m s

For example, the conversion between km m mm nm.

Given km, converted to m, multiplied by 1000

If you are given nm, the conversion is large, for example, nm is converted to m, multiplied by -10 to the 6th power.

Big for small, big many, can be multiplied, multiplied by multiples.

Small to large, you can also change from large to small, but it is a negative number multiplied by multiples, and you will do more.

Remember the clear progress rate, and then convert it to example: for example: 1kv = 1000v, then 110v =, that is, 1000 times smaller.

Middle School Physics. Common Unit Conversions:

Units of length: The units of length are kilometers (km), meters (m),decimeters(dm), centimeter (cm), millimeter (mm), micron (m), nanometer (nm). where meters (m) are internationalBase unit, the conversion between Authorities is as follows.

1km=10³m、1m=10dm=10²cm=10³mm

1mm=10³μm、1μm=10³nm、1nm=10-9m

Units of time: Time units (h), minutes (min), seconds (s), milliseconds (ms),microseconds（μm）、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

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

High School Entrance Examination Requirements. Society wants to progress.

The first is the development of science and technology, and there is a very important purpose of learning physics, which is to use these knowledge flexibly to innovate through the mastery and understanding of physical knowledge, to find new answers to unknown fields, and to develop science and technology to a higher field. This is also the direction and trend of the propositions in the physics examination. 3. Physics in the high school entrance examination is becoming more and more flexible, and students tend to think independently.

Pay attention to students' design ability, and increase the weight of experimental exams, and the types of experimental questions have changed more than in the past.

1 liter is 1L, which is 1dm3, that is, 1 cubic decimeter;

And 1 cubic decimeter is equal to a cubic meter, using scientific notation, it is written:

For example, since 1mm = 10 to the negative power, multiply 10 by the minus 2 power mm = minus fifth power m

1um = 10 to the minus sixth power, so minus seventh power m

1dm=, so 530dm=53m

1nm = 10 minus 9th DAO square, so negative quadratic nm = negative 11th square m1cm = 10mm 1mm = 10 to the 3rd power umSo the minus fourth power cm = cubic mm = 9th power nm

1m = 10 to the sixth power, so 9 m = 8 dm 4500cm = 45m = 7th power um

1mm= is expressed in scientific notation, which is 1mm=10 -3m, so the above equation should be.

The relationship between km, nm and cm can also be deduced. In general, there is a relationship between each other in physics books, and scientific notation should be the test point of the 3rd grade of elementary school = =

The conversion process of physical units, the conversion of physical length units in the second year of junior high school.

The conversion relationship between the units of the time searcher: 1h=60min=3600s, 1min=60s, the length unit, the conversion relationship between the units, the number of potatoes, 1 m =10-3km=10dm=102cm, 10 3 mm, 10 6 m, 10 9 nm, the pulley between the area units, 1cm2=10-4m2, 1dm2=10-2m2, the conversion relationship between volume units, 1cm3=10-6m2, 1dm3=10....

The unit conversion in physics is as follows:1 kilogram (kg) = 1000 grams (g).

Grams and kilograms are internationally accepted units of mass.

When measuring the mass of lighter items, it is usually used as "grams"; When measuring the mass of heavier items, it is usually measured in kilograms.

1 kg = 1000 grams, 1 kg = 1 kg, 1 kg = 2 catties, 1 kg = 500 grams.

1 catty = 10 taels, 1 tael = 50 grams.

Estimating the weight of the item should be combined with factors such as the size and texture of the item.

Common question types: 1. Unit conversion, for example: 3000 grams = 3 kilograms.

2. Compare the size, and the simple oak should be unified and then converted into a unified unit.

But four of the seven basic units of the International System of Units are not currently based on physical constants: amperes (current), Kelvin (temperature), moles (mass of matter), and kilograms (mass). Terry Quinn, Honorary Director of the International Bureau of Weights and Measures (BIPM), said:

All units will be based on physical constants, which are stable and invariant by definition of the future, and are ubiquitous. “

A kilogram of Kilogram Prototype (IPK) is made of a platinum alloy called "PT 10IR", which is 90% platinum and 10% iridium (by mass), and then the alloy is machine-made in an upright cylinder (height = diameter), which minimizes the surface area. The original kilogram is kept in a special vault at the headquarters of the International Bureau of Weights and Measures.