Physics conversion for junior 2, physics unit conversion skills for junior 2

It's not typeset, I'll do it.

1。 560km=560×10^3m=560×10^6mm=560×10^12nm

2。3。 6700m=6700×10^3mm=6700×10^6um=6700×10^9nm

Take a look below to convert.

In the International System of Units, the standard unit of length is the meter, which is denoted by the symbol "m". 1960 11th International Conference on Weights and Measures: "The length of the meter is equal to the 1650763 of the wavelength of the radiation in a vacuum with a transition between the 2p10 and 5d1 energy levels of the Krypton 86 atom".

Other units of length are: light year, petameter (pm), megameter (mm), kilometer (km), decimeter (dm), centimeter (cm), millimeter (mm), silk meter (dmm), franny meter (cm), micrometer (m), nanometer (nm), picometer (pm), femtometer (fm), ami (am), etc. Their conversion relationship with the meter is as follows:

1km = 1 10 3m (km).

1dm = 1 10 (-1)m (decimeter).

25px = 1 10 (-2)m (cm).

1mm=1 10 (-3)m (mm).

1dmm = 1 10 (-4) m (silk meter).

25pxm = 1 10 (-5)m (m).

1 m = 1 10 (-6)m (microns).

1nm = 1 10 (-9)m (nm).

This is too simple, no one, I'll come again,

Tips for converting units

1. Multiplication is used for large units to small units, and division is used for small units (abbreviation: Dahua Hinayana and small division) Students have learned in previous mathematics learning that when "large units are divided into small units, multiplication is used when small units are divided into large units, and division is used when small units are divided into large units". It can be found that students often do not know which one is a large unit or a small unit when learning.

2. Methods for judging large and small units.

The unit is different, if the unit is larger, the unit is smaller, and the unit is larger on the side with the smaller value. Such as:

1 meter 100 centimeters", since 1<100, it can be concluded that the unit "meter" is larger than "centimeter".

1 amp 1000 mA", since 1<1000, it can be concluded that the unit "ampere" is larger than "mA".

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、1kg=10³g1g=10³mg。

5. Area unit conversion:

1m2=102dm2=104cm2。

In the second year of junior high school, the physical unit conversion technique is to convert from large units to small units to multiply the advance rate, and divide the advance rate from small units to large units.

Physics is the study of the most general laws of the motion of matter and the basic structure of matter. Its theoretical structure makes full use of mathematics as its working language, and experiments as the only criterion for testing the correctness of theories, and it is the most sophisticated natural science discipline today.

In physics, in order to distinguish the symbols of physical quantities and units, the symbols of physical quantities, except for the standard atmospheric pressure atm which is a positive body, are italic, and the symbols of the units of physical quantities are all orthodox. A physical quantity is a measure of a physical property or a quantity that describes the state of motion of an object and the process of its change. Whereas, the unit of physical quantity is the standard used to measure physical quantity.

Unit conversion steps.

1. Analyze two units and determine which is the large unit and which is the small unit.

2. Clarify the rate of progress (that is, multiples) between the two units.

3. Vacate the number in front of the unit, if it is large or small, multiply by the advance rate; If it is smaller, divide by the advance rate.

3. Simplify the results.

Decimeter (1453000) micron = (1453000000) nanometer 9 m = (900) millimeter.

79 nm = (m.)

3 m = (300) cm (3000000) = μm = (3000000000) nm.

5 km = (500000) cm = (5000000000) microns.

Xiao Ming measured the circumference of a circle 5 times, and the value is, and one of the measurement errors is (, and the diameter of the circle can be known from the above data

The length of the classroom is that the scale used by the surveyor is (cm), the accurate value recorded is (, and the estimated value is (.

What is the length of the object? , what is the index value of the ruler? , Estimates ? _

I don't know if the question is incomplete, so I'm asking me after completing the question.

D 72m = 72 times 10 to the 9th power nm = multiplied by 10 to the 10th power nm to change the unit, the previous value does not move, first convert the unit, and then calculate the value must be measured from the 0 scale of the scale, not necessarily.

The results are recorded, and the units are not necessary for the wrong ones.

D is selected for the first question and B is selected for the second question

It is necessary to first figure out whether it is a conversion from a large unit to a small unit or a small unit to a large unit, and the conversion from a large unit to a small unit is multiplied by the advance rate, and the conversion rate from the small unit to the large unit is divided by the advance rate, such as: 5m s= km h The conversion process is 5m s=5*

v=s t (velocity formula).

1m/s=；

p = m v (density formula).

1g/cm^3=1*10^3kg/m^3

There are just two formulas in the first semester of the second semester of junior high school.,Next semester we've just revised it.,I don't know what the content is.。

If you look at the crown of words and the order of magnitude of **, you can know the unified idea of the naming of physical units. It is also necessary to practice the addition, subtraction, multiplication and division operations of scientific notation, and the unit conversion is easy to pass.

In fact, the formula should be used more often, and it is best to use scientific notation for conversion, which will be very convenient.

The conversion is best done using scientific notation.

The principal unit of density is kg m 3.

Commonly used density sheets are: t m 3;kg/dm^3；g/cm^3.

t::mass unit "ton").

Conversion relationship: 1t m 3 = 1kg dm 3 = 1g cm 3 = 10 3kg m 3.

So, in the unit of density, the main unit is kg m 3, which is the small unit. The rest of the units are large units.

Moreover, several large units are equal, all 1000 times larger than small units.

Physical significance: 1t m 3: the mass of each cubic meter is 1 ton; Or the volume of a substance with a mass of 1 ton is 1 cubic meter.

1kg dm 3: the mass of a substance with a volume of 1 cubic decimeter is 1 kg; Or the volume of a substance with a mass of 1 kilogram is 1 cubic decimeter.

1g cm3: The body is 1 cubic centimeter and the mass of a substance is 1 gram; Or the volume of a substance with a mass of 1 gram is 1 cubic centimeter.

Conversion process: 1t m 3 = 10 3kg m 3.

1t/m^3=10^3kg/dm^3=1kg/dm^3.

1t/m^3=10^6g/106cm^3=1g/cm^3.

Conversion method: When the unit is changed from small to large, the original number remains unchanged, as a multiple, multiplied by the positive exponential power of ten (or multiplied by the advance rate);

When a large unit becomes a small unit, the original number remains the same, as a multiple, multiplied by a negative exponential power of ten. (or divide by the advance rate).

Examples: 1) Find out that the density of a substance is grams cubic centimeters kilogram cubic meters.

2) The mass and volume given in the question are grams and cubic centimeters, and they are fill-in-the-blank and multiple-choice questions, so the density unit is gram cubic centimeters. p = kilogram cubic meter gram cubic centimeter.

1 meter per second = kilometers per second.

1 meter per second = kilometers per minute.

1 meter per second = kilometers per hour.

When the time units are the same, only the base units of the meter are converted.

When the distance units are the same, only the time units are converted.

1 meter per second = 1 10 -3 kilometers per second.

1 meter per second = 6 10 -2 kilometers per minute.

1 meter per second = kilometers per hour.

1 km per second = 1 10 3 m per second.

1 km per minute = 50 3 meters per second = meters per second.

1 km/h = 1 meter per second = meter per second.