How many meters is 1500mm?

Millimeter is a metric unit commonly used in length measurement, also known as millimeter, and the English symbol is abbreviated as mm, which is mainly used for rainfall measurement. Other commonly used units of length measurement include centimeters, decimeters and kilometers. In the international system of units, the basic unit of measurement of length is the meter, and the abbreviation of English symbols is m, and one millimeter is one thousandth of one meter, so 1500mm is equal to1500 ÷1000 =1.5m. ..

The decimal units are 10, 1 m equals 10 decimeter, 1 decimeter equals 10 cm, 1 cm equals 10 mm, and other units of length are feet, feet and inches. These units are also decimal. 1 foot equals 10 foot, 1 foot equals 10 inch. In addition, there are some distance units, such as kilometers and miles.

Development course of rice

During the period of 1792- 1799, under the guidance of French astronomers, he made a survey of the sky from Dunkirk, France to Barcelona, Spain.

1799, according to the measurement results, a short-section platinum rod of 3.5 mm× 25 mm was made, and the distance between the two ends of the rod was set as 1 m, which was kept by the French archives, so it was also called archival meter. This is the earliest definition of rice, and this primitive rice utensil has been kept in the French archives in Paris.

At the end of 19, scientists discovered the red spectral line of natural cadmium (Cd) in the experiment, which has very good clarity and reproducibility. In dry air at 15℃, its wavelength is equal to y = 6438.4696×10-10 meter.

After the 1960s, due to the appearance of laser, people discovered a superior light source. Using laser instead of krypton spectrum can make the length measurement more accurate. As long as a certain time interval is determined, the unit of length can be defined from the product of the speed of light and this time interval.