What are the SI units of measure for length, mass, and liquid volumes?
The correct answer and explanation is:
The SI unit of length is the meter, symbolized as “m.” It is the basic unit used to measure distance or length in the International System of Units (SI). The meter was originally defined as one ten-millionth of the distance from the equator to the North Pole along a meridian through Paris. Today, it is precisely defined by the distance light travels in a vacuum in 1/299,792,458 of a second.
The SI unit of mass is the kilogram, symbolized as “kg.” The kilogram is the only SI base unit that includes a prefix in its name. It is defined by the Planck constant, a fundamental constant of nature, with an exact fixed numerical value. Mass represents the amount of matter in an object and is a fundamental property in physics and engineering. One kilogram is equivalent to 1,000 grams.
The SI unit of liquid volume is the cubic meter, symbolized as “m³.” Volume measures the three-dimensional space occupied by an object or substance. Since liquid volume is often measured in smaller quantities, the liter (L) is commonly used. One liter equals one cubic decimeter (dm³), which means one liter is the volume of a cube measuring 10 centimeters on each side. Although the liter is not an official SI base unit, it is accepted for use with SI units because it is convenient for everyday measurements.
In summary, the meter measures length, the kilogram measures mass, and the cubic meter (or liter for practical liquid volumes) measures volume. These units form the foundation for measurement in science, engineering, and daily life across the world. The consistent use of SI units ensures clear communication and standardization in global activities such as trade, research, and industry.