We measure sound intensity (also referred to as sound power or sound pressure) in units called decibels. Decibels (dB) are named in honor of Alexander Graham Bell, the inventor of both the telephone and the audiometer.

decibel (dB)

watt

The candela is the base unit within the International System of Units (SI) that is used for such measurements of light. The power of optical radiation is measured in watts.

A base unit (also referred to as a fundamental unit) is a unit adopted for measurement of a base quantity. A base quantity is one of a conventionally chosen subset of physical quantities, where no quantity in the subset can be expressed in terms of the others.

A pascal is a pressure of one newton per square metre, or, in SI base units, one kilogram per metre per second squared. This unit is inconveniently small for many purposes, and the kilopascal (kPa) of 1,000 newtons per square metre is more commonly used.

Answer: The pascal (symbol: Pa) is the SI derived unit of pressure used to quantify internal pressure, stress, Young’s modulus and ultimate tensile strength. It is defined as one newton per square metre. It is named after the French polymath Blaise Pascal.

Newton metre is also called Joule regarding the greatest scientist Joule. Here we see the unit of work is derived with the help of other fundamental unit. So unit of work is derived unit.

A derived unit is a unit that results from a mathematical combination of SI base units. Calculations involving derived units follow the same principles as other unit conversion calculations.

The unit most commonly used in professional astronomy is the parsec (symbol: pc, about 3.26 light-years) which derives from astrometry: it is the distance at which one astronomical unit subtends an angle of one second of arc….Definitions.