Explain physical quantities and measurement.

Physical quantities: A physical quantity is the measurable property of an object or a system. Mass, time, speed, acceleration, temperature, force, pressure, power, energy, and, length are all physical quantities.

Physical quantities are measured by comparing them with arbitrarily chosen internationally accepted standards called Units. Units are necessary to express physical quantities.

For example, a metre is a unit of length and Celsius is a unit of temperature.

The International System of Units or the SI system is the internationally accepted unit of measurement for physical quantities. The SI units of various physical quantities are given below:

Physical Quantity SI unit
1. Mass kilogram
2. Time second
3. Speed m / s^2
4. Acceleration m / s^2
5. Temperature Kelvin
6. Force Newton
7. Pressure Pascal
8. Power Watt
9. Energy Joule
10. Length metres
Every physical quantity is measured in its accepted SI system.