Your Learning Roadmap: Explore the Lessons
1. Mass, physical quantity, unit & systems of units
2. S.I system, fundamental units, supplementary units & dimensional formula
3. Area, volume, specific volume, speed, velocity, angular velocity & acceleration
4. Mass density & relative density
5. Momentum, angular momentum, force, work, energy & power
Mass:
→ Mass is defined as the amount of matter in an object.
→ The mass of an object is the measure of its Inertia.
→ The mass of a body remains same while the weight changes from place to place.
→ The mass of an object is constant and does not change from place to place.
→ A quantity that can be measurable is called a physical quantity.
→ Some physical quantities have magnitude and unit (example: length is 2m).
→ Fundamental physical quantities are those which do not depend on other quantities and also independent of each other.
→ The units of base quantities are called fundamental or base units.
→ Derived physical quantities are those which are derived from fundamental physical quantities.
Unit:
It is a standard used to measure a physical quantity. (or)
It is the known quantity with respect to which something is measured.
→ The purpose of having standard units is uniformity in measurements.
Units are of two main types:
- Fundamental Units (or base units) and
- Derived Units
Systems of Units:
| System | Units | ||
|---|---|---|---|
| Length | Mass | Time | |
| F.P.S | foot | pound | second |
| C.G.S | centimeter | gram | second |
| M.K.S | meter | kilogram | second |
| S.I | meter | kilogram | second |
→ For M.K.S and S.I systems, the units of length, mass and time are same.
→ The fundamental unit which is common in F.P.S, C.G.S, M.K.S and S.I systems is second.
Page code: lkbpg50