Units-Of-Measurement-Systems-Of-Units-Si-Units-Fundamental-By-Prof-Sanjeev-Sanghi
Units of Measurement
-
Length:
- 1 meter (m) = 100 centimeters (cm)
- 1 meter (m) = 1000 millimeters (mm)
-
Mass:
- 1 kilogram (kg) = 1000 grams (g)
-
Time:
- 1 second (s) = 1000 milliseconds (ms)
-
Area:
- Area of a rectangle = Length × Width
-
Volume:
- Volume of a cube = Side³
- Volume of a cylinder = πr²h
SI Units
- Length: Meter (m)
- Mass: Kilogram (kg)
- Time: Second (s)
- Temperature: Kelvin (K)
- Electric Current: Ampere (A)
- Amount of Substance: Mole (mol)
- Luminous Intensity: Candela (cd)
Fundamental Constants
- Speed of Light in Vacuum (c): $$(3 \times 10^8) m/s$$
- Planck’s Constant (h): $$(6.626 \times 10^{-34}) Js$$
- Avogadro’s Number (Nₐ): $$(6.022 \times 10^{23}) mol⁻¹$$
- Gravitational Constant (G): $$(6.674 \times 10^{-11}) Nm²/kg²$$
Formulas
- Distance traveled ((d)) = Speed ((v)) × Time ((t))
- Speed $$((v)) = (\frac{d}{t})$$
- Acceleration $((a)) = (\frac{{\Delta v}}{t})$$
- Newton’s Second Law: (F = ma)
- Work ((W)) = Force ((F)) × Displacement ((d)) × cos(θ)
- Power $$((P)) = (\frac{W}{t})$$
- Kinetic Energy $$((KE)) = (\frac{1}{2}mv^2)$$
- Potential Energy ((PE)) = mgh (near the surface of the Earth)
- Ohm’s Law: (V = IR)
- Coulomb’s Law: $$(F = \frac{k|q_1q_2|}{r^2})$$
- Electric Power ((P)) = (VI)
Dimensional Analysis
- In dimensional analysis, ensure that the dimensions (units) on both sides of an equation are consistent.
Significant Figures
- When performing calculations with measured values, maintain the correct number of significant figures in your answers.