BASICS OF PHYSICS

🔹 1. Branches of Physics

Here are a few major areas:

Branch	What It Studies
Mechanics	Motion, forces, energy, and objects
Thermodynamics	Heat and temperature
Electromagnetism	Electricity, magnetism, and light
Optics	Behavior of light
Waves & Sound	Vibrations, wave properties
Modern Physics	Relativity, quantum mechanics
Nuclear Physics	Atomic nuclei and radioactive decay
Astrophysics	Physics of stars, planets, and the universe

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🔹 2. Key Concepts

⚙️ Mechanics (Motion & Forces)

• Speed = Distance ÷ Time

• Velocity = Speed with direction

• Acceleration = Change in velocity over time

• Force (F) = Mass (m) × Acceleration (a) → F = ma

• Newton's Laws of Motion:

  1. An object in motion stays in motion unless acted on by a force.

  2. F = ma

  3. For every action, there's an equal and opposite reaction.

🧱 Energy

• Kinetic Energy (KE) = ½mv²

• Potential Energy (PE) = mgh

• Law of Conservation of Energy: Energy can't be created or destroyed, only transformed.

🔌 Electricity & Magnetism

• Current (I) = Flow of electric charge

• Voltage (V) = Electric potential difference

• Ohm’s Law: V = IR (Voltage = Current × Resistance)

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🔹 3. Units of Measurement (SI Units)

Quantity	Unit	Symbol
Length	meter	m
Mass	kilogram	kg
Time	second	s
Force	newton	N
Energy	joule	J
Power	watt	W
Electric Current	ampere	A
Temperature	kelvin	K

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🔹 4. Formulas to Remember

Concept	Formula
Speed	( v = \frac{d}{t} )
Force	( F = ma )
Work	( W = F \cdot d )
Power	( P = \frac{W}{t} )
Kinetic Energy	( KE = \frac{1}{2}mv^2 )
Potential Energy	( PE = mgh )
Ohm’s Law	( V = IR )