Key Concepts in Physics

Gravitation: Attraction between masses; described by Newton's Law of Universal Gravitation and Einstein's General Relativity.
Electromagnetism: Interaction between charged particles; described by Coulomb's Law and Maxwell's Equations.
Weak Nuclear Force: Responsible for radioactive decay and neutrino interactions.
Strong Nuclear Force: Binds protons and neutrons in atomic nuclei.

Displacement: Change in position; vector quantity.
Velocity: Rate of change of displacement; vector quantity.
Acceleration: Rate of change of velocity; vector quantity.
Equations of Motion (for constant acceleration):
- ( v = u + at )
- ( s = ut + \frac{1}{2}at^2 )
- ( v^2 = u^2 + 2as )

Work: ( W = F \cdot d \cdot \cos(\theta) )
Kinetic Energy: ( KE = \frac{1}{2}mv^2 )
Potential Energy:
- Gravitational: ( PE = mgh )
- Elastic: ( PE = \frac{1}{2}kx^2 )
Conservation of Energy: Total energy in a closed system remains constant.

Zeroth Law: If two systems are in thermal equilibrium with a third, they are in equilibrium with each other.
First Law: ( \Delta U = Q - W ) (Change in internal energy = heat added - work done).
Second Law: Entropy of an isolated system always increases; heat cannot spontaneously flow from cold to hot.
Third Law: As temperature approaches absolute zero, the entropy of a perfect crystal approaches zero.

Wave Properties: Wavelength, frequency, amplitude, speed.
Types of Waves:
- Transverse: Oscillations are perpendicular to wave direction.
- Longitudinal: Oscillations are parallel to wave direction.
Sound: Longitudinal wave that requires a medium; speed depends on medium properties.

Speed of Light: ( c \approx 3 \times 10^8 ) m/s in vacuum.
Reflection: Angle of incidence equals angle of reflection.
Refraction: Bending of light as it passes between different mediums; described by Snell's Law.
Lenses: Convex (converging) and concave (diverging) lenses; focal length determines image properties.

Quantum Mechanics: Describes behavior of particles at atomic and subatomic levels; key principles include wave-particle duality and uncertainty principle.
Relativity: Special Relativity (speed of light is constant; time dilation and length contraction) and General Relativity (gravity as curvature of spacetime).

Momentum: ( p = mv ); conserved in isolated systems.
Circular Motion: Centripetal force required for an object moving in a circular path; ( F_c = \frac{mv^2}{r} ).
Simple Harmonic Motion: Motion of oscillating systems; characterized by restoring force proportional to displacement.

Gravitation: Newton's Law of Universal Gravitation describes the attractive force between masses; Einstein's General Relativity reformulates this, explaining gravity as the curvature of spacetime.
Electromagnetism: Interactions between charged particles governed by Coulomb's Law; Maxwell's Equations describe how electric and magnetic fields interact.
Weak Nuclear Force: Key player in processes like radioactive decay and neutrino interactions, influencing particle interactions at a fundamental level.
Strong Nuclear Force: Holds protons and neutrons together within atomic nuclei, countering their electromagnetic repulsion.

Displacement: The vector quantity representing the change in position of an object.
Velocity: Vector quantity measuring the rate at which displacement occurs.
Acceleration: Vector quantity that represents the rate of change of velocity over time.
Equations of Motion: Important formulas for objects under constant acceleration:
- ( v = u + at ) relates final velocity to initial velocity, acceleration, and time.
- ( s = ut + \frac{1}{2}at^2 ) calculates the distance traveled.
- ( v^2 = u^2 + 2as ) connects velocity, acceleration, and displacement.

Work: Defined as ( W = F \cdot d \cdot \cos(\theta) ), where ( F ) is force, ( d ) is displacement, and ( \theta ) is the angle between them.
Kinetic Energy: Given by the formula ( KE = \frac{1}{2}mv^2 ), where ( m ) is mass and ( v ) is velocity.
Potential Energy:
- Gravitational Potential Energy calculated as ( PE = mgh ), where ( g ) is acceleration due to gravity.
- Elastic Potential Energy calculated using ( PE = \frac{1}{2}kx^2 ), where ( k ) is spring constant and ( x ) is displacement from equilibrium.
Conservation of Energy: In isolated systems, the total energy remains constant; energy can change forms but cannot be created or destroyed.

Zeroth Law: Establishes thermal equilibrium; if two systems are each in equilibrium with a third, they are in equilibrium with each other.
First Law: ( \Delta U = Q - W ); the change in internal energy of a system equals the heat added minus the work done by the system.
Second Law: States that the entropy of an isolated system will always increase, prohibiting spontaneous heat flow from cold to hot.
Third Law: As temperature approaches absolute zero, the entropy of a perfect crystal approaches zero.

Wave Properties: Characterized by wavelength, frequency, amplitude, and speed.
Types of Waves:
- Transverse Waves: Oscillations are perpendicular to the wave direction.
- Longitudinal Waves: Oscillations are parallel to the wave direction.
Sound Waves: A specific type of longitudinal wave requiring a medium for propagation; speed varies based on medium properties.

Speed of Light: Approximately ( c \approx 3 \times 10^8 ) m/s in a vacuum.
Reflection: The principle that the angle of incidence equals the angle of reflection.
Refraction: The bending of light as it transitions between media, explained by Snell's Law.
Lenses: Comprised of convex (converging) and concave (diverging) types; focal length determines the characteristics of the images produced.

Quantum Mechanics: A framework for understanding atomic and subatomic particle behavior, highlighting concepts like wave-particle duality and the uncertainty principle.
Relativity: Encompasses Special Relativity (constant speed of light, effects like time dilation and length contraction) and General Relativity (gravity explained by spacetime curvature).

Momentum: Given by ( p = mv ); conserved quantity in isolated systems.
Circular Motion: Requires centripetal force, calculated as ( F_c = \frac{mv^2}{r} ).
Simple Harmonic Motion: Employs a restoring force proportional to the displacement from equilibrium, characteristic of oscillating systems.