Key Concepts in Physics

Gravitational Force: Attraction between masses; governs motion of planets and falling objects.
Electromagnetic Force: Interaction between charged particles; responsible for electricity and magnetism.
Strong Nuclear Force: Holds protons and neutrons together in atomic nuclei; strongest force but short range.
Weak Nuclear Force: Responsible for radioactive decay; plays a role in nuclear reactions.

Newton's First Law: An object at rest stays at rest, and an object in motion stays in motion unless acted upon by an external force.
Newton's Second Law: Force equals mass times acceleration (F = ma); describes the relationship between an object's mass, its acceleration, and the applied force.
Newton's Third Law: For every action, there is an equal and opposite reaction.

Work: Done when a force causes displacement; W = F × d × cos(θ).
Kinetic Energy (KE): Energy of motion; KE = 1/2 mv².
Potential Energy (PE): Stored energy due to position; gravitational PE = mgh.
Conservation of Energy: Energy cannot be created or destroyed, only transformed from one form to another.

Wave Properties: Frequency (f), wavelength (λ), amplitude (A), speed (v); v = f × λ.
Types of Waves:
- Transverse Waves: Particles move perpendicular to wave direction (e.g., light waves).
- Longitudinal Waves: Particles move parallel to wave direction (e.g., sound waves).
Interference: Superposition of waves leading to constructive (amplifying) or destructive (diminishing) interference.

Zeroth Law: If two systems are in thermal equilibrium with a third system, they are in equilibrium with each other.
First Law: Energy is conserved; ΔU = 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.

Electric Charge: Property of particles; like charges repel, opposite charges attract.
Ohm's Law: V = IR (Voltage = Current × Resistance); describes voltage, current, and resistance in electrical circuits.
Magnetic Field: A field around a magnet or current-carrying wire that exerts a force on other magnets or currents.

Relativity:
- Special Relativity: Time and space are relative; mass-energy equivalence (E = mc²).
- General Relativity: Gravity is a curvature of spacetime caused by mass.
Quantum Mechanics: Describes behavior of particles at atomic and subatomic levels; features wave-particle duality and uncertainty principle.

Friction: Opposes motion between surfaces in contact; can be static or kinetic.
Tension: Force transmitted through a string or rope when pulled tight.
Normal Force: Perpendicular contact force exerted by a surface on an object.

These concepts form the foundational knowledge necessary to understand and explore the field of physics comprehensively.

Gravitational Force: Attracts masses, influencing planetary motion and the falling of objects.
Electromagnetic Force: Operates between charged particles; essential for electrical interactions and magnetic phenomena.
Strong Nuclear Force: Binds protons and neutrons in atomic nuclei; the strongest force but only effective over short distances.
Weak Nuclear Force: Governs processes of radioactive decay; crucial in various nuclear reactions.

Newton's First Law: An object remains in its current state (rest or uniform motion) unless disrupted by an external force.
Newton's Second Law: Expresses the relationship of force, mass, and acceleration with the equation F = ma.
Newton's Third Law: Asserts that actions have equal and opposite reactions.

Work: Calculated as W = F × d × cos(θ); energy transferred when a force moves an object.
Kinetic Energy (KE): Defined as KE = 1/2 mv²; represents energy due to movement.
Potential Energy (PE): Energy at rest based on position; gravitational potential energy represented as PE = mgh.
Conservation of Energy: Principle stating energy's identity remains constant; it transforms rather than disappears.

Wave Properties: Characterized by frequency (f), wavelength (λ), amplitude (A), and speed (v); inherently v = f × λ.
Types of Waves:
- Transverse Waves: Particle motion is perpendicular to wave direction (e.g., light).
- Longitudinal Waves: Particle motion parallels wave movement (e.g., sound).
Interference: Result of wave superposition; can lead to constructive (amplifying) or destructive (diminishing) interference patterns.

Zeroth Law: Establishes conditions for thermal equilibrium among three systems; if A and C are in equilibrium with B, then A and C are in equilibrium with each other.
First Law: Establishes conservation of energy with ΔU = Q - W; captures changes in a system's internal energy.
Second Law: Highlights the natural tendency of isolated systems towards increasing entropy; prohibits spontaneous heat flow from colder to hotter regions.
Third Law: As temperature nears absolute zero, the entropy of a perfect crystal tends toward zero.

Electric Charge: Fundamental property of matter; like charges repel while opposite charges attract.
Ohm's Law: Describes the relationship between voltage (V), current (I), and resistance (R) with the formula V = IR.
Magnetic Field: Created around magnets or current-carrying wires; responsible for exerting force on other magnets or charged particles.

Relativity:
- Special Relativity: Introduces relative time and space; establishes mass-energy equivalence as E = mc².
- General Relativity: Describes gravity as the curvature of spacetime due to mass presence.
Quantum Mechanics: Analyzes particles at atomic and subatomic scales; incorporates wave-particle duality and the uncertainty principle.

Atoms: The basic units of matter made up of protons, neutrons, and electrons.
Atomic Number: Reflects the total number of protons in an atom; determines the element.
Isotopes: Variations of the same element distinguished by differing neutron counts.

Friction: Resists the motion between two surfaces in contact, with types including static and kinetic.
Tension: Force transmitted through strings or ropes, observable when they are pulled taut.
Normal Force: The perpendicular contact force that a surface exerts on an object resting on it.