Physics, the study of matter, energy, and their interactions, is governed by a set of fundamental laws and principles. These laws are often expressed mathematically in the form of equations, known as formulas. This article aims to provide a comprehensive list of essential physics formulas, categorized by their respective areas of study.
Mechanics
Mechanics is the branch of physics that deals with the motion of objects and the forces that cause those motions.
Kinematics:
Equations of motion:
v = u + at (velocity-time relationship)
s = ut + 1/2 at^2 (distance-time relationship)
v^2 = u^2 + 2as (velocity-distance relationship)
Centripetal acceleration: a = v^2/r
Centripetal force: F = mv^2/r
Dynamics:
Newton's Laws of Motion:
First Law: An object at rest stays at rest, and an object in motion stays in motion with a constant velocity unless acted upon by an external force.
Second Law: Force = mass acceleration (F = ma)
Third Law: For every action, there is an equal and opposite reaction.
Work, Energy, and Power:
Work: W = F d cos(theta)
Kinetic energy: KE = 1/2 mv^2
Potential energy: PE = mgh
Power: P = W/t
Electromagnetism
Electromagnetism is the study of the interaction between electric charges and magnetic fields.
Electric Field:
Electric field due to a point charge: E = kQ/r^2
Electric field due to a charged line: E = (lambda)/(2piepsilon_0r)
Electric field due to a charged sheet: E = (sigma)/(2epsilon_0)
Magnetic Field:
Magnetic field due to a straight current-carrying wire: B = (mu_0I)/(2pir)
Magnetic field at the center of a circular current loop: B = (mu_0I)/(2R)
Electromagnetic Induction:
Faraday's Law of Electromagnetic Induction: E = -d(phi)/dt
Lenz's Law: The direction of the induced current is such that it opposes the change in magnetic flux that produced it.
Optics
Optics is the study of light and its behavior.
Reflection:
Law of reflection: Angle of incidence = Angle of reflection
Refraction:
Snell's Law: n1sin(theta1) = n2sin(theta2)
Lenses:
Lens formula: 1/f = 1/v - 1/u
Magnification formula: m = -v/u
Waves
Waves are disturbances that propagate through a medium.
Wave equation: v = lambdaf
Doppler effect: f' = f(v +/- v_s)/(v +/- v_o)
Thermodynamics
Thermodynamics is the study of heat and temperature.
Zeroth Law of Thermodynamics: If two systems are each in thermal equilibrium with a third, then they are in thermal equilibrium with each other.
First Law of Thermodynamics: The change in internal energy of a system is equal to the heat added to the system minus the work done by the system. (Delta U = Q - W)
Second Law of Thermodynamics: Heat cannot spontaneously flow from a colder location to a hotter location.
Third Law of Thermodynamics: It is impossible to reach absolute zero temperature.
Quantum Mechanics
Quantum mechanics is the study of the behavior of matter and energy at the scale of atoms and subatomic particles.
Planck's equation: E = hf
Schrödinger equation: H(psi) = E(psi)
Heisenberg's uncertainty principle: (Delta x)(Delta p) >= h/(4pi)
Nuclear Physics
Nuclear physics is the study of the structure and behavior of atomic nuclei.
Radioactive decay: N(t) = N_0e^(-lambdat)
Half-life: T_1/2 = ln(2)/lambda
Conclusion
This article provides a comprehensive list of essential physics formulas, covering various areas of study. It is important to note that this list is not exhaustive, and there are many other important formulas in physics. However, this list should serve as a valuable resource for students and researchers alike.