List of Physics Formulas (original) (raw)

Last Updated : 23 Jul, 2025

**Physics is a fundamental branch of science that studies matter, its fundamental constituents, and its motion and behavior through space and time. Physics Formulas are very important during applications of various concepts of physics.

In this article, we will cover all important formulas related to physics ranging from mechanics to electromagnetism as well as thermodynamics and quantum mechanics.

List of all Physics Formula

Below is the list of all important formulas related to physics:

Mechanics Formulas

Few important mechanics formulas are given below:

**Newton's Second Law of Motion

**F = m × a

**Where:

• F is the force applied to an object,
• m is the mass of the object,
• a is the acceleration of the object.

**Work-Energy Theorem

**W = ΔKE

**Where:

• W is the work done on an object,
• ΔKE is the change in kinetic energy.

**Kinetic Energy

**KE = 1/2mv 2

Where:

• KE is the kinetic energy,
• m is the mass of the object,
• v is the velocity of the object.

**Potential Energy (Gravitational)

**PE = mgh

Where:

• PE is the potential energy,
• m is the mass,
• g is the acceleration due to gravity,
• h is the height.

**Hooke's Law (Spring Force)

**F s **= −kx

Where:

• Fs is the spring force,
• k is the spring constant,
• x is the displacement from the equilibrium position.

**Newton's Law of Universal Gravitation

**F = G ⋅ m 1 **⋅ m 2 / r 2

Where:

• F is the gravitational force between two masses,
• G is the gravitational constant,
• m1 and m2 are the masses,
• r is the distance between the centers of the masses.

Kinematics Formulas

Below are some important kinematics formulas:

**Displacement (s)

**s = ut + 1/2 at 2

Where:

• s is the displacement.
• u is the initial velocity
• a is the acceleration,
• t is the time.

**Final Velocity(v)

**v = u+ at

Where:

• v is the final velocity,
• u is the initial velocity,
• a is the acceleration,
• t is the time.

**Kinematic Third Equation of Motion

**v 2 **= u 2 + 2as

Where:

• v is the final velocity,
• u is the initial velocity,
• a is the acceleration,
• s is the displacement.

Average Velocity (v)

**v = Δx / Δt

Where:

• v is the average velocity.
• Δx is the displacement.
• Δt is the time interval.

Acceleration (a)

**a = Δv /Δt

Where:

a is the acceleration.

Δv is the change in velocity.

Δt is the time interval.

Electricity Formulas

Few important electricity formulas are given below:

Electric Current (I)

**I = Q/t

Where:

• I is the electric current (measured in Amperes, A).
• Q is the charge that passes through a given point.
• t is the time taken.

Electric Charge (Q)

**Q = I × t

Where:

• Q is the electric charge (measured in Coulombs, C).
• I is the electric current.
• t is the time taken.

**Ohm's Law

**V = IR

Where:

• V is the voltage,
• I is the current,
• R is the resistance.

**Power

**P = VI

Where:

• P is the power,
• I is the current,
• V is the voltage.

**Resistance

**R = ρl / A

Where:

• R is the resistance,
• ρ is resistivity,
• l is length, and
• A is area

Watt's Law

**P = I²R or P = V²/R

Where:

• R is the resistance,
• I is Current, and
• V is Voltage

Electric Energy

P = W x T

where:

• P is power,
• W is energy, and
• T is time

Voltage

**V = E / Q

where

• E is energy, and
• Q is charge

Electromagnetism Formulas

Important Electromagnetism Formulas are given below:

Electric Field (E)

**E = F/q

Where:

• E is the electric field.
• F is the force experienced by the charge.
• q is the magnitude of the charge.

Faraday's Law of Electromagnetic Induction

**ε = dΦ/dt

Where:

• ε is the induced EMF.
• Φ is the magnetic flux through the loop.
• t is time.

**Magnetic Force on a Moving Charge

**F = qvBsinθ

Where:

• F is the magnetic force,
• q is the charge,
• v is the velocity,
• B is the magnetic field strength,
• θ is the angle between v and B.

Gauss' Law for Electric Field

**Φ = q/ε o

Where:

• εo is the electric permittivity of free space
• Φ is the magnetic flux through the loop.
• q is the net charge enclosed by the surface.

Electric Potential (Voltage)

**V = W/q

Where:

• V is the electric potential (voltage).
• W is the electric potential energy.
• q is the charge.

Optics Formulas

Few important optics formula are:

**Snell's Law (Refraction)

**n 1 sinθ 1 = n 2 sinθ 2

Where:

• n1 incident index
• n2 refracted index
• θ1 incident angle
• θ2 refracted angle

**Lens Formula

**1/f = 1/v - 1/u

**Where:

• f is the focal length of the lens,
• u is the object distance,
• v is the image distance.

**Magnification for Lenses

**m = −v/u

Where:

• m is the magnification,
• v is the image distance,
• u is the object distance.

Magnifying Power

**M = 1 + d/f

Where:

• M is the magnifying power
• f is the focal distance
• d is the distance between the object and the lens

Thin Lens Formula

**1/f = 1/i + 1/o

Where:

• f is the focal length.
• i is the image distance.
• o is the object distance.

Sound Formulas

Important sound formulas are given below:

**Speed of Sound

**v = √(B/p)

Where:

• v is the speed of sound,
• B is the bulk modulus of the medium,
• ρ is the density of the medium.

**Wavelength (λ)

**λ = v/f

Where:

• λ is Wavelength
• v is Speed of sound
• f is Frequency of the sound wave

Frequency (f)

**f = v / λ

Where:

f is Frequency

v is Speed of sound

λ is Wavelength

Acoustic Impedance (Z)

**Z = ρ × c

Where:

• Z is Acoustic impedance
• ρ is Density of the medium
• c is Speed of sound in the medium

Fluid Mechanics Formulas

Few important formulas related to fluid mechanics are:

Density

**ρ = mV

Where:

• **ρ is density of fluid
• m is mass, and
• v is volume

**Pressure

**P = F/A

Where:

• P is the pressure of the fluid,
• F is applied Force,
• A is area

**Pressure at a Depth h in a Fluid of Constant Density

**p = p o **+ ρgh

**where:

• p is pressure at height h
• po is the pressure at the fluid's surface,
• ρ is the density of the fluid,
• g is the acceleration due to gravity, and
• h is the depth to which the object is submerged

**Viscosity

**η = FL/vA

Where:

• η is fluid viscosity
• F is force
• L is distance between the plates
• V is constant velocity
• A is area of the plate

**Pascal's Law

**F = PA

Where:

• F is applied Force
• P is Pressure, and
• A is area under cross-section.

Reynolds Number (Re)

**Re = pvL/μ

Where:

• ρ is the density of the fluid.
• v is the velocity of the fluid.
• L is a characteristic length (e.g., diameter of the pipe).
• μ is the dynamic viscosity of the fluid.

Thermodynamics formulas

Important thermodynamics formulas are illustrated below:

**First Law of Thermodynamics (Energy Conservation)

**ΔU = Q − W

Where:

• ΔU is the change in internal energy,
• Q is the heat added to the system,
• W is the work done by the system.

**Work Done in Isothermal Process (Ideal Gas)

**W = nRTln(V f /V i )

Where:

• W is the work done,
• n is the number of moles of gas,
• R is the ideal gas constant,
• T is the temperature,
• Vf is the final volume,
• Vi is the initial volume.

**Heat Transfer (Constant Pressure)

**Q = nC p ΔT

Where:

• Q is the heat added or removed,
• n is the number of moles of gas,
• Cp is the specific heat at constant pressure,
• ΔT is the change in temperature.

Ideal Gas Law

**PV = nRT

Where:

• P is the pressure of the gas.
• V is the volume of the gas.
• n is the number of moles of gas.
• R is the gas constant.
• T is the temperature of the gas.

Entropy Change

**ΔS = Q/T

Where:

• ΔS is the change in entropy.
• Q is the heat.
• T is the temperature.

Gibbs Free Energy

**ΔG = ΔH − TΔS

Where:

• ΔG is the change in Gibbs free energy,
• ΔH is the change in enthalpy,
• ΔS is the change in entropy, and
• T is the absolute temperature

Wave Formulas

Important formulas related to wave are described below:

Wave Velocity (v)

**v = f × λ

Where:

• v = Wave velocity (in meters per second, m/s)
• f = Frequency of the wave (in Hertz, Hz)
• λ = Wavelength of the wave (in meters, m)

Frequency (f)

**f = 1/T

Where:

• f = Frequency (in Hertz, Hz)
• T = Time period of one wave cycle (in seconds, s)

Wavelength (λ)

**λ = v/f

Where:

• λ = Wavelength (in meters, m)
• v = Wave velocity (in meters per second, m/s)
• f = Frequency (in Hertz, Hz)

Period (T)

**T = 1/f

Where:

• T = Period (in seconds, s)
• f = Frequency (in Hertz, Hz)

Intensity (I)

**I = P/A

where:

• P is the power
• A is the area.

Solved Examples on Physics Formulas

**Example 1: A stretched string has a displacement of 20 cm and a spring constant of 50Nm −1 . Calculate the potential energy that the stretched string contains.

**Solution:

The parameters that are given are

k = 50Nm−1

x is equal to 20 cm, or 0.2 m.

Potential energy is what it will be.

P.E. = 1/2 k × x2

P.E =3/4 X 50 × (0.2)2

P.E = 1 J

**Example 2: When x is in meters and t is in seconds, a body travels down the x-axis in accordance with the equation x = 1 – 2 t + 3t 2 . Determine the body's acceleration at t = 3s.

**Solution:

As we have

x = 1 - 2 t + 3t2 then;

Speed v = dx/dt = d(1 - 2t + 3t2)/dt = −2 + 6t

Now Acceleration a = dv/dt = d(−2+6t)/dt = 6

acceleration when t is 3s = 6 m/s2

**Example 3: Determine the weight of an item that weighs 50 kg on Earth.

**Solution:

We know, weight = m × g

w = (50 × 9.8) kg m/s2

w = 490 N

**Example 4: A person travels in 10 seconds from Point A to Point B and returns in 8 seconds. Determine the person's average speed if the distance is 36 meters between A and B.

**Solution:

This distance traveled in total is 36 + 36 = 72 meters.

18 seconds was the total time taken.

Thus, average speed is equal to the total distance traveled divided by total time.

average speed = 72/18 = 4 m/s.

Hence the average speed of the person is 4 m/s.

**Example 5: Determine the mass of an object having a kinetic energy of 100J and a velocity of 5 m/s.

**Solution:

We know, KE = ½ mv2.

100 = ½ x m x 5 x 5.

100 = 25 m/2

m = (100 × 2)/25

m = 8 kg

Practice Problems

**Problems 1: Determine the displacement that an object traveling at a speed of 60 m/s will cover in 3 seconds.

**Problems 2: A 50 cm long, thin rod has an evenly distributed total charge of 5 mC over it. Determine the linear density of charges.

**Problems 3: A automobile with a mass of 250 kg is moving at a speed of 10 meters per second. What is the kinetic energy of it?

**Problems 4: 400kcal of heat is required for the phase transition of a 2 kilogram material. Calculate the heat it contains latently.

**Problems 5: A cube immersed in water with a side length of 0.1 meters and a density of 800 kg/m3. Determine if the cube will sink or float by computing the buoyant force acting on it.