# Basic Physics Formula Part-3

## Electricity and Magnetism:

**F = qE**(Coulomb's law - the electric force between two charges is equal to the product of the charges divided by the square of the distance between them, multiplied by the electric constant)

**V = IR**(Ohm's law - the voltage across a resistor is equal to the current passing through it times its resistance)

**B = μI/2πr**(magnetic field strength at a point on the axis of a current-carrying loop equals the magnetic constant times the current times the area of the loop, divided by twice the distance between the point and the center of the loop)

## Mechanics:

**F = ma**(Newton's second law - the force acting on an object is equal to its mass times its acceleration)

**v = vo + at**(velocity equals initial velocity plus acceleration times time)

**d = vot + 1/2at^2**(displacement equals initial velocity times time plus one-half times acceleration times time squared)

## Astrophysics:

**F = Gm1m2/r^2**(Newton's law of gravitation - the gravitational force between two objects is equal to the product of their masses, divided by the square of the distance between them, multiplied by the gravitational constant)

**v = H0d**(Hubble's law - the velocity at which a galaxy is receding from us is proportional to its distance from us)

**E = hf**(Planck's law - the energy of a photon is equal to Planck's constant times its frequency)

## Relativity:

**E = mc^2**(mass-energy equivalence - the rest energy of an object is equal to its mass times the speed of light squared)

**t = t0 / sqrt(1 - v^2/c^2)**(time dilation - the time elapsed in a moving reference frame is equal to the time elapsed in a stationary frame divided by the square root of one minus the ratio of the velocity squared to the speed of light squared)

**L = L0 / sqrt(1 - v^2/c^2)**(length contraction - the length of an object in a moving reference frame is equal to its length in a stationary frame divided by the square root of one minus the ratio of the velocity squared to the speed of light squared)

## Atomic and Nuclear Physics:

**E = -13.6 eV (Z^2/n^2)**(energy levels of an electron in a hydrogen-like atom - the energy of an electron in a hydrogen-like atom is equal to negative 13.6 electron volts times the square of the ratio of the atomic number to the principal quantum number)

**Q = mcΔT**(specific heat capacity of a substance - the heat needed to raise the temperature of a substance by one degree Celsius is equal to its mass times its specific heat capacity times the change in temperature)

**E = hf - hf0**(photoelectric effect - the kinetic energy of an electron ejected from a metal surface by a photon is equal to the energy of the photon minus the work function of the metal)

## Fluid Mechanics:

**P = F/A**(pressure equals force divided by area)

**ρ = m/V**(density equals mass divided by volume)

**F = ρVg**(buoyant force - the force experienced by an object submerged in a fluid is equal to the density of the fluid times the volume of the object times the acceleration due to gravity)

These are just a few more basic physics formulas. As you continue to study physics, you will encounter many more formulas that describe the behavior of the physical world around us.