# Physics Equations

#### Astronomy Equations

Relating Synodic and Sidereal Periods

Planet's synodic period - Time required for the planet to complete one complete orbit (Time that elapse between two successive identical configuratio as seen fro...

#### Classical Mechanics

Momentum

Momentum in classical mechanics
If an object is moving in any reference frame, then it has momentum in that frame.The amount of momentum that an object has depends on two physical quantities: th...

Newtons second law of motion

Newton's second law: Law of Motion
The rate of change of momentum of a body is equal to the resultant force acting on the body and is in the same direction.
Newton's second law as originally state...

Point kinetics in a fixed coordinate system

DefinitioThe position the velocity and the acceleration are defined by:The following holds:When the acceleration is cotant this gives:
For the unit vecto in a direction perpen...

Point dynamics in a fixed coordinate system

Force, (angular)momentum and energy
Newton's 2nd law connects the force on an object and the resulting acceleration of the object where the momentum is given by ::Newton's 3rd law is given by...

Point dynamics in a moving coordinate system

Apparent forces
The total force in a moving coordinate system can be found by subtracting the apparent forces from the forces working in the reference frame: . The different apparent forces are give...

Dynamics of masspoint collections

The centre of mass
The velocity with respect to the centre of mass is given by The coordinates of the centre of mass are given by:In a 2-particle system, the coordinates of the centre of mas...

#### Electricity and Magnetism Equations

Maxwell equations

The Maxwell equatio
The classical electromagnetic field can be described by the Maxwell equatio. Those can be written both as differential and integral equatio:...

#### Optics Equations

Refractive Index

Refractive IndexSnell's Law
Two media of refractive indices n1 and n2 meet at a surface or interface. i incident angle and r is reflected angleFor air to dee medium we can simplify th...

#### Relativity Equations

Relativistic Mass, Momentum, and Energy

Given an object of invariant mass m0 traveling at velocity v the energy and momentum are given byE – Energy
p – Momentum
m0 – initial mass
c – Speed of lightThe speed of li...