Linear motion is when an object moves on a straight line.There are two types of linear motion: uniform linear motion (when the acceleration is zero and the velocity is constant) and non uniform linear motion (when the acceleration isn't zero and the velocity is varriable).

## Uniform Linear Motion

In uniform linear motion the velocity is constant so the kinematic equations are:

(1.1)

(1.2)

(1.3)

## Non-Uniform Linear Motion

In non-uniform motion the velocity isn't constant since there is some acceleration .

The kinematic equations for constant acceleration are:

(2.1)

(2.2)

Here,

is the initial speed,

is the final speed,

is the time

is the acceleration (it can be either positive or negative)

## Mathematical proof for the above formulas

(2.1)

(from (2.1))

(2.2)