# Motion

Written by Jerry Ratzlaff on . Posted in Classical Mechanics

Motion is the acceleration, displacement, or velocity of an object relative to a given frame of reference.  There are four basic types of motion with each one moving different than the other.  There is a fifth called irregular motion which does not actually count as one.

### Types of Motion

• Linear motion is anything that moves in a straight line.
• Oscillating motion (simple harmonic motion) moves repeatedly back and forth.
• Rotary motion is anything that moves in a circle.
• Reciprocating motion moves backwards and forwards in a straight line.
• Irregular motion is any motion that has no fixed pattern.

### Linear Motion Formula

$$\large{ s = v_i + at }$$

$$\large{ s = \frac{1}{2} \left( v_i + v_f \right) t }$$

$$\large{ s = v_i t + \frac{1}{2} at^2 }$$

$$\large{ s = v_f t - \frac{1}{2} at^2 }$$

Where:

$$\large{ s }$$ = displacement (linear motion)

$$\large{ a }$$ = acceleration

$$\large{ v_f }$$ = final velocity

$$\large{ v_i }$$ = initial velocity

$$\large{ t }$$ = time

Tags: Equations for Motion