Derivation of the Equations of Motion

 

Start with:

  

then:

 

Combine these two equations to get:

This is Equation 3 in the

discussion that follows.

 

From the definition of acceleration:

 

This is Equation 1.

 

Solve this equation for t:

 

Put this result in the 3rd equation from the top:

 

This is Equation 2.

 

Take  the 4th equation down and use it to replace v in the 3rd equation down:

 

This is Equation 4.