Speed and Velocity
 Speed is a scalar. It is the magnitude of the velocity.
 Velocity, the rate of change of position, is a vector that
represents how fast, and in what direction, something is traveling.
Average velocity:
v_{av} 
= 
Δx
 
Δt


= 
x_{f}  x_{i}
 
t_{f}  t_{i}


Instantaneous velocity: v

= 
dx
 
dt


The instantaneous velocity is the slope of the line on a positionversustime graph.
If the velocity is constant the instantaneous velocity is equal to the average velocity.
Integrating the last equation, the displacement is given by:
Displacement: Δx

= 
∫ 
v(t) dt 