What is the difference between speed and velocity?
You can think of speed as the
Speed is just that: a speed.
4 [meters per second]
25 [miles per hour]
Speed can never be negative because it is a magnitude.
Velocity is speed with a
4 meters per second [to the North]
25 miles per hour [15 degrees West of North]
We can make these quantities negative because it affects direction.
-4 meters per second [to the North] would actually be 4 meters per second [to the South]