Question

What is the difference between speed and velocity?

Answer 1

You can think of speed as the `magnitude` of velocity.

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 `direction`.

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]

Answer 2

See below.

Explanation:

`vec v` velocity.
`norm(vec v)` speed.