"Ockham" wrote in message
. uk...

"snapdragon31" wrote in message
...

| The equation "Distance = Speed * Time" was taught in grade school. I
| don't expect that you do not know that. Distance is a scaler
| quantity. Distance is always positive. Please don't add a negative
| sign to make it negative.

AB is a vector, BA = -(AB)

displacement is a vector .. distance is not a vector .. it is a non-negative
scalar.