Finding speed of node

General Discussion
#1

What would be the best way to find out how fast a node is moving?

I need to do this so I can set the animation speed of a model based upon how fast it is moving. Since I am using a physics engine on a hilly terrain, when the model goes up hill it is moves much slower, and I would like to set the animation speed based on this.

#2

On each frame record position of node and just calculate difference, thats your distance, and there is command that returns time between current and last frame.
And than its just distance/time.