samiko and QS you two give the answer.. many of us speeding over 80km/h and think that we can just stop 3 - 5 meters away from the stop object. and this totally wrong. we all should aware of this safey driving. i was waiting for someone actually said it 3 - 10 meters, but nobody else answer it and QS already give full physic and math calculation answer.

I have Smart driving course awhile back and will try to get the copy of the slide show material for ours info.

Everybody is right and Everybody is wrong, its depend where you stand