Attention Angular: Here's Your FATS Explanation.
#6
It's not quite that simple, but you're close.
You can't just assume the .1 second for the 3 mph differential since some cars obviously accelerate faster or slower than that. It's pretty easy to get a fairly accurate number though:
<img src="http://2k2s4.portfolioland.com/audiworld/forum/images/pcgt_fats.gif" border="1">
<img src="http://2k2s4.portfolioland.com/audiworld/forum/images/pcgt_fats.gif" border="1">