The fixed distance divided by {HEAD ~ the transit time} is equivalent to {TAIL ~ the average velocity} of the ball over the fixed distance 
The fixed distance divided by { HEAD ~ the transit time } is equivalent to { TAIL ~ the average velocity } of the ball over the fixed distance
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH