{TAIL ~ The ratio} of the outbound velocity to {HEAD ~ the inbound velocity} is commonly referred to as the coefficient of restitution  
{ TAIL ~ The ratio } of the outbound velocity to { HEAD ~ the inbound velocity } is commonly referred to as the coefficient of restitution
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH