/**
* Subtracts another velocity from this instance and returns a new instance
* with the difference.
*
* @param Velocity $b Velocity to subtract
*
* @return static Difference of the two velocity instances
*/
public function sub(Velocity $b)
{
$dist = $this->dist->sub($b->dist);
$velocity = new Velocity($dist, $this->time);
$velocity->format = $this->format;
return $velocity;
}
