public function sub(Velocity $b)
    {
        $dist     = $this->dist->sub($b->dist);
        $velocity = new Velocity($dist, $this->time);

        $velocity->format = $this->format;

        return $velocity;
    }
public function sub(Velocity $b)
    {
        $dist     = $this->dist->sub($b->dist);
        $velocity = new Velocity($dist, $this->time);

        $velocity->format = $this->format;

        return $velocity;
    }
public function sub ( Velocity $ b ) { $ dist = $ this -> dist -> sub ( $ b -> dist ) ; $ velocity = new Velocity ( $ dist , $ this -> time ) ; $ velocity -> format = $ this -> format ; return $ velocity ; }
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
Subtracts another velocity from this instance and returns a new instance with the difference .