DistanceofcarAfromthecrossingatanytimet=l1−v1tDistanceofcarBfromthecrossingatanytimet=l2−v2tDistancebetweenthesetwocars=√(l1−v1t)2+(l2−v2t)2=sdsdt=−2(l1−v1t)v1−2(l2−v2t)v22√(l1−v1t)2+(l2−v2t)2=0⇒t=l1v1+l2v2v21+v22mindistancebetweenthemissmin=v1v2√l21+l22v21+v22