No, if three vectors do not lie in a plane, they cannot give zero resultant.

Explanation:

Let A, B and C be three vectors. If they give zero resultant, then

     A+B+C=0

or, A= -(B+C)

Hence, they will produce zero resultant, if A is equal to negative of vector (B+C). The vector (B+C) lies in the plane of B and C. Hence, A will be equal to negative of (B+C) if A, B and C all lie in a plane.

Balance on a bicycle is a matter of constantly correcting against falls, and it's easier when the speed is higher because the inertia of moving forward overcomes the need for corrective actions.

conceptualizing the truth,in hegel's term. A lot of philosophers(like descartes' three kinds of ideas) in his time (and a lot of mindfulness practitioners these days)believed a higher form of truth(or knowledge) exists which cannot be articulated but is to be intuited and felt.Hegel didnt consider this to be scientific.you can never know if your intuition is true or its just you making the stuff up.