Can two vectors of unequal magnitude add up to give zero vector can three unequal vectors add up to give zero vector?

Vector Algebra and Vector Calculus are used widely in science, especially Physics and engineering.The physical world involves four dimensions, one scalar dimension and three vector dimensions. From this you can say that 3/4 of the world involve vectors.

1. Projectile motion:

(i) Time of flight T=2usinθg

(ii) Horizontal range R=u2sin2θg

(iii) Maximum height H=u2sin2θ2g

(iv) Trajectory equation (equation of path): y=xtanθ-gx22u2cos2θ=xtanθ1-xR

(v) Velocity after time t, v=ucosθi^+usinθ-gtj^

2. Relative motion:

(i) vAB (velocity of A with respect to B) =vA-vB

(ii) aAB (acceleration of A with respect to B) =aA-aB

3. Crossing river:

(i) A man in a river always moves in the direction of resultant of velocity of man and velocity of river.

(ii) Velocity with which man moves along the river Vmx=Vr-Vm,Rsin⁡θ

(iii) Velocity with which man moves perpendicular to the river Vmy=Vm,Rcos⁡θ

(iv) Time take to cross the river, t=WVm,Rcos⁡θ

(v) To get minimum time dtdθ=0⇒θ=0 

(vi) Drift in this case, d=VrWVm,R

(vii) For shortest path, drift must be zero in this case, and it happens when ⇒sin⁡θ=VrVm,R