Question

Does the phrase "direction of zero vector" have physical significance? Discuss it terms of velocity, force etc.

Answer 1

A zero vector has physical significance in physics, as the operations on the zero vector gives us a vector.
For any vector \[\vec{A}\] , assume that

\[\vec{A}  +  \vec{0}  =  \vec{A} \] 

 

\[ \vec{A}  -  \vec{0}  =  \vec{A} \] 

 

\[ \vec{A}  \times  \vec{0}  =  \vec{0}\]

Again, for any real number λ we have:

\[\lambda \vec{0} = \vec{0}\]

The significance of a zero vector can be better understood through the following examples:
The displacement vector of a stationary body for a time interval is a zero vector. 
Similarly, the velocity vector of the stationary body is a zero vector. 
When a ball, thrown upward from the ground, falls to the ground, the displacement vector is a zero vector, which defines the displacement of the ball.