Question

Is it possible in straight line motion a particle having zero speed and a non zero velocity ¿explain

Answer 1

NO a particle cannot have zero speed with non zero velocity because 

⇒Speed = Distance /Time taken 

⇒Since , Distance≠0 

   ∴Speed≠0

Answer 2

NO,In this condition particle cannot have a zero speed.

Yes, velocity will be a non-zero value.

Speed can only be zero if there is no movement,but since you mention the particles is in motion speed cannot be zero.

Velocity can be zero if displacement is zero, i.e if the particle returns to its original position, but since the particles are in straight line they cannot come back to its original position.Hence even velocity cannot be zero.