Question

Can a particle in one dimensionaal motion have zero speed and zero velocity

Answer 1

A particle can have zero velocity in one dimensional motion. As an example, when a particle returns to it's initial position from where it started then it's average velocity will be zero.

A particle cannot have zero speed in one dimensional motion. As the particle might have covered at least some distance in some time and speed is distance/time. It cannot have zero speed cause the distance is never zero for a particle.

Cheers!