Question

15m/s to the right. is it speed or velocity? why? and is it scalar or vector? why?

Answer 1

Velocity is a vector. That means it's got a magnitude and a direction. the magnitude of velocity is what we call speed. Speed is a scalar, it doesn't have a direction.
15 m/s by its own is a speed. together with the information that it's to the right gives it a direction and therefore it's a vector.