Which is a valid velocity reading for an object?

A) 45 m/s

B) 45 m/s north

C) 0 m/s south

D) 0 m/s

B. 45 m/s north

Velocity is a vector quantity such that it has magnitude and direction to it. In this case, all other options either had no magnitude or no direction, hence a correct statement for velocity would be 45 m/s north, which states the magnitude of 45 m/s and the direction of north.