Which is a valid velocity reading for an object? 45 m/s 45 m/s north 0 m/s south 0 m/s

Vector quantities are those quantities which have magnitude and direction both at the same time. Velocity is a vector quantity having magnitude as well as direction.

hence the correct choice are

45 m/s north

Since 45 m/s  represent the magnitude of velocity of the object and north  represent the associated direction for the object.

45 m/s north

Explanation:

it's a b and