Question

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

Explanation:

Velocity is a vector quantity, meaning it requires both a magnitude (speed) and a direction to be fully defined. A speed value alone (like 45 m/s or 0 m/s) is a scalar, not a complete velocity reading. A magnitude of 0 means no motion, so adding a direction to 0 m/s is redundant and not a valid velocity (since there is no direction of motion when speed is 0). Only a non-zero speed with a direction is a valid velocity.

Answer:

B. 45 m/s north