which is a valid velocity reading for an object?\n45 m/s\n45 m/s north\n0 m/s south\n0 m/s

Explanation:

Step1: Recall velocity definition

Velocity is a vector quantity, having both magnitude and direction.

Step2: Analyze each option

• 45 m/s is only a speed (magnitude), not velocity.
• 45 m/s north has magnitude (45 m/s) and direction (north), so it is a valid velocity.
• 0 m/s south has magnitude 0 and direction south, it is a valid velocity (object can have zero - velocity in a specified direction).
• 0 m/s has magnitude 0, and when direction is not specified for zero - velocity, it is also valid as the object is at rest.

Answer:

All of the options (45 m/s north, 0 m/s south, 0 m/s) are valid velocity readings.