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

The valid velocity reading for an object is 45 m/s north.

Explanation:

Velocity of an object is defined as the rate of change of its displacement. It is given by the relation :

x is the displacement

t is the time taken

Velocity is a vector quantity. This type of quantities posses both magnitude and direction. Out of 4 options, option (B) is correct. This is because, it shows both magnitude i.e. 45 m/s and direction north. Hence, this is the required solution.

your answer is, orbit around the nucleus