By definition, we have that the speed of an object is given by:
![v = \frac{d}{t}](https://tex.z-dn.net/?f=%20v%20%3D%20%5Cfrac%7Bd%7D%7Bt%7D%20%20)
Where,
d: distance [in units of length: meters, feet, miles]
t: time [in units of time: minutes, seconds, hours]
Therefore, knowing the distance traveled, and the time to travel this distance, we can know the speed of an object.
Then, since velocity is a vector, then we need the direction of the vector.
Therefore, the velocity vector can be written as:
![v = |v|(cos(\alpha) i + sin(\alpha) j)](https://tex.z-dn.net/?f=%20v%20%3D%20%7Cv%7C%28cos%28%5Calpha%29%20i%20%2B%20sin%28%5Calpha%29%20j%29%20)
Answer:
two things you need to know to describe the velocity of an object are:
1) Magnitude (speed)
2) direction