To determine velocity, you need two key pieces of information:

1. Speed: This tells you how fast an object is moving. It is the magnitude of the velocity.

2. Direction: This tells you the direction in which the object is moving.

Here's why both are crucial:

* Speed alone is insufficient: If you only know the speed, you don't know where the object is going. For example, a car traveling at 60 mph could be heading north, south, east, or west.

* Direction alone is insufficient: If you only know the direction, you don't know how fast the object is moving. For example, a car traveling eastward could be moving at 10 mph, 50 mph, or any other speed.

Therefore, velocity combines both speed and direction to give a complete description of an object's motion.

Here are some examples of how velocity is expressed:

* 5 meters per second (m/s) north

* 20 miles per hour (mph) southwest

* 10 kilometers per hour (km/h) at 30 degrees east of north

Remember:

* Velocity is a vector quantity, meaning it has both magnitude and direction.

* Speed is a scalar quantity, meaning it only has magnitude.

Let me know if you have any more questions!