Measurements that have both a magnitude (size) and a direction are known as vectors. If a measurement only has a magnitude it is called a scalar.
Displacement is a distance or length in a given direction.For example, 5km North-East is a displacement but 5km is a distance.
Speed is distance over time, while velocity is actually displacement over time. This means that velocity is a speed in a given direction.For example, 7km/h North-East is a velocity but 7km/h is a speed.
We need to make this distinction because the motion of an object travelling 15m/s South is clearly different from an object travelling at 15m/s in a Westerly direction. Their speeds are the same but their velocity are different. Also if we define a particular direction as positive then we can have a negative velocity to indicate that it is travelling in the opposite direction, but again the speeds could be exactly the same.
Fill in the table using examples from the notes above:
