Displacement, distance, etc

Scalars only have magnitude (size)
Vectors have magnitude and direction
Speed is a scalar
Velocity is a vector

Distance is a scalar, displacement s a vector, it has direction.

To understand a lot better:
A train and a bridge
The bridge is 550m and it takes the train 10s to cross the bridge
speed=distance/time
55m/s is the scalar quantity

Velocity=displacement/time
The displacement is 550m east
550m east/10s=55m/s east

If the velocity is negative, you’ve gone backwards
Objects don’t move at a constant speed
The equation for velocity will give you the average speed/velocity

Humans usually walk at 1.5m/s, run at 3m/s and cycle at 6m/s. Each of these vary across the person
A car could travel around 25m/s, a train could travel 55m/s and a plane travels 250m/s.
Not only objects vary, soundwaves do.
Soundwaves travel 330m/s when they are in air but when traveling through different mediums (e.g. water), the speed changes.

The wind can vary from 0m/s to faster than a train
This is because of temperature, atmospheric pressure and structures (buildings)

We use arrows to represent vectors
The length indicates the magnitude
The way it’s pointing indicates its direction