If a car is parked on the side of the road and not moving, what is its speed? What would it look like on a graph of time and distance?
The speed of a car is how fast the car is moving. How fast is a parked car moving?
If a car is not moving, then the distance does not change, and the speed remains constant.
How would that be represented on a graph of time and distance?
The line would be horizontal.
This is because the car isn't moving, which means at any time the car is in the same position.
In other words, the distance stays the same.