Displacement - Time Graph

In a Displacement-Time Graph, the gradient of the graph is equal to the velocity of motion.

Analysing Displacement - Time Graph

Gradient = 0
Hence, velocity = 0
Gradient is constant,
hence, velocity is Uniform
Gradient is negative and constant, hence velocity is uniform and in opposite direction
Gradient is increasing, hence velocity is increasing.
Gradient is decreasing, hence velocity is decreasing.

External Link
Interactive Mathematics - Displacement-Time Graph

Interactive Animation