Watch this video which describes displacement as the area under a velocity-time graph.
Read this document which reviews the concept that the area under a velocity-time graph is the object's displacement.
Examination of the motion in a velocity time graph should help make clear why the equations of kinematic motion only apply in situations where the acceleration of the object is constant. In situations however where an object's acceleration is not constant it is often possible to divide up the problem into sections where the acceleration in each section is constant and then apply the equations in each section to calculate the needed information.
A good example of this is found in this link to a Student Driving Situation. Solve the question posed in this exercise (ask your teacher for a paper copy) and compare your answer with this key.
Ask your teacher for a paper copy of Acceleration Problems Set #3. Complete this problem set and compare your answers against this key.
You are ready to take this acceleration pre-quiz. Compare your answers with this key.