Baby luke is playing with a bouncing ball in his playpen, and accidentally the ball bounces out of the playpen and rolls under a nearby chair. luke tries to get his mother to retrieve his ball by pointing in the direction of where the ball went under the chair. piaget would say this is an example of

Mental representation.

Explanation:

Sensorimotor Stage (Birth-2 yrs)

The main achievement during this stage is Object Permanence - knowing that an object still exists, even if it is hidden (the ball under the chair).

It requires the ability to form a mental representation (i.e., a schema) of the object.

Baby Luke has the schema of everything that happened: the ball bounces out of the playpen and rolls under the chair. He underestands that the ball is there (where he last saw it) even if it's hidden.

you get into a car crash and die