Question

A child is on a playground they start to slide down a large slide. At what point is the child in dynamic equilibrium with the slide?(1 point)
Responses

When the child pushes themselves down the slides.
When the child pushes themselves down the slides.

As the child is in motion as they are sliding down.
As the child is in motion as they are sliding down.

When the slide ends and the child has stopped moving .
When the slide ends and the child has stopped moving .

The child will not reach dynamic equilibrium.

Answer 1

Dynamic equilibrium means the net force is zero while the object is moving — i.e. it moves at constant velocity (no acceleration). So the child is in dynamic equilibrium only when they are sliding at a constant speed (when the downslope component of gravity is balanced by friction/air resistance). Not when they push off (accelerating) and not when they are stopped (that would be static equilibrium).