Which motion is the best model to use to illustrate passive transport?

Going over a hill

Going around a carousel

Going down a slide

Going through a tunnel

I assume with going down a slide since u urself are applying no force to move its just gravity

Answer: going down a slide.

Justification:

The term passive transport is used to the describe the movement of particles in circumsantaces that do not require the use of energy.

It is mainly used for some physical process related to particles like diffusion or osmosis.

For illustrative purposes. it is compared with the movment of an object down a hill (or a slide as in the case of this question) as the object will go from high to low without requiring the use of energy.