What kind of friction is shown between the skydiver and the air?

Fluid friction is the kind of friction between the skydiver and the air.

Objects moving through fluid experience fluid friction or drag. A skydiver diving in air is an example of fluid friction since air as a medium is fluid and thus air molecules resists the falling motion of a body. Weight of the object due to gravity decides the acceleration of a skydiver when in flight and the resisting frictional force (drag), opposes it.

So, a resultant force acts and his velocity increases proportionally at first and then becomes a constant terminal value. The extent of fluid friction is dependent on the size of body as well as its speed. Larger the size more is the friction; higher the speed more is the friction.

i guess that visual aids present persuasive examples to what you are presenting, some factors would be theme (does it fit with the color, information, what you are presenting), size (can you see it, is it a big enough span of data/information), and overall look of the visual aid.

hope this : )