However, density does affect the motion when a ball travels in air (or any other gas).

A good class exercise would be to form teams that could think of different ways density affects the behavior of different substances and processes.

Nymphal density also affects the dispersal of water striders.

The density of the air also affects how well an aircraft works.

Bottom-up effects occur when the density of a resource affects the density of its consumer.

The length, width, thickness and density of a fingerboard can affect timbre.

The density and type of vegetation coverage affects solar heat absorption, water retention, and rainfall on a regional level.

Purchasing power and density affect the spacing of centers and hierarchical arrangements.

And density alone affects the frequency with which mobs form.

The density of the residential area affected made it difficult for firefighters to quell the blaze.