When evaluating the forces acting on, and motion of, an object moving through the air, we often simplify the situation by excluding air drag. In many cases, it is appropriate to do so—the object may be shaped so that the drag force is negligible. But, when the object in question is large or moving fast, it is harder to justify excluding air drag.

In this experiment, you will evaluate the effect that mass has on air drag. You will use this data to re-evaluate the validity of the simple air drag force model Fdrag = –bv.


In this experiment, you will

  • Measure and compare the terminal velocity of six stacks of falling coffee filters of varying mass.
  • Evaluate how well the Fdrag = –bv model for air drag force describes the motion of the falling coffee filter as mass changes.
  • Refine the air drag model to better fit experimental data.