Operational Definitions/Measurement System Analysis. The focus for this month is on operational definitions. Operational definitions are one key to good data collection. They are a necessary, although not sufficient, condition for good data collection. Plus, we will look at how control charts can be used to evaluate the measurement system.
Air resistance induces a drag force on any body that falls through any atmosphere other than a perfect vacuum, and this drag force increases with velocity until it equals the gravitational force, leaving the object to fall at a constant terminal velocity.
What is the upward force on an object falling through the air? The drag force will always decrease the velocity of a fluid. The standard equation for drag force is: drag force = 1/2pv 2 C D A, with C equaling the drag coefficient. Drag will always depend on the size, shape and speed of an object, as well as the fluid.