Enter the density of the fluid (kg/m^3), the speed of the object (m/s), cross-sectional air (m^2), and the air resistance coefficient into the calculator to determine the Air Friction. 

Air Friction Formula

The following formula is used to calculate the Air Friction.

Fair = .5 * p * V^2 * C * A

  • Where Fair is the Air Friction (N)
  • p is the density of the fluid (kg/m^3) 
  • V is the speed of the object (m/s) 
  • C is the air resistance coefficient 
  • A is the cross-sectional area (m^2)

How to Calculate Air Friction?

The following example problems outline how to calculate the Air Friction.

Example Problem #1

  1. First, determine the density of the fluid (kg/m^3). In this example, the density of the fluid (kg/m^3) is given as 124 .
  2. Next, determine the speed of the object (m/s). For this problem, the speed of the object (m/s) is given as  35 .
  3. Next, determine the air resistance coefficient. In this case, the air resistance coefficient is found to be .6.
  4. Next, determine the cross-sectional area. In this example, this is .25m^2.
  5. Finally, calculate the Air Friction using the formula above: 

Fair = .5 * p * V^2 * C * A

Inserting the values from above yields: 

Fair = .5 * 124 * 35^2 * .6 * .25 = 11,392.5 (N)


Example Problem #2

Using the same method as above, determine the variables required by the equation. For this example problem, these are as follows:

density of the fluid (kg/m^3) = 145

speed of the object (m/s) = 5

air resistance coefficient = .80

cross-sectional area (m^2) = .34

Entering these given values and solving gives: 

Fair = .5 * 145 * 5^2 * .8 * .34 = 493 (N)