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Mechanics
Mechanics

Drag Force

FD=12CDρAv2F_D = \frac{1}{2}C_D \rho A v^2

Resistive force on object moving through fluid.

Variables

F_D
Drag force
Air resistance force
N
C_D
Drag coefficient
Shape-dependent constant
unitless
ρ
Fluid density
Density of fluid
kg/m³
A
Cross-sectional area
Projected area
m²
v
Velocity
Speed through fluid
m/s

Derivation

Derived from fluid dynamics and dimensional analysis.

Your notes

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Common questions

What is the Drag Force formula?

Drag Force is written F_D = 1/2C_D ρA v². Resistive force on object moving through fluid. It belongs to Mechanics, under Dynamics.

What are the units in F_D = 1/2C_D ρA v²?

In SI units, F_D is drag force, measured in kg·m/s²; C_D is drag coefficient (dimensionless); ρ is fluid density, measured in kg/m³; A is cross-sectional area, measured in m²; v is velocity, measured in m/s.

How is the Drag Force formula derived?

Derived from fluid dynamics and dimensional analysis. The result is F_D = 1/2C_D ρA v².