4.1.3 – Air Resistance

Viscous forces

Viscous force (or Drag force) is a force that acts on a body moving through a fluid (e.g. air or a liquid).

  • Drag force increases with:
    • relative speed of the object moving in the fluid
    • cross-sectional area of the object perpendicular to the velocity

Air Resistance

  • Air resistance is a common kind of drag force.
    • e.g. air resistance acting on a feather falling through air.
    • Air resistance increases with speed of moving body.
    • Air resistance can be neglected for low speeds, e.g. a body falling through a small height.

 

2025 Physics Lessons