🔋college physics i – introduction review

Archimedes’ principle

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

Archimedes’ principle states that a body immersed in a fluid experiences a buoyant force equal to the weight of the fluid displaced by the body. This principle explains why objects float or sink.

5 Must Know Facts For Your Next Test

  1. The buoyant force acts upwards, opposing the weight of the object.
  2. An object will float if its density is less than the density of the fluid it displaces.
  3. The principle applies to both liquids and gases.
  4. Archimedes’ principle can be used to determine an object's volume and density via fluid displacement methods.
  5. The magnitude of the buoyant force can be calculated using $F_b = \rho_f V_f g$, where $\rho_f$ is the fluid density, $V_f$ is the volume of displaced fluid, and $g$ is gravitational acceleration.

Review Questions

"Archimedes’ principle" also found in: