Fuerza de Flotación
Calcula la fuerza de flotación Fb = ρVg (principio de Arquímedes). Despeja densidad, volumen o si un objeto flota.
Fórmula principal
Fb = ρ V g
How do you calculate buoyant force?
Use Archimedes’ principle: Fb = ρ V g. Multiply fluid density by the displaced volume and by g. The result is an upward force in newtons. An object floats when Fb equals its weight, and sinks when its weight is larger than Fb for full submersion.
Sobre esta herramienta
El empuje (flotación) de Arquímedes es Fb = ρ V g. Calcula la fuerza de flotación a partir de densidad del fluido, volumen sumergido y g.
Cómo usar esta calculadora
- Elige la variable que quieres despejar y confirma qué valores ya conoces.
- Introduce los datos en unidades coherentes antes de calcular.
- Comprueba si el resultado es físicamente razonable comparándolo con las entradas.
- Usa el desglose paso a paso para ver cómo se aplicó la fórmula.
Ejemplos resueltos
Example 1: 0.020 m³ in fresh water
ρ = 1000 kg/m³, V = 0.020 m³, g = 9.81. Fb = (1000)(0.020)(9.81) = 196.2 N. Displaced fluid mass = ρV = 20 kg.
Example 2: same volume in seawater
ρ ≈ 1025 kg/m³, V = 0.020 m³, g = 9.81. Fb = (1025)(0.020)(9.81) = 201.105 N — a bit more lift than fresh water.
Example 3: will a 15 kg block float?
Weight W = mg = (15)(9.81) = 147.15 N. If fully submerged volume is 0.020 m³ in fresh water, Fb = 196.2 N > W, so it floats (only part submerged at equilibrium).
Preguntas frecuentes
What is the buoyant force formula?
Fb = ρ V g, where ρ is fluid density, V is the volume of fluid displaced, and g is gravitational acceleration. Fb points upward.
What is Archimedes’ principle?
The buoyant force on an object equals the weight of the fluid it displaces. That is the same statement as Fb = ρ V g.
What density should I use for water?
Fresh water is often taken as 1000 kg/m³ (or 997 near room temperature). Seawater is often about 1025 kg/m³. Use the value given on the paper when it differs.
Is displaced volume the same as the object’s volume?
Only when the object is fully submerged. A floating object displaces a volume whose fluid weight equals the object’s weight, which is usually less than the object’s full volume.
How do I know if something sinks or floats?
Compare weight W = mg to the maximum buoyant force when fully submerged (ρ V_object g). If W is larger, it sinks. If W is smaller, it floats with part of its volume above the surface.