The volume of the fluid pushed aside by the object.
Earth's standard gravity is 9.81 m/s².
Result:
Understanding the Fb Calculator: Archimedes' Principle
The Fb Calculator is a specialized tool designed to calculate the buoyant force (Fb) exerted on an object immersed in a fluid. This principle, discovered by the ancient Greek mathematician Archimedes, is fundamental to fluid mechanics, shipbuilding, and aerospace engineering.
The Buoyant Force Formula
To calculate the buoyant force, we use the following physical equation:
Fb = ρ × V × g
ρ (rho): The density of the fluid the object is in (measured in kg/m³).
V: The volume of the fluid displaced by the object (measured in m³).
g: The acceleration due to gravity (9.81 m/s² on Earth).
Practical Examples of Fb Calculations
Knowing the buoyant force helps determine if an object will sink, float, or remain neutrally buoyant. Here are two common scenarios:
Example 1: A Steel Sphere in Fresh Water
If a sphere displaces 0.2 m³ of fresh water (density 1000 kg/m³):
Fb = 1000 kg/m³ × 0.2 m³ × 9.81 m/s² = 1,962 Newtons.
Example 2: A Submersible in Saltwater
Saltwater is denser than fresh water (approx. 1025 kg/m³). If a probe displaces 0.05 m³:
Fb = 1025 kg/m³ × 0.05 m³ × 9.81 m/s² = 502.76 Newtons.
Why Use This Calculator?
Manual physics calculations are prone to rounding errors. This tool provides instant, accurate results for students, engineers, and hobbyists. It simplifies the process of determining the upward force exerted by any liquid or gas, whether you are designing a boat hull or a weather balloon.
function calculateFb() {
var rho = document.getElementById("fluidDensity").value;
var volume = document.getElementById("displacedVolume").value;
var gravity = document.getElementById("gravityConstant").value;
var resultDiv = document.getElementById("fb-result-container");
var resultText = document.getElementById("fb-final-value");
var explanationText = document.getElementById("fb-explanation");
if (rho === "" || volume === "" || gravity === "" || rho <= 0 || volume <= 0 || gravity <= 0) {
alert("Please enter valid positive numbers for all fields.");
return;
}
var rhoNum = parseFloat(rho);
var volumeNum = parseFloat(volume);
var gravityNum = parseFloat(gravity);
// Calculation: Fb = rho * V * g
var buoyantForce = rhoNum * volumeNum * gravityNum;
// Formatting result
var formattedFb = buoyantForce.toLocaleString(undefined, { minimumFractionDigits: 2, maximumFractionDigits: 2 });
resultText.innerHTML = "Fb = " + formattedFb + " Newtons (N)";
explanationText.innerHTML = "Based on a fluid density of " + rhoNum + " kg/m³ and a displaced volume of " + volumeNum + " m³, the upward buoyant force exerted is " + formattedFb + " Newtons.";
resultDiv.style.display = "block";
resultDiv.scrollIntoView({ behavior: 'smooth', block: 'nearest' });
}