function calculateDensity() {
var mass = parseFloat(document.getElementById("massValue").value);
var mUnit = document.getElementById("massUnit").value;
var volume = parseFloat(document.getElementById("volumeValue").value);
var vUnit = document.getElementById("volumeUnit").value;
if (isNaN(mass) || isNaN(volume) || volume <= 0) {
alert("Please enter valid positive numbers for mass and volume.");
return;
}
// Convert Mass to Grams
var massInGrams;
if (mUnit === "g") massInGrams = mass;
else if (mUnit === "kg") massInGrams = mass * 1000;
else if (mUnit === "lb") massInGrams = mass * 453.592;
else if (mUnit === "oz") massInGrams = mass * 28.3495;
// Convert Volume to Cubic Centimeters (cm3)
var volumeInCm3;
if (vUnit === "cm3") volumeInCm3 = volume;
else if (vUnit === "ml") volumeInCm3 = volume;
else if (vUnit === "m3") volumeInCm3 = volume * 1000000;
else if (vUnit === "l") volumeInCm3 = volume * 1000;
else if (vUnit === "in3") volumeInCm3 = volume * 16.3871;
else if (vUnit === "ft3") volumeInCm3 = volume * 28316.8;
var densityGCm3 = massInGrams / volumeInCm3;
var densityKgM3 = (massInGrams / 1000) / (volumeInCm3 / 1000000);
var resultBox = document.getElementById("densityResult");
var mainRes = document.getElementById("mainResultText");
var altRes = document.getElementById("alternateResultText");
resultBox.style.display = "block";
mainRes.innerHTML = densityGCm3.toLocaleString(undefined, {maximumFractionDigits: 4}) + " g/cm³";
altRes.innerHTML = "Equivalent to: " + densityKgM3.toLocaleString(undefined, {maximumFractionDigits: 2}) + " kg/m³";
}
How Do You Calculate Density?
Density is a fundamental physical property of matter that describes how much mass is contained within a specific volume. Essentially, it tells you how "compact" or "heavy" an object is for its size. In scientific terms, density measures the concentration of matter.
The Density Formula
To calculate density, you use a simple mathematical equation:
Density (ρ) = Mass (m) / Volume (V)
Mass (m): The amount of matter in an object (measured in grams, kilograms, etc.).
Volume (V): The amount of space an object occupies (measured in cm³, m³, or liters).
Density (ρ): The resulting value, usually expressed in units like g/cm³ or kg/m³.
Step-by-Step Calculation Example
Let's say you have a metal block with a mass of 150 grams and it occupies a volume of 30 cubic centimeters. Here is how you find the density:
Identify the Mass: m = 150 g
Identify the Volume: V = 30 cm³
Apply the Formula: Divide 150 by 30.
Result: The density is 5 g/cm³.
Common Substance Densities
Understanding the density of common materials helps provide context for your calculations:
Substance
Density (g/cm³)
Pure Water
1.00
Aluminum
2.70
Steel
7.85
Gold
19.30
Why is Density Important?
Density is crucial for determining if an object will float or sink. If an object's density is less than the fluid it is placed in (like water), it will float. If it is denser, it will sink. This principle is vital in fields ranging from shipbuilding and aeronautics to geology and materials science.