كيفية الحساب الكثافة (ρ = m/V): الكتلة ÷ Volume
احسب density with ρ = m/V. Unit traps (g/cm³ vs kg/m³), float vs sink, worked examples, and a free density calculator.
What الكثافة Asks
الكثافة tells you how much mass is packed into a given volume. A kilogram of steel takes less space than a kilogram of foam — steel has higher density.
The formula is ρ = m / V (rho = mass over volume). With mass in kilograms and volume in cubic metres, density is in kg/m³. Water is about 1000 kg/m³; many woods are less, most metals are more.
If you already have m and V (or ρ and one unknown), open the free density calculator first, then return here for unit traps and the link to buoyancy.
The الصيغةs
Keep units consistent. If mass is in grams and volume in cm³, density comes out in g/cm³. 1 g/cm³ = 1000 kg/m³ (same as water).
الكثافة and Floating
Buoyant force uses fluid density: Fb = ρ V g. See buoyant force and the
An object denser than the fluid tends to sink when fully submerged; less dense materials float. Compare object density to fluid density, or compare weight to maximum Fb.
Object weight is W = mg — use the weight calculator when you need newtons from kilograms.
Units
الشغلed Examples
Example 1: 12 kg in 0.003 m³
ρ = m/V = 12 / 0.003 = 4000 kg/m³.
Example 2: find mass
ρ = 7800 kg/m³ (steel-like), V = 0.002 m³. m = ρV = (7800)(0.002) = 15.6 kg.
Example 3: find volume
m = 2.0 kg, ρ = 1000 kg/m³ (water). V = m/ρ = 2.0/1000 = 0.002 m³ = 2.0 L.
Example 4: g/cm³ to kg/m³
ρ = 2.7 g/cm³ (aluminum). In SI: 2.7 × 1000 = 2700 kg/m³.
أخطاء شائعة
Check It on the Calculator
الكثافة calculator — ρ = m/V.
Learn ρ = m/V and confirm every homework number on the calculator.