What is Density? (Unit, Formula, Types)

An educational graphic illustrating the concept of density, defining it as mass per unit volume in various materials.

Table of Contents

Pressure is everywhere in your life, but have you ever stopped to think about it? It’s in the air you breathe, the tyres on your car, and even in a glass of water.

Think of pressure as how much force is pushing on something. It’s a simple idea with big effects. From weather changes to gadgets, pressure plays a huge role in how things work.

In this guide, I will break down what is Density, its formula, units, and types of density. It is easy to understand and super fascinating. Ready to learn something new? Sit back, have a cup of tea, Let’s get started!

What is Density?

Density measures how much mass is packed into a given volume of a substance.

SI Unit of Density,

Kilograms per cubic metre (kg/m³).

Formula of Density,

Density (ρ) = Mass (m) ÷  Volume (V)

Example of Density,

If a block of wood has a mass of 500 kg and a volume of 2 m³, its density is:

Density(ρ) = Mass (m) ÷  Volume (V) = 500 ÷  2 = 250 kg/m3

This means the wood’s density is 250 kg/m³.

Types of Density:

  • Absolute density
  • Relative density
  • Bulk density
  • Particle density
  • Neutral density
  • Area density
  • Linear density
  • Vapor density
  • Agricultural density

Absolute density

Absolute density refers to the mass of a substance per unit volume without considering external factors like temperature or pressure.

SI Unit of Absolute density,

Kilograms per cubic metre (kg/m³).

Formula of Absolute density,

Absolute Density (ρ) = Mass (m) ÷ Volume (V)

Example of Absolute Density,

If a metal block has a mass of 800 kg and a volume of 0.4 m³, its absolute density is:

Absolute Density (ρ)=Mass (m) ÷  Volume (V) = 800 ÷ 0.4 = 2000 kg/m3

This means the metal’s absolute density is 2000 kg/m³.

Relative Density:

Relative density compares the density of a substance to the density of water.

SI Unit of Relative Density,

It has no unit since it is a ratio.

Formula of Relative Density,

Relative Density = Density of substance ÷ Density of water

Example of Relative Density,

If a substance has a density of 800 kg/m³ and water’s density is 1000 kg/m³, its relative density is:

800 ÷ 1000 = 0.8

Bulk Density

Bulk density is the mass of a substance per unit volume, including air space.

SI Unit of Bulk Density,

Si unit is kg/m³.

Formula of Bulk Density,

Bulk Density = Mass ÷ Volume (including voids)

Example of Bulk Density,

If the mass is 1200 kg and the volume is 1.5 m³, bulk density is:

1200/1.5 = 800kg/m3

Particle Density

Particle density measures the mass per unit volume of individual particles.

SI Unit of Particle Density,

Si unit is kg/m³.

Formula of Particle Density,

Particle Density = Mass of particles ÷ Volume of particles

Example of Particle Density,

A particle with mass 300 kg and volume 0.1 m³ has particle density 300 ÷ 0.1 = 3000 kg/m3

Neutral Density

Neutral density compares the density of a substance to water, considering equal temperature and pressure.

SI Unit of Neutral Density,

It has no unit since it is a ratio.

Formula of Neutral Density,

Neutral Density = Density of substance ÷ Density of water at standard conditions​

Example of Particle Density,

A particle with mass 300 kg and volume 0.1 m³ has particle density 300 ÷ 0.1 = 3000 kg/m3.

Area Density

Area density measures the mass per unit area of a surface.

SI Unit of Area Density,

Si unit is kg/m².

Formula of Area Density,

Area Density = Mass ÷ Area​

Example of Area Density,

A material with mass 50 kg and area 2 m² has area density 50 ÷ 2 = 25 kg/m2.

Linear Density

Linear density measures mass per unit length.”

SI Unit of Linear Density,

Si unit is kg/m.

Formula of Linear Density,

Linear Density = Mass ÷ Length​

Example of Linear Density,

A wire with mass 200 g and length 5 m has linear density 200 ÷ 5=40 g/m.

Vapor Density

Vapor density compares the density of a gas to the density of hydrogen at the same temperature and pressure.

SI Unit of Vapour Density,

It has no unit since it is a ratio.

Formula of Vapour Density,

Vapor Density = Density of gas ÷ Density of hydrogen

Example of Vapour Density,

A gas with density 2.2 kg/m³ and hydrogen’s density 0.09 kg/m³ has vapor density 2.2 ÷ 0.09 = 24.44 .

Why Choose TutorHelpMe Physics Tutors?

  • Qualified Experts: Physics Tutors with in-depth knowledge of physics and years of teaching experience.
  • Tailored Lessons: Customised sessions based on your learning pace and academic needs.
  • Exam-Focused Preparation: Strategies and resources to excel in exams and tests.
  • Concept Clarity: Simplified explanations to make complex topics easy to understand.
  • Interactive Learning: Engaging teaching methods to keep you motivated and focused.
  • Flexible Scheduling: Study at times that suit your availability and routine.
  • Affordable Pricing: High-quality tutoring at a budget-friendly cost.
  • Practical Applications: Relating physics concepts to real-world examples for better understanding.
  • Doubt Clearance: One-on-one sessions to address all your questions and challenges.
  • Global Access: Online tutoring available from anywhere, ensuring convenience and accessibility.
  • Proven Results: Students achieve improved grades and enhanced confidence in physics.
  • Progress Tracking: Regular feedback and assessments to monitor growth.

Choose TutorHelpMe for a better physics learning experience!

Read More What is Velocity? Units, Formula, Types

Get in Touch 

    Get in Touch