Back to Dashboard

Friction

Friction

Content Standards

 In this lesson, learners will understand what friction is, why it arises, types of friction, and its role in daily life.

Performance Standards

Students will be able to:

  • Define and explain friction with examples.
  • Identify and differentiate between types of friction.
  • Conduct simple activities to explore the effect of friction on different surfaces.
  • Analyze how friction can be both useful and undesirable.

Alignment Standards

Reference: NCERT Book Alignment 

The lesson is aligned with the NCERT Grade 8 Science Textbook, Chapter 5: Exploring Forces, Section 5.4: What Are the Different Types of Forces? – Friction

Learning Objectives

By the end of the lesson, students will be able to:

  • Define friction as a contact force.
  • Explain why friction arises (irregularities of surfaces).
  • Distinguish between static, sliding, rolling, and fluid friction.
  • Demonstrate examples of friction in everyday life.
  • Suggest ways to increase or reduce friction.

Prerequisites (Prior Knowledge)

  • Understanding of force and its effect on motion.
  • Basic knowledge of motion of objects (rolling/sliding).

Introduction

In this session, students will explore why moving objects stop, how surfaces affect motion, and why wheels and lubricants reduce friction.

Timeline (40 Minutes)

TitleApproximate DurationProcedureReference Material
Engage5

Ask: “Why does a rolling ball stop after some time, even without anyone stopping it?” Introducing friction.

Slides

Explore10

Test motion of objects on smooth vs rough surfaces. Observe how friction changes speed and distance.

Slides

Explain10

Define friction, types (static, sliding, rolling, fluid), causes & real-life examples. 

Virtual Lab: Visualise interlocking surfaces and compare friction types.

Slides  and Virtual Lab

Evaluate10

Students will attempt the Self-Evaluation task on LMS.

Virtual Lab

Extend5

Ask: “Why do athletes wear shoes with spikes?”

Slides

Friction

Introduction

In this lesson, you will explore the force of friction—a force that opposes motion whenever two surfaces are in contact. You will discover why objects slow down and stop, how different surfaces affect motion, and how friction can be both helpful and troublesome in daily life.

Theory

What is Friction?

Friction is a contact force that resists the relative motion of objects. It acts in the opposite direction to motion and arises due to tiny irregularities in the surfaces of objects. Even smooth-looking surfaces have microscopic bumps that lock into each other.

Examples from Daily Life

  • A ball rolling on the ground stops after some time.
  • A bicycle slows down when we stop pedaling.
  • Rough roads stop vehicles sooner than smooth roads.

Activity 1: Sliding Objects

  • Push a flat object (like a lunch box) on a table.
  • It stops after moving a short distance → friction force is at work.
  • Friction always acts opposite to the direction of motion.

Activity 2: Friction on Different Surfaces

  • Slide the same object on glass, cloth, wood, tile, and sand.
  • On rougher surfaces, it stops quickly.
  • On smoother surfaces, it slides longer.
  • Conclusion: Friction depends on the nature of surfaces in contact.

Friction in Air and Water
 Friction is not limited to solids. Air and water also exert a resisting force called drag.

  • Aero planes, ships, and fast trains are designed with special streamlined shapes to reduce air and water resistance.

Applications of Friction

  • Useful: Helps us walk, write with a pen, or grip objects.
  • Problematic: Causes wear and tear in machines, slows down vehicles, wastes energy as heat.

Vocabulary

This is the list of vocabulary terms used throughout the lesson.

  • Friction – The resisting force when two surfaces are in contact.
  • Contact Force – A force that occurs when objects touch each other.
  • Irregularities – Tiny bumps on surfaces that interlock and create friction.
  • Sliding Friction – Force resisting objects when they slide over each other.
  • Rolling Friction – Force resisting objects when they roll; smaller than sliding friction.
  • Drag – Frictional force of air or water on moving objects.
  • Streamlined Shape – A smooth shape that reduces friction in air/water.
  • Resistance – Opposition to motion caused by friction.

Friction

Category

Introduction

In this VR lab, students will interactively observe how friction works by comparing sliding and rolling, testing different materials, and visualizing why roughness creates resistance.

Key Features

  • 3D Visualization: Surfaces with microscopic irregularities interlocking.
  • Sliding vs Rolling Comparison: Why wheels reduce friction.
  • Material Testing: Metal, wood, fabric, and plastic objects tested for friction levels.
  • Friction Types: Visual demonstration of sliding, rolling, and fluid friction.
  • Daily Life Links: Walking, cycling, vehicles, air/water drag.
  • Quick Quiz: 2 MCQs for instant reinforcement.

Step-by-Step Procedure for VR Experience

Step-by-step Procedure for VR Experience

  • Step 1 – Open the Virtual Lab
     Students enter the interactive simulation on friction.
  • Step 2 – Observe Rough Surfaces
     Watch how microscopic irregularities interlock when two surfaces touch.
  • Step 3 – Compare Sliding and Rolling
     See why sliding objects stop quickly while rolling objects (like wheels) move farther.
  • Step 4 – Test Different Materials
     Drag objects made of metal, wood, fabric, and plastic to observe how friction changes.
  • Step 5 – Explore Friction in Fluids
     Visualize how air and water create drag, and why vehicles and planes need streamlined shapes.
  • Step 6 – View Real-Life Applications
     Connect with examples: walking, cycling, vehicle tires, machines, and transport.
  • Step 7 – Take the Quiz
    Answer 2 MCQs to check understanding and receive instant feedback.
This site is registered on wpml.org as a development site. Switch to a production site key to remove this banner.