Non-Contact Forces

Content Standards

In this lesson, learners will demonstrate an understanding of non-contact forces (magnetic, electrostatic, and gravitational forces), ensuring they can recognise and represent them in visual, contextual, and real-life scenarios.

Performance Standards

Students will be able to:

Identify and describe magnetic, electrostatic, and gravitational forces.
Understand the principles of attraction and repulsion in magnets and charges.
Differentiate between contact and non-contact forces.
Apply the concept of non-contact forces to daily life situations and experiments.

Alignment Standards

Reference: NCERT Book Alignment

The lesson is aligned with the NCERT Grade 8 Science Textbook, Chapter 5: Exploring Forces

Section 5.4.2 –Non-Contact Forces

Learning Objectives

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

Identify and explain examples of non-contact forces.
Demonstrate through experiments how magnets, charges, and gravity act without contact.
Compare magnetic, electrostatic, and gravitational forces in terms of attraction/repulsion.
Apply the understanding of non-contact forces to real-world examples (e.g., magnets in daily use, balloon-static activity, objects falling).

Prerequisites (Prior Knowledge)

Basic understanding of force as push and pull.
Familiarity with magnets and magnetic poles (from earlier grades).
Awareness of simple real-life experiences (dropping a ball, rubbing a balloon).

Introduction

In this session, students will explore non-contact forces, which act even when objects are not in direct contact. Using engaging experiments like floating magnets, rubbing balloons, and throwing a ball, learners will gain both conceptual clarity and hands-on experience. The activities will help students see how invisible forces shape the physical world around them.

Timeline (40 Minutes)

Title	Approximate Duration	Procedure	Reference Material
Engage	5	Ask: “How can a magnet pull a pin without touching it?” Spark curiosity by discussing situations where objects move or attract without touching.	Slides
Explore	10	Think-Pair-Share: “What happens when two rubbed balloons are brought together?” Discuss forces: Magnetic, Electrostatic, Gravitational.	Slides
Explain	10	Define non-contact forces and explain types: Magnetic, Electrostatic, Gravitational. Show examples and diagrams.	Slides and Virtual Lab
Evaluate	10	Ask students to complete a self-evaluation task on the LMS	Virtual Lab
Extend	5	Fun with Balloons and Static Electricity: Perform the balloon experiment and discuss observations about attraction/repulsion.	Slides

Non-Contact Forces

Introduction

In this lesson, students will learn about non-contact forces—forces that act on objects without direct physical touch. Through demonstrations, interactive experiments, and real-life scenarios, students will explore how magnets attract or repel objects, how static electricity makes balloons and scales attract papers, and how gravity pulls everything towards the Earth. These forces explain many everyday experiences, from why objects fall to the ground to why magnets stick to refrigerators.

Theory

Introduction: Why Non-contact Forces?

Have you ever wondered why a magnet pulls pins without touching them, or why a balloon rubbed on your hair can attract paper bits? Why do objects thrown up always come back down? These everyday experiences show that some forces work without contact. Understanding these forces helps us explain natural phenomena and use them in technology.

What are Non-contact Forces?

Magnetic Force: A force exerted by magnets on magnetic materials or other magnets. Like poles repel, unlike poles attract.
Electrostatic Force: A force caused by static charges. Like charges repel, unlike charges attract.
Gravitational Force: A universal force of attraction exerted by the Earth (or any mass) pulling objects towards it.

Steps / Process / Rules

Magnetic Force

Step 1: Bring two magnets near each other.

Step 2: Like poles repel, unlike poles attract.

Step 3: Force acts without contact.

Electrostatic Force

Step 1: Rub a plastic scale with a cloth to build a charge.

Step 2: Bring it near small paper pieces.

Step 3: The papers get attracted due to the electrostatic force.

Gravitational Force

Step 1: Throw a ball upward.

Step 2: It slows down, stops, and falls back.

Step 3: Earth’s gravity pulls it down.

Applications / Why is it Useful?

Magnetic Force – Used in compasses, MRI machines, and refrigerator doors.
Electrostatic Force – Used in photocopiers, air purifiers, and spray painting.
Gravitational Force – Keeps planets in orbit, causes tides, and ensures objects stay on Earth.

Vocabulary

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

Force: A push or pull that can change the state of motion of an object.
Non-contact Force: A force that acts between objects without direct physical touch.
Magnetic Force: The force of attraction or repulsion exerted by magnets.
Electrostatic Force: The force exerted by charged objects on other charged or uncharged objects.
Gravitational Force: The force of attraction exerted by Earth (or any mass) pulling objects towards it.
Poles of a Magnet: Ends of a magnet where the magnetic force is strongest (North and South).
Static Charge: Electrical charge built up on an object’s surface when rubbed with another material.

Non-Contact Forces

Introduction

In this virtual lab, students will explore the concept of non-contact forces—magnetic force, electrostatic force, and gravitational force. Through interactive simulations and guided activities, learners will observe how objects exert force on one another without physical contact. The lab will combine demonstrations, interactive inputs, and gamified tasks to help students visualize invisible forces and understand their real-world applications.

Key Features

Clear and intuitive interface with guided instructions
Real-time animations of magnetic repulsion/attraction, balloon charging, and objects falling under gravity
Interactive controls (sliders, click-and-drag actions) to manipulate magnets, balloons, and balls
Instant feedback when learners make predictions or test outcomes
Optional quiz and reward points for completing all tasks successfully

Step-by-Step Procedure for VR Experience

Step-by-Step Procedure

Access the Virtual Lab using the provided link.
Follow the on-screen instructions for each section of the activity.

1. Explaining Force (General Concept)

Example: Imagine a ball rolling on a wooden floor. When you push it, it moves because of the applied force.
In the lab, you can drag and release a ball on a wooden plank to see how force sets it in motion.

2. Magnetic Force

Example: Bring a magnet close to some pins. Without touching, the pins get pulled towards the magnet.
In the lab:
Watch an animation of a magnet attracting pins.
Drag a magnet near pins to see attraction.

3. Electrostatic Force

Example: Rub a plastic scale on your hand or hair, then bring it near small paper pieces. The pieces jump and stick to the scale.

In the lab:

Informative: Watch how rubbing builds static charge.
Interactive: Rub the scale virtually and move it close to paper pieces.

4, Gravitational Force

Example: The Earth pulls the Moon with an invisible force—this is gravity keeping the Moon in orbit. Similarly, when you throw a ball up, it always comes down.
In the lab:
- Informative: View an animation showing Earth pulling objects down.
Review the final output – animations, predictions vs. results, and points earned.
Attempt the quiz/reflection questions at the end to check your understanding.
Exit the lab after saving or noting your performance summary.