Class: Senior Secondary School 1 (SS1, SS 1, SSS1, SSS 1)
Term: 1st Term
Week: 5
Age: 15 years
Duration: 45 minutes
Subject: Physics
Curriculum Theme: Physics
Previous Lesson: Physics: Meaning and Types of Motion.
Topic: MOTION
Subject Matter: Causes and effects of motion, types of force, friction (types, coefficient, advantages, disadvantages, reduction methods).

Specific Objectives

By the end of the lesson, pupils should be able to:

Cognitive Domain:

Define force and its effects on motion.
Distinguish between contact force and force field, providing examples.
Describe static friction and dynamic friction.
List at least three advantages and three disadvantages of friction.
State at least three methods of reducing friction.

Affective Domain:

Appreciate the role of friction in everyday activities.
Participate actively in class discussions on forces and friction.

Psychomotor Domain:

Observe demonstrations involving spring balance and magnets to understand forces.
Identify different types of forces and friction in their environment.

Collaborate with peers to identify examples of various forces and friction.

Reference Materials

The following resources were used in planning this lesson:

9 Years Basic Education Curriculum for Physics.
State Unified Scheme of Work for Senior Secondary School Physics.
New School Physics by P.N. Okeke and Anyakoha M.W.
https://www.physicsclassroom.com/class/newtlaws/Lesson-2/Types-of-Forces
https://www.britannica.com/science/friction/Types-of-friction

Instructional Materials

The teacher will teach this lesson with the aid of:

Spring balance
Magnets
Rough and smooth surfaces
Blocks of wood
Charts showing types of forces and friction
Measuring scale

Rationale for the Lesson

This lesson helps pupils understand the fundamental concepts of force and motion, which are essential for explaining how objects move and interact in the physical world. Understanding friction also enables pupils to appreciate its importance in daily life and how it can be managed.

Prerequisite/Previous Knowledge

Pupils have basic knowledge of push and pull actions, and simple observations of moving objects from their everyday experiences.

Lesson Content/Board Summary

MOTION AND FORCES

Causes and Effects of Motion

Force is a push or a pull that tends to change the state of rest or uniform motion of an object. Force is the cause of motion.

The following are the effects of force:

It can start a stationary object into motion.
It can stop a moving object.
It can change the direction of a moving object.
It can change the speed of a moving object.
It can change the shape or size of an object.

Types of Force

Forces can be broadly classified into two types:

Contact Force: This is a force that acts on an object by direct physical contact.

The following are examples of contact forces:

Friction
Tension
Air resistance
Normal force
Applied force

Force Field (Non-Contact Force): This is a force that acts on an object without direct physical contact between the interacting objects. These forces act through a field.

The following are examples of force fields:

Gravitational force
Magnetic force
Electrostatic force

Friction

Friction is a force that opposes the relative motion or tendency of motion between two surfaces in contact.

Types of Solid Friction

There are two main types of solid friction:

Static Friction: This is the friction that opposes the start of motion between two surfaces in contact when they are at rest relative to each other.
Dynamic Friction (Kinetic Friction): This is the friction that opposes the relative motion between two surfaces that are already sliding or rolling past each other.

Dynamic friction can be further divided into:

Sliding Friction: Occurs when one surface slides over another.
Rolling Friction: Occurs when one surface rolls over another.

Coefficient of Limiting Friction

The coefficient of limiting friction (μ) is the ratio of the limiting frictional force (F_f) to the normal reaction (R) between the two surfaces in contact when motion is about to begin. It is a dimensionless quantity.

μ = F_f / R

Advantages of Friction

The following are the advantages of friction:

It enables us to walk and run without slipping.
It allows vehicles to move and stop on roads.
It helps in holding objects, like gripping a pen.
It enables brakes to work effectively in vehicles and bicycles.
It helps in lighting a matchstick.
It allows nuts and bolts to hold objects together.

Disadvantages of Friction

The following are the disadvantages of friction:

It causes wear and tear in moving machine parts.
It generates unwanted heat in machines, leading to energy loss.
It reduces the efficiency of machines.
It makes it difficult to move heavy objects.
It produces noise in moving parts.

Methods of Reducing Friction

The following are methods used to reduce friction:

Lubrication: Using oils, grease, or graphite between surfaces.
Streamlining: Shaping objects to reduce air or fluid resistance.
Polishing/Smoothing: Making surfaces smoother.
Using Ball Bearings/Rollers: Replacing sliding friction with rolling friction.
Using Air Cushions: For example, in hovercrafts.

Teaching Methods/Instructional Techniques

Discussion, Lecture, Demonstration, Question and Answer, Visual Aids

Instructional Procedures

Step 1: Introduction

Time: 5 minutes
Teaching Skill: Set Induction
Teacher’s Activity: The teacher greets the pupils and asks questions related to their daily experiences with motion and forces, such as “What makes a ball stop rolling?” or “What makes a car move?”.
Pupils’ Activity: Pupils respond to the questions, sharing their observations and ideas.
Learning Point: Pupils recall prior knowledge related to force and motion.

Step 2: Explanation of Force and Motion

Time: 10 minutes
Teaching Skill: Explanation/Definition
Teacher’s Activity: The teacher defines force as a push or pull and explains its effects on the state of rest or motion of an object. The teacher uses simple examples.
Pupils’ Activity: Pupils listen attentively, take notes, and ask questions for clarification.
Learning Point: Pupils understand the definition of force and its various effects.

Step 3: Types of Force

Time: 10 minutes
Teaching Skill: Demonstration/Classification
Teacher’s Activity: The teacher explains and distinguishes between contact forces and force fields, providing examples for each. The teacher uses a spring balance to demonstrate contact force (pulling an object) and magnets to demonstrate magnetic force (a force field).
Pupils’ Activity: Pupils observe the demonstrations, identify examples of contact and force field, and differentiate between them.
Learning Point: Pupils can identify and differentiate between contact and non-contact forces.

Step 4: Introduction to Friction

Time: 5 minutes
Teaching Skill: Definition/Explanation
Teacher’s Activity: The teacher defines friction, explains it as an opposing force, and introduces the types of solid friction: static and dynamic friction. The teacher uses rough and smooth surfaces to illustrate.
Pupils’ Activity: Pupils listen, take notes, and observe the demonstration, understanding the concept and types of friction.
Learning Point: Pupils understand the definition and basic types of friction.

Step 5: Advantages and Disadvantages of Friction

Time: 5 minutes
Teaching Skill: Discussion/Listing
Teacher’s Activity: The teacher leads a discussion on the importance of friction in daily life, guiding pupils to list its advantages and disadvantages. The teacher also briefly introduces the concept of the coefficient of limiting friction.
Pupils’ Activity: Pupils contribute to the discussion, list the advantages and disadvantages of friction, and understand its significance.
Learning Point: Pupils identify the benefits and drawbacks of friction.

Step 6: Methods of Reducing Friction

Time: 5 minutes
Teaching Skill: Problem-Solving/Listing
Teacher’s Activity: The teacher discusses various methods used to reduce friction, explaining each with practical examples (e.g., oiling bicycle chains, streamlining cars).
Pupils’ Activity: Pupils listen, suggest methods, and note them down.
Learning Point: Pupils learn practical ways to reduce friction.

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

Define force.
Differentiate between contact force and force field, giving one example for each.
State two types of solid friction.
Mention three advantages of friction.
List two methods of reducing friction.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 8: Conclusion

Time: 5 minutes
Teaching Skill: Summarization
Teacher’s Activity: The teacher summarizes the key points of the lesson on forces, motion, and friction. The teacher assigns homework: “Research and write down two real-life applications where reducing friction is important.”
Pupils’ Activity: Pupils listen to the summary and copy the assignment.
Learning Point: Pupils consolidate their learning and prepare for further study.

Lesson Keywords

Force – A push or pull that can change an object’s motion.
Motion – The change in position of an object over time.
Contact Force – Force acting through direct physical contact.
Force Field – Force acting without direct physical contact.
Friction – A force that opposes motion between surfaces in contact.
Static Friction – Friction opposing the start of motion.
Dynamic Friction – Friction opposing motion between moving surfaces.
Lubrication – Using a substance to reduce friction.

Differentiation

For pupils who grasp concepts quickly, the teacher can provide additional questions on calculating frictional force. For pupils needing more support, the teacher will provide simplified examples and focused attention during demonstrations.

Note for teachers using this lesson plan

Teachers should ensure all instructional materials are available and in working condition before the lesson. Encourage pupil participation through questions and practical examples relevant to their environment. Emphasize safety during demonstrations.