Friction (JSS 2-Basic Technology Lesson Note: Second Term, Week Eight)

Lesson Plan for JSS Two (Age 12)

Subject: Basic Technology
Class: JSS 2
Week of the Term: 8th Week, Second Term
Topic: Friction
Sub-Topic: Definition and Causes of Friction; Effects, Advantages, and Disadvantages of Friction

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Objectives

At the end of the lesson, students should be able to:

1. Define friction and identify its causes.
2. Explain the effects of friction in everyday life.
3. Discuss the advantages and disadvantages of friction.

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Entry Behaviour

Students should have a basic understanding of motion and forces.

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Instructional Materials

1. Diagrams illustrating frictional forces and examples.
2. Everyday objects to demonstrate friction (e.g., rubber, wood, metal surfaces).
3. Videos explaining friction concepts.

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Reference Materials

Ekwukoma, V., Oliver, O. J. E., & Ogunniyi, D. (2014). Basic Technology For Junior Secondary School 2 Textbook (BEC Edition). Spectrum Books Limited.
Olugasa, O. J., & Bamidele, O. H. (2014). Basic Technology For Junior Secondary School 2 Textbook (BEC Edition). University Press PLC.

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Content

Definition and Causes of Friction

Friction is the resistance that one surface or object encounters when moving over another. It is a force that opposes the relative motion of two surfaces in contact. Friction is essential in everyday life, influencing how we walk, drive, and interact with objects.

Causes of Friction:

1. Surface Texture:
   • The roughness or smoothness of surfaces affects friction. Rough surfaces create more friction due to increased interlocking of surface irregularities.
2. Material Properties:
   • Different materials have varying friction coefficients. For example, rubber has a high friction coefficient with concrete, while ice has a low friction coefficient with metal.
3. Normal Force:
   • The force pressing two surfaces together influences friction. An increase in normal force (the weight of the object) leads to higher friction.
4. Contamination:
   • Presence of lubricants, dirt, or moisture can alter the friction between surfaces, either reducing it (as with oil) or increasing it (as with grit).
5. Motion Type:
   • The type of motion (static, kinetic, or rolling) also affects friction. Static friction occurs when objects are at rest, kinetic friction occurs when they are sliding, and rolling friction is present when wheels roll over a surface.

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Effects of Friction

1. Heat Generation:
   • Friction converts kinetic energy into heat, which can lead to wear and tear on surfaces and may cause overheating in mechanical systems.
2. Wear and Tear:
   • Continuous friction between moving parts can result in material degradation over time, affecting the longevity of machines and components.
3. Motion Control:
   • Friction is essential for controlling motion. It allows vehicles to accelerate, decelerate, and come to a stop effectively.
4. Sound Production:
   • Friction between surfaces can produce noise, such as the sound of brakes squeaking or tires on pavement.
5. Stability:
   • Friction provides stability in standing or resting objects, preventing them from sliding or toppling over.

Step 1: Introduction

Lesson Presentation (Step-by-Step Procedure)

Others removed.