Friction

Grade 11 · Physics

Semester 1 | Period 2 | Week 11

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Subject: Physics

Semester: 1

Period: 2

Week: 11

School Name:

Teacher’s Name:

Subject: Physics

Grade Level: Grade 11

Week & Period: Week 11, Period II

Date:

Sub-topic: Friction

Learning Objectives

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

  1. Define friction and its causes.
  2. Distinguish between static, sliding, and rolling friction.
  3. Calculate the coefficient of friction.
  4. Describe factors affecting friction.

 

Previous Knowledge

Forces and motion basics.

 

Instructional Materials

  • Wooden plank
  • Weights
  • Spring balance
  • Rough and smooth surfaces
  • Stopwatch

 

Anticipation (Warm-Up) – 5 minutes

Ask:

  • “Why do some objects slide easily while others don’t?”
  • “Can friction ever be helpful?”

 

Building Knowledge (Main Lesson) – 25 minutes

  1. Friction:
  • Force opposing relative motion between surfaces in contact.
  • Caused by surface roughness and molecular forces.
  1. Types of Friction:
  • Static friction: Prevents start of motion.
  • Sliding friction: Opposes motion during sliding.
  • Rolling friction: Opposes motion during rolling; generally smaller.

   

 

Example Calculation:

An object starts sliding down a 30° inclined plane. Find coefficient of static friction.

Learners’ Activities

  • Measure frictional forces on different surfaces.
  • Compare static and sliding friction.

 

Consolidation (Review and Assessment) – 10 minutes

Oral Questions:

  • What causes friction?
  • Differentiate static and sliding friction.
  • Calculate coefficient of friction given forces.

 

Homework / Assignment

  • Find frictional force acting on a box of 10 kg pulled with 30 N force.
  • Describe three ways to reduce friction.

 

Notes – Detailed and Explained

  • Friction is essential in walking, driving.
  • Excessive friction causes wear and energy loss.
  • Coefficient of friction depends on surface types.

 

Expanded Notes / Instructions

  • Use diagrams to explain friction forces.
  • Include real-life examples of friction use and control.

 

Inclusive / Differentiation

  • Practical demonstrations for all learners.
  • Stepwise problem-solving sessions.

 

Teacher’s Reflection

  • Was friction clearly understood?
  • Did experiment demonstrate friction effects?