Circular Motion

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Subject: Physics

Semester: 1

Period: 1

Week: 4

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School Name:

Teacher’s Name:

Subject: Physics

Grade Level: Grade 11

Week & Period: Week 4, Period I

Date:

Sub-topic: Circular Motion

Learning Objectives

By the end of this lesson, learners should be able to:

1. Define circular motion and distinguish between uniform and non-uniform circular motion.
2. Explain centripetal force and centripetal acceleration.
3. Calculate centripetal force, velocity, and acceleration in uniform circular motion.
4. Identify examples and applications of circular motion.

 

Previous Knowledge

Learners should understand basic motion concepts, vectors, and forces.

 

Instructional Materials

• String and rubber stopper (for demonstration)
• Stopwatch
• Meter rule
• Spring balance
• Whiteboard and markers

Anticipation (Warm-Up) – 5 minutes

Ask:

• “What happens when you swing a stone tied to a string in a circle?”
• “What keeps the stone moving in a circle?”
  Lead to discussion on forces involved in circular motion.

 

Building Knowledge (Main Lesson) – 25 minutes

1. Definition:

• Circular motion: Movement of an object along a circular path.

2. Types:

• Uniform circular motion: Speed is constant but direction changes continuously.
• Non-uniform circular motion: Speed changes as the object moves around the circle.

3. Centripetal Force:

• The inward force that keeps an object moving in a circle, directed towards the center.
• Examples: tension in string, gravitational force, friction.

    

 

 

Consolidation (Review and Assessment) – 10 minutes

Oral Questions:

• What direction does centripetal force act?
• Calculate centripetal acceleration for a car moving at 20 m/s around a curve of radius 50 m.
• Why does the stone not fly off tangentially when swung in a circle?

 

Homework / Assignment

• A car of mass 1000 kg moves at 15 m/s around a curve of radius 25 m. Calculate centripetal force.
• List 5 examples of circular motion from daily life.

 

Notes – Detailed and Explained

• Circular motion involves continuous change of velocity direction, hence acceleration.
• Centripetal force is essential to maintain circular motion, acting towards the center.
• Uniform circular motion has constant speed but changing velocity vector due to direction change.
• Centripetal force can arise from tension, gravity, friction, or other forces depending on context.

 

Expanded Notes / Instructions

• Demonstrate experimentally with string and stopper for kinesthetic learning.
• Emphasize distinction between centripetal force (center-seeking) and centrifugal effect (apparent outward force).

 

Inclusive / Differentiation

• Use hands-on experiments for tactile learners.
• Visual diagrams and animations to show force directions.
• Stepwise problem solving for learners needing extra support.

 

Teacher’s Reflection (Post-Lesson Questions)

• Were learners able to grasp centripetal force concept clearly?
• Did the experiment clarify the theory?
• How well did learners perform in calculating centripetal force and acceleration?