Coulomb's Law of Electrostatics

Grade 10 · Physics

Semester 2 | Period 5 | Week 26

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Subject: Physics

Semester: 2

Period: 5

Week: 26

School Name:

Teacher’s Name:

Subject: Physics

Grade Level: Grade 10

Week & Period: Week 26, Period V

Date:

Sub-topic: Coulomb’s Law of Electrostatics

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

  1. State and explain Coulomb’s law.
  2. Solve numerical problems using Coulomb’s law.
  3. Understand how force varies with charge and distance.
  4. Describe experimental verification of Coulomb’s law.

Instructional Materials:

  • Charged spheres (pith balls or metal-coated balls)
  • Coulomb torsion balance model or animation
  • Protractor
  • Insulating threads and stands
  • Rulers and calculators

Anticipation (Warm-Up): Ask: "Why do you think two charged balloons placed near each other sometimes push away from each other or come together?"

Building Knowledge:

  • Coulomb’s Law Statement:
    The electrostatic force (F) between two point charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them.

Experiment: Verification using pith balls:

  • Suspend two similarly charged pith balls close to each other using insulating threads.
  • Measure the repulsive force using angular deflection and apply calculations.

Activities:

  • Solve 3 numerical problems involving charges and varying distances.
  • Use rulers and calculators to simulate charge interactions.
  • Discuss what happens when distance doubles.

 

 Expanded Notes:

  • Electrostatic force acts along the line joining charges.
  • It can be attractive or repulsive depending on the charges.
  • The force increases greatly as distance decreases.
  • The unit of charge is Coulomb (C), which is a large unit.

Differentiation:

  • Visual learners use vector diagrams.
  • Hands-on learners use simulations or animations.
  • Group calculations for peer assistance.

Teacher’s Reflection:

  • Were learners able to connect theory to practice?
  • Did they correctly apply the formula?
  • Should more visual aids or repetition be used?