FISIKA Kelas 12 - Hukum Coulomb & Medan Listrik | GIA Academy

Introduction

This tutorial will guide you through the fundamental concepts of Coulomb's Law and electric fields, as covered in the FISIKA Kelas 12 video by GIA Academy. Understanding these principles is essential for students studying physics, especially in the context of static electricity and electrostatics.

Step 1: Understand Electric Charge

• Electric charge is a fundamental property of matter, occurring in two types: positive and negative.
• Like charges repel each other, while opposite charges attract.
• Familiarize yourself with the unit of charge, the coulomb (C), which quantifies the amount of electric charge.

Step 2: Explore Coulomb's Experiment

• Coulomb’s experiment measures the force between charged objects.
• Set up two charged spheres and measure the force acting between them at various distances.
• This experiment demonstrates the inverse square relationship between force and distance.

Step 3: Learn Coulomb's Law

• Coulomb's Law states that the force (F) between two point charges is directly proportional to the product of the charges and inversely proportional to the square of the distance (r) between them.
• The formula is expressed as: [ F = k \frac{q_1 \cdot q_2}{r^2} ] where:
  • F is the force between the charges,
  • ( q_1 ) and ( q_2 ) are the amounts of the charges,
  • r is the distance between the centers of the two charges,
  • k is Coulomb's constant (( 8.99 \times 10^9 , \text{N m}^2/\text{C}^2 )).

Step 4: Analyze Coulomb's Force as a Vector Quantity

• Understand that the force can be represented as a vector, having both magnitude and direction.
• For like charges, the force is repulsive, while for unlike charges, it is attractive.

Sub-step: Forces Between Similar Charges

• When considering two like charges:
  • The force is directed away from each charge.

Sub-step: Forces Between Dissimilar Charges

• For two unlike charges:
  • The force is directed towards each other.

Step 5: Calculate Forces in Different Configurations

• Three Charges in a Line:
  • Calculate the resultant force on one charge due to the other two.
• Triangle Configuration:
  • Use vector addition to determine the net force acting on a charge at each vertex of the triangle.
• Square Configuration:
  • Apply the same vector addition method to find the resultant force on a charge located at one of the corners of a square formed by four charges.

Step 6: Understand Electric Fields

• An electric field (E) is a region around a charged object where other charges experience a force.
• The strength of an electric field is defined as the force per unit charge: [ E = \frac{F}{q} ]
• The direction of the electric field is away from positive charges and towards negative charges.

Step 7: Calculate Electric Field Strength

• To find the electric field created by a point charge: [ E = k \frac{Q}{r^2} ] where:
  • E is the electric field strength,
  • Q is the source charge,
  • r is the distance from the charge to the point where the field is being measured.

Conclusion

In this tutorial, you learned about electric charges, Coulomb's Law, vector representation of forces, and electric fields. Mastery of these concepts is crucial for further studies in physics, particularly in understanding electrostatics and related applications. Next steps could include solving practice problems or conducting experiments to reinforce these principles.