Why do we need to square the separation in Coulomb's experiment?

  • Context: High School 
  • Thread starter Thread starter shio
  • Start date Start date
  • Tags Tags
    Coulomb Experiment
Click For Summary
SUMMARY

The Coulomb experiment utilizes a torsion balance to demonstrate that the electrical force between two charges is inversely proportional to the square of the separation distance (r). This relationship is established as the force is measured as a function of distance, resulting in a proportionality of 1/r². Additionally, the force is directly proportional to the product of the charges (Q1Q2), aligning the mathematical equations with observed physical reality. Understanding these principles is essential for grasping the fundamentals of electrostatics.

PREREQUISITES
  • Understanding of Coulomb's Law
  • Familiarity with torsion balance apparatus
  • Basic knowledge of electrostatics
  • Concept of inverse-square laws in physics
NEXT STEPS
  • Study the derivation of Coulomb's Law in detail
  • Explore the applications of the torsion balance in modern physics
  • Investigate the implications of inverse-square laws in gravitational and electromagnetic forces
  • Read about the historical context and experiments leading to the formulation of electrostatic principles
USEFUL FOR

Students of physics, educators teaching electrostatics, and anyone interested in the foundational principles of electrical forces and their mathematical representations.

shio
Messages
1
Reaction score
0
Coulomb experiment torsion balance.

I know that electrical force is inversely to the square of the separation r ...My question is why we take r square? why we need square? And another question, why Q1Q2(multiplication of charges) is proportional to electrical force? (why we need to multiply them?) I know it sounds like silly question..but I really want to know (my teacher didn't tell me anything .he told me "just remember the formula" )

Thank you in advance! :D
 
Last edited:
Physics news on Phys.org
The answer is because if we measure the force as a function of distance it is proportional to 1/r^2. Similarly if we measure the force as a function of charge it is proportional to q. Since we want the equations to match reality, that's what they look like.
 

Similar threads

Undergrad How does permittivity in Coulomb's law work?
  • · Replies 5 ·
Replies
5
Views
2K
Undergrad Why Is the Value of ε0 in Coulomb's Force Equation Important?
  • · Replies 11 ·
Replies
11
Views
3K
Graduate Why center of mass? Why not center of charge?
  • · Replies 22 ·
Replies
22
Views
3K
Graduate Why dielectrics get polarized instead of directly ionized?
  • · Replies 13 ·
Replies
13
Views
2K
Undergrad How did Coulomb charge his spheres to verify Coulomb's law?
  • · Replies 5 ·
Replies
5
Views
2K
Undergrad Coulomb's experiment (coulomb's law)
  • · Replies 1 ·
Replies
1
Views
3K
Undergrad Physics domain analysis of Voltage drop in series resistor
  • · Replies 7 ·
Replies
7
Views
3K
Graduate How do we know the mass of an electron?
  • · Replies 28 ·
Replies
28
Views
5K
Graduate Coulomb's law without a pure inverse square relationship?
  • · Replies 4 ·
Replies
4
Views
2K
High School How Can I Determine the Value of Charges in Coulomb's Law?
  • · Replies 9 ·
Replies
9
Views
2K