Comparing Gravitational and Electrostatic Forces

• What are the two types of forces compared in the study material?

  Gravitational and electrostatic forces

  
• What are the similarities between gravitational and electrostatic fields?

  • Field lines around point mass and charge are identical
  • Field lines in uniform fields are identical
  • Both follow inverse square law relationships
  • Both field strengths follow an inverse square law with distance
  • Both potentials follow an inverse relationship with distance
  • Equipotential surfaces are spherical or parallel lines
  • Work done is product of mass or charge and change in potential

  
• How are the field lines around a point mass and a negative point charge described?

  They are identical
• What is the relationship between gravitational and electric field strengths with distance?

  They both follow an inverse square law

  
• What is the formula that describes the relationship of gravitational and electric potential with distance?

  Inverse relationship (1/r)
• What shape do equipotential surfaces take around a point mass or charge?

  Spherical around point mass or charge

  
• How is the work done by gravitational and electrostatic fields calculated?

  Product of mass or charge and change in potential

  
• What are the differences between gravitational and electrostatic fields?

  • Gravitational force acts on mass; electrostatic on charge
  • Gravitational force is always attractive; electrostatic can be attractive or repulsive
  • Gravitational potential is always negative; electric potential can be negative or positive
  • Gravitational fields are weaker than electric fields

  
• On what type of particles does the gravitational force act?

  Particles with mass
• What is the nature of the gravitational force compared to the electrostatic force?

  Gravitational force is always attractive
• What can the electric potential be in contrast to gravitational potential?

  It can be either negative or positive
• How do gravitational fields compare to electric fields in terms of strength?

  Gravitational fields are relatively weak

  
• Why are gravitational fields weaker than electric fields?

  Gravitational constant G is much smaller than Coulomb constant k

  
• How should students prepare for questions on gravitational and electrostatic forces?

  • Summarize information for structured answers
  • Practice writing 6 mark responses