Chapter 25: Overview

CHAPTER 25: ELECTRIC CHARGES & FORCES

In an insulator, the electrons are bound to their molecules... they can shift slightly, creating a rather weak net attraction to a test charge that is brought close to the insulator's surface

In a conductor, free electrons will accumulate on the surface of the conductor nearest the positive test charge. This will create a strong attractive force if the test charge is placed very close to the conductor's surface.

Coulomb’s law:

F = K⋅|q₁|⋅|q₂| / r²

Electric field of a point charge
E = K ⋅ q/r² ⋅ (r^)

Useful:

Electric constant
ε₀ = 8.854×10^-12 F/m

SI Unit conversions
1 N = 1 kg⋅m⋅s^-2
1 C = A⋅s
1 F = A²⋅s⁴⋅kg^-1⋅m^-2