Coulomb's Law

Coulomb's law calculates the electric force F in newtons (N) between two electric charges q₁ and q₂ in coulombs (C)

with a distance of r in meters (m):

$F=k\frac{q_1\cdot q_2}{r^2}$

F is the force on q₁ and q₂ measured in newtons (N).

k is Coulomb's constant k = 8.988×10⁹ N⋅m²/C²

q₁ is the first charge in coulombs (C).

q₂ is the second charge in coulombs (C).

r is the distance between the 2 charges in meters (m).

When charges q1 and q2 is increased, the force F is increased.

When distance r is increased, the force F is decreased.

Find the force between 2 electric charges of 2×10^-5C and 3×10^-5C with distance of 40cm between them.

q₁= 2×10^-5C

q₂= 3×10^-5C

r = 40cm = 0.4m

F = k×q₁×q₂/ r² = 8.988×10⁹N⋅m²/C² × 2×10^-5C × 3×10^-5C / (0.4m)² = 37.705N

See also