Question

What is the force between two small charged spheres having charges of 2 x 10^-7C and 3 x 10^-7C placed 30 cm apart in the air?

Answer 1

q₁ = 2 x 10^-7 C, q₂ = 3 x 10^-7 C, r = 30 cm = 30 x 10^-2 m
F = 9 x 10⁹ = 9 x 10⁹ x \(\frac{2 \times 10^{-7} \times 3 \times 10^{-7}}{\left(30 \times 10^{-2}\right)^{2}}\)
= 0.06 x 10^-1 N
= 6 x 10^-3 N (repulsive)