Question

Interactive LearningWare 18.1 offers some perspective on this problem. Two tiny spheres have the same mass and carry charges of the same magnitude. The mass of each sphere is 3.20 × 10-6 kg. The gravitational force that each sphere exerts on the other is balanced by the electric force. Determine the charge magnitude.

Answer 1

using equilibrium of forces

electric force = gravitational force

k q^2 / r^2 = G m^2 / r^2

9*10^9* q^2 = 6.67*10^-11* (3.2*10^-6)^2

q = 2.755*10^-16 C

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