Two Point Charges Q = -8 $Q = + 15.0 \mu \mathrm { C }$

Short Answer

Two point charges q = -8.50 µC are fixed 10.0 cm apart along a horizontal bar, as shown in the figure. Their electrical forces will be used to balance the weight of a very small sphere carrying a charge $Q = + 15.0 \mu \mathrm { C }$ 10.0 cm from each of them in a place where g = 9.80 m/s2. What is the greatest mass M this sphere can have without falling? (k = 1/4πε₀ = 8.99 × 10⁹ N ∙ m²/C²)