Three point charges q, -2q and 2q are placed on the x-axis at distances x=0, x=3/4R and x=R respectively from the origin, as shown. If q=2×10⁻⁶ C and R=2 cm, the magnitude of the net force experienced by the charge -2q is N.

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5440. Distances from -2q: to q it is (3R)/4=1.5×10⁻² m, and to 2q it is R/4=0.5×10⁻² m. Force from q: F₁=(k q (2q))/((3R/4)²)=(9×10⁹×2×(2×10⁻⁶)²)/(2.25×10⁻⁴)=320 N, an attraction pulling -2q towards the origin. Force from 2q: F₂=(k (2q)(2q))/((R/4)²)=(9×10⁹×4×(2×10⁻⁶)²)/(2.5×10⁻⁵)=5760 N, an attraction pulling -2q the other way, towards x=R. The two pulls are opposite, so the net force is F₂-F₁=5760-320. F=5440 N, directed towards the charge 2q.

Three point charges q, -2q and 2q are placed on the x-axis at distances x=0, x=3/4R and x=R respectively from the origin, as shown. If q=2×10⁻⁶ C and R=2 cm, the magnitude of the net force experienced by the charge -2q is ______ N.

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