Three point charges q,-2 q and 2 q are placed on x -axis at a distance x=0, x=3/4 R and x=R respectively from origin as shown. If q =2 × 10^-6 C and…

Three point charges $\displaystyle \mathrm{q},-2 \mathrm{q}$ and $\displaystyle 2$ q are placed on $\displaystyle x$-axis at a distance $\displaystyle x=0$, $\displaystyle x=\frac{3}{4} R$ and $\displaystyle x=R$ respectively from origin as shown. If $\displaystyle \mathrm{q}=2 \times 10^{-6} \mathrm{C}$ and $\displaystyle \mathrm{R}=2 \mathrm{~cm}$, the magnitude of net force experienced by the charge $\displaystyle -2 q$ is $\displaystyle \_\_\_\_$ N.