Four point charges ,

PHYSICS · Subjective · CBSE · Physics · Electrostatic Potential and Capacitance · Electrostatic Potential and Capacitance

Problem

Four point charges

+8\,\mu\text{C}

-1\,\mu\text{C}

-1\,\mu\text{C}

and

+8\,\mu\text{C}

are fixed at the points

y=-\sqrt{27/2}\,\text{m}

y=-\sqrt{3/2}\,\text{m}

y=+\sqrt{3/2}\,\text{m}

and

y=+\sqrt{27/2}\,\text{m}

, respectively. A particle of mass

6\times10^{-4}\,\text{kg}

and charge

+0.1\,\mu\text{C}

moves along the negative x-direction. Its speed at

x=+\infty

v_0

. Find the least value of

v_0

for which the particle crosses the origin. Find also the kinetic energy of the particle at the origin. Assume space is gravity-free.