Two identical particles of mass $m$ carry a charge $Q$ each. Initially, one is at rest on a smooth horizontal plane and the other is projected along the plane directly towards the first particle from a large distance with speed $v$. The closest distance of approach is:

  • A
    $\frac{1}{4\pi \varepsilon_0} \frac{Q^2}{mv}$
  • B
    $\frac{1}{4\pi \varepsilon_0} \frac{4Q^2}{mv^2}$
  • C
    $\frac{1}{4\pi \varepsilon_0} \frac{2Q^2}{mv^2}$
  • D
    $\frac{1}{4\pi \varepsilon_0} \frac{3Q^2}{mv^2}$

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