A small glass marble hanging from a string is charged to $+7\mathrm{.}0$ nC $.$ A $4\mathrm{.}0$ g plastic bead is gently released $4\mathrm{.}0$ cm beneath the marble.

Part A

What charge in nC must the plastic bead have to hang suspended in space beneath the marble?

Express your answer in nanocoulombs.

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q$\_\{\backslash$mathrm$\{$b$\}\}=\backslash$quad $\backslash$mathrm$\{$nC$\}$

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