A $4\mathrm{.}77-$nF parallel plate capacitor with a sheet of Mylar $($ $=3\mathrm{.}10)$ filling the space between the plates is charged to a potential difference of $155$ V and is then disconnected.

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$($a$)$ How much work is required to completely remove the sheet of Mylar from the space between the two plates? $($You may enter your calculation using scientific notation.$)$

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J

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$($b$)$ What is the potential difference between the plates of the capacitor once the Mylar is completely removed?

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V