Problem $8$: $(7\backslash \%$ of Assignment Value$)$

The figure shows the arm of a person holding a book with their forearm horizontal to the ground with their upper arm and the forearm forming an angle of $\backslash (134^\{\backslash$circ$\}\backslash ).$ The forearm has a mass of $2\mathrm{.}5$ kg $,$ and the book has a mass of $1\mathrm{.}9$ kg $.$ The biceps exert a force $\backslash (\backslash$overrightarrow$\{$F$\_\{$B$\}\}\backslash )$ on the forearm, and $\backslash (\backslash$overrightarrow$\{$F$\_\{$E$\}\}\backslash )$ is the force of the elbow joint. The force of the elbow joint acts along the arm itself, though the force exerted by the biceps acts at a slightly different angle than the arm.

Calculate the magnitude of the force in the elbow joint in units of newtons.

$\backslash [$

F$\_\{\backslash$mathrm$\{$E$\}\}=$

$\backslash ]$

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