$7\mathrm{.}52$ The person exerts a force $\backslash (\backslash$mathbf$\{$F$\}=60\backslash$mathbf$\{$i$\}-40\backslash$mathbf$\{$j$\}(\backslash$mathrm$\{$~N$\})\backslash )$ on the handle of the exercise machine. Use Eq$.(7\mathrm{.}16)$ to determine the vector component of $\backslash (\backslash$mathbf$\{$F$\}\backslash )$ that is parallel to the line from the origin $\backslash ($ O $\backslash )$ to where the person grips the handle.