Warning: jsMath requires JavaScript to process the mathematics on this page.
If your browser supports JavaScript, be sure it is enabled.

Solution 3.10b

\displaystyle \begin{align} & \uparrow \ R-12g=0 \\ & R=12 \times 9 \textrm{.}8=117 \textrm{.}6 \text{ N} \\ \end{align}