http://wiki.sommarmatte.se/wikis/2009/bridgecoursemechanics/index.php?action=history&feed=atom&title=Solution_3.8Solution 3.8 - Revision history2026-05-28T13:01:18ZRevision history for this page on the wikiMediaWiki 1.11.1http://wiki.sommarmatte.se/wikis/2009/bridgecoursemechanics/index.php?title=Solution_3.8&diff=844&oldid=prevIan: New page: See diagram. <math>R1</math> is the reaction force holding up the combined weights of the two lighter boxes. Equilibrium of the two boxes gives <math>\begin{align} & \uparrow \ R1-(5+10...2010-03-19T13:26:21Z<p>New page: See diagram. <math>R1</math> is the reaction force holding up the combined weights of the two lighter boxes. Equilibrium of the two boxes gives <math>\begin{align} & \uparrow \ R1-(5+10...</p>
<p><b>New page</b></p><div>See diagram.<br />
<br />
<br />
<math>R1</math><br />
is the reaction force holding up the combined weights of the two lighter boxes.<br />
Equilibrium of the two boxes gives<br />
<br />
<math>\begin{align}<br />
& \uparrow \ R1-(5+10)g=0 \\ <br />
& \text{giving}\ R1=15\times 9\textrm{.}8=147\ \text{N} \\ <br />
\end{align}</math><br />
<br />
<br />
The weight is <br />
<math>mg=12\times 9\textrm{.}8=117\textrm{.}6\ \text{N}</math><br />
<br />
<br />
Finally the box is in equilibrium <br />
<br />
<math>\begin{align}<br />
& \uparrow \ R2-R1-mg=0 \\ <br />
& \text{giving}\ R2=147+117\textrm{.}6=264\textrm{.}6\ \text{N} \\ <br />
\end{align}</math></div>Ian