Design a hinge pin for a folding clothes line Part 2

In this video you will specify the wall anchors that secure the washing line to the wall. The process is similar to part 1, but it requires a different FBD.

Even if you just follow the process and don’t do all the calculation, make sure you understand the new FBD and how the external forces in the diagrams of part 1 become internal forces in the diagram in part 2. Only external forces appear on an FBD.

If you just listen to the video without doing the calculations it will take about 6 minutes.

If you are stuck (or even if you aren’t) you might like to look at the worked solution that is available from the Downloads section.

Talking points

• Share your thoughts on how internal forces on one FBD can become external forces on another.
• The instructions for our folding washing line will include a warning about hanging off it. But, should our design be capable of saving people from themselves?
• Can you think of other ways that the connection to the wall could fail?