Frames and Machines
Frames and Machines represent problems that are applications of using the
equilibrium equations. As such, they do not represent any new ideas.
Strategies and ideas for solving problems:
- Don't write down any
equations until you have developed your plan of action.
- Develop your strategy for
solving the problem by drawing free-body-diagrams of the entire frame or
machine and each one of sub-units. Remember that the free-body-diagram of
the complete body is equal to the sum of the free-body-diagrams of its
- For each free-body-diagram
analyze the diagram in terms of how you can use the equations to directly
solve for some unknowns (Don't write down the equations until you finish
analyzing all the free body diagrams).
- Look for any two force
- Remember that you can write
three equations for each free-body-diagram.
- Don't forget to take
advantage of the moment equation to eliminate unknowns.
- After you have analyzed all
the free body diagrams, look for the simplest way to get to the solution
without writing any extra equations. This will become your plan of attack.
- Once you have formulated your
plan, write down the necessary equations and solve for the unknowns.