BEAM forces

Where beams attach to the wall there exists a pin hinge. The pin hinge exerts a reaction force. This force is broken down into two smaller forces we are calling the vertical force, “V” and a horizontal force “H.” The vertical force, “V,” keep the beam from sliding down the wall. The horizontal force, “H,” keeps the beam from punching through the wall into the building. Identify the reaction force on your free body diagrams and extended free body diagrams two forces.

The weight of the beam is located at the center of mass of the beam. If you were to hold the beam up with one finger, you would lift at the center of mass with a force equal to the weight of the beam. If a beam is described as, "homogeneous," then the center of mass is located in the middle of the beam.

This YouTube video can be found at http://goo.gl/4Bj06P

This is the first diagram you write on the paper. Make it large! Notice that is missing all force components.

The body is no longer a dot. It is now a line that shows horizontal distances.

This is the second diagram you write on the paper. Make it large. Use about half the width of the paper. To highlight the differences in the two diagams the components are shown in red.

Click to see an example of what a notebook page looks like with this information.

Process for drawing extended freebody diagrams

1. Draw a line as the body. Draw it the same angle as the body.
2. Identify all the forces.
3. Draw the forces at the relative distances along the body.
4. Label the forces with variables and the distances with numbers and units.
5. Use trigonometry to break up the forces into components that are parallel and pependicular to the line that was drawn to represent the body. (Makesure the tails of the componenets and the original force are all touching.