# The Physics of Load Bearing Walls

## Watch the movie clip below.

1. Why did the bathtub go through the floor?
2. What should have been done to the structural integrity of the floor in order to avoid the bathtub from going through the floor?
The Money Pit - Tub Scene

## (Make sure to take some notes!)

Newton's Three Laws of Motion
Free-Body Diagrams
Simple Machines

## Gizmo Time!

1. Go to www.explorelearning.com
2. Create an account if you do not have one.
4. Hover your mouse over the gizmo until you see "Launch Gizmo".
5. Before you start working on the simulation, click on the "Lesson Info" button and open the "Student Exploration Sheet".
6. Follow the instructions outlined on the Student Exploration Sheet. Make sure to answer all the questions on the sheet and the quiz questions below the gizmo.

## Try This!

Take a close look at this image.

1. Sketch this diagram in your notebook.
2. Draw a free-body force diagram for the concrete block.
3. If the concrete block weighs 200.0 kg, how much force is it exerting on the ceiling joist?
4. What do you think would happen to the ceiling joist if the concrete block were placed the way it is placed in this diagram? Would there be anything you could do? Explain your answer.
Now take a close look at this image.

4. Sketch the diagram in your notebook and draw a free-body force diagram for the concrete block.

5. If the concrete block weighs 350.0 kg, how much force would it exert on the ceiling joist?

6. What would happen to the ceiling joist if the concrete block were placed the way is placed in this diagram? Explain your answer.

A 500.0-kg concrete block is placed on the roof (see image).

7. Calculate the total force exerted by the concrete block on the roof.

8. Sketch the diagram in your notebook, and draw a free-body force diagram for the concrete block

9. Why would it be best to use the support beams as shown in this image?

## Some Real-Life Application!

Watch the three videos below and answer the following questions:

1. How is the weight of a load distributed if pressure is applied to the ceiling joist? Draw a diagram to support your answer.
2. What do you think the purpose of the concrete footings is?
3. What does the term "non-bearing wall" mean?
4. If the ceiling joist lap over the wall, would that wall be considered a load bearing wall? Explain your answer.
5. How is the weight of roof rafters transferred to the concrete footings? Use a diagram to illustrate your answer.
6. Give one example of beam placement that would indicated that the wall is load bearing, and therefore cannot be removed.
7. How would you distinguish a load bearing wall from a non-bearing wall?
8. Using a diagram, illustrated how the pressure of a load gets transferred around windows and doors.

Load Bearing Wall Framing Basics - Structural Engineering and Home Building Part One
Interior Load Bearing Walls and Concrete Footings - Part Two
Load Transfers Around Windows and Doors - Structural Engineering and Home Building Part 4

## Reflection Time!

1. How do the Physics concepts of force and levers apply to load-bearing walls?
2. Why is it so important to learn about the Physics of load-bearing walls?
3. What would you have to do if you had to remove a load-bearing wall in your house?
4. If you had a chance to build a house from scratch, what would you do so that the owners could more easily identify load-bearing walls?