Student Activity Lesson Plan Subject/Strand/Topic: Science Structural Strength and Stability Grade(s) / Course(s): 7 Ontario Expectations: 7s85, 7s86, 7s87, 7s90, 7s102 Key Concepts: forces (compression, tension, bending, shear, torsion), loads (weight, soil, temp., wind, vibration, earthquake), materials (wood, plastic, aluminum, brick, concrete, iron, steel), shapes(rectangles, arches, triangles) Link: http://www.pbs.org/wgbh/buildingbig/lab/forces.html Required Materials: Pre-Assessment/Answer Key, Student Activity Handout, Student Activity Answer Key, Post- Assessment/Answer Key Before Starting: This activity works best during a double-period. Introduction (10 min including pre-assessment) 1. Ask students the following questions: Q: Predict what would happen if a building was built on soft soil. (It would sink into the soil and become unstable) Q: Predict what would happen if wood was used to build a large building in an area where it continually rained and snowed? (the wood would rot and weaken) 2. Introduce the learning object (this online activity will investigate factors involved in building structures) 3. Distribute the pre-assessment quiz and allow 5 min to complete; collect 4. Ensure students are in front of their computers prior to moving on Explanation of Activity Sheet (5 min) 1. Students should be placed in partners for this activity. 2. Distribute Activity sheet to each student 3. Provide direction on the organization and structure of the Activity sheet as needed 4. Inform students they will only by using the four headings at the top of the learning object and down the side of the screen and should not be using any other links on the page Use of Learning Object with Activity Sheet (45 minutes) 1. Teacher should circulate throughout the activity and ensure students are on task 2. Provide students with the following verbal time cues throughout the activity: Forces section 10 min Loads section 15 min Materials section 10 min Shapes section 10 min Consolidation Questions and Post-Assessment (10 minutes) Q: What are some important considerations when deciding what material to use for a building? (the environment it will be in, what it will be used for, how much material is needed (cost), etc.) Q: What kind of external factors must be considered in building structures? (Soil, temperature, natural events in the area, temperatures, safety, etc.) Q: Why is it important to plan the structure down to smallest details and make/test models prior to building? (you can only build once as repairs could be costly and involve loss of human life by testing, you know how strong you need to make things to withstand the elements, you also know if your structure will be stable and strong) 1. Distribute post-assessment quiz and allow 5 min to complete; collect 2. Activity sheet can be taken up as a class or collected and marked Teacher-Created Resources: Student Activity Lesson Plan Page 1 of 1
Student Activity Pre-Assessment _ Complete the following questions below. Each correct response is worth 1 mark. Birthday: 6 1. Torsion is an action that twists a material. 2. Cables in a suspension bridge are held by compression. 3. What is thermal load? 4. What is the difference between the dead load and the live load in a structure? 5. What building material is considered the strongest? 6. Draw the following structures in the table below in order of increasing strength (able to hold weight without collapsing). Teacher-Created Resources: Student Activity Pre-Assessment
Student Activity Pre-Assessment Name: Answer Key Complete the following questions below. Each correct response is worth 1 mark. 6 1. Torsion is an action that twists a material. 2. Cables in a suspension bridge are held by compression. 3. What is thermal load? The expanding or shrinking of a structure due to changes in temperature. 4. What is the difference between the dead load and the live load in a structure? The dead load is the weight of the materials used to build the building, the live load is the weight of the people, furniture, books, materials, etc. that are inside a building. 5. What building material is considered the strongest? Steel 6. Draw the following structures in the table below in order of increasing strength (able to hold weight without collapsing). Teacher-Created Resources: Student Activity Pre-Assessment
Student Activity Handout LINK: http://www.pbs.org/wgbh/buildingbig/lab/forces.html 42 FORCES [12 marks] Use the FORCES section to complete the table below by filling in the empty boxes. Important: For the last column (the examples) look at the examples in each section by choosing Then think of an example of the force in everyday life and write it down. Action Name of Force What does the force do? What does it look like? (Draw the force in action!) Example of the force in action! Squeezing Compression Squeezes material together. Stretching Stretches material apart. Bending When a straight material becomes curved, one side squeezes together and the other side stretches apart. Sliding Sliding two materials past one another in opposite direction. Twisting Teacher-Created Resources: Student Activity Handout Page 1 of 3
Student Activity Handout LOADS [15 marks] 1. What are loads? [1 mark] 2. What is the dead load? Give an example of what a dead load would include. [2 marks] 3. What is the live load? Give an example of what a live load would include. [2 marks] 4. A library is built from concrete walls and will hold a collection of children s books. Identify the dead load and live load in this example. [2 marks] 5. Complete the table below. [8 marks] What is the load called? Force acting on the structure Description of the load Preventing the load from occurring Settlement load Deep piles (heavy concrete pillars) to support the structure Temperature Shrinking or expanding due to changes in temperature Roller joints (inserts into building material to allow it to expand or contract) Earthquake load Push and pull in a horizontal direction Shear walls (walls of concrete reinforced with steel beams) Wind load Wind Vibration A load that changes over time Teacher-Created Resources: Student Activity Handout Page 2 of 3
Student Activity Handout MATERIALS [9 marks] 1. Why is it important to take into account the direction of the fibers when building with wood? [1 mark] 2. Why are circus tents made from plastic? [2 marks] 3. Aluminum is a building material that when combined with magnesium and copper (both metals) is almost as strong as steel. What do we call materials that are a combination of metals? [1 mark] 4. Why is brick not used in building modern structures (excluding houses)? [1 mark] 5. What is the difference between concrete and reinforced concrete? [1 mark] 6. Which force is significantly improved by using reinforced concrete versus concrete? [1 mark] 7. Cast iron can be molded to any shape but is not used as a modern day building material, why? [1 mark] 8. Which material is stronger than any other in both compression and tension? [1 mark] SHAPES [6 marks] 1. Compare the structural strength of the three shapes by using the slider on the right side to add and remove weight. Draw the shapes below in the order of greatest structural strength to least structural strength. [3 marks] Note: Move to slider to the very bottom to return to the introductory screen 2. Select each of the shapes to learn more about them. Complete the table below. [3 marks] Add a brace for support Add buttresses for support Circle the strongest point Teacher-Created Resources: Student Activity Handout Page 3 of 3
Student Activity Handout Answer Key LINK: http://www.pbs.org/wgbh/buildingbig/lab/forces.html 42 FORCES [12 marks] Use the FORCES section to complete the table below by filling in the empty boxes. Important: For the last column (the examples) look at the examples in each section by choosing Then think of an example of the force in everyday life and write it down. Action Name of Force What does the force do? What does it look like? (Draw the force in action!) Example of the force in action! Squeezing Compression Squeezes material together. Columns in a skyscraper are under compression. Stretching Tension Stretches material apart. Cables in a suspension bridge are in tension. Bending Bending When a straight material becomes curved, one side squeezes together and the other side stretches apart. Bending a metal bar. Sliding Shear Sliding two materials past one another in opposite direction. Roadway sliding in opposite directions in the event of an earthquake. Twisting Torsion Twisting a material. An unstable suspension bridge may twist during violent winds. NOTE FOR TEACHER: The answers in the last column will vary; the answers provided are those from the learning object which students are NOT to use in their answers. Teacher-Created Resources: Student Activity Handout Answer Key Page 1 of 3
Student Activity Handout Answer Key LOADS [15 marks] 1. What are loads? [1 mark] Loads are forces that act on structures 2. What is the dead load? Give an example of what a dead load would include. [2 marks] The weight of the structure. Building materials such as concrete, nuts, bolts, beams are examples of dead load. 3. What is the live load? Give an example of what a live load would include. [2 marks] The weight of objects on the structure. People, furniture, materials are examples of live load. 4. A library is built from concrete walls and will hold a collection of children s books. Identify the dead load and live load in this example. [2 marks] The dead load is the concrete walls of the library, the live load is the children s books. 5. Complete the table below. [8 marks] What is the load called? Settlement load Force acting on the structure Soft Soil Description of the load Soil beneath structure settles unevenly Preventing the load from occurring Deep piles (heavy concrete pillars) to support the structure Thermal load Temperature Shrinking or expanding due to changes in temperature Roller joints (inserts into building material to allow it to expand or contract) Earthquake load Earthquake Push and pull in a horizontal direction Shear walls (walls of concrete reinforced with steel beams) Wind load Wind Push in a horizontal direction Diagonal braces used to support and stabilize Dynamic load Vibration A load that changes over time Thick beams are used in structures that experience dynamic loads. Teacher-Created Resources: Student Activity Handout Answer Key Page 2 of 3
Student Activity Handout Answer Key MATERIALS [9 marks] 1. Why is it important to take into account the direction of the fibers when building with wood? [1 mark] The direction of the fibers is important because it is 3x easier to break wood if it is stretched across the direction of the fibers rather than in the direction of the fibers. 2. Why are circus tents made from plastic? [2 marks] Circus tents are made from plastic because the tents are pulled in many directions and cannot snap the long chains of molecules that make up plastic can be pulled in many directions without snapping. 3. Aluminum is a building material that when combined with magnesium and copper (both metals) is almost as strong as steel. What do we call materials that are a combination of metals? [1 mark] Alloy 4. Why is brick not used in building modern structures (excluding houses)? [1 mark] Brick is very heavy and breaks easily (weak in tension) 5. What is the difference between concrete and reinforced concrete? [1 mark] Reinforced concrete has steel beams through it whereas concrete does not. 6. Which force is significantly improved by using reinforced concrete versus concrete? [1 mark] Tension 7. Cast iron can be molded to any shape but is not used as a modern day building material, why? [1 mark] Cast iron is brittle and snaps without warning. 8. Which material is stronger than any other in both compression and tension? [1 mark] Steel SHAPES [6 marks] 1. Compare the structural strength of the three shapes by using the slider on the right side to add and remove weight. Draw the shapes below in the order of greatest structural strength to least structural strength. [3 marks] Note: Move to slider to the very bottom to return to the introductory screen 2. Select each of the shapes to learn more about them. Complete the table below. [3 marks] Add a brace for support Add buttresses for support Circle the strongest point Teacher-Created Resources: Student Activity Handout Answer Key Page 3 of 3
Student Activity Post-Assessment _ Complete the following questions below. Each correct response is worth 1 mark. Birthday: 6 1. Torsion is an action that twists a material. 2. Cables in a suspension bridge are held by compression. 3. What is thermal load? 4. What is the difference between the dead load and the live load in a structure? 5. What building material is considered the strongest? 6. Draw the following structures in the table below in order of increasing strength (able to hold weight without collapsing). Teacher-Created Resources: Student Activity Post-Assessment
Student Activity Post-Assessment Name: Answer Key Complete the following questions below. Each correct response is worth 1 mark. 6 1. Torsion is an action that twists a material. 2. Cables in a suspension bridge are held by compression. 3. What is thermal load? The expanding or shrinking of a structure due to changes in temperature. 4. What is the difference between the dead load and the live load in a structure? The dead load is the weight of the materials used to build the building, the live load is the weight of the people, furniture, books, materials, etc. that are inside a building. 5. What building material is considered the strongest? Steel 6. Draw the following structures in the table below in order of increasing strength (able to hold weight without collapsing). Teacher-Created Resources: Student Activity Post-Assessment