Unit D Lesson D1 Classifying Structures
Completion requirements
Lesson D1: Classifying Structures
Video Lesson
The world has a fantastic variety of structures. What are some ways that we can describe all the various types of structures? Watch the video below to find how structures are classified.
Lesson D1: Classifying Structures
Structures Everywhere!
People build structures in which to live. We make structures to help us do both fun and useful things. We use structures all the time. Even the human body is a structure made of many structures.
If we want to invent new and improved structures, understanding the general types of structures is helpful.
People build structures in which to live. We make structures to help us do both fun and useful things. We use structures all the time. Even the human body is a structure made of many structures.
If we want to invent new and improved structures, understanding the general types of structures is helpful.
Reading and Materials for This Lesson
Science in Action 7
Materials:
Science in Action 7
Reading: Pages 264–268
Materials:
cardboard, scissors, white glue, masking tape, ruler, some hardcover books
Figure D.1.1.1 – The Dancing House is an office building in Prague, Czech Republic.
Figure D.1.1.2 – A drinking straw is a structure that provides support to a liquid.
Structures: Different Types, Different Sizes
A structure is a physical object built of various parts. Sometimes a structure has only one part, such as a drinking straw.
Often, a structure has a variety of parts that are joined to provide support. Looking at Figure D.1.1.1 of the Dancing House in Prague, you might think that the building is about to collapse because it has only the slanted pillars on the bottom to hold up its eight storeys. However, the building was designed carefully by architects so that all parts of the building support the weight to make it strong and stable.
Some structures are extremely large, such as the Burj Khalifa (Figure D1.1.3), the tallest skyscraper in the world. Some structures are so small that we cannot see the details easily with our eyes, such as the tiny electric circuits on a computer chip.
A structure is a physical object built of various parts. Sometimes a structure has only one part, such as a drinking straw.
Often, a structure has a variety of parts that are joined to provide support. Looking at Figure D.1.1.1 of the Dancing House in Prague, you might think that the building is about to collapse because it has only the slanted pillars on the bottom to hold up its eight storeys. However, the building was designed carefully by architects so that all parts of the building support the weight to make it strong and stable.
Some structures are extremely large, such as the Burj Khalifa (Figure D1.1.3), the tallest skyscraper in the world. Some structures are so small that we cannot see the details easily with our eyes, such as the tiny electric circuits on a computer chip.
Figure D.1.1.3 – The Burj Khalifa is located in Dubai and is 829 metres high.
Figure D.1.1.4 – Computer chips are structures that operate many electronic devices.
Try It!
Comparing Cubes
This experiment explores the differences of solid, frame, and shell structures.
Materials:
This experiment explores the differences of solid, frame, and shell structures.
Materials:
- thick cardboard (A flattened cardboard box will work well.)
- scissors
- white glue
- masking tape
- ruler
- a few hardcover books
Safety Warning
Take care with scissors; don't cut yourself or anyone else!
Instructions:
- Cube 1 – Using the ruler, draw 15 to 20 squares on the flattened cardboard box. The squares should measure 5 cm by 5 cm. Cut the squares very carefully with scissors. Place the first square flat on a table. Put a thin layer of glue on it and stack another square on top. Repeat until you have a solid cube 5 cm high – it should look something like the Cube 1 diagram below.
- Cube 2 – Using the ruler, draw 12 strips of cardboard that measure 5 cm by ½ cm. Cut the strips very carefully with scissors. Use masking tape to connect the strips to form the outline of a cube – it should look something like the Cube 2 diagram below.
- Cube 3 – Using the ruler, draw six squares on the flattened cardboard box. The squares must measure 5 cm by 5 cm. Cut the squares very carefully with scissors. Use masking tape to connect the edges of the squares to form a cube – it should look something like the Cube 3 diagram below.
- Soon, you will test the strength of your cubes. Make a prediction! Which cube is the strongest?
- Now, test the strength of your cubes by balancing books on them. Hardcover books that are about the same size work best. Watch the cubes carefully as one by one you place books on each. If a cube collapses or squishes more than 1 mm, it has failed.
Questions:
Think about the following questions very carefully. Then, type or write your answers. After you have your answers, click the questions for feedback.
Think about the following questions very carefully. Then, type or write your answers. After you have your answers, click the questions for feedback.
Cube 2 represents a frame structure because it forms a skeleton outline of the cube.
Cube 1 represents a solid structure because the cube has no empty space inside.
Cube 3 represents a shell structure because it has a thin outer layer with empty space inside.
Congratulations if your prediction was correct! The cube that is the strongest depends on the type of cardboard you used and how well you constructed the cubes. Any of the cubes could win, but often, the solid cube wins because it has no empty space and
more cardboard supports the books. However, if it is made of weak cardboard, it may squish easily. The shell cube or frame cube may win if it is built in a very stable way and the cardboard in the shell or frame is positioned on end so that
it resists collapsing and squishing.
Structures of the same size are different in strength and stability because of the way they are built, the types of materials used to build them, and the varying amounts of empty space within them.
Figure D.1.1.5 – The root system of a tree is often bigger than the tree itself.
Figure D.1.1.6 – Insect wings have veins for support
Structures in Nature
Often, we think that only humans build structures. However, many structures are found in nature.
Structures are evident in the bodies of animals and plants. The solid underground roots of trees are structures that provide support and help trees stand upright despite winds. If trees had no roots, they would topple over easily.
An insect wing has a frame of veins that make the delicate wing stiffer. The veins provide support for the insect to fly.
Other organisms build structures for shelter and storage. A species of bird in Africa called the social weaver builds massive nests in trees. Their nests even have individual rooms, similar to an apartment building!
Often, we think that only humans build structures. However, many structures are found in nature.
Structures are evident in the bodies of animals and plants. The solid underground roots of trees are structures that provide support and help trees stand upright despite winds. If trees had no roots, they would topple over easily.
An insect wing has a frame of veins that make the delicate wing stiffer. The veins provide support for the insect to fly.
Other organisms build structures for shelter and storage. A species of bird in Africa called the social weaver builds massive nests in trees. Their nests even have individual rooms, similar to an apartment building!
Figure D.1.1.7 – The African social weaver bird
Figure D.1.1.8 – A social weaver colony, one of the most incredible bird-built structures.
Frame Structures That Help People
The structure inside people that helps give support to our bodies is our skeleton made of bones. Without a frame of bones, our bodies would be very floppy, and we would be unable to walk. We would be jellyfish!
A person might become paralyzed when his or her spinal cord is damaged in an accident, for example. Depending on the nature of the injuries, some people might be paralyzed in their legs only, and some might not be able to move any limbs.
For mobility, paralyzed people often depend on the frame structures of wheelchairs or other devices.
The structure inside people that helps give support to our bodies is our skeleton made of bones. Without a frame of bones, our bodies would be very floppy, and we would be unable to walk. We would be jellyfish!
A person might become paralyzed when his or her spinal cord is damaged in an accident, for example. Depending on the nature of the injuries, some people might be paralyzed in their legs only, and some might not be able to move any limbs.
For mobility, paralyzed people often depend on the frame structures of wheelchairs or other devices.
Figure D.1.1.9 – Humans have a skeletal structure to support movement.
Figure D.1.1.10 – A wheelchair is a frame structure that helps people who struggle with mobility.
Watch More
An amazing technology for human mobility has been developed recently. An exoskeleton is a frame structure worn on the outside of the body. Exoskeletons can help paralyzed people walk again! Watch this video to see how human exoskeleton technology works.
Make sure you have understood everything in this lesson. Use the Self-Check below, and the Self-Check & Lesson Review Tips to
guide your learning.
Unit D Lesson 1 Self-Check
Instructions
Complete the following 6 steps.
Don't skip steps – if you do them in order, you will confirm your
understanding of this lesson and create a study bank for the future.
- DOWNLOAD the self-check quiz by clicking here.
- ANSWER all the questions on the downloaded quiz in the spaces provided. Think carefully before typing your answers. Review this lesson if you need to. Save your quiz when you are done.
- COMPARE your answers with the suggested "Self-Check Quiz Answers" below. WAIT! You didn't skip step 2, did you? It's very important to carefully write out your own answers before checking the suggested answers.
-
REVISE your quiz answers if you need to. If you answered all the questions correctly, you can skip this step. Revise means to change, fix, and add extra notes if you need to. This quiz is NOT FOR MARKS, so it is perfectly OK to correct
any mistakes you made. This will make your self-check quiz an excellent study tool you can use later.
- SAVE your quiz to a folder on your computer, or to your Private Files. That way you will know where it is for later studying.
- CHECK with your teacher if you need to. If after completing all these steps you are still not sure about the questions or your answers, you should ask for more feedback from your teacher. To do this, post in the Course Questions Forum, or send your teacher an email. In either case, attach your completed quiz and ask; "Can you look at this quiz and give me some feedback please?" They will be happy to help you!
Self-Check Time!
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Self-Check Quiz Answers
Click each of the suggested answers below, and carefully compare your answers to the suggested answers.
If you have not done the quiz yet – STOP – and go back to step 1 above. Do not look at the answers without first trying the questions.
An igloo is a shell structure. It has a solid outer surface and a hollow interior.
A dam is a solid structure. It is made from a massive solid piece of concrete.
A grain silo can be both a shell or a frame structure. Often, a grain silo has a rigid metal skeleton frame on the outside. The silo is covered with solid metal and has a hollow interior, which makes it a shell.
A roller coaster is a frame structure. It has rigid metal bars connected together.
A football helmet can be both a shell and a frame structure. The shell structure has a solid plastic and foam outer surface and a hollow interior to cover the head. The face mask made of rigid metal bars is a frame structure.