Grade Level:
Middle School
Lesson Time:
240 minutes for classroom activities
Introduction:
In this lesson, students will analyze a conventional can opener. Students will be asked if they have ever had trouble opening a can with such a tool. What simple machines make up a can opener? Do you think you could improve this design if you had the tools and resources to do so?
State Standards:
No State Standards available.
National Standards:
Science
Standard 12. Level III. Understands the nature of scientific inquiry
1. Knows that there is no fixed procedure called "the scientific method," but that investigations involve systematic observations, carefully collected, relevant evidence, logical reasoning, and some imagination in developing hypotheses and explanations
3. Designs and conducts a scientific investigation (e.g., formulates hypotheses, designs and executes investigations, interprets data, synthesizes evidence into explanations)
9. Knows possible outcomes of scientific investigations (e.g., some may result in new ideas and phenomena for study; some may generate new methods or procedures for an investigation; some may result in the development of new technologies to improve the collection of data; some may lead to new investigations)
Objectives:
Students will be able to:
- analyze how simple machines (especially levers and wheels and axles) make work on an object (i.e., a can) easier by changing the direction, distance, and amount of effort and force applied to an object
- use the design process to solve problems and engage the world around them
Materials:
For each group of three to four students, you will need:
- handouts #1 and #2, and article
- traditional can opener
- dowel rods of .5” to 1” in diameter cut to the following lengths (two of each): 3 inches, 6 inches, 9 inches, 12 inches
- strong tape (duct, packing, etc.)
- scissors
- tin can with at least one end intact (Note: Precautions should be taken so that students do not cut themselves.)
- work or gardening gloves (for protection from cuts)
- ruler
- wooden craft sticks
- craft foam circles
Vocabulary:
Before this lesson, students should be familiar with the following terms: machine, work, energy, effort force, fulcrum, lever, wheel and axle, wedge, and diameter.
Procedures:
Day 1:
1. Pass out student handout.
2. Pass out materials listed above.
3. Students will examine a regular can opener and record observations on their handouts.
4. Students will be asked to make the existing can opener more efficient, using long and short wooden dowels for the levers and handle of the wheel-and-axle (on the worksheet).
5. Students will pierce the tin can with the can opener (altered and unaltered) to test the ease of use (work).
6. Students will record data on their handouts.
7. Students will discuss the effects of the changes of the handle lengths. Did it make it harder/easier to use? Why? Was the amount of work done increased/decreased? How do you know?
8. Class will discuss the effect of lever length on work.
Day 2:
1. Students will begin the design process of creating their own efficient manual can opener.
2. Each group will have a separate set of constraints.
3. Each group will draw from a hat and have to use the combination of simple machines given to them to design a can opener. They will only be allowed to use the simple machines that were given to them, i.e. Group one chooses the following card: Wedge, Screw, and Inclined plane. Then Group one will have to design a can opener using only the aforementioned simple machines.
4. Students will first sketch their design on a paper and label the sections.
5. Teacher will circulate among the groups, offering suggestions and asking students questions to get them thinking critically. (For example: What do you think would happen if you put this there, instead of that? Will making the effort arm shorter increase or decrease the amount of work done? Etc.)
6. Students will explain how the apparatus will work.
7. Teacher will give students wooden craft sticks, tape, glue, foam circles to create a prototype of their apparatus.
8. Students must be able to explain how their design is more efficient than the traditional can opener.
9. Students will have the rest of the period today and tomorrow to construct their design protocols.
Day 3:
1. Students will continue to build and create their prototypes.
Day 4:
1. Students will complete handout #2 explaining their designs and the design process.
2. Students will then present their prototypes to the class. Students must include how their design makes work easier and describe the simple machines used in its assembly.
3. Students will be encouraged to ask questions about each other’s designs.
4. Students will reflect on their designs and suggest any improvements that need to be made.
5. Teacher will wrap up the task by discussing the design process and how designers find a problem and work to solve that problem.
Assessment:
Mastery of the students would be determined by the answers on student handouts #1 and #2. The process has differentiation woven into it, since students of all ability levels will be able to design an appropriate prototype. Students with learning difficulties could also be given fewer restraints.
Enrichment
Extension Activities:
Within the assignment, students will be asked to think outside of the box and globally. How will your design make life better for people around the world? How have you contributed to society in your role as a designer?
Related
Files:
No related files are necessary.