Concept to be learned: There are six simple machines, the wedge, screw, lever, pulley, wheel & axle, and inclined plane, that can be combined to form more complex machines.
Process Skills: The students will use the following skills: observation, classification, communication, prediction, inferring, and formulating models
Science Attitudes: The students will experience the following attitudes: curiosity, openness to new experiences, appreciation for the role science plays in daily lives, and recognition that science has value.
Standards: Physical science
Introduction: The teacher makes a chart on the chalk board with six columns, the students will write in one of the six simple machines in each column. Then the following questions will be proposed to the class to answer in a discussion format:
„X How do simple machines help us to do work?
„X How do the simple machines help us in our everyday lives?
„X What else do you know about simple machines?
Exploration Activity: Students will be broken into five groups by the teacher. After given instructions, the groups will be given one appliance/device each. The appliances will be a radio, blender base, radio, toaster, and a hand held blender. Then the students will be directed to write down the function on the machine, and then to predict which of the six simple machines will be found most frequently in their machines, and explain why the predict this. Then each table will receive three to four different tools (hammer, wrench, screwdriver, pliers). They will dissect their machines and using the chart made earlier in class, to tally how often machines were found. For some simple machines, students will need to observe how the parts were used in order to classify them. This activity will take 15-20 minutes. Students then put dissected machines into a box at the front of the class, and wipe down lab tables.
Explanation activity: Discuss studentsˇ¦ findings. Ask probing questions about why certain machines were found more often than others. Decide as a class if the majority of predictions were correct or incorrect. Discover what the students found most surprising about their tally sheets. All complex machines are made up of two or more simple machines; the more complex the machine, the more likely the more simple machines. There are simple machines in common objects that we handle every day, and allow us to have the convenience and advantages of complex machines.
Expansion: Rube Goldberg was an engineer turned artist who created drawings of complex machines that completed simple tasks. Show the students Rube Goldbergˇ¦s picture (Self-Opening Umbrella) on overhead. Go through the steps of the simple machine with the students. Ask students where they see simple machines within the drawing. Then put the second Rube Goldberg drawing (An Automatic Back Scratcher) on the overhead. Allow students to take turns explaining each step of the picture.
Evaluation and Closure: Then have students locate simple machines in picture. Students will then create their own Rube Goldberg drawings that consist of at least 5 different steps, 3 different simple machines, and explanation of how each step works. Ask students what they have learned about simple machines, and how they effect our lives.
Safety Precautions: Make sure students are constructively dissecting machines. Students must be careful with the tools and the ways that they use them. Students should at no time put any plugs of the machine anywhere close to an outlet. Remind students that their Rube Goldberg drawings must be appropriate and cannot contain any weapons or dangerous or harmful steps.
Materials and resources: Teacher must locate enough appliances and devices before that day of class. Thrift stores are cheap and a great source. Overheads of Rube Goldberg drawings must be made. Tools must be present for Engaging step.
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