Name of Corresponding Unit Plan: Wedges
Grade Level: K-8
Content Areas: Science
Recommended Length/Duration: 30-50 minutes
Students will identify the uses of different tools, how the tools are used, the parts that do work and the parts where effort is applied. Primary students will identify if the wedge of the tool is sharp or dull. Intermediate students will measure the effort and resistance surfaces to calculate mechanical advantage.
- This activity can be done in the lab groups or as a learning center in the classroom.
- The teacher will present a variety of edged tools (splitting wedge, maul, hatchet, various sized knives, lawn mower blade, scissors, etc.)
- As an example the teacher will demonstrate how to measure the length and thickness of the wedge forming the cutting edge of the tool.
- Review the worksheet and the data students are to record.
- Have students work in groups or individually to identify the parts of the tools, measure their parts, and record their data.
- Intermediate students should calculate mechanical advantage using the formula: Effort distance / Resistance distance.
- Students should answer the questions on their data collection sheet.
- When all students have completed the activity, the teacher should review their findings and discuss how the tools are well designed for their purpose.
Assessments Informal assessment based on participation and general understand of key ideas or more formal assessment of measurements and calculations.
Materials/Resources: A collection of edged tools
Special Considerations: Review safety precautions – be sure there are no very sharp edges and that students understand and are able to handle tools safely.
Extension: Have students design a new tool that is an improvement on an existing tool for a particular job.