Planning Index: Mechanical Systems |
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Grade 8 Science Unit Plan Unit D - Mechanical Systems (Science and Technology Emphasis) Grade 8 Unit Overview (Alberta) Machines are used for many purposes in our daily lives, when we need to transfer energy into motion, or move materials in a controlled way. in learning about mechanical devices, students investigate how components are linked so that energy is transferred efficiently and desired functions are performed. A comparison of past and present technologies helps students recognize that different approaches have been used over time to meet common needs. Evaluation of efficiency, effectiveness and impacts on daily life, the community and the environment are important considerations in this unit.
Concepts Covered and Developed through Instruction
| | | - transmission of force and motion
| | - speed ratios and force ratios
| - measurement of work in joules
| - mechanical advantage and hydraulics
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What do the students know? | How do students think energy is transferred in a machine? Can they describe mechanical systems according to their function, mechanical advantage and efficiency ? | What must they Learn? | How energy is transferred in mechanical devices and how these devices provide for the controlled application of energy in ways that are efficient, effective and responsible? |
| General Learner Outcome | Specific Learner Outcomes | Instructional Focus | Focus 1 | Timeline of Machines |
| Illustrate the development of science and technology by describing, comparing and interpreting mechanical devices that have been improved over time | 1.0 | - water moving devices ( Persian wheel, Archimedes wheel, mill wheel ) - lifting devices - trial and error | Textual resources / Research Lab Activities / Demonstrations Problem solving
| | Analyze machines by describing structures and functions of the overall system, the subsystems and the component parts | 2.0 | - analysis of a device - function of the device - subsystems - types of simple machines - energy source - gears, belt drives | Scientific Illustrations Lab Activities / Demonstrations Building a Model Textual Resources / Research Textual Resources / Research Lab Activities / Demonstrations | | Investigate and describe the transmission of force and energy between parts of a mechanical system analyze mechanical devices to determine speed ratios and force ratios | 3.0 | - turning ratios - efficiency (friction) - work input/output - fluid pressure - Pascal's Law - pressure formula - hydraulic jack - technologies | Building Models Problem Solving Activities Problem Solving Activities / Calculations Lab Activities Textual / Audio-Visual Resourses Problem Solving Activities / Calculations Lab Activities Textual Resources / Research | Focus 4 | Technology and Machines |
| Analyze the social and environmental contexts of science and technology, as they apply to the development of mechanical device | 4.0 | - evaluation of design - criteria - reciprocal influences | Research Building an evaluation model Case Study | |