1. GK-12 Lesson Planning 8 th Grade Science / Engineering Simple Machines An Activity Series Aida Peterson (Teacher) Matthew Silbernagel (Fellow)

2. A.P. / M.S. GK-122 Outline Physical Science: Goals, Standards, & Benchmarks (CDE) Introduction: Work & Simple Machines Hands-on Investigations –Lever –Pulley –Inclined Plane, Screw, Wedge –Wheel & Axle Assessment Alternative Approaches / Adaptations

3. 3 Goals Define and give examples of “work” and “machine” Identify simple machines (i.e., inclined plane, screw, lever, wheel & axle, wedge, and pulley Quantify work and mechanical advantage Classify simple and compound machines

4. 4 Standards 8.1 Students understand the processes of scientific investigation and design, conduct, communicate about, and evaluate such investigations. 8.2 Physical Science: Students know and understand common properties, forms, and changes in energy. (Focus: Physics and Chemistry) Source: CDE

5. 5 Benchmarks (1) 1.1 Scientific Investigation Using examples to demonstrate that scientific ideas are used to explain previous observations and to predict future events Using appropriate tools, technologies, and measurement units to gather and organize data Interpreting and evaluating data in order to formulate conclusions Communicating results of their investigations in appropriate ways (for example, written reports, graphic displays, oral presentations) Using metric units in measuring, calculating, and reporting results Explaining that scientific investigations sometimes result in unexpected findings that lead to new questions and more investigations Source: CDE

6. 6 Benchmarks (2) 2.3 Students understand that interactions can produce changes in a system, although the total quantities of matter and energy remain unchanged. Identifying and classifying factors causing change within a system (for example, force, light, heat) Identifying and predicting what will change and what will remain unchanged when matter experiences an external force or energy change (for example, boiling a liquid; comparing the force, distance, and work involved in simple machines) Describing, measuring (for example, time, distance, mass, force) and calculating quantities that characterize moving objects and their interactions within a system (for example, force, velocity, acceleration, potential energy, kinetic energy) Source: CDE

7. 7 Simple Machines (Review) Define “work” and “simple machine” Identify simple machines – inclined plane – screw – wedge – lever – wheel & axle – pulley

8. 8 Materials paint can paint stick book spring scale meter stick string several pulleys toy car (weighted) three boards (same length) three boards (different length) long pole (ring stand) milk carton

9. 9 Lever – Activity Station They multiply the effort force and change its direction. Mechanical Advantage is usually greater than one if the fulcrum is closer to the resistance force than the effort force.

10. 10 Pulleys – Activity Station Fixed vs. Movable Pulleys

11. 11 Inclined Plane, Screw, & Wedge – Activity Station Inclined Plane Advantage – less effort force Disadvantage – more effort distance The mechanical advantage (M.A.) is the length (Effort distance) divided by the height (Resistance distance ). M.A. = dE / dR. Can the advantage be less than 1 (M.A.<1?)

12. 12 Wheel and Axle – Activity Station The wheel/axle combination is just a lever that rotates in a circle! If effort force is applied to the wheel, effort force is multiplied because the wheel moves a greater distance than the axle. The mechanical advantage is greater than one. M.A. = radius of wheel / radius of axle. If effort force is applied to the axle, the mechanical advantage is less than one. M.A. = radius of axle / radius of wheel.

13. 13 Assessment Verbal Interaction: –Initial class survey –Table/Individual inquiries –Identifications with team competitions Written responses: –Quantitative analysis –“What if” questions –Applications (open-ended)

14. 14 Alternative Approaches & Adaptations Research body parts (biomechanics), construction equipment, or household objects that are used as simple machines Efficiency: eff = W o / W i x 100% References on work and simple machines –http://www.avon.k12.ct.us/avonhigh/Academics/Departments/Science/Physics/Si mpleMachine.htmhttp://www.avon.k12.ct.us/avonhigh/Academics/Departments/Science/Physics/Si mpleMachine.htm –http://www.iit.edu/~smile/ph9005.htmlhttp://www.iit.edu/~smile/ph9005.html –http://www.cfaitc.org/LessonPlans/pdf/109.pdfhttp://www.cfaitc.org/LessonPlans/pdf/109.pdf Interactive websites (?) –http://mws.mcallen.isd.tenet.edu/mchi/ipc/ch15htm/ch15sec4.htmhttp://mws.mcallen.isd.tenet.edu/mchi/ipc/ch15htm/ch15sec4.htm

15. 15 Questions / Comments ?

16. 16 Backup slides