Unit 2, Chapter 4

1. Unit 2, Chapter 4 Integrated Science

2. Unit Two: Work and Energy Chapter 4 Machines and Mechanical Systems • 4.1 Force and Machines • 4.2 The Lever • 4.3 Gears and Design

3. Chapter 4 Learning Goals • Describe and explain a simple machine. • Apply the concepts of input force and output force to any machine. • Determine the mechanical advantage of a machine. • Construct and analyze a block and tackle machine. • Describe the difference between science and engineering. • Understand and apply the engineering cycle to the development of an invention or product. • Describe the purpose and construction of a prototype. • Design and analyze a lever. • Calculate the mechanical advantage of a lever. • Recognize the three classes of levers. • Build machines with gears and deduce the rule for how pairs of gears turn. • Design and build a gear machine that solves a specific problem.

4. engineering gear engineering cycle engineers force fulcrum gear input input arm input force input gear lever machine mechanical advantage mechanical systems output output arm output force output gear prototype simple machine Chapter 4 Vocabulary Terms

5. Key Question: How do simple machines work? 4.1 Forces in Machines *Read text section 4.1 AFTER Investigation 4.1

6. 4.1 Mechanical Advantage Output force (N) MA = Fo Fi mechanical advantage Input force (N)

8. Key Question: How does a lever work? 4.2 The Lever *Read text section 4.2 AFTER Investigation 4.2

10. Key Question: How do gears work? 4.3 Gears and Design *Read text section 4.3 AFTER Investigation 4.3

11. 4.3 Gear Ratios Number of teeth on input gear To=Ni Ti No Turns of output gear Turns of input gear Number of teeth on input gear

12. Machines