1. Integrated Science
Unit 2, Chapter 4

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. Chapter 4 Vocabulary Terms
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

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

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

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

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

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

12. Machines