CK-12 Physical Science Concepts - For Middle School

4.39. Simple Machines http://www.ck12.org some of these simple machines yourself. Most machines are combinations of two or more ...

http://www.ck12.org Chapter 4. Motion and Forces Vocabulary machine: Any device that makes work easier by changing a force. Ex ...

4.40. Efficiency http://www.ck12.org 4.40 Efficiency Explain why all machines must overcome friction. Define the efficiency of ...

http://www.ck12.org Chapter 4. Motion and Forces Machine Efficiency Efficiency is the percent of work put into a machine by the ...

4.40. Efficiency http://www.ck12.org You can calculate the efficiency of a machine with this equation: Efficiency=Output workIn ...

http://www.ck12.org Chapter 4. Motion and Forces 4.41 Mechanical Advantage Define actual and ideal mechanical advantage. Show h ...

4.41 Mechanical Advantage Note that this equation represents theactualmechanical advantage of a machine. The actual mechanical a ...

http://www.ck12.org Chapter 4. Motion and Forces Mechanical Advantage of Different Types of Machines Many machines—including inc ...

4.41. Mechanical Advantage http://www.ck12.org What is the mechanical advantage of the lever in question 1? Review What is th ...

http://www.ck12.org Chapter 4. Motion and Forces 4.42 Inclined Plane Describe an inclined plane. Explain how an inclined plane ...

4.42 Inclined Plane FIGURE 4.82 the mechanical advantage is greater than 1. The more gradual the slope of the inclined plane, th ...

http://www.ck12.org Chapter 4. Motion and Forces FIGURE 4.84 Review What is an inclined plane? How does an inclined plane make ...

4.43. Wedge http://www.ck12.org 4.43 Wedge Describe a wedge. Explain how a wedge changes force to make work easier. Identify th ...

http://www.ck12.org Chapter 4. Motion and Forces FIGURE 4.85 FIGURE 4.86 output force is applied over a shorter distance, so for ...

4.43. Wedge http://www.ck12.org FIGURE 4.87 Summary A wedge is a simple machine that consists of two inclined planes, giving it ...

http://www.ck12.org Chapter 4. Motion and Forces FIGURE 4.88 Review What is a wedge? How does a wedge change the force applied ...

4.44. Screw http://www.ck12.org 4.44 Screw Describe a screw, and give examples of screws. Explain how a screw works. Identify t ...

http://www.ck12.org Chapter 4. Motion and Forces To see some other examples of screws, go to this URL: http://www.beaconlearning ...

4.44. Screw http://www.ck12.org FIGURE 4.90 Vocabulary screw: Simple machine that consists of an inclined plane wrapped around ...

http://www.ck12.org Chapter 4. Motion and Forces 4.45 Lever Define lever. Describe the three classes of levers. Outline how eac ...