# Chapter 7 Lesson 2 - Central Lyon

Chapter 14 Lesson 4 The Simple Machine I. Lever System A. Def A lever is a bar that is free to pivot

or turn about a fixed point. B. Parts of a lever 1. Fulcrum fixed point of the lever 2. Effort arm part where force is applied to the lever. 3. Resistance arm part where the

resistance is found on the lever. C. Ideal Mechanical Advantage 1. IMA = Length of effort arm Length of resistance arm or

Le Lr 2. Ex: A worker uses an iron bar to raise a manhole cover weighing 65 N. The effort arm of the lever is 60

cm long. The resistance arm is 10 cm long. What is the ideal mechanical advantage of the bar? 60 cm Le = Lr =

10 cm = 6 (IMA) D. Types of Levers

1. 1st Class -E F R -Common Ex: teeter totter scissors pliers

claw of hammer 2. 2nd Class -FRE - Common Ex: stapler

bottle opener wheelbarrow nut cracker 3. 3rd Class (increase speed) -FER

- Common Ex: fishing rod tweezers mousetrap baseball bat softball bat

II. Pulleys A. Def a grooved wheel with a rope or chain running along the groove. 1. similar to 1st class lever 2. uses rope instead of bar

3. has effort arm and resistance arm. B. Types of Pulleys 1. Fixed -Fixed pulley does not move

-MA = 1 2. Movable -Movable pulley is movable -MA = 2 (can vary)

3. Block and Tackle -uses fixed and movable -Large Mechanical advantage -MA = # of ropes in

the pulley system -MA = 2 What is the MA? =4

III. Wheel and Axle A. Def a simple machine consisting of 2 different sized wheels that rotate together. 1. Parts

-small wheel = axle 2. Effort force is applied to large wheel 3. Large wheel turns the axle 4. IMA = rw / ra 5. Ex: Bike, doorknobs, ice cream makers, cars

6. Ex: An ice cream maker has a wheel radius of 20cm. The axle has a radius of 15 cm. What is the ideal mechanical advantage of the wheel and axle?

20 / 15 =1.3 IMA IV. Inclined Plane, Wedge, Screw A. Inclined Plane 1. Def a sloped surface used to

raise objects 2. IMA = length of slope / height of slope 3. Ex: any ramp 4. Remember** Force is smaller but distance is greater.

B. Screw 1. Def Inclined plane wrapped in a spiral cylindrical post. 2. Ex: screws, lids, drill bits C. Wedge

1. Def Inclined plane with 1 or 2 sloping sides 2. Used to cut or split 3. Ex: knives, ax blades, chisels

## Recently Viewed Presentations

• une augmentation substantielle du coût de la ressource . provoquerait inéluctablement un ralentissement hautement significatif de la production et surtout de l'exportation de la spéculation de base de la région à savoir les dattes. 4. Résultats de quelques un des...
• Multiple use of other modes creates a necessity to learn to use new tools and symbolic 'codes'. Multiple representations can make it easier to access information, but may provide new opportunities for control. Access is split across multiple modes and...
• In this respect it is not dissimilar to Owen'sDulce Et Decorum Est. It is a poem keen to give the reader a sense of the reality - the almost clumsy changes in meter and rhyme, various uses of alliteration, assonance...
• The discussion is guided by students' response to what they have read. You may hear talk about events and characters in the book, the author's craft, or personal experiences related to the story."SchlickNoe, K. L. & Johnson. N.L., Getting Started...
• Melting and dissolving are the same thing. [Lee (93), MS: Key] B.5.1.1 . Salt becomes liquid salt when it dissolves ... Kansas State University. (C/O Emmett Wright, College of Education, Bluemont Hall, Kansas State University, Manhattan, KS 1-913-532-7838) Use of...
• Article "Providing Culturally Responsive Teaching" - Method, Participants, and Instruments. provide effective instruction utilizing evidence-based best practices and curriculum and pedagogyresponsive to the needs ofstudents with high incidence disabilities in urban school settings.
• Free exercise prohibits the abridgement of citizens' freedom to worship or not to worship . ... The first 10 Amendments to the U.S. Constitution, which define such basic liberties as freedom of religion, speech, and the press, and they guarantee...
• Moscow and Berlin The Golden Twenties ... N. Altman, N. Gabo, F. A. Lutz. El Lissitzky Viktor Vasnetsov Battle of the Scythians and the Slavs Boris Kustodiev Merchant's Wife Abram Arkhipov Washer Women Piotr Konchalovsky Oaks Aristarkh Lentulov Church with...