AIDE Physical Science Assignment Guide and Key Points

 

Chapter 8 "Work and Machines"

 

Lesson 1 "What is Work"

Turn to page205 look at the picture on those pages read about it and the short introduction to Chapter 8

Visually Scan Pages 206-208; focus on the blue boxes, which contain the key vocabulary terms.

Visually Scan Pages 206-208 for pictures and diagrams, read each of the captions.

Look for and read any little blue boxes on pages 206-208

Read Pages 206-207 (take notes of important ideas)

Do you know the answers to the questions on page 208? (See Key Points below for help)

Do you know the vocabulary words? (See Key Points below for help)

Take the quiz on Lesson 1 "What is Work" (You may use the book, notes and Key Points for help on the quizzes. NOT ON TESTS!)

Review answers on the quiz and print it out. This will be very useful when you are studying for the test.

 

Lesson 1 Key Points

Vocabulary Terms

work - What happens when an object changes its position by moving in the direction of the force that is being applied.

joule - the metric unit of work.

 

Section Review Answers

  1. Work is what happens when an object changes position by moving in the direction of the applied force.
  2. You need to know how much force was applied and the distance the object moved in the direction of the force.
  3. The metric unit of work is a joule.
  4. 8 newtons x 13 meters = 104 joules.
  5. The person who picked up the kitten did more work.

Did you learn these Objectives?

Can you define and explain work?

Are you able to measure and calculate work?

 

Lesson 2 "Power"

Visually Scan Pages 209-210; focus on the blue boxes, which contain the key vocabulary terms.

Visually Scan Pages 209-210 for pictures and diagrams, read each of the captions.

Read Pages 209 (take notes of important ideas)

Do you know the answers to the questions on page 210? (See Key Points below for help)

Do you know the vocabulary words? (See Key Points below for help)

Take the quiz on Lesson 2 "Power" (You may use the book, notes and Key Points for help on the quizzes. NOT ON TESTS!)

Review answers on the quiz and print it out. This will be very useful when you are studying for the test.

 

Lesson 2 Key Points

Vocabulary Terms

power - the amount of work a person does within a given period of time.

watt - the unit used to measure power.

 

Section Review Answers

  1. Power is the amount of work done in a given amount of time.
  2. Power depends on joules of work and seconds of time.
  3. 100 newtons x 10 meters/10 seconds = 100 joules/second or 100 watts
  4. 100 newtons x 10 meters/5 seconds = 200 joules/second or 200 watts.
  5. When the time is shorter, the power used increases. It requires more power to do an equal amount of work in a shorter time.

Did you learn these Objectives?

Can you define and explain power?

Are you able to measure and calculate power?

 

Lesson 3 "Energy"

Visually Scan Pages 211-215; focus on the blue boxes, which contain the key vocabulary terms.

Visually Scan Pages 211-215 for pictures and diagrams, read each of the captions.

Visually Scan for an read the short articles in the blue boxes that you find on Pages 211-215.

Read Pages 211-214 (take notes of important ideas)

Do you know the answers to the questions on page 215? (See Key Points below for help)

Do you know the vocabulary words? (See Key Points below for help)

Take the quiz on Lesson 3 "Energy" (You may use the book, notes and Key Points for help on the quizzes. NOT ON TESTS!)

Review answers on the quiz and print it out. This will be very useful when you are studying for the test.

 

Lesson 3 Key Points

Vocabulary Terms

energy - the ability to do work.

kinetic energy - energy of motion

potential energy - stored energy

generator - a device used to convert mechanical energy to electrical energy

Law of conservation of energy - energy cannot be created or destroyed.

 

 

Section Review Answers

  1. Energy is the ability to do work.
  2. Kinetic energy is energy of motion. Potential energy is stored energy.
  3. The law of conservation of energy says that energy can change form but it cannot be created or destroyed.
  4. The six forms of energy are: chemical, heat, mechanical, nuclear, radiant, and electrical.
  5. A chemical energy changes to mechanical energy (sound). B mechanical energy changes to mechanical energy. C chemical energy changes to heat energy and light energy.

Did you learn these Objectives?

Can you relate energy to work?

Are you able to explain the difference between kinetic and potential energy?

Are you able to explain the law of conservation of energy?

 Investigation 8-1 "Mass, Height, and Energy"

Optional, (must complete 3 this quarter)

Gather the materials you need; safety glasses, paper cup, grooved ruler, textbook, safety scissors, small marble, large marble.

Follow the procedure on page 216-217.

Complete the follow-up investigation quiz. (The 2 questions will be the same as the two questions on P217)

 

Lesson 4 "Using Levers"

Visually Scan Pages 218-223; focus on the blue boxes, which contain the key vocabulary terms.

Visually Scan Pages 218-223 for pictures and diagrams, read each of the captions.

Visually Scan for an read the short articles and questions in the blue boxes that you find on Pages 218-223.

Read Pages 218-222 (take notes of important ideas)

Do you know the answers to the questions on page 223? (See Key Points below for help)

Do you know the vocabulary words? (See Key Points below for help)

Take the quiz on Lesson 5 "Using Levers" (You may use the book, notes and Key Points for help on the quizzes. NOT ON TESTS!)

Review answers on the quiz and print it out. This will be very useful when you are studying for the test.

 

Lesson 4 Key Points

Vocabulary Terms

simple machine - a tool with few parts that makes it easier or possible to do work.

Lever - a simple machine containing a bar that can turn around a fixed point.

Fulcrum - a fixed point around which a lever rotates

Effort force, Fe - the force applied to a machine by the user.

Resistance force, Fr - the force applied to a machine by the object to be moved.

Work input - work put into a machine by its user.

Work output - work done by a machine against the resistance.

Efficiency - how well a machine performs.

 

 

Section Review Answers

  1. Check students' drawings. The fulcrum is between the effort and the resistance in a first-class lever.
  2. Check students' drawings. In a second-class lever, the resistance is between the effort and the fulcrum.
  3. Check students' drawings. In a third-class lever, the effort is between the fulcrum and the resistance.
  4. Work input is the work put into a machine by its user, effort force x effort distance. Work output is the work done by a machine against the resistance, force distance x resistance distance.
  5. Efficiency tells you what percent of work input is translated into useful work when a certain machine is used.

Did you learn these Objectives?

Can you explain what a simple machine is?

Are you able to describe how a lever works?

Are you able to distinguish among the three classes of levers?

Can you analyze work and efficiency for levers?

 

Lesson 5 "Mechanical Advantage"

Visually Scan Pages 224-226; focus on the blue boxes, which contain the key vocabulary terms.

Visually Scan Pages 224-226 for pictures and diagrams, read each of the captions.

Visually Scan for an read the short articles and questions in the blue boxes that you find on Pages 224-226.

Read Pages 224-225 (take notes of important ideas)

Do you know the answers to the questions on page 226? (See Key Points below for help)

Do you know the vocabulary words? (See Key Points below for help)

Take the quiz on Lesson 5 "Mechanical" (You may use the book, notes and Key Points for help on the quizzes. NOT ON TESTS!)

Review answers on the quiz and print it out. This will be very useful when you are studying for the test.

 

Lesson 5 Key Points

Vocabulary Terms

Mechanical advantage, MA - factor by which a machine multiplies the effort force.

Effort arm - the distance between the fulcrum and the effort force of a lever.

Resistance arm - the distance between the fulcrum and resistance force of a lever.

 

Section Review Answers

  1. Mechanical advantage is the number of times by which a machine multiplies effort force.
  2. You would divide the resistance force by the effort force.
  3. You would divide the effort arm by the resistance arm.
  4. The mechanical advantage is 8.
  5. The resistance force is 40 newtons.

Did you learn these Objectives?

Can you explain and calculate mechanical advantage?

Are you able to use effort arm and resistance arm to determine the mechanical advantage of a lever?

Investigation 8-2 "Finding the Mechanical Advantage of a Lever"

Optional, (must complete 3 this quarter)

Contact the instructor if you need the materials for this lab.

Follow the procedure on page 227-228.

Complete the follow-up investigation quiz. (The 5 questions will be the same as the 5 questions on P228)

 

 

Lesson 6 "Some Other Kinds of Simple Machines"

Visually Scan Pages 229-234; focus on the blue boxes, which contain the key vocabulary terms.

Visually Scan Pages 229-234 for pictures and diagrams, read each of the captions.

Visually Scan for an read the short articles and questions in the blue boxes that you find on Pages 229-234.

Read Pages 229-233 (take notes of important ideas)

Do you know the answers to the questions on page 234? (See Key Points below for help)

Do you know the vocabulary words? (See Key Points below for help)

Take the quiz on Lesson 6 "Some Other Kinds of Simple Machines" (You may use the book, notes and Key Points for help on the quizzes. NOT ON TESTS!)

Review answers on the quiz and print it out. This will be very useful when you are studying for the test.

 

Lesson 6 Key Points

Vocabulary Terms

Pulley - a simple machine made up of a rope, chain, or belt wrapped around a wheel.

inclined plane - a simple machine made up of a ramp, used to lift an object.

screw - a simple machine made up of an inclined plane wrapped around a straight piece of metal.

Wedge - a simple machine made up of an inclined plane or pair of inclined planes that are moved.

Wheel and axle - a simple machine made up of a wheel attached to a shaft.

 

Section Review Answers

  1. A fixed pulley is a simple machine consisting of a rope, chain, or belt around a wheel.
  2. A fixed pulley rotates but does not move up or down and has a MA of 1. A movable pulley is free to move up or down and increases MA by the number of wheels used.
  3. A MA = 2; B MA = 1
  4. Having two ropes that pull upward on a movable pulley system doubles the mechanical advantage; MA = 2.
  5. An inclined plane is a ramp used to lift objects.
  6. You can find the MA of an inclined plane by dividing the running length of the slanted surface by the vertical height.
  7. Screws and wedges are both variations of an inclined plane.
  8. The screw with closely spaced threads will have a greater MA because its inclined plane is longer and has a more gradual slope.
  9. A thin, gradual wedge will have a greater MA because each of its inclined planes is longer, with a more gradual slope.
  10. A bus usually has a larger steering wheel because the mechanical advantage is increased to handle the larger mass of the bus.

Did you learn these Objectives?

Can you explain how pulleys work and how to estimate their mechanical advantage?

Can you explain how inclined planes work and how to estimate their mechanical advantage?

Are you able to explain how screws work and relate them to inclined planes?

Are you able to explain how wedges work and relate them to inclined planes?

Are you able to explain how wheels and axles work?

 Preparing for Chapter 8 Test

Turn to Page 235 and read the Chapter 8 summary.

On pages 236-237 you will find the Chapter 8 review, complete the review.

Check your answers with those in the Key Points.

Take the Chapter 8 Test "Work and Machines"

Review the answers then print the results for your records.

 

Chapter 8 Review answers

  1. potential energy, kinetic energy
  2. energy
  3. effort force
  4. law of conservation of energy
  5. joule
  6. C
  7. D
  8. B
  9. A
  10. D
  11. C
  12. B
  13. A first-class lever appears in the diagram. You can tell because the fulcrum lies between the effort force and the resistance.
  14. Examples of three simple machines may include any three of these: wheel and axle, screw, wedge, inclined plane, lever, pulley. Machines multiply force of change the direction of a force to make work easier. Some machines increase the distance or speed the resistance will move.

 

Congratulations you finished the eighth chapter !!