CHAPTER 4 SECTIONS 1 & 2 Work, Power and Machines.
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Transcript of CHAPTER 4 SECTIONS 1 & 2 Work, Power and Machines.
![Page 1: CHAPTER 4 SECTIONS 1 & 2 Work, Power and Machines.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649ecf5503460f94bdd3bd/html5/thumbnails/1.jpg)
CHAPTER 4 SECTIONS 1 & 2
Work, Power and
Machines
![Page 2: CHAPTER 4 SECTIONS 1 & 2 Work, Power and Machines.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649ecf5503460f94bdd3bd/html5/thumbnails/2.jpg)
1. What is work?
• A. The type of energy that a moving object has
• B. The rate at which work is done or energy is transformed
• C. The unit used to express power• D. The transfer of energy using a force that causes an object to move in the direction of the force
![Page 3: CHAPTER 4 SECTIONS 1 & 2 Work, Power and Machines.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649ecf5503460f94bdd3bd/html5/thumbnails/3.jpg)
ANSWER:
•Work is…•D. The transfer of energy using a force that causes an object to move in the direction of the force
![Page 4: CHAPTER 4 SECTIONS 1 & 2 Work, Power and Machines.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649ecf5503460f94bdd3bd/html5/thumbnails/4.jpg)
2. What is power?
• A. The type of energy that a moving object has
• B. The rate at which work is done or energy is transformed
• C. The unit used to express power• D. The transfer of energy using a force that causes an object to move in the direction of the force
![Page 5: CHAPTER 4 SECTIONS 1 & 2 Work, Power and Machines.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649ecf5503460f94bdd3bd/html5/thumbnails/5.jpg)
ANSWER
•Power is…•B. The rate at which work is done or energy is transformed
![Page 6: CHAPTER 4 SECTIONS 1 & 2 Work, Power and Machines.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649ecf5503460f94bdd3bd/html5/thumbnails/6.jpg)
3. What is kinetic energy?
• A. The type of energy that a moving object
has• B. The rate at which work is done or energy is transformed
• C. The unit used to express power• D. The transfer of energy using a force that causes an object to move in the direction of the force
![Page 7: CHAPTER 4 SECTIONS 1 & 2 Work, Power and Machines.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649ecf5503460f94bdd3bd/html5/thumbnails/7.jpg)
ANSWER
•Kinetic energy is …•A. The type of energy that a moving object has
![Page 8: CHAPTER 4 SECTIONS 1 & 2 Work, Power and Machines.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649ecf5503460f94bdd3bd/html5/thumbnails/8.jpg)
4. What is a machine?
• A. The type of energy that a moving object
has• B. The rate at which work is done or energy is
transformed• C. A device that helps do work by either overcoming a force or changing the direction of the force
• D. The transfer of energy using a force that causes an object to move in the direction of the force
![Page 9: CHAPTER 4 SECTIONS 1 & 2 Work, Power and Machines.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649ecf5503460f94bdd3bd/html5/thumbnails/9.jpg)
ANSWER
•A machine is…•C. A device that helps do work by either overcoming a force or changing the direction of the force
![Page 10: CHAPTER 4 SECTIONS 1 & 2 Work, Power and Machines.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649ecf5503460f94bdd3bd/html5/thumbnails/10.jpg)
5. What is work input?
•A. A number that tells how many times a machine multiplies a force
•B. A quantity, usually expressed as a percentage, that measures the ratio of work output to work input
•C. The work done ON a machine•D. The work done BY a machine
![Page 11: CHAPTER 4 SECTIONS 1 & 2 Work, Power and Machines.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649ecf5503460f94bdd3bd/html5/thumbnails/11.jpg)
ANSWER
•Work input is…•C. The work done ON a machine
![Page 12: CHAPTER 4 SECTIONS 1 & 2 Work, Power and Machines.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649ecf5503460f94bdd3bd/html5/thumbnails/12.jpg)
6. What is work output?
•A. A number that tells how many times a machine multiplies a force
•B. A quantity, usually expressed as a percentage, that measures the ratio of work output to work input
•C. The work done ON a machine•D. The work done BY a machine
![Page 13: CHAPTER 4 SECTIONS 1 & 2 Work, Power and Machines.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649ecf5503460f94bdd3bd/html5/thumbnails/13.jpg)
ANSWER
•Work output is…• D. The work done BY a machine
![Page 14: CHAPTER 4 SECTIONS 1 & 2 Work, Power and Machines.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649ecf5503460f94bdd3bd/html5/thumbnails/14.jpg)
7. What is mechanical advantage?
•A. A number that tells how many times a machine multiplies a force
•B. A quantity, usually expressed as a percentage, that measures the ratio of work output to work input
•C. The work done ON a machine•D. The work done BY a machine
![Page 15: CHAPTER 4 SECTIONS 1 & 2 Work, Power and Machines.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649ecf5503460f94bdd3bd/html5/thumbnails/15.jpg)
ANSWER
Mechanical advantage is…•A. A number that tells how many times a machine multiplies a force
![Page 16: CHAPTER 4 SECTIONS 1 & 2 Work, Power and Machines.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649ecf5503460f94bdd3bd/html5/thumbnails/16.jpg)
8. What is mechanical efficiency?
•A. A number that tells how many times a machine multiplies a force
•B. A quantity, usually expressed as a percentage, that measures the ratio of work output to work input
•C. The work done ON a machine•D. The work done BY a machine
![Page 17: CHAPTER 4 SECTIONS 1 & 2 Work, Power and Machines.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649ecf5503460f94bdd3bd/html5/thumbnails/17.jpg)
ANSWER
Mechanical efficiency is…•B. A quantity, usually expressed as a percentage, that measures the ratio of work output to work input
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9. In which situation is a person doing work on an object?
• A. A school crossing guard raises a stop
sign that weighs 10 N.• B. A student walks while wearing a
backpack that weighs 15 N.• C. A man exerts 350 N force on a rope
attached to a house.• D. A worker holds a box 1 m off the floor.
![Page 19: CHAPTER 4 SECTIONS 1 & 2 Work, Power and Machines.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649ecf5503460f94bdd3bd/html5/thumbnails/19.jpg)
ANSWER
•A. A school crossing guard raises a stop sign that weighs 10 N.
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10. Scott applies a force of 100 N to move a box 5 meters. How much work did he do?
•A. 100 J•B. 500 J•C. 5 J•D. 500 N
![Page 21: CHAPTER 4 SECTIONS 1 & 2 Work, Power and Machines.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649ecf5503460f94bdd3bd/html5/thumbnails/21.jpg)
ANSWER
•B. 500 J
![Page 22: CHAPTER 4 SECTIONS 1 & 2 Work, Power and Machines.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649ecf5503460f94bdd3bd/html5/thumbnails/22.jpg)
11. If a barbell weighs 160 N, what other information do you need to calculate how much work it takes to lift it?
• A. The shape of the weights• B. The height the barbell is being lifted• C. The strength of the person doing the
lifting• D. The amount of output force
![Page 23: CHAPTER 4 SECTIONS 1 & 2 Work, Power and Machines.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649ecf5503460f94bdd3bd/html5/thumbnails/23.jpg)
ANSWER
•B. The height the barbell is being lifted
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12. Tom used 75 N of force to push a box 3 m across the floor. How much work did he do?
a. 25 J
b. 25 N
c. 225 J
d. 225 W
![Page 25: CHAPTER 4 SECTIONS 1 & 2 Work, Power and Machines.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649ecf5503460f94bdd3bd/html5/thumbnails/25.jpg)
ANSWER
75 N x 3 m =
c. 225 J
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13. Which of the following prevents machines from being 100% efficient?
a. friction
b. input force
c. output force
d. power
![Page 27: CHAPTER 4 SECTIONS 1 & 2 Work, Power and Machines.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649ecf5503460f94bdd3bd/html5/thumbnails/27.jpg)
ANSWER
a. friction
![Page 28: CHAPTER 4 SECTIONS 1 & 2 Work, Power and Machines.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649ecf5503460f94bdd3bd/html5/thumbnails/28.jpg)
GOOD LUCK ON TUESDAY!!
STUDY HARD!!
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