newton’s second law coach dave edinger j. c. booth middle school physical science (8a) mrs. coach...
TRANSCRIPT
![Page 1: Newton’s Second Law Coach Dave Edinger J. C. Booth Middle School Physical Science (8A) Mrs. Coach Ed R-O-C-K-S !!!](https://reader035.vdocuments.us/reader035/viewer/2022062423/56649c915503460f9494bfcb/html5/thumbnails/1.jpg)
Newton’s Second Law
Coach Dave EdingerJ. C. Booth Middle
SchoolPhysical Science (8A)
Mrs. Coach
Ed
R-O-C-K-S !!!
![Page 2: Newton’s Second Law Coach Dave Edinger J. C. Booth Middle School Physical Science (8A) Mrs. Coach Ed R-O-C-K-S !!!](https://reader035.vdocuments.us/reader035/viewer/2022062423/56649c915503460f9494bfcb/html5/thumbnails/2.jpg)
Newton’s 1st law REVIEW
Summarize what the law states.
What does an object at rest need for it to move?
What is another name for Newton’s first law of motion?
What is inertia?
What causes a moving object to stop moving?
The (more/less) mass an object has, the harder it is to move.
The (more/less) mass an object has, the easier it is to move.
![Page 3: Newton’s Second Law Coach Dave Edinger J. C. Booth Middle School Physical Science (8A) Mrs. Coach Ed R-O-C-K-S !!!](https://reader035.vdocuments.us/reader035/viewer/2022062423/56649c915503460f9494bfcb/html5/thumbnails/3.jpg)
NEWTON’S second law
The acceleration of an object depends on the mass of the object and the amount of force applied.
VOLUNTEERS!!!!!TWO “pushers” of similar sizeONE small 8th graderONE big 8th grader
![Page 4: Newton’s Second Law Coach Dave Edinger J. C. Booth Middle School Physical Science (8A) Mrs. Coach Ed R-O-C-K-S !!!](https://reader035.vdocuments.us/reader035/viewer/2022062423/56649c915503460f9494bfcb/html5/thumbnails/4.jpg)
Part 1: Acceleration depends on massAcceleration of an object
decreases as its mass increases.
Acceleration of an object increases as its mass decreases.
Which would be easier to push?
WHY?
![Page 5: Newton’s Second Law Coach Dave Edinger J. C. Booth Middle School Physical Science (8A) Mrs. Coach Ed R-O-C-K-S !!!](https://reader035.vdocuments.us/reader035/viewer/2022062423/56649c915503460f9494bfcb/html5/thumbnails/5.jpg)
Part 2: Acceleration depends on forceAcceleration of an object increases
as the force on it increases
Acceleration of an object decreases as the force on it decreases
VOLUNTEERS!!!!!
ONE to sit in chairONE to push chair
![Page 6: Newton’s Second Law Coach Dave Edinger J. C. Booth Middle School Physical Science (8A) Mrs. Coach Ed R-O-C-K-S !!!](https://reader035.vdocuments.us/reader035/viewer/2022062423/56649c915503460f9494bfcb/html5/thumbnails/6.jpg)
Newton’s law with MATH
Formula: Force = mass • acceleration
UNITS
accleration: m/s² (meters per second squared)
force: N (Newtons)mass: kg
(kilograms)
F
m a
![Page 7: Newton’s Second Law Coach Dave Edinger J. C. Booth Middle School Physical Science (8A) Mrs. Coach Ed R-O-C-K-S !!!](https://reader035.vdocuments.us/reader035/viewer/2022062423/56649c915503460f9494bfcb/html5/thumbnails/7.jpg)
Tricky…tricky….
You don’t use Newtons to find acceleration in this formula
1 N = 1 kg∙m/s²
So…4 N = 4 kg∙m/s²And….500 N = 500 kg∙m/s²
And 395 N = ?
![Page 8: Newton’s Second Law Coach Dave Edinger J. C. Booth Middle School Physical Science (8A) Mrs. Coach Ed R-O-C-K-S !!!](https://reader035.vdocuments.us/reader035/viewer/2022062423/56649c915503460f9494bfcb/html5/thumbnails/8.jpg)
Newton and math exampleMass of apple: 0.102kgForce: 1N
What is the acceleration?
![Page 9: Newton’s Second Law Coach Dave Edinger J. C. Booth Middle School Physical Science (8A) Mrs. Coach Ed R-O-C-K-S !!!](https://reader035.vdocuments.us/reader035/viewer/2022062423/56649c915503460f9494bfcb/html5/thumbnails/9.jpg)
Newton and math exampleMass of apple: 0.102kgForce: 1N
What is the acceleration?a = F/m
![Page 10: Newton’s Second Law Coach Dave Edinger J. C. Booth Middle School Physical Science (8A) Mrs. Coach Ed R-O-C-K-S !!!](https://reader035.vdocuments.us/reader035/viewer/2022062423/56649c915503460f9494bfcb/html5/thumbnails/10.jpg)
Newton and math exampleMass of apple: 0.102kgForce: 1N
What is the acceleration?a = F/m
a = 1N / 0.102kg
![Page 11: Newton’s Second Law Coach Dave Edinger J. C. Booth Middle School Physical Science (8A) Mrs. Coach Ed R-O-C-K-S !!!](https://reader035.vdocuments.us/reader035/viewer/2022062423/56649c915503460f9494bfcb/html5/thumbnails/11.jpg)
Newton and math exampleMass of apple: 0.102kgForce: 1N
What is the acceleration?a = F/m
a = 1N / 0.102kga= 1 kg∙m/s² / 0.102kg
a= 9.8 m/s2
![Page 12: Newton’s Second Law Coach Dave Edinger J. C. Booth Middle School Physical Science (8A) Mrs. Coach Ed R-O-C-K-S !!!](https://reader035.vdocuments.us/reader035/viewer/2022062423/56649c915503460f9494bfcb/html5/thumbnails/12.jpg)
Practice
What is the acceleration of a 7kg mass if a force of 68.6 N is used to move the mass?
a = F / m
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Practice
What is the acceleration of a 7kg mass if a force of 68.6 N is used to move it toward earth?
a = F / ma = 68.6 N / 7 kg
![Page 14: Newton’s Second Law Coach Dave Edinger J. C. Booth Middle School Physical Science (8A) Mrs. Coach Ed R-O-C-K-S !!!](https://reader035.vdocuments.us/reader035/viewer/2022062423/56649c915503460f9494bfcb/html5/thumbnails/14.jpg)
Practice
What is the acceleration of a 7kg mass if a force of 68.6 N is used to move it toward earth?
a = F / ma = 68.6 N / 7 kg
a = 68.6 kg • m/s2 / 7 kg
![Page 15: Newton’s Second Law Coach Dave Edinger J. C. Booth Middle School Physical Science (8A) Mrs. Coach Ed R-O-C-K-S !!!](https://reader035.vdocuments.us/reader035/viewer/2022062423/56649c915503460f9494bfcb/html5/thumbnails/15.jpg)
Practice
What is the acceleration of a 7kg mass if a force of 68.6 N is used to move it toward earth?
a = F / ma = 68.6 N / 7 kg
a = 68.6 kg • m/s2 / 7 kga = 9.8 m/s2
![Page 16: Newton’s Second Law Coach Dave Edinger J. C. Booth Middle School Physical Science (8A) Mrs. Coach Ed R-O-C-K-S !!!](https://reader035.vdocuments.us/reader035/viewer/2022062423/56649c915503460f9494bfcb/html5/thumbnails/16.jpg)
Practice
What is the acceleration of a 7kg mass if a force of 68.6 N is used to move it toward earth?
a = F / ma = 68.6 N / 7 kg
a = 68.6 kg • m/s2 / 7 kga = 9.8 m/s2
![Page 17: Newton’s Second Law Coach Dave Edinger J. C. Booth Middle School Physical Science (8A) Mrs. Coach Ed R-O-C-K-S !!!](https://reader035.vdocuments.us/reader035/viewer/2022062423/56649c915503460f9494bfcb/html5/thumbnails/17.jpg)
Practice
What is the acceleration of a 7kg mass if a force of 68.6 N is used to move it toward earth?
a = F / ma = 68.6 N / 7 kg
a = 68.6 kg • m/s2 / 7 kga = 9.8 m/s2
![Page 18: Newton’s Second Law Coach Dave Edinger J. C. Booth Middle School Physical Science (8A) Mrs. Coach Ed R-O-C-K-S !!!](https://reader035.vdocuments.us/reader035/viewer/2022062423/56649c915503460f9494bfcb/html5/thumbnails/18.jpg)
Challenge question
What force is necessary to accelerate a 1,250kg car at a rate of 40 m/s² ?
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Challenge question
What force is necessary to accelerate a 1,250kg car at a rate of 40 m/s² ?
F = ma
![Page 20: Newton’s Second Law Coach Dave Edinger J. C. Booth Middle School Physical Science (8A) Mrs. Coach Ed R-O-C-K-S !!!](https://reader035.vdocuments.us/reader035/viewer/2022062423/56649c915503460f9494bfcb/html5/thumbnails/20.jpg)
Challenge question
What force is necessary to accelerate a 1,250kg car at a rate of 40 m/s² ?
F = maF = 1250 kg • 40 m/s2
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Challenge question
What force is necessary to accelerate a 1,250kg car at a rate of 40 m/s² ?
F = maF = 1250 kg • 40 m/s2
F = 50,000 kg • m/s2
![Page 22: Newton’s Second Law Coach Dave Edinger J. C. Booth Middle School Physical Science (8A) Mrs. Coach Ed R-O-C-K-S !!!](https://reader035.vdocuments.us/reader035/viewer/2022062423/56649c915503460f9494bfcb/html5/thumbnails/22.jpg)
Challenge question
What force is necessary to accelerate a 1,250kg car at a rate of 40 m/s² ?
F = maF = 1250 kg • 40 m/s2
F = 50,000 kg • m/s2
F = 50,000 N
![Page 23: Newton’s Second Law Coach Dave Edinger J. C. Booth Middle School Physical Science (8A) Mrs. Coach Ed R-O-C-K-S !!!](https://reader035.vdocuments.us/reader035/viewer/2022062423/56649c915503460f9494bfcb/html5/thumbnails/23.jpg)
Another challenging question
Zookeepers carry a stretcher that holds a sleeping lion. The total mass of the lion and the stretcher is 175 kg. The lion’s forward acceleration is 2 m/s². What is the force necessary to produce this acceleration?
![Page 24: Newton’s Second Law Coach Dave Edinger J. C. Booth Middle School Physical Science (8A) Mrs. Coach Ed R-O-C-K-S !!!](https://reader035.vdocuments.us/reader035/viewer/2022062423/56649c915503460f9494bfcb/html5/thumbnails/24.jpg)
Another challenging question
Zookeepers carry a stretcher that holds a sleeping lion. The total mass of the lion and the stretcher is 175 kg. The lion’s forward acceleration is 2 m/s². What is the force necessary to produce this acceleration?
F = ma
![Page 25: Newton’s Second Law Coach Dave Edinger J. C. Booth Middle School Physical Science (8A) Mrs. Coach Ed R-O-C-K-S !!!](https://reader035.vdocuments.us/reader035/viewer/2022062423/56649c915503460f9494bfcb/html5/thumbnails/25.jpg)
Another challenging question
Zookeepers carry a stretcher that holds a sleeping lion. The total mass of the lion and the stretcher is 175 kg. The lion’s forward acceleration is 2 m/s². What is the force necessary to produce this acceleration?
F = maF = 175 kg • 2 m/s2
![Page 26: Newton’s Second Law Coach Dave Edinger J. C. Booth Middle School Physical Science (8A) Mrs. Coach Ed R-O-C-K-S !!!](https://reader035.vdocuments.us/reader035/viewer/2022062423/56649c915503460f9494bfcb/html5/thumbnails/26.jpg)
Another challenging question
Zookeepers carry a stretcher that holds a sleeping lion. The total mass of the lion and the stretcher is 175 kg. The lion’s forward acceleration is 2 m/s². What is the force necessary to produce this acceleration?
F = maF = 175 kg • 2 m/s2
F = 350 kg • m/s2
![Page 27: Newton’s Second Law Coach Dave Edinger J. C. Booth Middle School Physical Science (8A) Mrs. Coach Ed R-O-C-K-S !!!](https://reader035.vdocuments.us/reader035/viewer/2022062423/56649c915503460f9494bfcb/html5/thumbnails/27.jpg)
Another challenging question
Zookeepers carry a stretcher that holds a sleeping lion. The total mass of the lion and the stretcher is 175 kg. The lion’s forward acceleration is 2 m/s². What is the force necessary to produce this acceleration?
F = maF = 175 kg • 2 m/s2
F = 350 kg • m/s2
F = 350 N