Unit 3, Chapter 9 CPO Science Foundations of Physics Chapter 9.
Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.
-
Upload
bryce-fletcher -
Category
Documents
-
view
253 -
download
4
Transcript of Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.
![Page 1: Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.](https://reader033.fdocuments.net/reader033/viewer/2022061610/56649ceb5503460f949b6881/html5/thumbnails/1.jpg)
Unit 2, Chapter 5
CPO ScienceFoundations of Physics
Chapter 9Chapter 9
![Page 2: Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.](https://reader033.fdocuments.net/reader033/viewer/2022061610/56649ceb5503460f949b6881/html5/thumbnails/2.jpg)
Unit 2: Motion and Force in One Dimension
5.1 The First Law: Force and Inertia5.2 The Second Law: Force, Mass, and Acceleration
5.3 The Third Law: Action and Reaction
Chapter 5: Newton's Laws: Force and Motion
![Page 3: Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.](https://reader033.fdocuments.net/reader033/viewer/2022061610/56649ceb5503460f949b6881/html5/thumbnails/3.jpg)
Chapter 5 Objectives1. Describe how the law of inertia affects the motion of
an object.2. Give an example of a system or invention designed to
overcome inertia.3. Measure and describe force in newtons (N) and
pounds (lbs).4. Calculate the net force for two or more forces acting
along the same line.5. Calculate the acceleration of an object from the net
force acting on it.6. Determine whether an object is in equilibrium by
analyzing the forces acting on it.7. Draw a diagram showing an action-reaction pair of
forces.8. Determine the reaction force when given an action
force.
![Page 4: Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.](https://reader033.fdocuments.net/reader033/viewer/2022061610/56649ceb5503460f949b6881/html5/thumbnails/4.jpg)
Chapter 5 Vocabulary Terms
force inertia law of inertia Newton’s first law net force dynamic
equilibrium
static Newton’s second
law locomotion newton (N) action reaction Newton’s third law
![Page 5: Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.](https://reader033.fdocuments.net/reader033/viewer/2022061610/56649ceb5503460f949b6881/html5/thumbnails/5.jpg)
5.1 The First Law: Force and Inertia
Key Question:
How does the first law apply to objects at rest and in motion?
*Students read Section 5.1 BEFORE Investigation 5.1
![Page 6: Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.](https://reader033.fdocuments.net/reader033/viewer/2022061610/56649ceb5503460f949b6881/html5/thumbnails/6.jpg)
5.1 Force Force is an action that can change
motion.— A force is what we call a push or a pull,
or any action that has the ability to change an object’s motion.
— Forces can be used to increase the speed of an object, decrease the speed of an object, or change the direction in which an object is moving.
![Page 7: Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.](https://reader033.fdocuments.net/reader033/viewer/2022061610/56649ceb5503460f949b6881/html5/thumbnails/7.jpg)
5.1 Inertia Inertia is a term used to measure the ability of an
object to resist a change in its state of motion. An object with a lot of inertia takes a lot of force
to start or stop; an object with a small amount of inertia requires a small amount of force to start or stop.
The word “inertia” comes from the Latin word inertus, which can be translated to mean “lazy.”
![Page 8: Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.](https://reader033.fdocuments.net/reader033/viewer/2022061610/56649ceb5503460f949b6881/html5/thumbnails/8.jpg)
5.1 Newton's First Law
Can you explain why the long table would make the trick hard to do?
![Page 9: Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.](https://reader033.fdocuments.net/reader033/viewer/2022061610/56649ceb5503460f949b6881/html5/thumbnails/9.jpg)
![Page 10: Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.](https://reader033.fdocuments.net/reader033/viewer/2022061610/56649ceb5503460f949b6881/html5/thumbnails/10.jpg)
5.2 Newton's Second Law
The acceleration of an object is equal to the force you apply divided by the mass of the object.
![Page 11: Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.](https://reader033.fdocuments.net/reader033/viewer/2022061610/56649ceb5503460f949b6881/html5/thumbnails/11.jpg)
5.2 Newton's Second Law
If you apply more force to an object, it accelerates at a higher rate.
![Page 12: Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.](https://reader033.fdocuments.net/reader033/viewer/2022061610/56649ceb5503460f949b6881/html5/thumbnails/12.jpg)
5.2 Newton's Second Law
If an object has more mass it accelerates at a lower rate because mass has inertia.
![Page 13: Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.](https://reader033.fdocuments.net/reader033/viewer/2022061610/56649ceb5503460f949b6881/html5/thumbnails/13.jpg)
5.2 Newton's Second Law
a = F m
Force (newtons, N)
Mass (kg)
Acceleration (m/sec2)
![Page 14: Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.](https://reader033.fdocuments.net/reader033/viewer/2022061610/56649ceb5503460f949b6881/html5/thumbnails/14.jpg)
![Page 15: Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.](https://reader033.fdocuments.net/reader033/viewer/2022061610/56649ceb5503460f949b6881/html5/thumbnails/15.jpg)
5.2 Newton's Second Law
Three forms of the second law:
![Page 16: Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.](https://reader033.fdocuments.net/reader033/viewer/2022061610/56649ceb5503460f949b6881/html5/thumbnails/16.jpg)
5.2 Calculate acceleration
A cart rolls down a ramp.
The cart has a mass of 500 grams (0.5 kg).
Using a spring scale, you measure a net force of 2 newtons pulling the car down.
Calculate the acceleration of the cart.
![Page 17: Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.](https://reader033.fdocuments.net/reader033/viewer/2022061610/56649ceb5503460f949b6881/html5/thumbnails/17.jpg)
5.2 Calculate acceleration
Three people are pulling on a wagon applying forces of 100 N,150 N, and 200 N.
The wagon has a mass of 25 kilograms. Determine the acceleration and the
direction the wagon moves.
![Page 18: Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.](https://reader033.fdocuments.net/reader033/viewer/2022061610/56649ceb5503460f949b6881/html5/thumbnails/18.jpg)
5.2 Calculate force
An airplane needs to accelerate at 5 m/sec2 to reach take-off speed before reaching the end of the runway.
The mass of the airplane is 5,000 kilograms.
How much force is needed from the engine?
![Page 19: Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.](https://reader033.fdocuments.net/reader033/viewer/2022061610/56649ceb5503460f949b6881/html5/thumbnails/19.jpg)
5.2 Calculate force A tennis ball contacts the racquet
for much less than one second. High-speed photographs show
that the speed of the ball changes from -30 to +30 m/sec in 0.006 seconds.
If the mass of the ball is 0.2 kg, how much force is applied by the racquet?
![Page 20: Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.](https://reader033.fdocuments.net/reader033/viewer/2022061610/56649ceb5503460f949b6881/html5/thumbnails/20.jpg)
5.2 Equilibrium The condition of zero acceleration
is called equilibrium. In equilibrium, all forces cancel
out leaving zero net force. Objects that are standing still are
in equilibrium because their acceleration is zero.
Objects that are moving at constant speed and direction are also in equilibrium.
A static problem usually means there is no motion.
![Page 21: Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.](https://reader033.fdocuments.net/reader033/viewer/2022061610/56649ceb5503460f949b6881/html5/thumbnails/21.jpg)
5.2 Calculate force A woman is holding
two dogs on a leash. If each dog pulls
with a force of 80 newtons, how much force does the woman have to exert to keep the dogs from moving?
![Page 22: Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.](https://reader033.fdocuments.net/reader033/viewer/2022061610/56649ceb5503460f949b6881/html5/thumbnails/22.jpg)
5.2 The Second Law:Force, Mass, and AccelerationKey Question: What is the relationship between force, mass, and
acceleration?
*Students read Section 5.2
BEFORE Investigation 5.2
![Page 23: Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.](https://reader033.fdocuments.net/reader033/viewer/2022061610/56649ceb5503460f949b6881/html5/thumbnails/23.jpg)
5.3 Newton's Third Law
“For every action there is an equal and opposite reaction.”
This statement is known as Newton’s third law of motion.
Newton’s third law discusses pairs of objects and the interactions between them.
![Page 24: Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.](https://reader033.fdocuments.net/reader033/viewer/2022061610/56649ceb5503460f949b6881/html5/thumbnails/24.jpg)
5.3 Newton's Third Law The astronauts working on the space station have a
serious problem when they need to move around in space: There is nothing to push on.
The solution is to throw something opposite the direction you want to move.
This works because all forces always come in pairs.
![Page 25: Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.](https://reader033.fdocuments.net/reader033/viewer/2022061610/56649ceb5503460f949b6881/html5/thumbnails/25.jpg)
![Page 26: Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.](https://reader033.fdocuments.net/reader033/viewer/2022061610/56649ceb5503460f949b6881/html5/thumbnails/26.jpg)
5.3 Calculate force
Three people are each applying 250 newtons of force to try to move a heavy cart.
The people are standing on a rug. Someone nearby notices that the rug is slipping. How much force must be applied to the rug to keep it
from slipping? Sketch the action and reaction forces acting between
the people and the cart and between the people and the rug.
![Page 27: Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.](https://reader033.fdocuments.net/reader033/viewer/2022061610/56649ceb5503460f949b6881/html5/thumbnails/27.jpg)
5.3 Newton's Third Law
Locomotion is the act of moving or the ability to move from one place to another.
![Page 28: Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.](https://reader033.fdocuments.net/reader033/viewer/2022061610/56649ceb5503460f949b6881/html5/thumbnails/28.jpg)
5.3 The Third Law: Action and Reaction
Key Question:
Can you identify action-reaction forces?
*Students read Section 5.3 BEFORE Investigation 5.3
![Page 29: Unit 2, Chapter 5 CPO Science Foundations of Physics Chapter 9.](https://reader033.fdocuments.net/reader033/viewer/2022061610/56649ceb5503460f949b6881/html5/thumbnails/29.jpg)
Application: Biomechanics