# Physics. Chapter 9 Gravity

Save this PDF as:

Size: px
Start display at page:

## Transcription

1 Physics Chapter 9 Gravity

2 The Newtonian Synthesis Gravity is a Universal Force

3 The Newtonian Synthesis According to legend, Newton discovered gravity while sitting under an apple tree.

4 The Falling Moon If the Moon did not fall, it would move off in a straight line.

5 The Falling Moon Original drawing by Newton: Shows how a projectile fired fast enough would fall around Earth and become an Earth satellite.

6 The Falling Moon Tangential velocity is the sideways velocity the component of velocity perpendicular to the pull of gravity.

7 Newton s Apple-Moon Test For Newton s idea to advance from hypothesis to scientific theory, it would have to be tested.

8 Newton s Apple-Moon Test An apple falls 5 m during its first second of fall when it is near Earth s surface. Newton asked how far the moon would fall in the same time if it were 60 times farther from the center of Earth.

9 The Falling Moon If the force that pulls apples off trees also pulls the moon into orbit, the circle of the moon s orbit should fall 1.4 mm below a point along the straight line where the moon would otherwise be one second later.

10 The Falling Earth Newton s theory of gravity confirmed the Copernican Theory of the solar system. The tangential velocity of Earth about the Sun allows it to fall around it rather than directly into it.

11 Newton s Law of Universal Gravitation Every object attracts every other object with a force that for any two objects is directly proportional to the mass of each object. That the force decreases as the SQUARE of the distance between the centers of mass of the objects increases.

12 Newton s Law of Universal Gravitation

13 Newton s Law of Universal Gravitation

14 The Universal Gravitational Constant, G The universal gravitational constant, G, in the equation for universal gravitation describes the strength of gravity.

15 The Universal Gravitational Constant, G Philipp von Jolly developed a method of measuring the attraction between two masses.

16 The Universal Gravitational Constant, G The value of G tells us that gravity is a very weak force. It is the weakest of the presently known four fundamental forces. We sense gravitation only when masses like that of Earth are involved.

17 The Mass of the Earth Cavendish s first measure of G was called the Weighing the Earth experiment. Mass of Earth m 1 = kilograms.

18 The Mass of the Earth

19 Understanding Gravity Gravity decreases according to the inverse-square law. The force of gravity weakens as the square of distance.

20 Gravity & Distance: The Inverse Square Law

21 Gravity & Distance: The Inverse Square Law d F R 10 N 2R ¼ (10 N) 3R (1/9) (10 N) 4R (1/16) (10 N) When a quantity varies as the inverse square of its distance from its source, it follows an inverse-square law.

22 Gravity & Distance: Inverse Square Law Q: At what distance will the gravitational force become zero? A: You are always affected! No matter how far away you go, Earth s gravitational influence extends through ALL space!

23 Gravity and Distance: Inverse Square Law

24 Check Question Suppose that an apple at the top of a tree is pulled by Earth s gravity with a force of 1 N. If the tree were twice as tall, would the force of gravity on the apple be only 1/4 as strong? Explain your answer.

25 Check Question Calculate the resulting force of gravitational attraction between two masses if one of the masses was to double and the distance between them was to triple.

26 Gravitational Field Newton himself couldn t understand how two objects could exert force over a distance. Moon and Earth are not in contact. It s hard to imagine a force reaching out through nothingness?

27 Gravitational Field Field lines can also represent the pattern of Earth s gravitational field. ΣF = F g ma = mg a = g

28 Finding Surface Gravity We now have two equations for the force of gravity on an object here on earth. Let s set these two equal to each other and solve for g...

29 Finding Surface Gravity To solve for the gravity on any planet at a point in space:

30 Check Question Calculate the surface gravity of the Moon. The Moon has a mass of 7.36 x kilograms and a radius of 1.74 x 10 6 meters.

31 Tangential Orbital Velocity Consider a satellite of mass m orbiting a central body, M. Can you see that the gravitational force is a centripetal force? M v F g m Let s equate the two and then solve for orbital speed: F g = F c...

32 Tangential Orbital Velocity M v F g m M is the mass of a planet or star. Note that m is missing! The speed of an orbiting satellite does not depend on its own mass!

33 Check Question A satellite orbiting at a speed of v and a radius of r above the center of a planet climbs to a radius 2r. What is the satellite s new orbital speed?

34 Gravitational Field Inside a Planet The gravitational field of Earth exists inside Earth as well as outside. Imagine a hole drilled completely through Earth. Consider the kind of motion you would undergo if you fell into such a hole.

35 Gravitational Field You would oscillate back and forth, approximating simple harmonic motion. Each round trip would take nearly 90 minutes. Interestingly enough, we will see in the next chapter that an Earth satellite in close orbit about Earth also takes the same 90 minutes to make a complete round trip.

36 Gravity and Distance: Inverse Square Law

37 Gravitational Field

38 Weight and Weightlessness The force of gravity, like any force, causes acceleration. Objects under the influence of gravity are pulled toward each other and accelerate. We are almost always in contact with Earth, so we think of gravity as something that presses us against Earth rather than as something that accelerates us.

39 Weight and Weightlessness

40 Weight and Weightlessness Rather than define your weight as the force of gravity that acts on you, it is more practical to define weight as the force you exert against a supporting floor. According to this definition, you are as heavy as you feel. The condition of weightlessness is not the absence of gravity, but the absence of a support force.

41 Weight and Weightlessness Both people are without a support force and therefore experience weightlessness.

42 Weight and Weightlessness Exactly how much less gravity does an astronaut experience than we do on the surface?

43 Ocean Tides Newton showed that the ocean tides are caused by differences in the gravitational pull of the moon on opposite sides of Earth.

44 Ocean Tides This difference in pulls across Earth slightly elongates it. The oceans bulge out about 1 meter on average, on opposite sides of Earth. Because Earth spins once per day, a fixed point on Earth passes beneath both of these bulges each day, producing two sets of ocean tides per day two high tides and two low tides.

45 Factors Affecting Ocean Tides The sun also contributes to ocean tides. Its pull on Earth is 180 times greater than the moon s pull on Earth, so why aren t solar tides 180 times greater than lunar tides? The difference in gravitational pulls by the sun on opposite sides of Earth is very small.

46 Spring Tides When the sun, the moon, and Earth are aligned, spring tides occur.

47 Neap Tides When the attractions of the sun and the moon are at right angles to each other (at the time of a half moon), neap tides occur.

48 Ocean Tides The tilt of Earth s axis, interfering landmasses, friction with the ocean bottom, and other factors complicate tidal motions.

49 Ocean Tides - Question Why does the gravitation pull of the moon create almost no tide in a lake? The moon produces scarcely any tides in a lake because no part of the lake is significantly closer to the moon than any other part this means there is no significant difference in the moon s pull on different parts of the lake.

50 Einstein s Theory of Gravitation In the early 20 th century, Einstein realized something else about gravity: Gravity is a dent, a bend or a curve in space-time.

51 Black Holes Two main processes go on continuously in stars like our sun. Gravitation tends to crush all solar material toward the center. Thermonuclear fusion, consisting of reactions similar to those in a hydrogen bomb, tends to blow solar material outward. When the processes of gravitation and thermonuclear fusion balance each other, the result is the sun of a given size.

52 Black Holes The size of the sun is the result of a tug of war between two opposing processes: nuclear fusion and gravitational contraction.

53 Black Holes If the fusion rate increases, the sun will get hotter and bigger. If the fusion rate decreases, the sun will get cooler and smaller. When the sun runs out of fusion fuel (hydrogen), gravitation will dominate and the sun will start to collapse.

54 Black Holes For a star that is at least two to three times more massive than our sun, once the flame of thermonuclear fusion is extinguished, gravitational collapse takes over and it doesn t stop! The star caves in on itself and the atoms that compose the star cave in on themselves until there are no empty spaces. The density becomes infinite near these black holes. Even light cannot escape a black hole.

55 Black Holes Suppose you are on a star and you are indestructible: F = 10,000 N F = 40,000 N R ½ R

56 Gravitational Field Around Black Holes A black hole is no more massive than the star from which it collapsed. The gravitational field near the black hole may be enormous but the field beyond the original radius of the star is no different after collapse than before. The amount of mass has not changed, so there is no change in the field at any point beyond this distance.

57 Gravitational Field Near Black Holes The gravitational field strength near a giant star that collapses to become a black hole is the same before collapse (left) and after collapse (right).

58 Black Holes The gravitational field around a black hole is usually represented as a warped two-dimensional surface.

59 Universal Gravitation The Earth is round because of gravitation. Since everything attracts everything else, Earth had attracted itself together before it became solid. The sun, the moon, and Earth are all fairly spherical because they have to be.

60 Universal Gravitation Gravity played a role in the formation of the solar system.

61 Universal Gravitation If everything pulls on everything else, then the planets must pull on each other. The net force that controls Jupiter, for example, is not just from the sun, but from the planets also. Their effect is small compared with the pull of the more massive sun, but it still shows. The deviation of an orbiting object from its path caused by the action of an additional center of force is called a perturbation.

62 Universal Gravitation The shapes of distant galaxies provide further evidence that the law of gravity applies to larger distances. According to current scientific understanding, the universe originated and grew from a tiny singularity, inflating rapidly over the next 13.7 billion years to become the cosmos we know today. This is the Big Bang theory of the origin of the universe.

63 Problems Earth, with its mass of 5.98 x 1024 kg pulls a 60-kilogram person downward with a force of 600 N. With what force does the person pull on the earth?

64 Problems A satellite of mass m orbits Earth at a height of h and a speed of v. What would the speed be for a satellite of mass 3m at a height of h?

65 Problems Determine the acceleration of gravity, in terms of g, at a point in space that is located a distance equal to two Earth radii (2r E ) above the surface of Earth, shown in the figure above.

66 Problems A very large star of mass M and radius r undergoes a transformation into a neutron star. Assume that the mass remains constant while the radius of the star becomes 1/1000 its original size, (1x10-3 )r. How does the change in the radius of the star affect the force of gravity, Fg, acting between the star and a planet that is orbiting the star?

67 Problems What would the surface gravity be on a planet with three times the mass of Earth and a radius twice that of Earth?

68 Problems The gravitational force of attraction between two masses is 16 newtons. If the distance between the masses is quadrupled, what is the resulting force of attraction?

### Chapter 3 - Gravity and Motion. Copyright (c) The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Chapter 3 - Gravity and Motion Copyright (c) The McGraw-Hill Companies, Inc. Permission required for reproduction or display. In 1687 Isaac Newton published the Principia in which he set out his concept

### Conceptual Physics Fundamentals

Conceptual Physics Fundamentals Chapter 6: GRAVITY, PROJECTILES, AND SATELLITES This lecture will help you understand: The Universal Law of Gravity The Universal Gravitational Constant, G Gravity and Distance:

### 7.4 Universal Gravitation

Circular Motion Velocity is a vector quantity, which means that it involves both speed (magnitude) and direction. Therefore an object traveling at a constant speed can still accelerate if the direction

### 2010 Pearson Education, Inc. Chapter 4 Making Sense of the Universe: Understanding Motion, Energy, and Gravity

Chapter 4 Making Sense of the Universe: Understanding Motion, Energy, and Gravity 4.1 Describing Motion: Examples from Daily Life Some of the topics we will explore: How do we describe motion? (Speed,

### Chapter 9 Lecture. Pearson Physics. Gravity and Circular Motion. Prepared by Chris Chiaverina Pearson Education, Inc.

Chapter 9 Lecture Pearson Physics Gravity and Circular Motion Prepared by Chris Chiaverina Chapter Contents Newton's Law of Universal Gravity Applications of Gravity Circular Motion Planetary Motion and

### Gravitation. Objectives. The apple and the Moon. Equations 6/2/14. Describe the historical development of the concepts of gravitational force.

Gravitation Objectives Describe the historical development of the concepts of gravitational force. Describe and calculate how the magnitude of the gravitational force between two objects depends on their

### Gravity & The Distances to Stars. Lecture 8. Homework 2 open Exam on Tuesday in class bring ID and #2 pencil

1 Gravity & The Distances to Stars Lecture 8 Homework 2 open Exam on Tuesday in class bring ID and #2 pencil 2 Preparing for the Exam 1 Exams in this class are multiple choice, but the questions can be

### Copyright 2010 Pearson Education, Inc. GRAVITY. Chapter 12

GRAVITY Chapter 12 Units of Chapter 12 Newton s Law of Universal Gravitation Gravitational Attraction of Spherical Bodies Kepler s Laws of Orbital Motion Gravitational Potential Energy Energy Conservation

### g = Gm / r 2 The Big Idea

The Big Idea Over 2500 years ago Aristotle proposed two laws of physics governing motion. One for Earthly bodies (objects on Earth) that states objects naturally go in straight lines and one for Heavenly

### AP Physics-B Universal Gravitation Introduction: Kepler s Laws of Planetary Motion: Newton s Law of Universal Gravitation: Performance Objectives:

AP Physics-B Universal Gravitation Introduction: Astronomy is the oldest science. Practical needs and imagination acted together to give astronomy an early importance. For thousands of years, the motions

### End-of-Chapter Exercises

End-of-Chapter Exercises Exercises 1 12 are primarily conceptual questions that are designed to see if you have understood the main concepts of the chapter. Treat all balls with mass as point masses. 1.

### Nm kg. The magnitude of a gravitational field is known as the gravitational field strength, g. This is defined as the GM

Copyright FIST EDUCATION 011 0430 860 810 Nick Zhang Lecture 7 Gravity and satellites Newton's Law of Universal Gravitation Gravitation is a force of attraction that acts between any two masses. The gravitation

### AP Physics Multiple Choice Practice Gravitation

AP Physics Multiple Choice Practice Gravitation 1. Each of five satellites makes a circular orbit about an object that is much more massive than any of the satellites. The mass and orbital radius of each

### Quest Chapter 12. What things did Newton bring together and what did he toss? Read the text or check your notes. How does the moon move?

1 What is the Newtonian synthesis? 1. All objects near the Earth free-fall with the same acceleration. 2. The combination of forces on each planet directed towards the Sun 3. The combination of all forces

### PSI AP Physics C Universal Gravity Multiple Choice Questions

PSI AP Physics C Universal Gravity Multiple Choice Questions 1. Who determined the value of the gravitational constant (G)? (A) Newton (B) Galileo (C) Einstein (D) Schrödinger (E) Cavendish 2. Who came

### Science Unit Test Grade: 8 Unit 6: Gravity

Science Unit Test Grade: 8 Unit 6: Gravity Name Date 1. Which of these is best used to measure weight in newtons? a. Spring scale b. Triple beam balance c. Double pan balance d. Simple lever 2. Which of

### Newton's Laws. Before Isaac Newton

Newton's Laws Before Isaac Newton Newton's Laws There were facts and laws about the way the physical world worked, but no explanations After Newton There was a unified system that explained those facts

### = v = 2πr. = mv2 r. = v2 r. F g. a c. F c. Text: Chapter 12 Chapter 13. Chapter 13. Think and Explain: Think and Solve:

NAME: Chapters 12, 13 & 14: Universal Gravitation Text: Chapter 12 Chapter 13 Think and Explain: Think and Explain: Think and Solve: Think and Solve: Chapter 13 Think and Explain: Think and Solve: Vocabulary:

### 12-Feb-18. Newton's Laws. Newton's Laws. Prelude to Newton's Laws

Newton's Laws Newton's Laws Before Isaac Newton There were facts and laws about the way the physical world worked, but no explanations After Newton There was a unified system that explained those facts

### Where do objects get their energy?

Where do objects get their energy? Energy makes matter move. Energy is always 'conserved' Conservation of Energy Energy can neither be created nor destroyed The total energy content of the universe was

### How do we describe motion?

Chapter 4 Making Sense of the Universe: Understanding Motion, Energy, and Gravity How do we describe motion? Precise definitions to describe motion: Speed: Rate at which object moves \$ speed = distance!#"units

### 4.1 Describing Motion. How do we describe motion? Chapter 4 Making Sense of the Universe: Understanding Motion, Energy, and Gravity

Chapter 4 Making Sense of the Universe: Understanding Motion, Energy, and Gravity 4.1 Describing Motion Our goals for learning: How do we describe motion? How is mass different from weight? How do we describe

### Chapter 5 Circular Motion; Gravitation

Chapter 5 Circular Motion; Gravitation Units of Chapter 5 Kinematics of Uniform Circular Motion Dynamics of Uniform Circular Motion Highway Curves, Banked and Unbanked Nonuniform Circular Motion Centrifugation

### Proficient. a. The gravitational field caused by a. The student is able to approximate a numerical value of the

Unit 6. Circular Motion and Gravitation Name: I have not failed. I've just found 10,000 ways that won't work.-- Thomas Edison Big Idea 1: Objects and systems have properties such as mass and charge. Systems

### AP Physics QUIZ Gravitation

AP Physics QUIZ Gravitation Name: 1. If F1 is the magnitude of the force exerted by the Earth on a satellite in orbit about the Earth and F2 is the magnitude of the force exerted by the satellite on the

### Experiencing Acceleration: The backward force you feel when your car accelerates is caused by your body's inertia. Chapter 3.3

Experiencing Acceleration: The backward force you feel when your car accelerates is caused by your body's inertia. Chapter 3.3 Feeling of apparent weight: Caused your body's reaction to the push that the

### Circular Motion and Gravitation Notes 1 Centripetal Acceleration and Force

Circular Motion and Gravitation Notes 1 Centripetal Acceleration and Force This unit we will investigate the special case of kinematics and dynamics of objects in uniform circular motion. First let s consider

### Chapter 5 Part 2. Newton s Law of Universal Gravitation, Satellites, and Weightlessness

Chapter 5 Part 2 Newton s Law of Universal Gravitation, Satellites, and Weightlessness Newton s ideas about gravity Newton knew that a force exerted on an object causes an acceleration. Most forces occurred

### How do we describe motion?

Chapter 4 Making Sense of the Universe: Understanding Motion, Energy, and Gravity How do we describe motion? Precise definitions to describe motion: Speed: Rate at which object moves example: speed of

### N t ew on L s aws Monday, February 2

Newton s Laws Monday, February Isaac Newton (1643-177): English Discovered: three laws of motion, one law of universal gravitation. Newton s great book: Newton s laws are universal in scope, and mathematical

### Unit 3 Lesson 2 Gravity and the Solar System. Copyright Houghton Mifflin Harcourt Publishing Company

Florida Benchmarks SC.8.N.1.4 Explain how hypotheses are valuable if they lead to further investigations, even if they turn out not to be supported by the data. SC.8.N.1.5 Analyze the methods used to develop

Please turn on your clickers HW #1, due 1 week from today Quiz in class Wednesday Sections meet in Planetarium Honors meeting tonight in my office Sterling 5520 at 5:30-6pm Newton s First Law An object

### Gravity: What s the big attraction? Dan Wilkins Institute of Astronomy

Gravity: What s the big attraction? Dan Wilkins Institute of Astronomy Overview What is gravity? Newton and Einstein What does gravity do? Extreme gravity The true power of gravity Getting things moving

### Physics Mechanics Lecture 30 Gravitational Energy

Physics 170 - Mechanics Lecture 30 Gravitational Energy Gravitational Potential Energy Gravitational potential energy of an object of mass m a distance r from the Earth s center: Gravitational Potential

### AP Physics C Textbook Problems

AP Physics C Textbook Problems Chapter 13 Pages 412 416 HW-16: 03. A 200-kg object and a 500-kg object are separated by 0.400 m. Find the net gravitational force exerted by these objects on a 50.0-kg object

### The force of gravity holds us on Earth and helps objects in space stay

96 R E A D I N G The force of gravity holds us on Earth and helps objects in space stay in orbit. The planets in the Solar System could not continue to orbit the Sun without the force of gravity. Astronauts

### When you walk around, you are stuck to the ground. You can jump up. You always come back down. Why is this?

Gravity When you walk around, you are stuck to the ground. You can jump up. You always come back down. Why is this? Isaac Newton was a scientist. He saw that planets go around the sun. He saw how things

### Understanding Motion, Energy & Gravity

Speed, Velocity & Acceleration Understanding Motion, Energy & Gravity Chapter 4 speed: distance traveled per unit time (e.g., m/s, mph, km/ hr) velocity: speed & direction acceleration: change in velocity

### 4.2. The Normal Force, Apparent Weight and Hooke s Law

4.2. The Normal Force, Apparent Weight and Hooke s Law Weight The weight of an object on the Earth s surface is the gravitational force exerted on it by the Earth. When you weigh yourself, the scale gives

### Newton s Law of Universal Gravitation

SECTION 2 Plan and Prepare Preview Vocabulary Scientific Meanings Parabola is a geometric term that is widely used in many scientific and technical fields. A parabola is an open curve generated by intersecting

### Agenda Announce: 4.1 Describing Motion. Tests. How do we describe motion?

Chapter 4 Making Sense of the Universe: Understanding Motion, Energy, and Gravity Agenda Announce: Stony Brook talk this Friday on Precision Cosmology Project Part I due in one week before class: one paragraph

### Describing Motion. Newton Newton s Laws of Motion. Position Velocity. Acceleration. Key Concepts: Lecture 9

Key Concepts: Lecture 9 Newton Newton s Laws of Motion More on Kepler s Laws Describing Motion Position Velocity Rate of change of position (speed & direction) 80 km/hr Acceleration 40 km/hr Rate of change

### 4.3 Conservation Laws in Astronomy

4.3 Conservation Laws in Astronomy Our goals for learning: Why do objects move at constant velocity if no force acts on them? What keeps a planet rotating and orbiting the Sun? Where do objects get their

### Lunar Eclipse. Solar Eclipse

Lunar Eclipse SUN Moon Solar Eclipse SUN SUN Moon Total solar eclipse Partial solar eclipse Moon Phases What does the moon look like from at each position? G H F A E B D C SUNLIGHT Refracting Telescopes

### Gravitational and Electric Forces. chapter 3

Gravitational and Electric Forces chapter 3 95 What is Gravitational Force? Standard 3: Students will understand the factors determining the strength of gravitational and electric forces. Standard 3, Objective

### Centripetal force keeps an Rotation and Revolution

Centripetal force keeps an object in circular motion. Which moves faster on a merry-go-round, a horse near the outside rail or one near the inside rail? While a hamster rotates its cage about an axis,

### Gravitation. Luis Anchordoqui

Gravitation Kepler's law and Newton's Synthesis The nighttime sky with its myriad stars and shinning planets has always fascinated people on Earth. Towards the end of the XVI century the astronomer Tycho

### FORCE. The 4 Fundamental Forces of Nature

FORCE - Force a push or pull. Results only from interaction with another object. Without interaction, forces cannot be present. - Measured in Newtons (N) 1 Newton is the amount of force required to give

### Ch Forces & Motion. Forces can: 1. Cause a resting object to move 2. Accelerate a moving object (by changing speed or direction)

Ch. 12 - Forces & Motion Force --> a push or a pull that acts on an object Forces can: 1. Cause a resting object to move 2. Accelerate a moving object (by changing speed or direction) Force is measured

### Slide 1 / The discovery of Universal Gravitation is associated with: Robert Hook Isaac Newton James Joule Max Plank Christian Huygens

Slide 1 / 22 1 The discovery of Universal Gravitation is associated with: Robert Hook Isaac Newton James Joule Max Plank hristian Huygens Slide 2 / 22 2 Two objects with equal masses of 1 kg each are separated

### AY2 Winter 2017 Midterm Exam Prof. C. Rockosi February 14, Name and Student ID Section Day/Time

AY2 Winter 2017 Midterm Exam Prof. C. Rockosi February 14, 2017 Name and Student ID Section Day/Time Write your name and student ID number on this printed exam, and fill them in on your Scantron form.

### ASTR 200 : Lecture 30. More Gravity: Tides, GR, and Gravitational Waves

ASTR 200 : Lecture 30 More Gravity: Tides, GR, and Gravitational Waves 1 Topic One : Tides Differential tidal forces on the Earth. 2 How do tides work???? Think about 3 billiard balls sitting in space

### Chapter 8. Dynamics II: Motion in a Plane

Chapter 8. Dynamics II: Motion in a Plane Chapter Goal: To learn how to solve problems about motion in a plane. Slide 8-2 Chapter 8 Preview Slide 8-3 Chapter 8 Preview Slide 8-4 Chapter 8 Preview Slide

### Chapter: The Laws of Motion

Table of Contents Chapter: The Laws of Motion Section 1: Newton s Second Law Section 2: Gravity Section 3: The Third Law of Motion 1 Newton s Second Law Force, Mass, and Acceleration Newton s first law

### Lesson 9. Luis Anchordoqui. Physics 168. Tuesday, October 24, 17

Lesson 9 Physics 168 1 Static Equilibrium 2 Conditions for Equilibrium An object with forces acting on it but that is not moving is said to be in equilibrium 3 Conditions for Equilibrium (cont d) First

Question 8.1: the following: (a) You can shield a charge from electrical forces by putting it inside a hollow conductor. Can you shield a body from the gravitational influence of nearby matter by putting

### How do we describe motion?

Chapter 4 Making Sense of the Universe: Understanding Motion, Energy, and Gravity If I have seen farther than others, it is because I have stood on the shoulders of giants. Sir Isaac Newton (1642 1727)

Study Island Copyright 2014 Edmentum - All rights reserved. Generation Date: 04/03/2014 Generated By: Cheryl Shelton Title: Grade 8 Earth & Space Science 1. Astronomers classify galaxies by their shape.

### TIDES. n What are tides? The periodic rise and fall of the sea level under the gravitational pull of the moon. n Tides are one of the most

Tides TIDES What are tides? The periodic rise and fall of the sea level under the gravitational pull of the moon Tides are one of the most reliable phenomena in the world. As the sun rises in the east

### 4. As you increase your push, will friction on the crate increase also? Ans. Yes it will.

Ch. 4 Newton s Second Law of Motion p.65 Review Questions 3. How great is the force of friction compared with your push on a crate that doesn t move on a level floor? Ans. They are equal in magnitude and

### Forces, Momentum, & Gravity. Force and Motion Cause and Effect. Student Learning Objectives 2/16/2016

Forces, Momentum, & Gravity (Chapter 3) Force and Motion Cause and Effect In chapter 2 we studied motion but not its cause. In this chapter we will look at both force and motion the cause and effect. We

### Can you shield a body from the gravitational influence of nearby matter by putting it inside a hollow sphere or by some other means?

Question 8.1: the following: You can shield a charge from electrical forces by putting it inside a hollow conductor. Can you shield a body from the gravitational influence of nearby matter by putting it

### Chapter 12 Forces and Motion

Chapter 12 Forces and Motion GOAL: Students will be able to interpret and apply Newton s three laws of motion and analyze the motion of an object in terms of its position, velocity, and acceleration. Standard:

### CIRCULAR MOTION AND GRAVITATION

CIRCULAR MOTION AND GRAVITATION An object moves in a straight line if the net force on it acts in the direction of motion, or is zero. If the net force acts at an angle to the direction of motion at any

### 12/1/2014. Chapter 5 Circular Motion; Gravitation. Contents of Chapter 5. Contents of Chapter Kinematics of Uniform Circular Motion

Lecture PowerPoints Chapter 5 Physics: Principles with Applications, 7 th edition Giancoli Chapter 5 Circular Motion; Gravitation This work is protected by United States copyright laws and is provided

### Mass and Weight. Aren t they the same? 19/05/2016. cgrahamphysics.com 2016

Mass and Weight Aren t they the same? Starter One of Four Which of these are the units of speed? meters 0 C miles m/s Which of these are the units of speed? meters 0 C miles m/s Which of these has the

### The Solar System CHAPTER 6. Vocabulary. star an object in space that makes its own light and heat. moon an object that circles around a planet

CHAPTER 6 The Solar System Vocabulary star an object in space that makes its own light and heat moon an object that circles around a planet Sun astronomical unit the distance between Earth and the Sun

### 5. Forces and Free-Body Diagrams

5. Forces and Free-Body Diagrams A) Overview We will begin by introducing the bulk of the new forces we will use in this course. We will start with the weight of an object, the gravitational force near

### IF A NUCLEUS IS FULL OF POSITIVELY CHARGED PROTONS, WHY DOESN T IT FLY APART?

IF A NUCLEUS IS FULL OF POSITIVELY CHARGED PROTONS, WHY DOESN T IT FLY APART? An introduction to the fundamental forces that control our world. Remembering that like charges repel each other, you may have

### TEACHER BACKGROUND INFORMATION FORCE

TEACHER BACKGROUND INFORMATION FORCE WHAT IS FORCE? Force is anything that can change the state of motion of a body. In simpler terms, force is a push or a pull. For example, wind pushing on a flag is

### /////// ///////////// Module ONE /////////////// ///////// Space

// // / / / / //// / ////// / /// / / // ///// ////// ////// Module ONE Space 1 Gravity Knowledge and understanding When you have finished this chapter, you should be able to: define weight as the force

### Classical mechanics: conservation laws and gravity

Classical mechanics: conservation laws and gravity The homework that would ordinarily have been due today is now due Thursday at midnight. There will be a normal assignment due next Tuesday You should

### 3 Newton s First Law of Motion Inertia. Forces cause changes in motion.

Forces cause changes in motion. A ball at rest in the middle of a flat field is in equilibrium. No net force acts on it. If you saw it begin to move across the ground, you d look for forces that don t

### Selected Questions from Minute Papers. Outline - March 2, Stellar Properties. Stellar Properties Recap. Stellar properties recap

Black Holes: Selected Questions from Minute Papers Will all the material in the Milky Way eventually be sucked into the BH at the center? Does the star that gives up mass to a BH eventually get pulled

### Chapter 5. Preview. Section 1 Measuring Motion. Section 2 What Is a Force? Section 3 Friction: A Force That Opposes Motion

Matter in Motion Preview Section 1 Measuring Motion Section 2 What Is a Force? Section 3 Friction: A Force That Opposes Motion Section 4 Gravity: A Force of Attraction Concept Mapping Section 1 Measuring

### 1 A Solar System Is Born

CHAPTER 16 1 A Solar System Is Born SECTION Our Solar System California Science Standards 8.2.g, 8.4.b, 8.4.c, 8.4.d BEFORE YOU READ After you read this section, you should be able to answer these questions:

### Version 001 circular and gravitation holland (2383) 1

Version 00 circular and gravitation holland (383) This print-out should have 9 questions. Multiple-choice questions may continue on the next column or page find all choices before answering. AP B 993 MC

### MOTION IN THE SOLAR SYSTEM ENGAGE, EXPLORE, EXPLAIN

MOTION IN THE SOLAR SYSTEM ENGAGE, EXPLORE, EXPLAIN ENGAGE THE ATTRACTION TANGO THE ATTRACTION TANGO In your science journal, on the next clean page, title the page with The Attraction Tango. In your group,

### PHYSICS. Chapter 8 Lecture FOR SCIENTISTS AND ENGINEERS A STRATEGIC APPROACH 4/E RANDALL D. KNIGHT Pearson Education, Inc.

PHYSICS FOR SCIENTISTS AND ENGINEERS A STRATEGIC APPROACH 4/E Chapter 8 Lecture RANDALL D. KNIGHT Chapter 8. Dynamics II: Motion in a Plane IN THIS CHAPTER, you will learn to solve problems about motion

### SAMPLE First Midterm Exam

Astronomy 1000 Dr C. Barnbaum SAMPLE First Midterm Exam Note: This is a sample exam. It is NOT the exam you will take. I give out sample exams so that you will have an understanding of the depth of knowledge

### Tides Supplement. Brian Arbic

Tides Supplement Brian Arbic OVERVIEW QUESTIONS What causes the tides? How is a lunar day different from a solar day? Which body creates a larger tidal influence on Earth: the Moon or the Sun? How do the

### Earth in Space. Guide for Reading How does Earth move in space? What causes the cycle of seasons on Earth?

Earth in Space How does Earth move in space? What causes the cycle of seasons on Earth? The study of the moon, stars, and other objects in space is called astronomy. Ancient astronomers studied the movements

### What path do the longest sparks take after they leave the wand? Today we ll be doing one more new concept before the test on Wednesday.

What path do the longest sparks take after they leave the wand? Today we ll be doing one more new concept before the test on Wednesday. Centripetal Acceleration and Newtonian Gravitation Reminders: 15

### 16 Relativity Momentum, Mass, Energy, and Gravity

According to special relativity, mass and energy are equivalent. According to general relativity, gravity causes space to become curved and time to undergo changes. One of the most celebrated outcomes

### ASTR 150. Planetarium Shows begin Sept 9th. Register your iclicker! Last time: The Night Sky Today: Motion and Gravity. Info on course website

Planetarium Shows begin Sept 9th Info on course website Register your iclicker! Last time: The Night Sky Today: Motion and Gravity ASTR 150 Hang on tight! Most math all semester-- get it over with right

### Practice Test for Midterm Exam

A.P. Physics Practice Test for Midterm Exam Kinematics 1. Which of the following statements are about uniformly accelerated motion? Select two answers. a) If an object s acceleration is constant then it

### Astronomy Hour Exam 2 March 10, 2011 QUESTION 1: The half-life of Ra 226 (radium) is 1600 years. If you started with a sample of 100 Ra 226

Astronomy 101.003 Hour Exam 2 March 10, 2011 QUESTION 1: The half-life of Ra 226 (radium) is 1600 years. If you started with a sample of 100 Ra 226 atoms, approximately how many Ra 226 atoms would be left

### GRAVITATIONAL FORCE NEAR EARTH

GRAVITATIONAL FORCE NEAR EARTH Recap: Gravitational Force Field Recall that gravity is an action-at-adistance force that pulls on objects (regardless of their size or mass) without making any contact with

### A force is could described by its magnitude and by the direction in which it acts.

8.2.a Forces Students know a force has both direction and magnitude. P13 A force is could described by its magnitude and by the direction in which it acts. 1. Which of the following could describe the

### Astronomy Unit Notes Name:

Astronomy Unit Notes Name: (DO NOT LOSE!) To help with the planets order 1 My = M 2 V = Venus 3 Eager = E 4 M = Mars 5 Just = J 6 Served = Saturn 7 Us = Uranus 8 N = N 1 Orbit: The path (usually elliptical)

### Newton s Laws of Motion. Newton s Second Law

Newton s Laws of Motion What is the reason for Kepler s three descriptive laws? Newton s Law of Gravity Modern view of Kepler s Laws 1 & 3 can be derived from Newton s laws of motion Emmy Noether: 2 can

### Basic Physics Content

Basic Physics Content The purpose of these 38 questions is to let me know what your initial grasp is of the material that lies ahead. This is not graded, so don t stress out. Enjoy thinking about and answering

### POGIL: Newton s First Law of Motion and Statics. Part 1: Net Force Model: Read the following carefully and study the diagrams that follow.

POGIL: Newton s First Law of Motion and Statics Name Purpose: To become familiar with the forces acting on an object at rest Part 1: Net Force Model: Read the following carefully and study the diagrams

### 3 Newton s First Law of Motion Inertia. Forces cause changes in motion.

Forces cause changes in motion. A ball at rest in the middle of a flat field is in equilibrium. No net force acts on it. If you saw it begin to move across the ground, you d look for forces that don t

### 9/13/ Describing Motion: Examples from Everyday Life. Chapter 4: Making Sense of the Universe Understanding Motion, Energy, and Gravity

9/13/17 Lecture Outline 4.1 Describing Motion: Examples from Everyday Life Chapter 4: Making Sense of the Universe Understanding Motion, Energy, and Gravity Our goals for learning: How do we describe motion?

### Isaac Newton was a British scientist whose accomplishments

E8 Newton s Laws of Motion R EA D I N G Isaac Newton was a British scientist whose accomplishments included important discoveries about light, motion, and gravity. You may have heard the legend about how

### They developed a graph, called the H-R diagram, that relates the temperature of a star to its absolute magnitude.

Ejnar Hertzsprung and Henry Russell noticed that stars with higher temperatures and large sizes also have brighter absolute magnitudes the actual amount of light given off by a star. (also referred to

### TEACHER BACKGROUND INFORMATION

TEACHER BACKGROUND INFORMATION (The Universe) A. THE UNIVERSE: The universe encompasses all matter in existence. According to the Big Bang Theory, the universe was formed 10-20 billion years ago from a