Lesson 14: Friction. a) Fill in the table that follows by constructing a force diagram for the block (the system) for these five situations.
|
|
- Bernadette Chambers
- 6 years ago
- Views:
Transcription
1 Lesson 14: Friction 14.1 Observe and Find a Pattern Perform the following experiment: Rest a wooden block (or some other object, like your shoe) on a table. Attach a large spring scale to a string attached to the front of the block. Pull the scale harder and harder. Notice what happens to the scale reading while the block does not move. Notice the reading right before the block starts moving and right after. Keep the block moving but not accelerating. a) Fill in the table that follows by constructing a force diagram for the block (the system) for these five situations. The block sits on the table with no scale pulling it. The spring pulls on the block, which does not start moving. harder, but the block still does not move. on the block, and the block is just about to start moving. the block at a slow, constant velocity. b) Describe in words how the magnitude of the force that the table s surface exerts on the block varies with the force exerted by the spring pulling on the block. c) Compare the magnitude of the force just before the block starts moving to the magnitude when it is moving at a constant velocity. What do you observe? d) What object is exerting this friction force for the scenarios given above? e) Summarize your findings for the friction force exerted on an object at rest and on the same object moving at a constant velocity. Did You Know? The friction force is a resistive force exerted by the surface on an object. There are two kinds of friction forces you observed in the experiments above. The static friction force is variable. As you saw, once the maximum static friction force is overcome, the object will start to move. The kinetic friction force is the resistive force exerted on a moving object. 67
2 14.2 Observe and Find a Pattern Instead of the block in the previous activity, you have rectangular blocks with different surface areas and different types of surfaces on which the block slides horizontally. The force that the string exerts on the block (as measured by the spring scale reading) when the block just starts to slide is recorded in the table that follows. This force is equal in magnitude to the maximum static friction force (as we discovered in the previous activity). Examine the data in the table that follows. Mass of the block Surface area Quality of Maximum surfaces static friction force 1 kg 0.1 m 2 Medium smooth 3.1 N 1 kg 0.2 m 2 Medium smooth 3.0 N 1 kg 0.3 m 2 Medium smooth 3.1 N 1 kg 0.1 m 2 A little rougher 4.2 N 1 kg 0.1 m 2 Even rougher 5.1 N 1 kg 0.1 m 2 Roughest 7.0 N Now decide how the maximum static friction force that the surface exerts on the block depends on the surface area of the block and on the roughness of the two surfaces Observe and Find a Pattern A spring scale pulls a 1 kg block over a medium smooth surface. The reading of the scale can be used to determine the magnitude of the maximum static friction force in this instance, the force when the block starts to slide. In some experiments, a compressible spring also pushes vertically down on the block (see the second block). Spring pushes down Use the data in the table to draw a graph of the maximum static friction force versus the normal force the surface exerts on the block. Extra downward force exerted on the 1-kg block 1 kg 1 kg Normal force exerted by the board on the block 0 N 10 N 3 N 5 N 15 N 4.5 N 10 N 20 N 6 N 20 N 30 N 9 N Maximum static friction force 68
3 b) Express mathematically a relationship between the normal force and the maximum static friction force Test your idea Design an experiment to test that the magnitude of the maximum static friction force is equal to f s surface on object = µn surface on object. Describe what you will do, what data you will collect and what the predicted outcome should be if the expression is correct. Then perform the experiment and make a judgment about the hypothesis Reason a) Take a textbook and drag it with your pinky finger. Repeat but this time have your neighbor push down lightly on the book. Repeat 3 more times with your neighbor pushing down successively harder. Draw a force diagram for each case. What can you say about the maximum static friction force? b) Consider the previous activity. Why would we consider the normal force exerted on the object rather than the force of Earth exerted on the object? c) A person is holding a book against a vertical wall, pushing on it horizontally. The book is at rest. Draw a force diagram for the book. Check if all forces balance. Which force prevents the book from falling down? Why, if you do not push on the book hard enough, does the book start falling? Did You Know? When two objects touch each other, they exert a normal force on each other. In physics it is customary to break the force that each exerts on the other into two forces a force perpendicular to the surfaces and the force parallel to the surfaces. Normal force: This is the perpendicular component of the total force that one object exerts on the other object. it points perpendicular to the surface of contact. Often one symbol N is used to denote this force (do not confuse with the Newton, N). There is no equation for calculating the normal force. Its magnitude must be determined for each situation by some other method. Static friction force: The parallel component of the force that two objects exert on each other is called a friction force. The friction force of the one object on the other object points parallel to the surfaces of contact. If the objects are not moving with respect to each other, the friction force that they exert on each other is static. The static friction force between two surfaces opposes the tendency of one surface to move across the other and provides flexible resistance (as much as is needed) to prevent motion up to some maximum value. This maximum static friction force depends on the relative roughness of the surfaces (on the coefficient of static friction s between the surfaces) and on the magnitude of the normal force N between the surfaces. The magnitude of the static friction force is always less than or equal to the product of these two quantities: F s surface on object = µ s N 69
4 Kinetic friction force: The kinetic friction force between two surfaces is exerted parallel to the surfaces and opposes the motion of one surface relative to the other surface. The kinetic friction force depends on the relative roughness of the surfaces (on the coefficient of kinetic friction k ) and on the magnitude of the normal force N between the surfaces: F k surface on object = µ k N 14.6 Design an Experiment Use Phet simulations apply your understanding of friction forces. Go to Forces in 1 Dimension. This time do not turn off Friction. Choose three objects and design experiments that will allow you to determine what coefficient of static and kinetic friction the programmers who write the simulation used. Write a report in which you will describe the experiments and explain how you used the results to determine the coefficients. Do your results make sense? Did the programmers use the knowledge of Newton s laws and friction forces to write the program? 14.7 Observe and Represent Homework Imagine that you could watch yourself walk in slow motion. Analyze your steps in terms of the force of friction that the floor exerts on your foot and in terms of Newton s Second and Third Laws. In order to do this, break the step into two parts: (1) when you put the foot down to finish up the previous step, and (2) when you are pushing off the floor to start a new step. Draw force diagrams to represent your reasoning Evaluate Jamie says that the force of friction is something that we should reduce in order to make the cars go faster. What friction force could she mean? Do you agree or disagree with her opinion? If you agree, how would you argue for it? If you disagree, how would you argue against it? 14.9 Represent and Reason Some students are trying to move a heavy desk across the room. Diana pushes it across the floor at the same time that Omar and Jeff pull on it. Omar pulls on the desk, exerting a (-150) N force, and Jeff pulls exerting a (-125) N force. There is also a (-200) N friction force exerted by the floor on the desk. The net force exerted on the desk is 27 N. a) Make a sketch of the situation. b) Draw a force diagram for the desk. Draw a motion diagram. c) Write an algebraic statement that describes the force diagram you drew. d) How hard is Diana pushing? e) Is the desk moving with a constant velocity or is it speeding up? How do you know? 70
5 f) What would happen if, after a few seconds, the boys stopped pulling? Regular problem According to Auto Week magazine, a Chevrolet Blazer traveling at 60 mph (97 km/h) can stop in 48 m on a level road. Determine the coefficient of friction between the tires and the road. Do you think this is kinetic or static friction? Explain Regular Problem A 50-kg box rests on the floor. The coefficients of static and kinetic friction between the bottom of the box and the floor are 0.70 and 0.50, respectively. (a) What is the minimum force a person needs to exert on it to start the box sliding? (b) After the box starts sliding, the person continues to push it exerting the same force. What is the acceleration of the box? Reason A car is moving to the right increasingly faster. A leaf is on the back vertical side of the car and does not slide down. Explain how this can be Regular problem The Ford P2000 fuel cell car has a mass of 1520-kg. While it is traveling at 20 m/s, the driver applies the brakes to stop the car on a wet surface with a 0.40 coefficient of friction. (a) How far does the car travel before stopping? (b) If a different car with the mass 1.5 times as much as the mass of the Ford P2000 is on the road traveling at the same speed and the coefficient of friction between the road and the tires is the same, what will its stopping distance be? Does the answer make sense to you? Reason Compare the ease of pulling a lawn mower and pushing it. In particular, in which case is the friction force that the grass exerts on the mower greater? (a) The same. (b) Pulling is easier. (c) Pushing is easier. (d) Not enough information to answer. 71
Friction Can Be Rough
9.1 Observe and Find a Pattern Friction Can Be Rough Perform the following experiment: Rest a brick on a rough surface. Tie a string around the brick and attach a large spring scale to it. Pull the scale
More informationFriction Can Be Rough
10.1 Observe and Find a Pattern Friction Can Be Rough Observe the following experiment: Rest a brick on a rough surface. Tie a string around the brick and attach a large spring scale to it. Pull the scale
More informationFriction Can Be Rough
8.1 Observe and Find a Pattern Friction Can Be Rough Perform the following experiment: Rest a brick on a rough surface. Tie a string around the brick and attach a large spring scale to it. Pull the scale
More informationThe spring pulls harder, but the block still does not move.
PUM Physics II - Dynamics Lesson 14 Solutions Page 1 of 8 14.1 Observe and Find a Pattern a) The block sits on the table with no scale pulling it. The spring pulls on the block, which does not start moving.
More information2. Kinetic friction - The force that acts against an object s motion. - Occurs once static friction has been overcome and object is moving
Section 2.14: Friction Friction is needed to move. Without friction, a car would sit in one spot spinning its tires, and a person would not be able to step forward. However, the motion of an object along
More information+F N = -F g. F g = m٠a g
Force Normal = F N Force Normal (or the Normal Force, abbreviated F N ) = F N = The contact force exerted by a surface on an object. The word Normal means perpendicular to Therefore, the Normal Force is
More informationDynamics; Newton s Laws of Motion
Dynamics; Newton s Laws of Motion Force A force is any kind of push or pull on an object. An object at rest needs a force to get it moving; a moving object needs a force to change its velocity. The magnitude
More informationThere are two main types of friction:
Section 4.15: Friction Friction is needed to move. Without friction, a car would sit in one spot spinning its tires, and a person would not be able to step forward. However, the motion of an object along
More informationYear 11 Physics Tutorial 84C2 Newton s Laws of Motion
Year 11 Physics Tutorial 84C2 Newton s Laws of Motion Module Topic 8.4 Moving About 8.4.C Forces Name Date Set 1 Calculating net force 1 A trolley was moved to the right by a force applied to a cord attached
More informationGeneral Physics I Spring Forces and Newton s Laws of Motion
General Physics I Spring 2011 Forces and Newton s Laws of Motion 1 Forces and Interactions The central concept in understanding why things move is force. If a tractor pushes or pulls a trailer, the tractor
More informationLesson 11: Newton s Third Law: Quantitative
11.1 Observe and Find a Pattern Lesson 11: Newton s Third Law: Quantitative The goal of this experiment is to determine a mathematical relationship between the force that object A exerts on object B and
More informationMotion *All matter in the universe is constantly at motion Motion an object is in motion if its position is changing
Aim: What is motion? Do Now: Have you ever seen a race? Describe what occurred during it. Homework: Vocabulary Define: Motion Point of reference distance displacement speed velocity force Textbook: Read
More informationForces and Newton s Laws Reading Notes. Give an example of a force you have experienced continuously all your life.
Forces and Newton s Laws Reading Notes Name: Section 4-1: Force What is force? Give an example of a force you have experienced continuously all your life. Give an example of a situation where an object
More informationTopic: Force PHYSICS 231
Topic: Force PHYSICS 231 Current Assignments Homework Set 2 due this Thursday, Jan 27, 11 pm Reading for next week: Chapters 10.1-6,10.10,8.3 2/1/11 Physics 231 Spring 2011 2 Key Concepts: Force Free body
More informationUniversity Physics (Prof. David Flory) Chapt_06 Saturday, October 06, 2007 Page 1
University Physics (Prof. David Flory) Chapt_06 Saturday, October 06, 2007 Page 1 Name: Date: 1. A crate resting on a rough horizontal floor is to be moved horizontally. The coefficient of static friction
More informationMotion and Forces. Forces
CHAPTER 8 Motion and LESSON 3 What do you think? Read the two statements below and decide whether you agree or disagree with them. Place an A in the Before column if you agree with the statement or a D
More informationEngage I 1. What do you think about this design? If the car were to suddenly stop, what would happen to the child? Why?
AP Physics 1 Lesson 4.a Nature of Forces Outcomes Define force. State and explain Newton s first Law of Motion. Describe inertia and describe its relationship to mass. Draw free-body diagrams to represent
More informationMotion and Forces study Guide
Motion and Forces study Guide Completion Complete each statement. 1. The motion of an object looks different to observers in different. 2. The SI unit for measuring is the meter. 3. The direction and length
More informationApplying Newton s Laws
Applying Newton s Laws Free Body Diagrams Draw and label the forces acting on the object. Examples of forces: weight, normal force, air resistance, friction, applied forces (like a push or pull) Velocity
More information1N the force that a 100g bar of chocolate exerts on your hand.
Forces: - - > cause change in motions Newton's first law = law of inertia In absence of a net external force acting upon it, a body will either remain at rest or continue in its rectilinear uniform motion.
More informationForces and Newton s Laws Notes
Forces and Newton s Laws Notes Force An action exerted on an object which can change the motion of the object. The SI unit for force is the Newton (N) o N = (kg m)/s 2 o Pound is also a measure of force
More informationHSC PHYSICS ONLINE B F BA. repulsion between two negatively charged objects. attraction between a negative charge and a positive charge
HSC PHYSICS ONLINE DYNAMICS TYPES O ORCES Electrostatic force (force mediated by a field - long range: action at a distance) the attractive or repulsion between two stationary charged objects. AB A B BA
More informationChapter Four Holt Physics. Forces and the Laws of Motion
Chapter Four Holt Physics Forces and the Laws of Motion Physics Force and the study of dynamics 1.Forces - a. Force - a push or a pull. It can change the motion of an object; start or stop movement; and,
More informationChapter 5 Matter in Motion Focus Notes
Chapter 5 Matter in Motion Focus Notes Section 1 Define the following terms: Motion, Speed, Velocity, and Acceleration Motion: an object s change in position relative to a reference point. Speed: the distance
More informationIsaac Newton ( ) 1687 Published Principia Invented Calculus 3 Laws of Motion Universal Law of Gravity
Isaac Newton (1642-1727) 1687 Published Principia Invented Calculus 3 Laws of Motion Universal Law of Gravity Newton s First Law (Law of Inertia) An object will remain at rest or in a constant state of
More informationChapter 05 Test A. Name: Class: Date: Multiple Choice Identify the choice that best completes the statement or answers the question.
Class: Date: Chapter 05 Test A Multiple Choice Identify the choice that best completes the statement or answers the question. 1. The SI unit of force preferred by scientists is the: a. kilogram. b. newton.
More informationForce a push or a pull exerted on some object the cause of an acceleration, or the change in an objects velocity
Chapter 4 Physics Notes Changes in Motion Force a push or a pull exerted on some object the cause of an acceleration, or the change in an objects velocity Forces cause changes in velocity Causes a stationary
More informationStatic and Kinetic Friction
Static and Kinetic Friction Part 1: factors affecting frictional forces 1. For a body moving on a horizontal plane, what are the forces acting on the body when you pull it along the surface? What do you
More informationChapter 5 Force and Motion
Chapter 5 Force and Motion Chapter Goal: To establish a connection between force and motion. Slide 5-2 Chapter 5 Preview Slide 5-3 Chapter 5 Preview Slide 5-4 Chapter 5 Preview Slide 5-5 Chapter 5 Preview
More informationReview: Advanced Applications of Newton's Laws
Review: Advanced Applications of Newton's Laws 1. The free-body diagram of a wagon being pulled along a horizontal surface is best represented by a. A d. D b. B e. E c. C 2. The free-body diagram of a
More informationStatic and Kinetic Friction
Experiment Static and Kinetic Friction Prelab Questions 1. Examine the Force vs. time graph and the Position vs. time graph below. The horizontal time scales are the same. In Region I, explain how an object
More informationReview of Lectures 1, 2 and 3
Physics 22000 General Physics Lecture 5 Applying Newton s Laws Fall 2016 Semester Prof. Matthew Jones 1 Review of Lectures 1, 2 and 3 Algebraic description of linear motion with constant acceleration:
More informationChapter Review USING KEY TERMS UNDERSTANDING KEY IDEAS. Skills Worksheet. Multiple Choice
Skills Worksheet Chapter Review USING KEY TERMS Complete each of the following sentences by choosing the correct term from the word bank. mass gravity friction weight speed velocity net force newton 1.
More informationNewton s First Law of Motion. Newton s Second Law of Motion. Weight 9/30/2015
Forces Newton s Three Laws of Motion Types of Forces Weight Friction Terminal Velocity Periodic Motion Forces Defined as a push or a pull Types of Forces 1) Gravitational - attractive force that exists
More informationForces. Unit 2. Why are forces important? In this Unit, you will learn: Key words. Previously PHYSICS 219
Previously Remember From Page 218 Forces are pushes and pulls that can move or squash objects. An object s speed is the distance it travels every second; if its speed increases, it is accelerating. Unit
More informationPOGIL: 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
More informationSection /07/2013. PHY131H1F University of Toronto Class 9 Preclass Video by Jason Harlow. Based on Knight 3 rd edition Ch. 5, pgs.
PHY131H1F University of Toronto Class 9 Preclass Video by Jason Harlow Based on Knight 3 rd edition Ch. 5, pgs. 116-133 Section 5.1 A force is a push or a pull What is a force? What is a force? A force
More informationPhysics 2A Chapter 4: Forces and Newton s Laws of Motion
Physics 2A Chapter 4: Forces and Newton s Laws of Motion There is nothing either good or bad, but thinking makes it so. William Shakespeare It s not what happens to you that determines how far you will
More informationChapter 5: Forces in Two Dimensions. Click the mouse or press the spacebar to continue.
Chapter 5: Forces in Two Dimensions Click the mouse or press the spacebar to continue. Chapter 5 Forces in Two Dimensions In this chapter you will: Represent vector quantities both graphically and algebraically.
More informationChapter 4 Force and Motion
Chapter 4 Force and Motion Units of Chapter 4 The Concepts of Force and Net Force Inertia and Newton s First Law of Motion Newton s Second Law of Motion Newton s Third Law of Motion More on Newton s Laws:
More informationLesson 12: Position of an Accelerating Object as a Function of Time
Lesson 12: Position of an Accelerating Object as a Function of Time 12.1 Hypothesize (Derive a Mathematical Model) Recall the initial position and clock reading data from the previous lab. When considering
More informationFriction: A Force That Opposes Motion
3 What You Will Learn The magnitude of the force of can vary. Kinetic is a force that, when unbalanced, can change the velocity of a moving object. Static balances an applied force and can prevent motion.
More information66 Chapter 6: FORCE AND MOTION II
Chapter 6: FORCE AND MOTION II 1 A brick slides on a horizontal surface Which of the following will increase the magnitude of the frictional force on it? A Putting a second brick on top B Decreasing the
More information3 Friction: A Force That Opposes Motion
CHAPTER 1 SECTION Matter in Motion 3 Friction: A Force That Opposes Motion BEFORE YOU READ After you read this section, you should be able to answer these questions: What is friction? How does friction
More information9/20/11. Physics 101 Tuesday 9/20/11 Class 8" Chapter " Weight and Normal forces" Frictional Forces"
Reading Quiz Physics 101 Tuesday 9/20/11 Class 8" Chapter 5.6 6.1" Weight and Normal forces" Frictional Forces" The force due to kinetic friction is usually larger than the force due to static friction.
More informationWelcome to Forces an anticipation guide A force is defined as a push or a pull When answering the following true or false statements, offer a
Welcome to Forces an anticipation guide A force is defined as a push or a pull When answering the following true or false statements, offer a real-life example that justifies your answer. You haven t answered
More informationUnit 2 Forces. Fundamental Forces
Lesson14.notebook July 10, 2013 Unit 2 Forces Fundamental Forces Today's goal: I can identify/name applied forces and draw appropriate free body diagrams (FBD's). There are 4 fundamental forces Gravity
More informationLesson 1: Force as an Interaction
1.1 Observe and Represent Lesson 1: Force as an Interaction a) Pick up a tennis ball and hold it in your hand. Now pick up a medicine ball and hold it. Do you feel the difference? How can you describe
More informationNewton. Galileo THE LAW OF INERTIA REVIEW
Galileo Newton THE LAW OF INERTIA REVIEW 1 MOTION IS RELATIVE We are moving 0 m/s and 30km/s Find the resultant velocities MOTION IS RELATIVE Position versus Time Graph. Explain how the car is moving.
More informationFree-Body Diagrams: Introduction
Free-Body Diagrams: Introduction Learning Goal: To learn to draw free-body diagrams for various real-life situations. Imagine that you are given a description of a real-life situation and are asked to
More informationWS-CH-4 Motion and Force Show all your work and equations used. Isaac Newton ( )
AP PHYSICS 1 WS-CH-4 Motion and Force Show all your work and equations used. Isaac Newton (1643-1727) Isaac Newton was the greatest English mathematician of his generation. He laid the foundation for differential
More informationGeneral Physics I Spring Applying Newton s Laws
General Physics I Spring 2011 pplying Newton s Laws 1 Friction When you push horizontally on a heavy box at rest on a horizontal floor with a steadily increasing force, the box will remain at rest initially,
More informationExperimenting with Forces
A mother hears a loud crash in the living room. She walks into the room to see her seven-year-old son looking at a broken vase on the floor. How did that happen? she asks. I don t know. The vase just fell
More informationMULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
Exam Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) You are standing in a moving bus, facing forward, and you suddenly fall forward as the
More informationIsaac Newton. What is a force? Newton s Three Laws of Motion. What is the acceleration of the car?
Aim: What did Isaac Newton teach us about motion? Do Now: 1. A 2009 Ford Mustang convertible is travelling at constant velocity on Interstate 95 south from Philadelphia to Wilmington Delaware. It passes
More information1. A sphere with a radius of 1.7 cm has a volume of: A) m 3 B) m 3 C) m 3 D) 0.11 m 3 E) 21 m 3
1. A sphere with a radius of 1.7 cm has a volume of: A) 2.1 10 5 m 3 B) 9.1 10 4 m 3 C) 3.6 10 3 m 3 D) 0.11 m 3 E) 21 m 3 2. A 25-N crate slides down a frictionless incline that is 25 above the horizontal.
More informationIsaac 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
More informationChapter 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
More informationReview 3: Forces. 1. Which graph best represents the motion of an object in equilibrium? A) B) C) D)
1. Which graph best represents the motion of an object in equilibrium? A) B) C) D) 2. A rock is thrown straight up into the air. At the highest point of the rock's path, the magnitude of the net force
More informationEnd-of-Chapter Exercises
End-of-Chapter Exercises For all these exercises, assume that all strings are massless and all pulleys are both massless and frictionless. We will improve our model and learn how to account for the mass
More informationVISUAL PHYSICS ONLINE DYNAMICS TYPES OF FORCES FRICTION
VISUAL PHYSICS ONLINE DYNAMICS TYPES OF FORCES FRICTION Friction force: the force acting on the object which acts in a direction parallel to the surface. A simple model for friction F f is that it is proportional
More informationBEFORE YOU READ. Forces and Motion Gravity and Motion STUDY TIP. After you read this section, you should be able to answer these questions:
CHAPTER 2 1 SECTION Forces and Motion Gravity and Motion BEFORE YOU READ After you read this section, you should be able to answer these questions: How does gravity affect objects? How does air resistance
More informationNewton s 3 Laws of Motion
Newton s 3 Laws of Motion 1. If F = 0 No change in motion 2. = ma Change in motion Fnet 3. F = F 1 on 2 2 on 1 Newton s First Law (Law of Inertia) An object will remain at rest or in a constant state of
More information3. The diagram shows two bowling balls, A and B, each having a mass of 7.00 kilograms, placed 2.00 meters apart.
1. Which statement describes the gravitational force and the electrostatic force between two charged particles? A) The gravitational force may be either attractive or repulsive, whereas the electrostatic
More informationNet Force and Acceleration
NEWTON'S SECOND LAW Net Force and Acceleration According to Newton: v A constant velocity is the natural state of motion To accelerate a physical system requires a force F The amount of force required
More informationWhat does the lab partner observe during the instant the student pushes off?
Motion Unit Review State Test Questions 1. To create real-time graphs of an object s displacement versus time and velocity versus time, a student would need to use a A motion sensor.b low- g accelerometer.
More informationChapter 5. Forces in Two Dimensions
Chapter 5 Forces in Two Dimensions Chapter 5 Forces in Two Dimensions In this chapter you will: Represent vector quantities both graphically and algebraically. Use Newton s laws to analyze motion when
More informationChapter 5 The Force Vector
Conceptual Physics/ PEP Name: Date: Chapter 5 The Force Vector Section Review 5.1 1. Indicate whether each of the following units of measurement are scalar or vector units: Speed _scalar time scalar mass
More informationCONTENTS (BOOK PAGES )
CONTENTS (BOOK PAGES 164-227) Contents...1 nt6 Work and Energy...3 nt6a-wwt1: Object Changing Velocity Work...3 nt6a-cct2: Bicyclist on a Straight Road Work...4 nt6a-wwt3: Boat Position vs. Time Graphs
More informationUnit 2 Part 2: Forces Note 1: Newton`s Universal Law of Gravitation. Newton`s Law of Universal Gravitation states: Gravity. Where: G = M = r =
Unit 2 Part 2: Forces Note 1: Newton`s Universal Law of Gravitation Gravity Newton`s Law of Universal Gravitation states: Where: G = = M = m = r = Ex 1: What is the force of gravity exerted on a 70.0 kg
More information3/10/2019. What Is a Force? What Is a Force? Tactics: Drawing Force Vectors
What Is a Force? A force acts on an object. A force requires an agent, something that acts on the object. If you throw a ball, your hand is the agent or cause of the force exerted on the ball. A force
More informationForce Test Review. 1. Give two ways to increase acceleration. You can increase acceleration by decreasing mass or increasing force.
Force Test Review 1. Give two ways to increase acceleration. You can increase acceleration by decreasing mass or increasing force. 2. Define weight. The force of gravity on an object at the surface of
More informationMechanics II. Which of the following relations among the forces W, k, N, and F must be true?
Mechanics II 1. By applying a force F on a block, a person pulls a block along a rough surface at constant velocity v (see Figure below; directions, but not necessarily magnitudes, are indicated). Which
More informationUnit 15 LESSON 1 WHAT ARE FORCES?
Unit 15 LESSON 1 WHAT ARE FORCES? Pushing and Pulling A force is a push or pull. Forces can cause an object at rest to move, speed up, slow down, change direction, or stop. Forces can change the shape
More informationChapter 4. Forces in One Dimension
Chapter 4 Forces in One Dimension Chapter 4 Forces in One Dimension In this chapter you will: *VD Note Use Newton s laws to solve problems. Determine the magnitude and direction of the net force that causes
More informationOr why this won t work very well
Friction Friction Friction causes objects to slow down. Friction creates heat. Friction degrades an object s energy Friction is: Friction: A force that resists the relative motion or tendency to such motion
More informationSection 2: Friction, Gravity, and Elastic Forces
Chapter 10, Section 2 Friction, Gravity, & Elastic Forces Section 2: Friction, Gravity, and Elastic Forces What factors determine the strength of the friction force between two surfaces? What factors affect
More informationQ2. A book whose mass is 2 kg rests on a table. Find the magnitude of the force exerted by the table on the book.
AP Physics 1- Dynamics Practice Problems FACT: Inertia is the tendency of an object to resist a change in state of motion. A change in state of motion means a change in an object s velocity, therefore
More informationWhat Is a Force? Slide Pearson Education, Inc.
What Is a Force? A force acts on an object. A force requires an agent, something that acts on the object. If you throw a ball, your hand is the agent or cause of the force exerted on the ball. A force
More informationReading Quiz. Chapter 5. Physics 111, Concordia College
Reading Quiz Chapter 5 1. The coefficient of static friction is A. smaller than the coefficient of kinetic friction. B. equal to the coefficient of kinetic friction. C. larger than the coefficient of kinetic
More informationThe Laws of Motion. Gravity and Friction
The Laws of Motion Gravity and Friction What do you think? Read the two statements below and decide whether you agree or disagree with them. Place an A in the Before column if you agree with the statement
More informationChapter 4. Table of Contents. Section 1 Changes in Motion. Section 2 Newton's First Law. Section 3 Newton's Second and Third Laws
Forces and the Laws of Motion Table of Contents Section 1 Changes in Motion Section 2 Newton's First Law Section 3 Newton's Second and Third Laws Section 4 Everyday Forces Section 1 Changes in Motion Objectives
More informationPhysics Mechanics. Lecture 11 Newton s Laws - part 2
Physics 170 - Mechanics Lecture 11 Newton s Laws - part 2 Newton s Second Law of Motion An object may have several forces acting on it; the acceleration is due to the net force: Newton s Second Law of
More information2. FORCE AND MOTION. In the above, the objects are being moved by a push or pull. A push or pull acting on objects is called a force.
2. FORCE AND MOTION Force We do many jobs in our daily life like lifting things, moving things from one place to another, cutting objects, etc. To do these jobs, we have to move. We are surrounded by a
More informationPhysics Chapter 4 Newton s Laws of Motion
Physics Chapter 4 Newton s Classical Mechanics Classical Mechanics Describes the relationship between the motion of objects in our everyday world and the forces acting on them Conditions when Classical
More informationChapter: Newton s Laws of Motion
Table of Contents Chapter: Newton s Laws of Motion Section 1: Motion Section 2: Newton s First Law Section 3: Newton s Second Law Section 4: Newton s Third Law 1 Motion What is motion? Distance and Displacement
More informationPHYSICS. Chapter 5 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 5 Lecture RANDALL D. KNIGHT Chapter 5 Force and Motion IN THIS CHAPTER, you will learn about the connection between force and motion.
More informationSPS8. STUDENTS WILL DETERMINE RELATIONSHIPS AMONG FORCE, MASS, AND MOTION.
MOTION & FORCES SPS8. STUDENTS WILL DETERMINE RELATIONSHIPS AMONG FORCE, MASS, AND MOTION. A. CALCULATE VELOCITY AND ACCELERATION. B. APPLY NEWTON S THREE LAWS TO EVERYDAY SITUATIONS BY EXPLAINING THE
More informationChapter 6 Dynamics I: Motion Along a Line
Chapter 6 Dynamics I: Motion Along a Line Chapter Goal: To learn how to solve linear force-and-motion problems. Slide 6-2 Chapter 6 Preview Slide 6-3 Chapter 6 Preview Slide 6-4 Chapter 6 Preview Slide
More informationPHY131H1F - Class 9. Today, finishing Chapter 5: Kinetic Friction Static Friction Rolling without slipping (intro) Drag
PHY131H1F - Class 9 Today, finishing Chapter 5: Kinetic Friction Static Friction Rolling without slipping (intro) Drag Microscopic bumps and holes crash into each other, causing a frictional force. Kinetic
More informationFree Body Diagram Practice
Name: Free Body Diagram Practice Per: Read each scenario and draw a diagram of the forces acting upon the object(s). 1. A book is at rest on a table top. Diagram the forces acting on the book. 2. A girl
More informationChapter 6. Force and Motion II
Chapter 6 Force and Motion II 6 Force and Motion II 2 Announcement: Sample Answer Key 3 4 6-2 Friction Force Question: If the friction were absent, what would happen? Answer: You could not stop without
More informationCh 6 Using Newton s Laws. Applications to mass, weight, friction, air resistance, and periodic motion
Ch 6 Using Newton s Laws Applications to mass, weight, friction, air resistance, and periodic motion Newton s 2 nd Law Applied Galileo hypothesized that all objects gain speed at the same rate (have the
More informationForces and Newton s Laws
chapter 3 section 1 Forces Forces and Newton s Laws What You ll Learn how force and motion are related what friction is between objects the difference between mass and weight Before You Read When you hit
More informationPHYSICS. Chapter 5 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 5 Lecture RANDALL D. KNIGHT Chapter 5 Force and Motion IN THIS CHAPTER, you will learn about the connection between force and motion.
More informationNewton s Laws. A force is simply a push or a pull. Forces are vectors; they have both size and direction.
Newton s Laws Newton s first law: An object will stay at rest or in a state of uniform motion with constant velocity, in a straight line, unless acted upon by an external force. In other words, the bodies
More informationA 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
More informationWork and Energy. Work
Work and Energy Objectives: Students will define work. Students will define and give examples of different forms of energy. Students will describe and give examples of kinetic energy and potential energy.
More informationOnline homework #6 due on Tue March 24
Online homework #6 due on Tue March 24 Problem 5.22 Part A: give your answer with only 2 significant digits (i.e. round answer and drop less significant digits) 51 Equilibrium Question 52 1 Using Newton
More informationName Period Date. Record all givens, draw a picture, arrow all vectors, write the formula, substitute and solve. units
Example Problems 5.2 Friction E1. A monkey is dragging a box full of books from his office to his car. The combined weight of the box and books is 134 N. If the coefficient of static friction between the
More information