Lecture 9. Friction in a viscous medium Drag Force Quantified

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "Lecture 9. Friction in a viscous medium Drag Force Quantified"

Transcription

1 Lecture 9 Goals Describe Friction in Air (Ch. 6) Differentiate between Newton s 1 st, 2 nd and 3 rd Laws Use Newton s 3 rd Law in problem solving Assignment: HW4, (Chap. 6 & 7, due 10/5) 1 st Exam Thurs., Oct. 7 th from 7:15-8:45 PM Chapters 1-7 in rooms 2103, 2141, & 2223 Chamberlin Hall Physics 207: Lecture 8, Pg 1 Friction in a viscous medium Drag Force Quantified With a cross sectional area, A (in m 2 ), coefficient of drag of 1.0 (most objects), ρ sea-level density of air, and velocity, v (m/s), the drag force is: D = ½ C ρ A v 2 c A v 2 c = ¼ kg/m 3 in Newtons In falling, when D = mg, then at terminal velocity Example: Bicycling at 10 m/s (22 m.p.h.), with projected area of 0.5 m 2 exerts a force of ~30 Newtons At low speeds air drag is proportional to v but at high speeds it is v 2 Minimizing drag is often important Physics 207: Lecture 8, Pg 2 Page 1

2 Newton s Third Law: If object 1 exerts a force on object 2 (F 2,1 ) then object 2 exerts an equal and opposite force on object 1 (F 1,2 ) F 1,2 = -F 2,1 For every action there is an equal and opposite reaction IMPORTANT: Newton s 3 rd law concerns force pairs which act on two different objects (not on the same object)! Physics 207: Lecture 8, Pg 3 Force Pairs vs. Free Body Diagrams Consider the following two cases (a falling ball and ball on table), Compare and contrast Free Body Diagram and Action-Reaction Force Pair sketch Physics 207: Lecture 8, Pg 4 Page 2

3 Free body diagrams mg F B,T = N mg Ball Falls For Static Situation N = mg Physics 207: Lecture 8, Pg 5 Force Pairs 1 st and 2 nd Laws Free-body diagram Relates force to acceleration 3 rd Law Action/reaction pairs Shows how forces act between objects F B,E = -mg F E,B = mg F B,T = N F T,B = -N F B,E = -mg F E,B = mg Physics 207: Lecture 8, Pg 6 Page 3

4 Example (non-contact) Consider the forces on an object undergoing projectile motion EARTH F B,E = - m B g F E,B = m B g F B,E = - m B g F E,B = m B g Question: By how much does g change at an altitude of 40 miles? (Radius of the Earth ~4000 mi) Physics 207: Lecture 8, Pg 7 Note on Gravitational Forces Newton also recognized that gravity is an attractive, long-range force between any two objects. When two objects with masses m 1 and m 2 are separated by distance r, each object pulls on the other with a force given by Newton s law of gravity, as follows: Physics 207: Lecture 8, Pg 8 Page 4

5 Cavendish s Experiment F = m 1 g = G m 1 m 2 / r 2 g = G m 2 / r 2 If we know big G, little g and r then will can find m 2 the mass of the Earth!!! Physics 207: Lecture 8, Pg 9 Example (non-contact) Consider the force on a satellite undergoing projectile motion 40 km above the surface of the earth: EARTH F B,E = - m B g F E,B = m B g F B,E = - m B g F E,B = m B g Compare: g = G m 2 / g = G m 2 / ( ) 2 g / g = / ( ) 2 / = 0.98 Physics 207: Lecture 8, Pg 10 Page 5

6 A conceptual question: A flying bird in a cage You have a bird in a cage that is resting on your upward turned palm. The cage is completely sealed to the outside (at least while we run the experiment!). The bird is initially sitting at rest on the perch. It decides it needs a bit of exercise and starts to fly. Question: How does the weight of the cage plus bird vary when the bird is flying up, when the bird is flying sideways, when the bird is flying down? Follow up question: So, what is holding the airplane up in the sky? Physics 207: Lecture 8, Pg 11 Static Friction with a bicycle wheel You are pedaling hard and the bicycle is speeding up. What is the direction of the frictional force? You are breaking and the bicycle is slowing down What is the direction of the frictional force? Physics 207: Lecture 8, Pg 12 Page 6

7 Exercise Newton s Third Law A fly is deformed by hitting the windshield of a speeding bus. v The force exerted by the bus on the fly is, A. greater than B. equal to C. less than that exerted by the fly on the bus. Physics 207: Lecture 8, Pg 13 Exercise 2 Newton s Third Law Same scenario but now we examine the accelerations A fly is deformed by hitting the windshield of a speeding bus. v The magnitude of the acceleration, due to this collision, of the bus is A. greater than B. equal to C. less than that of the fly. Physics 207: Lecture 8, Pg 14 Page 7

8 Exercise 3 Newton s 3rd Law Two blocks are being pushed by a finger on a horizontal frictionless floor. How many action-reaction force pairs are present in this exercise? a b A. 2 B. 4 C. 6 D. Something else Physics 207: Lecture 8, Pg 15 Force pairs on an Inclined plane Forces on the block Normal means perpendicular Normal Force f Friction Force mg sin θ mg cos θ θ y θ θ x Block weight is mg Physics 207: Lecture 8, Pg 16 Page 8

9 Force pairs on an Inclined plane Forces on the block (equilibrium case) Normal Force f= µn Friction Force Forces on the plane θ y x Physics 207: Lecture 8, Pg 17 Force pairs on an Inclined plane Forces on the block (non equilibrium case) Friction Force f Normal Force Forces on the plane θ y x Physics 207: Lecture 8, Pg 18 Page 9

10 Example: Friction and Motion A box of mass m 1 = 1 kg is being pulled by a horizontal string having tension T = 40 N. It slides with friction (µ k = 0.5) on top of a second box having mass m 2 = 2 kg, which in turn slides on a smooth (frictionless) surface. What is the acceleration of the second box? 1 st Question: What is the force on mass 2 from mass 1? (A) a = 0 N (B) a = 5 N (C) a = 20 N (D) can t tell T m 1 v slides with friction (µ k =0.5 ) a =? m 2 slides without friction Physics 207: Lecture 8, Pg 19 Example Solution First draw FBD of the top box: v N 1 T m 1 f k = µ K N 1 = µ K m 1 g m 1 g Physics 207: Lecture 8, Pg 20 Page 10

11 Example Solution Newtons 3 rd law says the force box 2 exerts on box 1 is equal and opposite to the force box 1 exerts on box 2. As we just saw, this force is due to friction: Reaction f 2,1 = -f 1,2 m 1 Action f 1,2 = µ K m 1 g = 5 N m 2 (A) a = 0 N (B) a = 5 N (C) a = 20 N (D) can t tell Physics 207: Lecture 8, Pg 21 Example Solution Now consider the FBD of box 2: N 2 f 2,1 = µ k m 1 g m 2 m 2 g m 1 g Physics 207: Lecture 8, Pg 22 Page 11

12 Example Solution Finally, solve F x = ma in the horizontal direction: µ K m 1 g = m 2 a a = = 2.5 m/s 2 m 1µ k m 2 g = 5 N 2 kg f 2,1 = µ K m 1 g m 2 Physics 207: Lecture 8, Pg 23 Home Exercise Friction and Motion, Replay A box of mass m 1 = 1 kg, initially at rest, is now pulled by a horizontal string having tension T = 10 N. This box (1) is on top of a second box of mass m 2 = 2 kg. The static and kinetic coefficients of friction between the 2 boxes are µ s =1.5 and µ k = 0.5. The second box can slide freely (frictionless) on an smooth surface. Compare the acceleration of box 1 to the acceleration of box 2? a 1 T m 1 friction coefficients µ s =1.5 and µ k =0.5 a 2 m 2 slides without friction Physics 207: Lecture 8, Pg 24 Page 12

13 Home Exercise Friction and Motion, Replay in the static case A box of mass m 1 = 1 kg, initially at rest, is now pulled by a horizontal string having tension T = 10 N. This box (1) is on top of a second box of mass m 2 = 2 kg. The static and kinetic coefficients of friction between the 2 boxes are µ s =1.5 and µ k = 0.5. The second box can slide freely on an smooth surface (frictionless). If no slippage then the maximum frictional force between 1 & 2 is (A) 20 N (B) 15 N (C) 5 N (D) depends on T a 1 T m 1 friction coefficients µ s =1.5 and µ k =0.5 a 2 m 2 slides without friction Physics 207: Lecture 8, Pg 25 Home Exercise Friction and Motion f S µ S N = µ S m 1 g = 1.5 x 1 kg x 10 m/s 2 which is 15 N (so m 2 can t break free) f s = 10 N and the acceleration of box 1 is Acceleration of box 2 equals that of box 1, with a = T / (m 1 +m 2 ) and the frictional force f is m 2 a (Notice that if T were in excess of 15 N then it would break free) T N m 1 g f S a 1 T m 1 friction coefficients µ s =1.5 and µ k =0.5 a 2 m 2 slides without friction Physics 207: Lecture 8, Pg 26 Page 13

14 Recap Wednesday: Review for exam Physics 207: Lecture 8, Pg 27 Page 14

AP Physics Newton's Laws Practice Test

AP Physics Newton's Laws Practice Test AP Physics Newton's Laws Practice Test Answers: A,D,C,D,C,E,D,B,A,B,C,C,A,A 15. (b) both are 2.8 m/s 2 (c) 22.4 N (d) 1 s, 2.8 m/s 16. (a) 12.5 N, 3.54 m/s 2 (b) 5.3 kg 1. Two blocks are pushed along a

More information

THE NATURE OF FORCES Forces can be divided into two categories: contact forces and non-contact forces.

THE NATURE OF FORCES Forces can be divided into two categories: contact forces and non-contact forces. SESSION 2: NEWTON S LAWS Key Concepts In this session we Examine different types of forces Review and apply Newton's Laws of motion Use Newton's Law of Universal Gravitation to solve problems X-planation

More information

Ground Rules. PC1221 Fundamentals of Physics I. Force. Zero Net Force. Lectures 9 and 10 The Laws of Motion. Dr Tay Seng Chuan

Ground Rules. PC1221 Fundamentals of Physics I. Force. Zero Net Force. Lectures 9 and 10 The Laws of Motion. Dr Tay Seng Chuan PC1221 Fundamentals of Physics I Lectures 9 and 10 he Laws of Motion Dr ay Seng Chuan 1 Ground Rules Switch off your handphone and pager Switch off your laptop computer and keep it No talking while lecture

More information

Newton s Laws Pre-Test

Newton s Laws Pre-Test Newton s Laws Pre-Test 1.) Consider the following two statements and then select the option below that is correct. (i) It is possible for an object move in the absence of forces acting on the object. (ii)

More information

Physics 11 Chapter 4 HW Solutions

Physics 11 Chapter 4 HW Solutions Physics 11 Chapter 4 HW Solutions Chapter 4 Conceptual Question: 5, 8, 10, 18 Problems: 3, 3, 35, 48, 50, 54, 61, 65, 66, 68 Q4.5. Reason: No. If you know all of the forces than you know the direction

More information

Newton s Laws of Motion

Newton s Laws of Motion Physics Newton s Laws of Motion Newton s Laws of Motion 4.1 Objectives Explain Newton s first law of motion. Explain Newton s second law of motion. Explain Newton s third law of motion. Solve problems

More information

Chapter Test. Teacher Notes and Answers Forces and the Laws of Motion. Assessment

Chapter Test. Teacher Notes and Answers Forces and the Laws of Motion. Assessment Assessment Chapter Test A Teacher Notes and Answers Forces and the Laws of Motion CHAPTER TEST A (GENERAL) 1. c 2. d 3. d 4. c 5. c 6. c 7. c 8. b 9. d 10. d 11. c 12. a 13. d 14. d 15. b 16. d 17. c 18.

More information

C B A T 3 T 2 T 1. 1. What is the magnitude of the force T 1? A) 37.5 N B) 75.0 N C) 113 N D) 157 N E) 192 N

C B A T 3 T 2 T 1. 1. What is the magnitude of the force T 1? A) 37.5 N B) 75.0 N C) 113 N D) 157 N E) 192 N Three boxes are connected by massless strings and are resting on a frictionless table. Each box has a mass of 15 kg, and the tension T 1 in the right string is accelerating the boxes to the right at a

More information

Newton s First Law (Law of Inertia) An object will remain at rest or in a constant state of motion unless acted upon by net external forces.

Newton s First Law (Law of Inertia) An object will remain at rest or in a constant state of motion unless acted upon by net external forces. Newton s Third Law Newton s First Law (Law of Inertia) F = 0 An object will remain at rest or in a constant state of motion unless acted upon by net external forces. Newton s First Law If F = 0 => No Change

More information

1) A 2) B 3) C 4) A and B 5) A and C 6) B and C 7) All of the movies A B C. PHYS 11: Chap. 2, Pg 2

1) A 2) B 3) C 4) A and B 5) A and C 6) B and C 7) All of the movies A B C. PHYS 11: Chap. 2, Pg 2 1) A 2) B 3) C 4) A and B 5) A and C 6) B and C 7) All of the movies A B C PHYS 11: Chap. 2, Pg 2 1 1) A 2) B 3) C 4) A and B 5) A and C 6) B and C 7) All three A B PHYS 11: Chap. 2, Pg 3 C 1) more than

More information

What is a force? Identifying forces. What is the connection between force and motion? How are forces related when two objects interact?

What is a force? Identifying forces. What is the connection between force and motion? How are forces related when two objects interact? Chapter 4: Forces What is a force? Identifying forces. What is the connection between force and motion? How are forces related when two objects interact? Application different forces (field forces, contact

More information

Forces. Isaac Newton was the first to discover that the laws that govern motions on the Earth also applied to celestial bodies.

Forces. Isaac Newton was the first to discover that the laws that govern motions on the Earth also applied to celestial bodies. Forces Now we will discuss the part of mechanics known as dynamics. We will introduce Newton s three laws of motion which are at the heart of classical mechanics. We must note that Newton s laws describe

More information

For every action, there is an and.

For every action, there is an and. SPH4C1 Lesson 03 Newton s Laws NEWTON S THIRD LAW LEARNING GOALS Students will: Be able to state Newton s 3 rd Law and apply it in qualitative and quantitative terms to explain the effect of forces acting

More information

College Physics 140 Chapter 4: Force and Newton s Laws of Motion

College Physics 140 Chapter 4: Force and Newton s Laws of Motion College Physics 140 Chapter 4: Force and Newton s Laws of Motion We will be investigating what makes you move (forces) and how that accelerates objects. Chapter 4: Forces and Newton s Laws of Motion Forces

More information

Newton s Laws of Motion

Newton s Laws of Motion Chapter 4 Newton s Laws of Motion PowerPoint Lectures for University Physics, Thirteenth Edition Hugh D. Young and Roger A. Freedman Lectures by Wayne Anderson Goals for Chapter 4 To understand the meaning

More information

Chapter 4. Forces and Newton s Laws of Motion. continued

Chapter 4. Forces and Newton s Laws of Motion. continued Chapter 4 Forces and Newton s Laws of Motion continued 4.9 Static and Kinetic Frictional Forces When an object is in contact with a surface forces can act on the objects. The component of this force acting

More information

Version 001 Quest 3 Forces tubman (20131) 1

Version 001 Quest 3 Forces tubman (20131) 1 Version 001 Quest 3 Forces tubman (20131) 1 This print-out should have 19 questions. Multiple-choice questions may continue on the next column or page find all choices before answering. l B Conceptual

More information

Section Review Answers. Chapter 12

Section Review Answers. Chapter 12 Section Review Answers Chapter 12 Section 1 1. Answers may vary. Students should say in their own words that an object at rest remains at rest and an object in motion maintains its velocity unless it experiences

More information

Physics 101 Exam 1 NAME 2/7

Physics 101 Exam 1 NAME 2/7 Physics 101 Exam 1 NAME 2/7 1 In the situation below, a person pulls a string attached to block A, which is in turn attached to another, heavier block B via a second string (a) Which block has the larger

More information

Newton s Laws of Motion. Chapter 4

Newton s Laws of Motion. Chapter 4 Newton s Laws of Motion Chapter 4 Changes in Motion Section 4.1 Force is simply a push or pull It is an interaction between two or more objects Force is a vector so it has magnitude and direction In the

More information

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

MULTIPLE 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) The following four forces act on a 4.00 kg object: 1) F 1 = 300 N east F 2 = 700 N north

More information

Chapter 4 Newton s Laws: Explaining Motion

Chapter 4 Newton s Laws: Explaining Motion Chapter 4 Newton s s Laws: Explaining Motion Newton s Laws of Motion The concepts of force, mass, and weight play critical roles. A Brief History! Where do our ideas and theories about motion come from?!

More information

Physics 101 Prof. Ekey. Chapter 5 Force and motion (Newton, vectors and causing commotion)

Physics 101 Prof. Ekey. Chapter 5 Force and motion (Newton, vectors and causing commotion) Physics 101 Prof. Ekey Chapter 5 Force and motion (Newton, vectors and causing commotion) Goal of chapter 5 is to establish a connection between force and motion This should feel like chapter 1 Questions

More information

2. (P2.1 A) a) A car travels 150 km in 3 hours, what is the cars average speed?

2. (P2.1 A) a) A car travels 150 km in 3 hours, what is the cars average speed? Physics: Review for Final Exam 1 st Semester Name Hour P2.1A Calculate the average speed of an object using the change of position and elapsed time 1. (P2.1 A) What is your average speed if you run 140

More information

Lecture 07: Work and Kinetic Energy. Physics 2210 Fall Semester 2014

Lecture 07: Work and Kinetic Energy. Physics 2210 Fall Semester 2014 Lecture 07: Work and Kinetic Energy Physics 2210 Fall Semester 2014 Announcements Schedule next few weeks: 9/08 Unit 3 9/10 Unit 4 9/15 Unit 5 (guest lecturer) 9/17 Unit 6 (guest lecturer) 9/22 Unit 7,

More information

BROCK UNIVERSITY. PHYS 1P21/1P91 Solutions to Mid-term test 26 October 2013 Instructor: S. D Agostino

BROCK UNIVERSITY. PHYS 1P21/1P91 Solutions to Mid-term test 26 October 2013 Instructor: S. D Agostino BROCK UNIVERSITY PHYS 1P21/1P91 Solutions to Mid-term test 26 October 2013 Instructor: S. D Agostino 1. [10 marks] Clearly indicate whether each statement is TRUE or FALSE. Then provide a clear, brief,

More information

Ch 6 Forces. Question: 9 Problems: 3, 5, 13, 23, 29, 31, 37, 41, 45, 47, 55, 79

Ch 6 Forces. Question: 9 Problems: 3, 5, 13, 23, 29, 31, 37, 41, 45, 47, 55, 79 Ch 6 Forces Question: 9 Problems: 3, 5, 13, 23, 29, 31, 37, 41, 45, 47, 55, 79 Friction When is friction present in ordinary life? - car brakes - driving around a turn - walking - rubbing your hands together

More information

Friction and Newton s 3rd law

Friction and Newton s 3rd law Lecture 4 Friction and Newton s 3rd law Pre-reading: KJF 4.8 Frictional Forces Friction is a force exerted by a surface. The frictional force is always parallel to the surface Due to roughness of both

More information

F N A) 330 N 0.31 B) 310 N 0.33 C) 250 N 0.27 D) 290 N 0.30 E) 370 N 0.26

F N A) 330 N 0.31 B) 310 N 0.33 C) 250 N 0.27 D) 290 N 0.30 E) 370 N 0.26 Physics 23 Exam 2 Spring 2010 Dr. Alward Page 1 1. A 250-N force is directed horizontally as shown to push a 29-kg box up an inclined plane at a constant speed. Determine the magnitude of the normal force,

More information

CHAPTER 3 NEWTON S LAWS OF MOTION

CHAPTER 3 NEWTON S LAWS OF MOTION CHAPTER 3 NEWTON S LAWS OF MOTION NEWTON S LAWS OF MOTION 45 3.1 FORCE Forces are calssified as contact forces or gravitational forces. The forces that result from the physical contact between the objects

More information

3) a 1 = a 2. 5) a 1 = 2 a 2

3) a 1 = a 2. 5) a 1 = 2 a 2 ConcepTest Pulley Two masses are connected by a light rope as shown below. What is the 1) a 1 = 1/3 a 2 2) a 1 = ½ a 2 relationship between the magnitude of 3) a 1 = a 2 the acceleration of m 1 to that

More information

Physics: Principles and Applications, 6e Giancoli Chapter 4 Dynamics: Newton's Laws of Motion

Physics: Principles and Applications, 6e Giancoli Chapter 4 Dynamics: Newton's Laws of Motion Physics: Principles and Applications, 6e Giancoli Chapter 4 Dynamics: Newton's Laws of Motion Conceptual Questions 1) Which of Newton's laws best explains why motorists should buckle-up? A) the first law

More information

Recap. A force is the product of an object s mass and acceleration. Forces are the reason why objects change their velocity. Newton s second law:

Recap. A force is the product of an object s mass and acceleration. Forces are the reason why objects change their velocity. Newton s second law: Recap A force is the product of an object s mass and acceleration. Forces are the reason why objects change their velocity. Newton s second law: Unit: 1 N = 1 kg m/s 2 Forces are vector quantities, since

More information

PHYS101 The Laws of Motion Spring 2014

PHYS101 The Laws of Motion Spring 2014 The Laws of Motion 1. An object of mass m 1 = 55.00 kg placed on a frictionless, horizontal table is connected to a string that passes over a pulley and then is fastened to a hanging object of mass m 2

More information

Forces: Equilibrium Examples

Forces: Equilibrium Examples Physics 101: Lecture 02 Forces: Equilibrium Examples oday s lecture will cover extbook Sections 2.1-2.7 Phys 101 URL: http://courses.physics.illinois.edu/phys101/ Read the course web page! Physics 101:

More information

2.1 Force and Motion Kinematics looks at velocity and acceleration without reference to the cause of the acceleration.

2.1 Force and Motion Kinematics looks at velocity and acceleration without reference to the cause of the acceleration. 2.1 Force and Motion Kinematics looks at velocity and acceleration without reference to the cause of the acceleration. Dynamics looks at the cause of acceleration: an unbalanced force. Isaac Newton was

More information

Chapter 5 Newton s Laws of Motion

Chapter 5 Newton s Laws of Motion Chapter 5 Newton s Laws of Motion Sir Isaac Newton (1642 1727) Developed a picture of the universe as a subtle, elaborate clockwork slowly unwinding according to well-defined rules. The book Philosophiae

More information

Mechanics 1. Revision Notes

Mechanics 1. Revision Notes Mechanics 1 Revision Notes July 2012 MECHANICS 1... 2 1. Mathematical Models in Mechanics... 2 Assumptions and approximations often used to simplify the mathematics involved:... 2 2. Vectors in Mechanics....

More information

Lesson 04: Newton s laws of motion

Lesson 04: Newton s laws of motion www.scimsacademy.com Lesson 04: Newton s laws of motion If you are not familiar with the basics of calculus and vectors, please read our freely available lessons on these topics, before reading this lesson.

More information

Ch.4 Forces. Conceptual questions #1, 2, 12 Problem 1, 2, 5, 6, 7, 10, 12, 15, 16, 19, 20, 21, 23, 24, 26, 27, 30, 38, 39, 41, 42, 47, 50, 56, 66

Ch.4 Forces. Conceptual questions #1, 2, 12 Problem 1, 2, 5, 6, 7, 10, 12, 15, 16, 19, 20, 21, 23, 24, 26, 27, 30, 38, 39, 41, 42, 47, 50, 56, 66 Ch.4 Forces Conceptual questions #1, 2, 12 Problem 1, 2, 5, 6, 7, 10, 12, 15, 16, 19, 20, 21, 23, 24, 26, 27, 30, 38, 39, 41, 42, 47, 50, 56, 66 Forces Forces - vector quantity that changes the velocity

More information

This week s homework. 2 parts Quiz on Friday, Ch. 4 Today s class: Newton s third law Friction Pulleys tension. PHYS 2: Chap.

This week s homework. 2 parts Quiz on Friday, Ch. 4 Today s class: Newton s third law Friction Pulleys tension. PHYS 2: Chap. This week s homework. 2 parts Quiz on Friday, Ch. 4 Today s class: Newton s third law Friction Pulleys tension PHYS 2: Chap. 19, Pg 2 1 New Topic Phys 1021 Ch 7, p 3 A 2.0 kg wood box slides down a vertical

More information

A Review of Vector Addition

A Review of Vector Addition Motion and Forces in Two Dimensions Sec. 7.1 Forces in Two Dimensions 1. A Review of Vector Addition. Forces on an Inclined Plane 3. How to find an Equilibrant Vector 4. Projectile Motion Objectives Determine

More information

Example (1): Motion of a block on a frictionless incline plane

Example (1): Motion of a block on a frictionless incline plane Firm knowledge of vector analysis and kinematics is essential to describe the dynamics of physical systems chosen for analysis through ewton s second law. Following problem solving strategy will allow

More information

Chapter 4 Dynamics: Newton s Laws of Motion. Copyright 2009 Pearson Education, Inc.

Chapter 4 Dynamics: Newton s Laws of Motion. Copyright 2009 Pearson Education, Inc. Chapter 4 Dynamics: Newton s Laws of Motion Force Units of Chapter 4 Newton s First Law of Motion Mass Newton s Second Law of Motion Newton s Third Law of Motion Weight the Force of Gravity; and the Normal

More information

Newton s Laws of Motion

Newton s Laws of Motion Newton s Laws of Motion FIZ101E Kazım Yavuz Ekşi My contact details: Name: Kazım Yavuz Ekşi Email: eksi@itu.edu.tr Notice: Only emails from your ITU account are responded. Office hour: Wednesday 10.00-12.00

More information

Lecture Outline Chapter 5. Physics, 4 th Edition James S. Walker. Copyright 2010 Pearson Education, Inc.

Lecture Outline Chapter 5. Physics, 4 th Edition James S. Walker. Copyright 2010 Pearson Education, Inc. Lecture Outline Chapter 5 Physics, 4 th Edition James S. Walker Chapter 5 Newton s Laws of Motion Dynamics Force and Mass Units of Chapter 5 Newton s 1 st, 2 nd and 3 rd Laws of Motion The Vector Nature

More information

physics 111N forces & Newton s laws of motion

physics 111N forces & Newton s laws of motion physics 111N forces & Newton s laws of motion forces (examples) a push is a force a pull is a force gravity exerts a force between all massive objects (without contact) (the force of attraction from the

More information

Newton s Third Law. object 1 on object 2 is equal in magnitude and opposite in direction to the force exerted by object 2 on object 1

Newton s Third Law. object 1 on object 2 is equal in magnitude and opposite in direction to the force exerted by object 2 on object 1 Newton s Third Law! If two objects interact, the force exerted by object 1 on object 2 is equal in magnitude and opposite in direction to the force exerted by object 2 on object 1!! Note on notation: is

More information

Chapter 5 Newton s Laws of Motion

Chapter 5 Newton s Laws of Motion Chapter 5 Newton s Laws of Motion Force and Mass Units of Chapter 5 Newton s First Law of Motion Newton s Second Law of Motion Newton s Third Law of Motion The Vector Nature of Forces: Forces in Two Dimensions

More information

Chapter 4: Newton s Laws: Explaining Motion

Chapter 4: Newton s Laws: Explaining Motion Chapter 4: Newton s Laws: Explaining Motion 1. All except one of the following require the application of a net force. Which one is the exception? A. to change an object from a state of rest to a state

More information

Newton s Law of Motion

Newton s Law of Motion chapter 5 Newton s Law of Motion Static system 1. Hanging two identical masses Context in the textbook: Section 5.3, combination of forces, Example 4. Vertical motion without friction 2. Elevator: Decelerating

More information

Serway_ISM_V1 1 Chapter 4

Serway_ISM_V1 1 Chapter 4 Serway_ISM_V1 1 Chapter 4 ANSWERS TO MULTIPLE CHOICE QUESTIONS 1. Newton s second law gives the net force acting on the crate as This gives the kinetic friction force as, so choice (a) is correct. 2. As

More information

Forces & Newton s Laws. Teacher Packet

Forces & Newton s Laws. Teacher Packet AP * PHYSICS B Forces & Newton s Laws eacher Packet AP* is a trademark of the College Entrance Examination Board. he College Entrance Examination Board was not involved in the production of this material.

More information

Chapter 4 - Forces and Newton s Laws of Motion w./ QuickCheck Questions

Chapter 4 - Forces and Newton s Laws of Motion w./ QuickCheck Questions Chapter 4 - Forces and Newton s Laws of Motion w./ QuickCheck Questions 2015 Pearson Education, Inc. Anastasia Ierides Department of Physics and Astronomy University of New Mexico September 8, 2015 Review

More information

UNIT 2D. Laws of Motion

UNIT 2D. Laws of Motion Name: Regents Physics Date: Mr. Morgante UNIT 2D Laws of Motion Laws of Motion Science of Describing Motion is Kinematics. Dynamics- the study of forces that act on bodies in motion. First Law of Motion

More information

University Physics 226N/231N Old Dominion University. Newton s Laws and Forces Examples

University Physics 226N/231N Old Dominion University. Newton s Laws and Forces Examples University Physics 226N/231N Old Dominion University Newton s Laws and Forces Examples Dr. Todd Satogata (ODU/Jefferson Lab) satogata@jlab.org http://www.toddsatogata.net/2012-odu Wednesday, September

More information

F = ma. F = mg. Forces. Forces. Free Body Diagrams. Find the unknown forces!! Ex. 1 Ex N. Newton s First Law. Newton s Second Law

F = ma. F = mg. Forces. Forces. Free Body Diagrams. Find the unknown forces!! Ex. 1 Ex N. Newton s First Law. Newton s Second Law Forces Free Body Diagrams Push or pull on an object Causes acceleration Measured in Newtons N = Kg m s Shows all forces as vectors acting on an object Vectors always point away from object Used to help

More information

Physics I Honors: Chapter 4 Practice Exam

Physics I Honors: Chapter 4 Practice Exam Physics I Honors: Chapter 4 Practice Exam Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. 1. Which of the following statements does not describe

More information

Forces. Lecturer: Professor Stephen T. Thornton

Forces. Lecturer: Professor Stephen T. Thornton Forces Lecturer: Professor Stephen T. Thornton Reading Quiz: Which of Newton s laws refers to an action and a reaction acceleration? A) First law. B) Second law. C) Third law. D) This is a trick question.

More information

Normal Force Example: Incline

Normal Force Example: Incline Normal Force Example: Incline α The angle of the frictionless incline is α = 30. Mass slides down the incline, starting from rest. What is the speed of the mass after it slid 10 meters downhill? [use g

More information

Newton s Laws of Motion

Newton s Laws of Motion Section 3.2 Newton s Laws of Motion Objectives Analyze relationships between forces and motion Calculate the effects of forces on objects Identify force pairs between objects New Vocabulary Newton s first

More information

Conceptual Physics Review (Chapters 4, 5, & 6)

Conceptual Physics Review (Chapters 4, 5, & 6) Conceptual Physics Review (Chapters 4, 5, & 6) Solutions Sample Questions and Calculations. If you were in a spaceship and launched a cannonball into frictionless space, how much force would have to be

More information

Units DEMO spring scales masses

Units DEMO spring scales masses Dynamics the study of the causes and changes of motion Force Force Categories ContactField 4 fundamental Force Types 1 Gravity 2 Weak Nuclear Force 3 Electromagnetic 4 Strong Nuclear Force Units DEMO spring

More information

Physics 2101, First Exam, Fall 2007

Physics 2101, First Exam, Fall 2007 Physics 2101, First Exam, Fall 2007 September 4, 2007 Please turn OFF your cell phone and MP3 player! Write down your name and section number in the scantron form. Make sure to mark your answers in the

More information

Section 3 Newton s Laws of Motion

Section 3 Newton s Laws of Motion Section 3 Newton s Laws of Motion Key Concept Newton s laws of motion describe the relationship between forces and the motion of an object. What You Will Learn Newton s first law of motion states that

More information

Physics 111: Lecture 4: Chapter 4 - Forces and Newton s Laws of Motion. Physics is about forces and how the world around us reacts to these forces.

Physics 111: Lecture 4: Chapter 4 - Forces and Newton s Laws of Motion. Physics is about forces and how the world around us reacts to these forces. Physics 111: Lecture 4: Chapter 4 - Forces and Newton s Laws of Motion Physics is about forces and how the world around us reacts to these forces. Whats a force? Contact and non-contact forces. Whats a

More information

Ch 4 Test Review. Why do we say a speeding object doesn t have force? (Assume this object is speeding through space) (Explain)

Ch 4 Test Review. Why do we say a speeding object doesn t have force? (Assume this object is speeding through space) (Explain) Ch 4 Test Review Why do we say a speeding object doesn t have force? (Assume this object is speeding through space) (Explain) If the forces that act on a cannonball and the recoiling cannon from which

More information

Chapter 4. Forces and Newton s Laws of Motion. continued

Chapter 4. Forces and Newton s Laws of Motion. continued Chapter 4 Forces and Newton s Laws of Motion continued Clicker Question 4.3 A mass at rest on a ramp. How does the friction between the mass and the table know how much force will EXACTLY balance the gravity

More information

Name: Partners: Period: Coaster Option: 1. In the space below, make a sketch of your roller coaster.

Name: Partners: Period: Coaster Option: 1. In the space below, make a sketch of your roller coaster. 1. In the space below, make a sketch of your roller coaster. 2. On your sketch, label different areas of acceleration. Put a next to an area of negative acceleration, a + next to an area of positive acceleration,

More information

Worksheet #1 Free Body or Force diagrams

Worksheet #1 Free Body or Force diagrams Worksheet #1 Free Body or Force diagrams Drawing Free-Body Diagrams Free-body diagrams are diagrams used to show the relative magnitude and direction of all forces acting upon an object in a given situation.

More information

circular motion & gravitation physics 111N

circular motion & gravitation physics 111N circular motion & gravitation physics 111N uniform circular motion an object moving around a circle at a constant rate must have an acceleration always perpendicular to the velocity (else the speed would

More information

HW#4b Page 1 of 6. I ll use m = 100 kg, for parts b-c: accelerates upwards, downwards at 5 m/s 2 A) Scale reading is the same as person s weight (mg).

HW#4b Page 1 of 6. I ll use m = 100 kg, for parts b-c: accelerates upwards, downwards at 5 m/s 2 A) Scale reading is the same as person s weight (mg). HW#4b Page 1 of 6 Problem 1. A 100 kg person stands on a scale. a.) What would be the scale readout? b.) If the person stands on the scale in an elevator accelerating upwards at 5 m/s, what is the scale

More information

Objective: Equilibrium Applications of Newton s Laws of Motion I

Objective: Equilibrium Applications of Newton s Laws of Motion I Type: Single Date: Objective: Equilibrium Applications of Newton s Laws of Motion I Homework: Assignment (1-11) Read (4.1-4.5, 4.8, 4.11); Do PROB # s (46, 47, 52, 58) Ch. 4 AP Physics B Mr. Mirro Equilibrium,

More information

Name: Date: PRACTICE QUESTIONS PHYSICS 201 FALL 2009 EXAM 2

Name: Date: PRACTICE QUESTIONS PHYSICS 201 FALL 2009 EXAM 2 Name: Date: PRACTICE QUESTIONS PHYSICS 201 FALL 2009 EXAM 2 1. A force accelerates a body of mass M. The same force applied to a second body produces three times the acceleration. What is the mass of the

More information

STUDY GUIDE UNIT 10-Newton s Third Law

STUDY GUIDE UNIT 10-Newton s Third Law Name ANSWERS STUDY GUIDE UNIT 10-Newton s Third Law Date Agenda HW Tues, Jan 5 Wed., Jan 6 Review Video Read Section 6.1-6.3 Fill in Reading Notes (p. 2) Worksheet - Action-Reaction Pairs (p. 3) Go over

More information

Force. A force is a push or a pull. Pushing on a stalled car is an example. The force of friction between your feet and the ground is yet another.

Force. A force is a push or a pull. Pushing on a stalled car is an example. The force of friction between your feet and the ground is yet another. Force A force is a push or a pull. Pushing on a stalled car is an example. The force of friction between your feet and the ground is yet another. Force Weight is the force of the earth's gravity exerted

More information

Physics 11 Assignment KEY Dynamics Chapters 4 & 5

Physics 11 Assignment KEY Dynamics Chapters 4 & 5 Physics Assignment KEY Dynamics Chapters 4 & 5 ote: for all dynamics problem-solving questions, draw appropriate free body diagrams and use the aforementioned problem-solving method.. Define the following

More information

Forces. Definition Friction Falling Objects Projectiles Newton s Laws of Motion Momentum Universal Forces Fluid Pressure Hydraulics Buoyancy

Forces. Definition Friction Falling Objects Projectiles Newton s Laws of Motion Momentum Universal Forces Fluid Pressure Hydraulics Buoyancy Forces Definition Friction Falling Objects Projectiles Newton s Laws of Motion Momentum Universal Forces Fluid Pressure Hydraulics Buoyancy Definition of Force Force = a push or pull that causes a change

More information

Newton's laws of motion

Newton's laws of motion Newton's laws of motion Forces Forces as vectors Resolving vectors Explaining motion - Aristotle vs Newton Newton s first law Newton s second law Weight Calculating acceleration Newton s third law Moving

More information

B) 286 m C) 325 m D) 367 m Answer: B

B) 286 m C) 325 m D) 367 m Answer: B Practice Midterm 1 1) When a parachutist jumps from an airplane, he eventually reaches a constant speed, called the terminal velocity. This means that A) the acceleration is equal to g. B) the force of

More information

Chapter 5 Using Newton s Laws: Friction, Circular Motion, Drag Forces. Copyright 2009 Pearson Education, Inc.

Chapter 5 Using Newton s Laws: Friction, Circular Motion, Drag Forces. Copyright 2009 Pearson Education, Inc. Chapter 5 Using Newton s Laws: Friction, Circular Motion, Drag Forces Units of Chapter 5 Applications of Newton s Laws Involving Friction Uniform Circular Motion Kinematics Dynamics of Uniform Circular

More information

Newton s Laws of Motion

Newton s Laws of Motion Chapter 4 Newton s Laws of Motion PowerPoint Lectures for University Physics, Twelfth Edition Hugh D. Young and Roger A. Freedman Lectures by James Pazun Modified by P. Lam 7_8_2016 Goals for Chapter 4

More information

STATIC AND KINETIC FRICTION

STATIC AND KINETIC FRICTION STATIC AND KINETIC FRICTION LAB MECH 3.COMP From Physics with Computers, Vernier Software & Technology, 2000. INTRODUCTION If you try to slide a heavy box resting on the floor, you may find it difficult

More information

Physics Notes Class 11 CHAPTER 5 LAWS OF MOTION

Physics Notes Class 11 CHAPTER 5 LAWS OF MOTION 1 P a g e Inertia Physics Notes Class 11 CHAPTER 5 LAWS OF MOTION The property of an object by virtue of which it cannot change its state of rest or of uniform motion along a straight line its own, is

More information

1206EL - Concepts in Physics. Friday, September 18th

1206EL - Concepts in Physics. Friday, September 18th 1206EL - Concepts in Physics Friday, September 18th Notes There is a WebCT course for students on September 21st More information on library webpage Newton s second law Newton's first law of motion predicts

More information

Physics-1 Recitation-3

Physics-1 Recitation-3 Physics-1 Recitation-3 The Laws of Motion 1) The displacement of a 2 kg particle is given by x = At 3/2. In here, A is 6.0 m/s 3/2. Find the net force acting on the particle. (Note that the force is time

More information

Newton s Laws of Motion. I. Law of Inertia II. F=ma III. Action-Reaction

Newton s Laws of Motion. I. Law of Inertia II. F=ma III. Action-Reaction Newton s Laws of Motion I. Law of Inertia II. F=ma III. Action-Reaction While most people know what Newton's laws say, many people do not know what they mean (or simply do not believe what they mean).

More information

5. Forces and Motion-I. Force is an interaction that causes the acceleration of a body. A vector quantity.

5. Forces and Motion-I. Force is an interaction that causes the acceleration of a body. A vector quantity. 5. Forces and Motion-I 1 Force is an interaction that causes the acceleration of a body. A vector quantity. Newton's First Law: Consider a body on which no net force acts. If the body is at rest, it will

More information

TEACHER ANSWER KEY November 12, 2003. Phys - Vectors 11-13-2003

TEACHER ANSWER KEY November 12, 2003. Phys - Vectors 11-13-2003 Phys - Vectors 11-13-2003 TEACHER ANSWER KEY November 12, 2003 5 1. A 1.5-kilogram lab cart is accelerated uniformly from rest to a speed of 2.0 meters per second in 0.50 second. What is the magnitude

More information

Best Angle for QUICK LAB. Analyze and Conclude. 22 MHR Unit 1 Forces and Motion: Dynamics

Best Angle for QUICK LAB. Analyze and Conclude. 22 MHR Unit 1 Forces and Motion: Dynamics 5. Pushing a grocery cart with a force of 95 N, applied at an angle of 35 down from the horizontal, makes the cart travel at a constant speed of 1.2 m/s. What is the frictional force acting on the cart?

More information

Physics Midterm Review. Multiple-Choice Questions

Physics Midterm Review. Multiple-Choice Questions Physics Midterm Review Multiple-Choice Questions 1. A train moves at a constant velocity of 90 km/h. How far will it move in 0.25 h? A. 10 km B. 22.5 km C. 25 km D. 45 km E. 50 km 2. A bicyclist moves

More information

7. Kinetic Energy and Work

7. Kinetic Energy and Work Kinetic Energy: 7. Kinetic Energy and Work The kinetic energy of a moving object: k = 1 2 mv 2 Kinetic energy is proportional to the square of the velocity. If the velocity of an object doubles, the kinetic

More information

Physics 2A, Sec B00: Mechanics -- Winter 2011 Instructor: B. Grinstein Final Exam

Physics 2A, Sec B00: Mechanics -- Winter 2011 Instructor: B. Grinstein Final Exam Physics 2A, Sec B00: Mechanics -- Winter 2011 Instructor: B. Grinstein Final Exam INSTRUCTIONS: Use a pencil #2 to fill your scantron. Write your code number and bubble it in under "EXAM NUMBER;" an entry

More information

Two-Body System: Two Hanging Masses

Two-Body System: Two Hanging Masses Specific Outcome: i. I can apply Newton s laws of motion to solve, algebraically, linear motion problems in horizontal, vertical and inclined planes near the surface of Earth, ignoring air resistance.

More information

Summary Notes. to avoid confusion it is better to write this formula in words. time

Summary Notes. to avoid confusion it is better to write this formula in words. time National 4/5 Physics Dynamics and Space Summary Notes The coloured boxes contain National 5 material. Section 1 Mechanics Average Speed Average speed is the distance travelled per unit time. distance (m)

More information

B Answer: neither of these. Mass A is accelerating, so the net force on A must be non-zero Likewise for mass B.

B Answer: neither of these. Mass A is accelerating, so the net force on A must be non-zero Likewise for mass B. CTA-1. An Atwood's machine is a pulley with two masses connected by a string as shown. The mass of object A, m A, is twice the mass of object B, m B. The tension T in the string on the left, above mass

More information

Conceptual Questions: Forces and Newton s Laws

Conceptual Questions: Forces and Newton s Laws Conceptual Questions: Forces and Newton s Laws 1. An object can have motion only if a net force acts on it. his statement is a. true b. false 2. And the reason for this (refer to previous question) is

More information

Chapter 4 Dynamics: Newton s Laws of Motion

Chapter 4 Dynamics: Newton s Laws of Motion Chapter 4 Dynamics: Newton s Laws of Motion Units of Chapter 4 Force Newton s First Law of Motion Mass Newton s Second Law of Motion Newton s Third Law of Motion Weight the Force of Gravity; and the Normal

More information

2. (b). The newton is a unit of weight, and the quantity (or mass) of gold that weighs 1 newton is m 1 N

2. (b). The newton is a unit of weight, and the quantity (or mass) of gold that weighs 1 newton is m 1 N QUICK QUIZZS 1. Newton s second law says that the acceleration of an object is directly proportional to the resultant (or net) force acting on. Recognizing this, consider the given statements one at a

More information

Explaining Motion:Forces

Explaining Motion:Forces Explaining Motion:Forces Chapter Overview (Fall 2002) A. Newton s Laws of Motion B. Free Body Diagrams C. Analyzing the Forces and Resulting Motion D. Fundamental Forces E. Macroscopic Forces F. Application

More information