Chapter 6. Force and Motion-II

Size: px
Start display at page:

Download "Chapter 6. Force and Motion-II"

Transcription

1 Chapter 6 Force and Motion-II

2 6.2 Friction

3 Frictional Forces Friction has its basis in surfaces that are not completely smooth:

4 Frictional Forces The static frictional force keeps an object from starting to move when a force is applied. The static frictional force has a maximum value, but may take on any value from zero to the maximum, depending on what is needed to keep the sum of forces zero.

5 Frictional Forces where The static frictional force is also independent of the area of contact and the relative speed of the surfaces.

6 Frictional Forces The kinetic frictional force is also independent of the relative speed of the surfaces, and of their area of contact.

7 Frictional Forces Kinetic friction: the friction experienced by surfaces sliding against one another The frictional forces (Both static and kinetic) depends on the normal force: The constant is called the coefficient of kinetic friction.

8 6.2 Frictional Force: motion of a crate with applied forces There is no attempt at sliding. Thus, no friction and no motion. NO FRICTION Force F attempts sliding but is balanced by the frictional force. No motion. STATIC FRICTION Force F is now stronger but is still balanced by the frictional force. No motion. LARGER STATIC FRICTION Force F is now even stronger but is still balanced by the frictional force. No motion. EVEN LARGER STATIC FRICTION f s is the static frictional force f k is the kinetic frictional force Finally, the applied force has overwhelmed the static frictional force. Block slides and accelerates. WEAK KINETIC FRICTION To maintain the speed, weaken force F to match the weak frictional force. SAME WEAK KINETIC FRICTION Static frictional force can only match growing applied force. Kinetic frictional force has only one value (no matching).

9 6.2 Friction Static frictional force acts when there is no relative motion between the body and the contact surface The magnitude of the static frictional force increases as the applied force to the body is increased Finally when the there is relative motion between the body and the contact surface, kinetic friction starts to act. Usually, the magnitude of the kinetic frictional force, which acts when there is motion, is less than the maximum magnitude of the static frictional force, which acts when there is no motion.

10 6.2 Frictional Force Often, the sliding motion of one surface over another is jerky because the two surfaces alternately stick together and then slip. Examples: Tires skid on dry pavement Fingernails scratch on a chalkboard A rusty hinge is forced to open A bow is drawn on a violin string

11 Frictional Forces

12 Summary: friction Property 1. If the body does not move, then the static frictional force and the component of F that is parallel to the surface balance each other. They are equal in magnitude, and is f s directed opposite that component of F. Property 2. The magnitude of has a maximum value f s,max that is given by where μ s is the coefficient of static friction and F N is the magnitude of the normal force on the body from the surface. If the magnitude of the component of F that is parallel to the surface exceeds f s,max, then the body begins to slide along the surface. Property 3. If the body begins to slide along the surface, the magnitude of the frictional force rapidly decreases to a value f k given by where μ k is the coefficient of kinetic friction. Thereafter, during the sliding, a kinetic frictional force f k opposes the motion.

13 Sample Problem, friction applied at an angle

14 Circular Motion An object moving in a circle must have a force acting on it; otherwise it would move in a straight line. The direction of the force is towards the center of the circle.

15 Uniform circular motion Uniform circular motion: body moving with speed v in uniform circular motion feels a centripetal acceleration directed towards the center of the circle of radius R. Examples: 1.When a car moves in the circular arc, it has an acceleration that is directed toward the center of the circle. The frictional force on the tires from the road provide the centripetal force responsible for that. 2.In a space shuttle around the earth, both the rider and the shuttle are in uniform circular motion and have accelerations directed toward the center of the circle. Centripetal forces, causing these accelerations, are gravitational pulls exerted by Earth and directed radially inward, toward the center of Earth.

16 6.5: Uniform circular motion A centripetal force accelerates a body by changing the direction of the body s velocity without changing the body s speed. From Newton s 2 nd Law: Since the speed v here is constant, the magnitudes of the acceleration and the force are also constant.

17 Circular Motion Some algebra gives us the magnitude of the acceleration, and therefore the force, required to keep an object of mass m moving in a circle of radius r. The magnitude of the force is given by:

18 Circular Motion This force may be provided by the tension in a string, the normal force, or friction, among others.

19 Circular Motion

20 6.5: Uniform circular motion Example of a hockey puck: Fig. 6-8 An overhead view of a hockey puck moving with constant speed v in a circular path of radius R on a horizontal frictionless surface. The centripetal force on the puck is T, the pull from the string, directed inward along the radial axis r extending through the puck.

Actually, no perfectly frictionless surface exists. For two surfaces in contact, tangential forces, called friction forces, will develop if one

Actually, no perfectly frictionless surface exists. For two surfaces in contact, tangential forces, called friction forces, will develop if one Chapter 8 Friction Actually, no perfectly frictionless surface exists. For two surfaces in contact, tangential forces, called friction forces, will develop if one attempts to move one relative to the other.

More information

Chapter 6. Force and Motion-II (Friction, Drag, Circular Motion)

Chapter 6. Force and Motion-II (Friction, Drag, Circular Motion) Chapter 6 Force and Motion-II (Friction, Drag, Circular Motion) 6.2 Frictional Force: Motion of a crate with applied forces There is no attempt at sliding. Thus, no friction and no motion. NO FRICTION

More information

Chapter 6 Applications of Newton s Laws. Copyright 2010 Pearson Education, Inc.

Chapter 6 Applications of Newton s Laws. Copyright 2010 Pearson Education, Inc. Chapter 6 Applications of Newton s Laws Units of Chapter 6 Frictional Forces Strings and Springs Translational Equilibrium Connected Objects Circular Motion 6-1 Frictional Forces Friction has its basis

More information

Chapter 6. Force and Motion II

Chapter 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 information

Lecture Outline Chapter 6. Physics, 4 th Edition James S. Walker. Copyright 2010 Pearson Education, Inc.

Lecture Outline Chapter 6. Physics, 4 th Edition James S. Walker. Copyright 2010 Pearson Education, Inc. Lecture Outline Chapter 6 Physics, 4 th Edition James S. Walker Chapter 6 Applications of Newton s Laws Units of Chapter 6 Frictional Forces Strings and Springs Translational Equilibrium Connected Objects

More information

Circular Motion Concept Questions

Circular Motion Concept Questions Circular Motion Concept Questions Question 1 A bead is given a small push at the top of a hoop (position A) and is constrained to slide around a frictionless circular wire (in a vertical plane). Circle

More information

Chapter 5 Circular Motion; Gravitation

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 Newton s Law of Universal Gravitation

More information

1. In which situation is an object undergoing centripetal acceleration? (C) a car accelerating on a drag strip (D) a hockey puck gliding on ice

1. In which situation is an object undergoing centripetal acceleration? (C) a car accelerating on a drag strip (D) a hockey puck gliding on ice Physics 3204 Assignment 2.1 UCM DUE: Thursday Nov 24, 2017 Name: Part A. Multiple Choice: Select the best possible answer. Place the answer on the answer sheet. 1. In which situation is an object undergoing

More information

Circular Motion Dynamics Concept Questions

Circular Motion Dynamics Concept Questions Circular Motion Dynamics Concept Questions Problem 1: A puck of mass m is moving in a circle at constant speed on a frictionless table as shown above. The puck is connected by a string to a suspended bob,

More information

Chapter 5 Circular Motion; Gravitation

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

More information

Mini Exam # 1. You get them back in the the recitation section for which you are officially enrolled.

Mini Exam # 1. You get them back in the the recitation section for which you are officially enrolled. Mini Exam # 1 You get them back in the the recitation section for which you are officially enrolled. One third of you did very well ( 18 points out of 20). The average was 13.4. If you stay in average,

More information

Lecture PowerPoints. Chapter 5 Physics for Scientists & Engineers, with Modern Physics, 4 th edition. Giancoli

Lecture PowerPoints. Chapter 5 Physics for Scientists & Engineers, with Modern Physics, 4 th edition. Giancoli Lecture PowerPoints Chapter 5 Physics for Scientists & Engineers, with Modern Physics, 4 th edition 2009 Pearson Education, Inc. This work is protected by United States copyright laws and is provided solely

More information

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

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

More information

Lecture 10. Example: Friction and Motion

Lecture 10. Example: Friction and Motion Lecture 10 Goals: Exploit Newton s 3 rd Law in problems with friction Employ Newton s Laws in 2D problems with circular motion Assignment: HW5, (Chapter 7, due 2/24, Wednesday) For Tuesday: Finish reading

More information

66 Chapter 6: FORCE AND MOTION II

66 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 information

Choose the best answer for Questions 1-15 below. Mark your answer on your scantron form using a #2 pencil.

Choose the best answer for Questions 1-15 below. Mark your answer on your scantron form using a #2 pencil. Name: ID #: Section #: PART I: MULTIPLE CHOICE QUESTIONS Choose the best answer for Questions 1-15 below. Mark your answer on your scantron form using a #2 pencil. 1. A 55.0-kg box rests on a horizontal

More information

General Physics I Spring Applying Newton s Laws

General 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 information

Circular Motion Test Review

Circular Motion Test Review Circular Motion Test Review Name: Date: 1) Is it possible for an object moving with a constant speed to accelerate? Explain. A) No, if the speed is constant then the acceleration is equal to zero. B) No,

More information

Uniform Circular Motion. Uniform Circular Motion

Uniform Circular Motion. Uniform Circular Motion Uniform Circular Motion Uniform Circular Motion Uniform Circular Motion An object that moves at uniform speed in a circle of constant radius is said to be in uniform circular motion. Question: Why is uniform

More information

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

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

More information

Exam 2 Phys Fall 2002 Version A. Name ID Section

Exam 2 Phys Fall 2002 Version A. Name ID Section Closed book exam - Calculators are allowed. Only the official formula sheet downloaded from the course web page can be used. You are allowed to write notes on the back of the formula sheet. Use the scantron

More information

CIRCULAR MOTION AND GRAVITATION

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

More information

Circular Motion.

Circular Motion. 1 Circular Motion www.njctl.org 2 Topics of Uniform Circular Motion (UCM) Kinematics of UCM Click on the topic to go to that section Period, Frequency, and Rotational Velocity Dynamics of UCM Vertical

More information

Wiley Plus. Final Assignment (5) Is Due Today: Before 11 pm!

Wiley Plus. Final Assignment (5) Is Due Today: Before 11 pm! Wiley Plus Final Assignment (5) Is Due Today: Before 11 pm! Final Exam Review December 9, 009 3 What about vector subtraction? Suppose you are given the vector relation A B C RULE: The resultant vector

More information

Circular Motion. - The velocity is tangent to the path and perpendicular to the radius of the circle

Circular Motion. - The velocity is tangent to the path and perpendicular to the radius of the circle Circular Motion Level : Physics Teacher : Kim 1. Uniform Circular Motion - According to Newton s 1 st law, an object in motion will move in a straight line at a constant speed unless an unbalance force

More information

Chapter 8: Dynamics in a plane

Chapter 8: Dynamics in a plane 8.1 Dynamics in 2 Dimensions p. 210-212 Chapter 8: Dynamics in a plane 8.2 Velocity and Acceleration in uniform circular motion (a review of sec. 4.6) p. 212-214 8.3 Dynamics of Uniform Circular Motion

More information

SPH3U1 - Dynamics Problems Set 3

SPH3U1 - Dynamics Problems Set 3 SPH3U1 - Dynamics Problems Set 3 Problems 1. A force of 1.2 N [ ] is applied to an object of mass 1.5 kg. It accelerates at 0.50 m/s 2 [ ] along a surface. Determine the force of friction that is acting

More information

Unit 5 Circular Motion and Gravitation

Unit 5 Circular Motion and Gravitation Unit 5 Circular Motion and Gravitation In the game of tetherball, the struck ball whirls around a pole. In what direction does the net force on the ball point? 1) Tetherball 1) toward the top of the pole

More information

General Physics I Spring Forces and Newton s Laws of Motion

General 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 information

PH 2213 : Chapter 05 Homework Solutions

PH 2213 : Chapter 05 Homework Solutions PH 2213 : Chapter 05 Homework Solutions Problem 5.4 : The coefficient of static friction between hard rubber and normal street pavement is about 0.90. On how steep a hill (maximum angle) can you leave

More information

Chapter 8. Dynamics II: Motion in a Plane

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

More information

Dynamics Review Checklist

Dynamics Review Checklist Dynamics Review Checklist Newton s Laws 2.1.1 Explain Newton s 1 st Law (the Law of Inertia) and the relationship between mass and inertia. Which of the following has the greatest amount of inertia? (a)

More information

Review of Lectures 1, 2 and 3

Review 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 information

WS-CH-4 Motion and Force Show all your work and equations used. Isaac Newton ( )

WS-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 information

PHYS 124 Section A1 Mid-Term Examination Spring 2006 SOLUTIONS

PHYS 124 Section A1 Mid-Term Examination Spring 2006 SOLUTIONS PHYS 14 Section A1 Mid-Term Examination Spring 006 SOLUTIONS Name Student ID Number Instructor Marc de Montigny Date Monday, May 15, 006 Duration 60 minutes Instructions Items allowed: pen or pencil, calculator

More information

TYPICAL NUMERIC QUESTIONS FOR PHYSICS I REGULAR QUESTIONS TAKEN FROM CUTNELL AND JOHNSON CIRCULAR MOTION CONTENT STANDARD IB

TYPICAL NUMERIC QUESTIONS FOR PHYSICS I REGULAR QUESTIONS TAKEN FROM CUTNELL AND JOHNSON CIRCULAR MOTION CONTENT STANDARD IB TYPICAL NUMERIC QUESTIONS FOR PHYSICS I REGULAR QUESTIONS TAKEN FROM CUTNELL AND JOHNSON CIRCULAR MOTION CONTENT STANDARD IB 1. A car traveling at 20 m/s rounds a curve so that its centripetal acceleration

More information

There are two main types of friction:

There 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 information

Algebra Based Physics Uniform Circular Motion

Algebra Based Physics Uniform Circular Motion 1 Algebra Based Physics Uniform Circular Motion 2016 07 20 www.njctl.org 2 Uniform Circular Motion (UCM) Click on the topic to go to that section Period, Frequency and Rotational Velocity Kinematics of

More information

AP Physics Free Response Practice Dynamics

AP Physics Free Response Practice Dynamics AP Physics Free Response Practice Dynamics 14) In the system shown above, the block of mass M 1 is on a rough horizontal table. The string that attaches it to the block of mass M 2 passes over a frictionless

More information

Dynamics Review Checklist

Dynamics Review Checklist Dynamics Review Checklist Newton s Laws 2.1.1 Explain Newton s 1 st Law (the Law of Inertia) and the relationship between mass and inertia. Which of the following has the greatest amount of inertia? (a)

More information

SEE the list given for chapter 04 where Newton s laws were introduced.

SEE the list given for chapter 04 where Newton s laws were introduced. PH2213 : Examples from Chapter 5 : Applying Newton s Laws Key Concepts Newton s Laws (basically Σ F = m a ) allow us to relate the forces acting on an object (left-hand side) to the motion of the object,

More information

HATZIC SECONDARY SCHOOL

HATZIC SECONDARY SCHOOL HATZIC SECONDARY SCHOOL PROVINCIAL EXAMINATION ASSIGNMENT CIRCULAR MOTION MULTIPLE CHOICE / 30 OPEN ENDED / 65 TOTAL / 95 NAME: 1. An object travels along a path at constant speed. There is a constant

More information

Extension of Circular Motion & Newton s Laws. Chapter 6 Mrs. Warren Kings High School

Extension of Circular Motion & Newton s Laws. Chapter 6 Mrs. Warren Kings High School Extension of Circular Motion & Newton s Laws Chapter 6 Mrs. Warren Kings High chool Review from Chapter 4 Uniform Circular Motion Centripetal Acceleration Uniform Circular Motion, Force F r A force is

More information

+F N = -F g. F g = m٠a g

+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 information

Phys101 Second Major-162 Zero Version Coordinator: Dr. Kunwar S. Saturday, March 25, 2017 Page: 1

Phys101 Second Major-162 Zero Version Coordinator: Dr. Kunwar S. Saturday, March 25, 2017 Page: 1 Coordinator: Dr. Kunwar S. Saturday, March 25, 2017 Page: 1 Q1. Only two horizontal forces act on a 3.0 kg body that can move over a frictionless floor. One force is 20 N, acting due east, and the other

More information

Chapter 6. Force and motion II

Chapter 6. Force and motion II Chapter 6. Force and motion II Friction Static friction Sliding (Kinetic) friction Circular motion Physics, Page 1 Summary of last lecture Newton s First Law: The motion of an object does not change unless

More information

Dynamics Review Checklist

Dynamics Review Checklist Dynamics Review Checklist Newton s Laws 2.1.1 Explain Newton s 1 st Law (the Law of Inertia) and the relationship between mass and inertia. Which of the following has the greatest amount of inertia? (a)

More information

Angular Speed and Angular Acceleration Relations between Angular and Linear Quantities

Angular Speed and Angular Acceleration Relations between Angular and Linear Quantities Angular Speed and Angular Acceleration Relations between Angular and Linear Quantities 1. The tires on a new compact car have a diameter of 2.0 ft and are warranted for 60 000 miles. (a) Determine the

More information

Name Period Date. 75 kg. Horizontal, frictionless surface. Label a coordinate system, write the formula, substitute and solve.

Name Period Date. 75 kg. Horizontal, frictionless surface. Label a coordinate system, write the formula, substitute and solve. Example Problems 5.3 Net Force E1. Two horizontal forces, 225 N and 165 N, are exerted in the same direction on a 75 kg crate as shown below. Find the net force and the acceleration of the crate. 165 N

More information

Chapter 9 TORQUE & Rotational Kinematics

Chapter 9 TORQUE & Rotational Kinematics Chapter 9 TORQUE & Rotational Kinematics This motionless person is in static equilibrium. The forces acting on him add up to zero. Both forces are vertical in this case. This car is in dynamic equilibrium

More information

Name Period Date. Record all givens, draw a picture, arrow all vectors, write the formula, substitute and solve. units

Name 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

Exam 2: Equation Summary

Exam 2: Equation Summary MASSACHUSETTS INSTITUTE OF TECHNOLOGY Department of Physics 8.01 Physics Fall Term 2012 Exam 2: Equation Summary Newton s Second Law: Force, Mass, Acceleration: Newton s Third Law: Center of Mass: Velocity

More information

4) Vector = and vector = What is vector = +? A) B) C) D) E)

4) Vector = and vector = What is vector = +? A) B) C) D) E) 1) Suppose that an object is moving with constant nonzero acceleration. Which of the following is an accurate statement concerning its motion? A) In equal times its speed changes by equal amounts. B) In

More information

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

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

More information

Uniform Circular Motion

Uniform Circular Motion Slide 1 / 112 Uniform Circular Motion 2009 by Goodman & Zavorotniy Slide 2 / 112 Topics of Uniform Circular Motion (UCM) Kinematics of UCM Click on the topic to go to that section Period, Frequency, and

More information

Random sample problems

Random sample problems UNIVERSITY OF ALABAMA Department of Physics and Astronomy PH 125 / LeClair Spring 2009 Random sample problems 1. The position of a particle in meters can be described by x = 10t 2.5t 2, where t is in seconds.

More information

Chapter 2. Force and Newton s Laws

Chapter 2. Force and Newton s Laws Chapter 2 Force and Newton s Laws 2 1 Newton s First Law Force Force A push or pull that one body exerts on another body. Examples : 2 Categories of Forces Forces Balanced Forces Unbalanced Forces Balanced

More information

Physics for Scientist and Engineers third edition Newton s Laws. Example Problem. Variables. Drawing. Solution. Answer: O, 10 N, 20 N, 38N, 39N, 29N

Physics for Scientist and Engineers third edition Newton s Laws. Example Problem. Variables. Drawing. Solution. Answer: O, 10 N, 20 N, 38N, 39N, 29N Our 10.0 kg mystery bx rest on a horizontal floor. The coefficent of static friction is µs= 0.40 and the coefficent of kinetic friction is µk= 0.30. Determine the force of friction Ffr acting on the box

More information

UNIVERSITY OF SASKATCHEWAN Department of Physics and Engineering Physics

UNIVERSITY OF SASKATCHEWAN Department of Physics and Engineering Physics UNIVERSITY OF SASKATCHEWAN Department of Physics and Engineering Physics Physics 111.6 MIDTERM TEST #2 November 15, 2001 Time: 90 minutes NAME: STUDENT NO.: (Last) Please Print (Given) LECTURE SECTION

More information

AP PHYSICS Chapter 5. Friction Inclines Circular Motion

AP PHYSICS Chapter 5. Friction Inclines Circular Motion AP PHYSICS Chapter 5 Friction Inclines Circular Motion Friction Force that opposes motion due to contact between surfaces. Depends on: Composition and Qualities of the two surfaces in contact (μ) Roughness,

More information

Consider the case of a 100 N. mass on a horizontal surface as shown below:

Consider the case of a 100 N. mass on a horizontal surface as shown below: 1.9.1 Introduction The study of friction is called: The force of friction is defined as: The force of friction acting between two surfaces has three properties: i) ii) iii) Consider the case of a 100 N.

More information

Multiple Choice Portion

Multiple Choice Portion Unit 5: Circular Motion and Gravitation Please Note that the gravitational potential energy questions are located in Unit 4 (Energy etc.) Multiple Choice Portion 1. What is the centripetal acceleration

More information

What is a Force? Free-Body diagrams. Contact vs. At-a-Distance 11/28/2016. Forces and Newton s Laws of Motion

What is a Force? Free-Body diagrams. Contact vs. At-a-Distance 11/28/2016. Forces and Newton s Laws of Motion Forces and Newton s Laws of Motion What is a Force? In generic terms: a force is a push or a pull exerted on an object that could cause one of the following to occur: A linear acceleration of the object

More information

AP Physics C: Mechanics Practice (Newton s Laws including friction, resistive forces, and centripetal force).

AP Physics C: Mechanics Practice (Newton s Laws including friction, resistive forces, and centripetal force). AP Physics C: Mechanics Practice (Newton s Laws including friction, resistive forces, and centripetal force). 1981M1. A block of mass m, acted on by a force of magnitude F directed horizontally to the

More information

Chapter 5 Lecture Notes

Chapter 5 Lecture Notes Formulas: a C = v 2 /r a = a C + a T F = Gm 1 m 2 /r 2 Chapter 5 Lecture Notes Physics 2414 - Strauss Constants: G = 6.67 10-11 N-m 2 /kg 2. Main Ideas: 1. Uniform circular motion 2. Nonuniform circular

More information

2. A 10 kg box is being pushed by a 100 N force 30 above the horizontal. The acceleration of the box is 5 m/s 2. What is the value of µ k?

2. A 10 kg box is being pushed by a 100 N force 30 above the horizontal. The acceleration of the box is 5 m/s 2. What is the value of µ k? Physics Whiteboard Forces with Friction 1. A 70 kg block is being pushed across a tabletop with a constant force of 350 N exerted in the direction of travel. If the coefficient of kinetic friction (µ k

More information

Units. EMU Physics Department. Ali ÖVGÜN.

Units. EMU Physics Department. Ali ÖVGÜN. Units Ali ÖVGÜN EMU Physics Department www.aovgun.com 1 mile = 1609 m January 22-25, 2013 January 22-25, 2013 Vectors Ali ÖVGÜN EMU Physics Department www.aovgun.com Example 1: Operations with Vectors

More information

AP Physics 1 - Test 05 - Force and Motion

AP Physics 1 - Test 05 - Force and Motion P Physics 1 - Test 05 - Force and Motion Score: 1. brick slides on a horizontal surface. Which of the following will increase the magnitude of the frictional force on it? Putting a second brick on top

More information

1D-04 Radial Acceleration & Tangential Velocity

1D-04 Radial Acceleration & Tangential Velocity 1D-04 Radial Acceleration & Tangential Velocity Once the string is cut, where is the ball going? AT ANY INSTANT, THE VELOCITY VECTOR OF THE BALL IS DIRECTED ALONG THE TANGENT. AT THE INSTANT WHEN THE BLADE

More information

AP Mechanics Summer Assignment

AP Mechanics Summer Assignment 2012-2013 AP Mechanics Summer Assignment To be completed in summer Submit for grade in September Name: Date: Equations: Kinematics (For #1 and #2 questions: use following equations only. Need to show derivation

More information

Newton s Laws.

Newton s Laws. Newton s Laws http://mathsforeurope.digibel.be/images Forces and Equilibrium If the net force on a body is zero, it is in equilibrium. dynamic equilibrium: moving relative to us static equilibrium: appears

More information

Experiment #7 Centripetal Force Pre-lab Questions Hints

Experiment #7 Centripetal Force Pre-lab Questions Hints Experiment #7 Centripetal Force Pre-lab Questions Hints The following are some hints for this pre-lab, since a few of these questions can be a little difficult. Note that these are not necessarily the

More information

AP practice ch 7-8 Multiple Choice

AP practice ch 7-8 Multiple Choice AP practice ch 7-8 Multiple Choice 1. A spool of thread has an average radius of 1.00 cm. If the spool contains 62.8 m of thread, how many turns of thread are on the spool? "Average radius" allows us to

More information

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Diagram 1 A) B - A. B) A - B. C) A + B. D) A B.

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Diagram 1 A) B - A. B) A - B. C) A + B. D) A B. Exam Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) In the diagram shown, the unknown vector is 1) Diagram 1 A) B - A. B) A - B. C) A + B.

More information

Circular Motion and Universal Law of Gravitation. 8.01t Oct 4, 2004

Circular Motion and Universal Law of Gravitation. 8.01t Oct 4, 2004 Circular Motion and Universal Law of Gravitation 8.01t Oct 4, 2004 Summary: Circular Motion arc length s= Rθ tangential velocity ds v = = dt dθ R = Rω dt 2 d θ 2 dt tangential acceleration a θ = dv θ =

More information

Circular Motion. A car is traveling around a curve at a steady 45 mph. Is the car accelerating? A. Yes B. No

Circular Motion. A car is traveling around a curve at a steady 45 mph. Is the car accelerating? A. Yes B. No Circular Motion A car is traveling around a curve at a steady 45 mph. Is the car accelerating? A. Yes B. No Circular Motion A car is traveling around a curve at a steady 45 mph. Which vector shows the

More information

Figure 5.1a, b IDENTIFY: Apply to the car. EXECUTE: gives.. EVALUATE: The force required is less than the weight of the car by the factor.

Figure 5.1a, b IDENTIFY: Apply to the car. EXECUTE: gives.. EVALUATE: The force required is less than the weight of the car by the factor. 51 IDENTIFY: for each object Apply to each weight and to the pulley SET UP: Take upward The pulley has negligible mass Let be the tension in the rope and let be the tension in the chain EXECUTE: (a) The

More information

PH201 Chapter 5 Solutions

PH201 Chapter 5 Solutions PH201 Chapter 5 Solutions 5.4. Set Up: For each object use coordinates where +y is upward. Each object has Call the objects 1 and 2, with and Solve: (a) The free-body diagrams for each object are shown

More information

University 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 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 information

1 A car moves around a circular path of a constant radius at a constant speed. Which of the following statements is true?

1 A car moves around a circular path of a constant radius at a constant speed. Which of the following statements is true? Slide 1 / 30 1 car moves around a circular path of a constant radius at a constant speed. Which of the following statements is true? The car s velocity is constant The car s acceleration is constant The

More information

Physics 2A Chapter 4: Forces and Newton s Laws of Motion

Physics 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 information

Physics 111: Mechanics Lecture 9

Physics 111: Mechanics Lecture 9 Physics 111: Mechanics Lecture 9 Bin Chen NJIT Physics Department Circular Motion q 3.4 Motion in a Circle q 5.4 Dynamics of Circular Motion If it weren t for the spinning, all the galaxies would collapse

More information

Physics 12. Unit 5 Circular Motion and Gravitation Part 1

Physics 12. Unit 5 Circular Motion and Gravitation Part 1 Physics 12 Unit 5 Circular Motion and Gravitation Part 1 1. Nonlinear motions According to the Newton s first law, an object remains its tendency of motion as long as there is no external force acting

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. Common Quiz Mistakes / Practice for Final Exam Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) A ball is thrown directly upward and experiences

More information

Multiple Choice (A) (B) (C) (D)

Multiple Choice (A) (B) (C) (D) Multiple Choice 1. A ball is fastened to a string and is swung in a vertical circle. When the ball is at the highest point of the circle its velocity and acceleration directions are: (A) (B) (C) (D) 2.

More information

LECTURE 12 FRICTION & SPRINGS. Instructor: Kazumi Tolich

LECTURE 12 FRICTION & SPRINGS. Instructor: Kazumi Tolich LECTURE 12 FRICTION & SPRINGS Instructor: Kazumi Tolich Lecture 12 2 Reading chapter 6-1 to 6-2 Friction n Static friction n Kinetic friction Springs Origin of friction 3 The origin of friction is electromagnetic

More information

Circular Motion (Chapter 5)

Circular Motion (Chapter 5) Circular Motion (Chapter 5) So far we have focused on linear motion or motion under gravity (free-fall). Question: What happens when a ball is twirled around on a string at constant speed? Ans: Its velocity

More information

Practice. Newton s 3 Laws of Motion. Recall. Forces a push or pull acting on an object; a vector quantity measured in Newtons (kg m/s²)

Practice. Newton s 3 Laws of Motion. Recall. Forces a push or pull acting on an object; a vector quantity measured in Newtons (kg m/s²) Practice A car starts from rest and travels upwards along a straight road inclined at an angle of 5 from the horizontal. The length of the road is 450 m and the mass of the car is 800 kg. The speed of

More information

Chapter 4: Forces. Goals of Period Net Force and Acceleration. Force 1 Force 2

Chapter 4: Forces. Goals of Period Net Force and Acceleration. Force 1 Force 2 Chapter 4: Forces Goals of Period 4 Section 4.1: To discuss the effect of net forces acting on objects Section 4.2: To examine the acceleration of falling objects Section 4.3: To describe the frictional

More information

Newton s Laws. A force is simply a push or a pull. Forces are vectors; they have both size and direction.

Newton 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 information

Chapter 4. The Laws of Motion. 1. Force. 2. Newton s Laws. 3. Applications. 4. Friction

Chapter 4. The Laws of Motion. 1. Force. 2. Newton s Laws. 3. Applications. 4. Friction Chapter 4 The Laws of Motion 1. Force 2. Newton s Laws 3. Applications 4. Friction 1 Classical Mechanics What is classical Mechanics? Under what conditions can I use it? 2 Sir Isaac Newton 1642 1727 Formulated

More information

Chapter 5 Applying Newton s Laws

Chapter 5 Applying Newton s Laws Chapter 5 Applying Newton s Laws In this chapter we will introduce further applications of Newton s 1 st and 2 nd law. In summary, all of the contact forces and action-at-a-distance forces will go on the

More information

Exam 1 Solutions. Kinematics and Newton s laws of motion

Exam 1 Solutions. Kinematics and Newton s laws of motion Exam 1 Solutions Kinematics and Newton s laws of motion No. of Students 80 70 60 50 40 30 20 10 0 PHY231 Spring 2012 Midterm Exam 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Raw Score 1. In which

More information

2. Kinetic friction - The force that acts against an object s motion. - Occurs once static friction has been overcome and object is moving

2. 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

Physics 53 Summer Exam I. Solutions

Physics 53 Summer Exam I. Solutions Exam I Solutions In questions or problems not requiring numerical answers, express the answers in terms of the symbols for the quantities given, and standard constants such as g. In numerical questions

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

1. 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) 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 information

Rotational Motion Examples:

Rotational Motion Examples: Rotational Motion Examples: 1. A 60. cm diameter wheel rotates through 50. rad. a. What distance will it move? b. How many times will the wheel rotate in this time? 2. A saw blade is spinning at 2000.

More information

PHYSICS 231 Laws of motion PHY 231

PHYSICS 231 Laws of motion PHY 231 PHYSICS 231 Laws of motion 1 Newton s Laws First Law: If the net force exerted on an object is zero the object continues in its original state of motion; if it was at rest, it remains at rest. If it was

More information

In this lecture we will discuss three topics: conservation of energy, friction, and uniform circular motion.

In this lecture we will discuss three topics: conservation of energy, friction, and uniform circular motion. 1 PHYS:100 LECTURE 9 MECHANICS (8) In this lecture we will discuss three topics: conservation of energy, friction, and uniform circular motion. 9 1. Conservation of Energy. Energy is one of the most fundamental

More information