Chapter 7 WORK, ENERGY, AND Power Work Done by a Constant Force Kinetic Energy and the WorkEnergy Theorem Work Done by a Variable Force Power


 Vincent Summers
 5 years ago
 Views:
Transcription
1 Chapter 7 WORK, ENERGY, AND Power Work Done by a Constant Force Kinetic Energy and the WorkEnergy Theorem Work Done by a Variable Force Power Examples of work. (a) The work done by the force F on this lawn mower is Fd cos θ. Note that F cos θ is the component of the force in the direction of motion. (b) A person holding a briefcase does no work on it, because there is no motion. No energy is transferred to or from the briefcase. (c) (d) (e) The person moving the briefcase horizontally at a constant speed does no work on it, and transfers no energy to it. Work is done on the briefcase by carrying it up stairs at constant speed, because there is necessarily a component of force F in the direction of the motion. Energy is transferred to the briefcase and could in turn be used to do work. When the briefcase is lowered, energy is transferred out of the briefcase and into an electric generator. Here the work done on the briefcase by the generator is negative, removing energy from the briefcase, because F and d are in opposite directions.
2 (a) A graph of F cos θ vs. d, when F cos θ is constant. The area under the curve represents the work done by the force. (b) A graph of F cos θ vs. d in which the force varies. The work done for each interval is the area of each strip; thus, the total area under the curve equals the total work done.
3 The speed of a roller coaster increases as gravity pulls it downhill and is greatest at its lowest point. Viewed in terms of energy, the rollercoasterearth system s gravitational potential energy is converted to kinetic energy. If work done by friction is negligible, all ΔPE g is converted to KE.
4 (a)an undeformed spring has no PEs stored in it. (b)the force needed to stretch (or compress) the spring a distance x has a magnitude F = kx, and the work done to stretch (or compress) it is 1 2 kx2 (c)because the force is conservative, this work is stored as potential energy (PEs) in the spring, and it can be fully recovered. (d)a graph of F vs. x has a slope of k, and the area under the graph is 1 kx2. Thus the work done or potential energy stored is 2 1 kx2. 2
5 A toy car is pushed by a compressed spring and coasts up a slope. Assuming negligible friction, the potential energy in the spring is first completely converted to kinetic energy, and then to a combination of kinetic and gravitational potential energy as the car rises. The details of the path are unimportant because all forces are conservative the car would have the same final speed if it took the alternate path shown.
6 Work Done by a Constant Force The definition of work, when the force is parallel to the displacement: SI unit: newtonmeter (N m) = joule, J
7 Work Done by a Constant Force If the force is at an angle to the displacement:
8 Work Done by a Constant Force The work can also be written as the dot product of the force and the displacement:
9 The work done may be positive, zero, or negative, depending on the angle between the force and the displacement:
10 If there is more than one force acting on an object, we can find the work done by each force, and also the work done by the net force:
11 Kinetic Energy and the WorkEnergy Theorem When positive work is done on an object, its speed increases; when negative work is done, its speed decreases. After algebraic manipulations of the equations of motion, we find: Therefore, we define the kinetic energy:
12 WorkEnergy Theorem: The total work done on an object is equal to its change in kinetic energy. Work Done by a Variable Force If the force is constant, we can interpret the work done graphically: If the force takes on several successive constant values:
13 We can then approximate a continuously varying force by a succession of constant values.
14 The force needed to stretch a spring an amount x is F = kx. Therefore, the work done in stretching the spring is
15 Conservative and Nonconservative Forces Potential Energy and the Work Done by Conservative Forces Conservation of Mechanical Energy Work Done by Nonconservative Forces Potential Energy Curves and Equipotentials Conservative force: the work it does is stored in the form of energy that can be released at a later time Example of a conservative force: gravity Example of a nonconservative force: friction Also: the work done by a conservative force moving an object around a closed path is zero; this is not true for a nonconservative force
16 Work done by gravity on a closed path is zero: Work done by friction on a closed path is not zero:
17 The work done by a conservative force is zero on any closed path: The Work Done by Conservative Forces If we pick up a ball and put it on the shelf, we have done work on the ball. We can get that energy back if the ball falls back off the shelf; in the meantime, we say the energy is stored as potential energy.
18 Conservation of Mechanical Energy Definition of mechanical energy:
19 Work Done by Nonconservative Forces In the presence of nonconservative forces, the total mechanical energy is not conserved:
20 Potential Energy Curves and Equipotentials The curve of a hill or a roller coaster is itself essentially a plot of the gravitational potential energy:
21 Potential Energy Curves and Equipotentials The potential energy curve for a spring:
22 Power Power is a measure of the rate at which work is done: SI unit: J/s = watt, W 1 horsepower = 1 hp = 746 W If an object is moving at a constant speed in the face of friction, gravity, air resistance, and so forth, the power exerted by the driving force can be written:
23 Summary If the force is constant and parallel to the displacement, work is force times distance If the force is not parallel to the displacement, The total work is the work done by the net force: SI unit of work: the joule, J Total work is equal to the change in kinetic energy:
24
WORK DONE BY A CONSTANT FORCE
WORK DONE BY A CONSTANT FORCE The definition of work, W, when a constant force (F) is in the direction of displacement (d) is W = Fd SI unit is the Newtonmeter (Nm) = Joule, J If you exert a force of
More informationChapter 6 Work and Energy
Chapter 6 WORK AND ENERGY PREVIEW Work is the scalar product of the force acting on an object and the displacement through which it acts. When work is done on or by a system, the energy of that system
More informationCHAPTER 6 WORK AND ENERGY
CHAPTER 6 WORK AND ENERGY CONCEPTUAL QUESTIONS. REASONING AND SOLUTION The work done by F in moving the box through a displacement s is W = ( F cos 0 ) s= Fs. The work done by F is W = ( F cos θ). s From
More informationphysics 111N work & energy
physics 111N work & energy conservation of energy entirely gravitational potential energy kinetic energy turning into gravitational potential energy gravitational potential energy turning into kinetic
More informationAP Physics  Chapter 8 Practice Test
AP Physics  Chapter 8 Practice Test Multiple Choice Identify the choice that best completes the statement or answers the question. 1. A single conservative force F x = (6.0x 12) N (x is in m) acts on
More informationWork. Work = Force x parallel distance (parallel component of displacement) F v
Work Work = orce x parallel distance (parallel component of displacement) W k = d parallel d parallel Units: N m= J = " joules" = ( kg m2/ s2) = average force computed over the distance r r When is not
More information8. Potential Energy and Conservation of Energy Potential Energy: When an object has potential to have work done on it, it is said to have potential
8. Potential Energy and Conservation of Energy Potential Energy: When an object has potential to have work done on it, it is said to have potential energy, e.g. a ball in your hand has more potential energy
More information9. The kinetic energy of the moving object is (1) 5 J (3) 15 J (2) 10 J (4) 50 J
1. If the kinetic energy of an object is 16 joules when its speed is 4.0 meters per second, then the mass of the objects is (1) 0.5 kg (3) 8.0 kg (2) 2.0 kg (4) 19.6 kg Base your answers to questions 9
More informationCh 7 Kinetic Energy and Work. Question: 7 Problems: 3, 7, 11, 17, 23, 27, 35, 37, 41, 43
Ch 7 Kinetic Energy and Work Question: 7 Problems: 3, 7, 11, 17, 23, 27, 35, 37, 41, 43 Technical definition of energy a scalar quantity that is associated with that state of one or more objects The state
More informationChapter 6. Work and Energy
Chapter 6 Work and Energy The concept of forces acting on a mass (one object) is intimately related to the concept of ENERGY production or storage. A mass accelerated to a nonzero speed carries energy
More informationPhysics Notes Class 11 CHAPTER 6 WORK, ENERGY AND POWER
1 P a g e Work Physics Notes Class 11 CHAPTER 6 WORK, ENERGY AND POWER When a force acts on an object and the object actually moves in the direction of force, then the work is said to be done by the force.
More information3 Work, Power and Energy
3 Work, Power and Energy At the end of this section you should be able to: a. describe potential energy as energy due to position and derive potential energy as mgh b. describe kinetic energy as energy
More informationWorkEnergy Bar Charts
Name: WorkEnergy Bar Charts Read from Lesson 2 of the Work, Energy and Power chapter at The Physics Classroom: http://www.physicsclassroom.com/class/energy/u5l2c.html MOP Connection: Work and Energy:
More informationWork Energy & Power. September 2000 Number 05. 1. Work If a force acts on a body and causes it to move, then the force is doing work.
PhysicsFactsheet September 2000 Number 05 Work Energy & Power 1. Work If a force acts on a body and causes it to move, then the force is doing work. W = Fs W = work done (J) F = force applied (N) s = distance
More informationKE =? v o. Page 1 of 12
Page 1 of 12 CTEnergy1. A mass m is at the end of light (massless) rod of length R, the other end of which has a frictionless pivot so the rod can swing in a vertical plane. The rod is initially horizontal
More informationName: 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 informationChapter 8: Potential Energy and Conservation of Energy. Work and kinetic energy are energies of motion.
Chapter 8: Potential Energy and Conservation of Energy Work and kinetic energy are energies of motion. Consider a vertical spring oscillating with mass m attached to one end. At the extreme ends of travel
More informationConservative vs. Nonconservative forces Gravitational Potential Energy. Work done by nonconservative forces and changes in mechanical energy
Next topic Conservative vs. Nonconservative forces Gravitational Potential Energy Mechanical Energy Conservation of Mechanical energy Work done by nonconservative forces and changes in mechanical energy
More informationCh 8 Potential energy and Conservation of Energy. Question: 2, 3, 8, 9 Problems: 3, 9, 15, 21, 24, 25, 31, 32, 35, 41, 43, 47, 49, 53, 55, 63
Ch 8 Potential energ and Conservation of Energ Question: 2, 3, 8, 9 Problems: 3, 9, 15, 21, 24, 25, 31, 32, 35, 41, 43, 47, 49, 53, 55, 63 Potential energ Kinetic energ energ due to motion Potential energ
More informationWork, Energy and Power Practice Test 1
Name: ate: 1. How much work is required to lift a 2kilogram mass to a height of 10 meters?. 5 joules. 20 joules. 100 joules. 200 joules 5. ar and car of equal mass travel up a hill. ar moves up the hill
More informationWork, Energy & Momentum Homework Packet Worksheet 1: This is a lot of work!
Work, Energy & Momentum Homework Packet Worksheet 1: This is a lot of work! 1. A student holds her 1.5kg psychology textbook out of a second floor classroom window until her arm is tired; then she releases
More informationCurso20122013 Física Básica Experimental I Cuestiones Tema IV. Trabajo y energía.
1. A body of mass m slides a distance d along a horizontal surface. How much work is done by gravity? A) mgd B) zero C) mgd D) One cannot tell from the given information. E) None of these is correct. 2.
More informationWork, Energy, Conservation of Energy
This test covers Work, echanical energy, kinetic energy, potential energy (gravitational and elastic), Hooke s Law, Conservation of Energy, heat energy, conservative and nonconservative forces, with soe
More informationUnit 3 Work and Energy Suggested Time: 25 Hours
Unit 3 Work and Energy Suggested Time: 25 Hours PHYSICS 2204 CURRICULUM GUIDE 55 DYNAMICS Work and Energy Introduction When two or more objects are considered at once, a system is involved. To make sense
More informationProblem Set #8 Solutions
MASSACHUSETTS INSTITUTE OF TECHNOLOGY Physics Department 8.01L: Physics I November 7, 2015 Prof. Alan Guth Problem Set #8 Solutions Due by 11:00 am on Friday, November 6 in the bins at the intersection
More informationENERGYand WORK (PART I and II) 9MAC
ENERGYand WORK (PART I and II) 9MAC Purpose: To understand work, potential energy, & kinetic energy. To understand conservation of energy and how energy is converted from one form to the other. Apparatus:
More informationReview D: Potential Energy and the Conservation of Mechanical Energy
MSSCHUSETTS INSTITUTE OF TECHNOLOGY Department of Physics 8.01 Fall 2005 Review D: Potential Energy and the Conservation of Mechanical Energy D.1 Conservative and Nonconservative Force... 2 D.1.1 Introduction...
More informationPS6.2 Explain the factors that determine potential and kinetic energy and the transformation of one to the other.
PS6.1 Explain how the law of conservation of energy applies to the transformation of various forms of energy (including mechanical energy, electrical energy, chemical energy, light energy, sound energy,
More informationWORKSHEET: KINETIC AND POTENTIAL ENERGY PROBLEMS
WORKSHEET: KINETIC AND POTENTIAL ENERGY PROBLEMS 1. Stored energy or energy due to position is known as Potential energy. 2. The formula for calculating potential energy is mgh. 3. The three factors that
More informationWeight The weight of an object is defined as the gravitational force acting on the object. Unit: Newton (N)
Gravitational Field A gravitational field as a region in which an object experiences a force due to gravitational attraction Gravitational Field Strength The gravitational field strength at a point in
More informationChapter 6. Work and Energy
Chapter 6 Work and Energy ENERGY IS THE ABILITY TO DO WORK = TO APPLY A FORCE OVER A DISTANCE= Example: push over a distance, pull over a distance. Mechanical energy comes into 2 forms: Kinetic energy
More informationObjective: Work Done by a Variable Force Work Done by a Spring. Homework: Assignment (125) Do PROBS # (64, 65) Ch. 6, + Do AP 1986 # 2 (handout)
Double Date: Objective: Work Done by a Variable Force Work Done by a Spring Homework: Assignment (125) Do PROBS # (64, 65) Ch. 6, + Do AP 1986 # 2 (handout) AP Physics B Mr. Mirro Work Done by a Variable
More informationPotential / Kinetic Energy Remedial Exercise
Potential / Kinetic Energy Remedial Exercise This Conceptual Physics exercise will help you in understanding the Law of Conservation of Energy, and its application to mechanical collisions. Exercise Roles:
More informationLesson 3  Understanding Energy (with a Pendulum)
Lesson 3  Understanding Energy (with a Pendulum) Introduction This lesson is meant to introduce energy and conservation of energy and is a continuation of the fundamentals of roller coaster engineering.
More informationPHYSICS STUDY GUIDE CHAPTER 10: WORKENERGY. WORK: Potential to do something ( A transfer of energy into or out of the system ).
TOPICS: Work Power Kinetic Energy Gravitational Potential Energy Elastic Potential Energy Conservation of Mechanical energy DEFINITIONS PHYSICS STDY GIDE CHAPTER 10: WORKENERGY WORK: Potential to do something
More informationGravitational Potential Energy
Gravitational Potential Energy Consider a ball falling from a height of y 0 =h to the floor at height y=0. A net force of gravity has been acting on the ball as it drops. So the total work done on the
More informationSHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
Exam Name SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. 1) A person on a sled coasts down a hill and then goes over a slight rise with speed 2.7 m/s.
More informationWork and Energy. Physics 1425 Lecture 12. Michael Fowler, UVa
Work and Energy Physics 1425 Lecture 12 Michael Fowler, UVa What is Work and What Isn t? In physics, work has a very restricted meaning! Doing homework isn t work. Carrying somebody a mile on a level road
More informationVELOCITY, ACCELERATION, FORCE
VELOCITY, ACCELERATION, FORCE velocity Velocity v is a vector, with units of meters per second ( m s ). Velocity indicates the rate of change of the object s position ( r ); i.e., velocity tells you how
More informationPHYS 101 Lecture 10  Work and kinetic energy 101
PHYS 101 Lecture 10  Work and kinetic energy 101 Lecture 10  Work and Kinetic Energy What s important: impulse, work, kinetic energy, potential energy Demonstrations: block on plane balloon with propellor
More informationGeneral Physical Science
General Physical Science Chapter 4 Work and Energy Work The work done by a constant force F acting upon an object is the product of the magnitude of the force (or component of the force) and the parallel
More informationPhysics 2048 Test 1 Solution (solutions to problems 25 are from student papers) Problem 1 (Short Answer: 20 points)
Physics 248 Test 1 Solution (solutions to problems 25 are from student papers) Problem 1 (Short Answer: 2 points) An object's motion is restricted to one dimension along the distance axis. Answer each
More informationAt the skate park on the ramp
At the skate park on the ramp 1 On the ramp When a cart rolls down a ramp, it begins at rest, but starts moving downward upon release covers more distance each second When a cart rolls up a ramp, it rises
More informationName Period WORKSHEET: KINETIC AND POTENTIAL ENERGY PROBLEMS. 1. Stored energy or energy due to position is known as energy.
Name Period Date WORKSHEET: KINETIC AND POTENTIAL ENERGY PROBLEMS 1. Stored energy or energy due to position is known as energy. 2. The formula for calculating potential energy is. 3. The three factors
More informationwww.mathsbox.org.uk Displacement (x) Velocity (v) Acceleration (a) x = f(t) differentiate v = dx Acceleration Velocity (v) Displacement x
Mechanics 2 : Revision Notes 1. Kinematics and variable acceleration Displacement (x) Velocity (v) Acceleration (a) x = f(t) differentiate v = dx differentiate a = dv = d2 x dt dt dt 2 Acceleration Velocity
More informationWork and Conservation of Energy
Work and Conservation of Energy Topics Covered: 1. The definition of work in physics. 2. The concept of potential energy 3. The concept of kinetic energy 4. Conservation of Energy General Remarks: Two
More informationWork, Power, Energy Multiple Choice. PSI Physics. Multiple Choice Questions
Work, Power, Energy Multiple Choice PSI Physics Name Multiple Choice Questions 1. A block of mass m is pulled over a distance d by an applied force F which is directed in parallel to the displacement.
More informationFRICTION, WORK, AND THE INCLINED PLANE
FRICTION, WORK, AND THE INCLINED PLANE Objective: To measure the coefficient of static and inetic friction between a bloc and an inclined plane and to examine the relationship between the plane s angle
More informationName Class Date. You do twice as much work. b. You lift two identical books one meter above the ground.
Exercises 9.1 Work (pages 145 146) 1. Circle the letter next to the correct mathematical equation for work. work = force distance work = distance force c. work = force distance d. work = force distance
More informationSpring Simple Harmonic Oscillator. Spring constant. Potential Energy stored in a Spring. Understanding oscillations. Understanding oscillations
Spring Simple Harmonic Oscillator Simple Harmonic Oscillations and Resonance We have an object attached to a spring. The object is on a horizontal frictionless surface. We move the object so the spring
More informationAP Physics C Fall Final Web Review
Name: Class: _ Date: _ AP Physics C Fall Final Web Review Multiple Choice Identify the choice that best completes the statement or answers the question. 1. On a position versus time graph, the slope of
More informationProblem Set 5 Work and Kinetic Energy Solutions
MASSACHUSETTS INSTITUTE OF TECHNOLOGY Department o Physics Physics 8.1 Fall 1 Problem Set 5 Work and Kinetic Energy Solutions Problem 1: Work Done by Forces a) Two people push in opposite directions on
More informationPhysics 125 Practice Exam #3 Chapters 67 Professor Siegel
Physics 125 Practice Exam #3 Chapters 67 Professor Siegel Name: Lab Day: 1. A concrete block is pulled 7.0 m across a frictionless surface by means of a rope. The tension in the rope is 40 N; and the
More informationA) F = k x B) F = k C) F = x k D) F = x + k E) None of these.
CT161 Which of the following is necessary to make an object oscillate? i. a stable equilibrium ii. little or no friction iii. a disturbance A: i only B: ii only C: iii only D: i and iii E: All three Answer:
More informationAP Physics C. Oscillations/SHM Review Packet
AP Physics C Oscillations/SHM Review Packet 1. A 0.5 kg mass on a spring has a displacement as a function of time given by the equation x(t) = 0.8Cos(πt). Find the following: a. The time for one complete
More informationPHY231 Section 2, Form A March 22, 2012. 1. Which one of the following statements concerning kinetic energy is true?
1. Which one of the following statements concerning kinetic energy is true? A) Kinetic energy can be measured in watts. B) Kinetic energy is always equal to the potential energy. C) Kinetic energy is always
More informationSpeed A B C. Time. Chapter 3: Falling Objects and Projectile Motion
Chapter 3: Falling Objects and Projectile Motion 1. Neglecting friction, if a Cadillac and Volkswagen start rolling down a hill together, the heavier Cadillac will get to the bottom A. before the Volkswagen.
More informationLesson 39: Kinetic Energy & Potential Energy
Lesson 39: Kinetic Energy & Potential Energy Total Mechanical Energy We sometimes call the total energy of an object (potential and kinetic) the total mechanical energy of an object. Mechanical energy
More informationReview Assessment: Lec 02 Quiz
COURSES > PHYSICS GUEST SITE > CONTROL PANEL > 1ST SEM. QUIZZES > REVIEW ASSESSMENT: LEC 02 QUIZ Review Assessment: Lec 02 Quiz Name: Status : Score: Instructions: Lec 02 Quiz Completed 20 out of 100 points
More informationWork, Energy and Power
Name: KEY Work, Energy and Power Objectives: 1. To understand work and its relation to energy. 2. To understand how energy can be transformed from one form into another. 3. To compute the power from the
More informationAP1 Oscillations. 1. Which of the following statements about a springblock oscillator in simple harmonic motion about its equilibrium point is false?
1. Which of the following statements about a springblock oscillator in simple harmonic motion about its equilibrium point is false? (A) The displacement is directly related to the acceleration. (B) The
More informationWork, Energy and Power
Work, Energy and Power In this section of the Transport unit, we will look at the energy changes that take place when a force acts upon an object. Energy can t be created or destroyed, it can only be changed
More informationLecture 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 informationAnswer, Key Homework 7 David McIntyre 45123 Mar 25, 2004 1
Answer, Key Hoework 7 David McIntyre 453 Mar 5, 004 This printout should have 4 questions. Multiplechoice questions ay continue on the next colun or page find all choices before aking your selection.
More informationPhysics Midterm Review Packet January 2010
Physics Midterm Review Packet January 2010 This Packet is a Study Guide, not a replacement for studying from your notes, tests, quizzes, and textbook. Midterm Date: Thursday, January 28 th 8:1510:15 Room:
More informationIn order to describe motion you need to describe the following properties.
Chapter 2 One Dimensional Kinematics How would you describe the following motion? Ex: random 1D path speeding up and slowing down In order to describe motion you need to describe the following properties.
More informationChapter 3 Falling Objects and Projectile Motion
Chapter 3 Falling Objects and Projectile Motion Gravity influences motion in a particular way. How does a dropped object behave?!does the object accelerate, or is the speed constant?!do two objects behave
More informationIn science, energy is the ability to do work. Work is done when a force causes an
What is energy? In science, energy is the ability to do work. Work is done when a force causes an object to move in the direction of the force. Energy is expressed in units of joules (J). A joule is calculated
More informationEnergy  Key Vocabulary
Energy  Key Vocabulary Term Potential Energy Kinetic Energy Joules Gravity Definition The energy an object possesses due to its position. PE = mgh The energy an object possesses when it is in motion.
More informationSection 15.1 Energy and Its Forms (pages 446 452)
Section 15.1 and Its Forms (pages 446 452) This section describes how energy and work are related. It defines kinetic energy and potential energy, and gives examples for calculating these forms of energy.
More informationWORK, POWER, KINETIC ENERGY
WORK, POWER, KINETIC ENERGY by John S. Ross, Rollins College 1. Introduction.............................................. 1 WORK, POWER, KINETIC ENERGY 2. Work a. Meanings Associated with Work.........................
More informationF 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 250N force is directed horizontally as shown to push a 29kg box up an inclined plane at a constant speed. Determine the magnitude of the normal force,
More informationName Partners Date. Energy Diagrams I
Name Partners Date Visual Quantum Mechanics The Next Generation Energy Diagrams I Goal Changes in energy are a good way to describe an object s motion. Here you will construct energy diagrams for a toy
More informationConceptual 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 informationC 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 informationKinetic Energy (A) stays the same stays the same (B) increases increases (C) stays the same increases (D) increases stays the same.
1. A cart full of water travels horizontally on a frictionless track with initial velocity v. As shown in the diagram, in the back wall of the cart there is a small opening near the bottom of the wall
More informationP211 Midterm 2 Spring 2004 Form D
1. An archer pulls his bow string back 0.4 m by exerting a force that increases uniformly from zero to 230 N. The equivalent spring constant of the bow is: A. 115 N/m B. 575 N/m C. 1150 N/m D. 287.5 N/m
More informationEDUH 1017  SPORTS MECHANICS
4277(a) Semester 2, 2011 Page 1 of 9 THE UNIVERSITY OF SYDNEY EDUH 1017  SPORTS MECHANICS NOVEMBER 2011 Time allowed: TWO Hours Total marks: 90 MARKS INSTRUCTIONS All questions are to be answered. Use
More informationWork and Energy. W =!KE = KE f
Activity 19 PS2826 Work and Energy Mechanics: workenergy theorem, conservation of energy GLX setup file: work energy Qty Equipment and Materials Part Number 1 PASPORT Xplorer GLX PS2002 1 PASPORT Motion
More informationKinetic Energy and Work
PH 13A Fall 009 Kinetic Energy and Work Lecture 1011 11 Chapter 7 (Halliday/Resnick/Walker, Fundamentals of Physics 8 th edition) Chapter 7 Kinetic Energy and Work In this chapter we will introduce the
More informationSimple Harmonic Motion
Simple Harmonic Motion 1 Object To determine the period of motion of objects that are executing simple harmonic motion and to check the theoretical prediction of such periods. 2 Apparatus Assorted weights
More informationConservative forces and the potential energy function. Nonconservative forces and the workenergy theorem
Nonconservative forces and the workenergy theorem Consider an object falling with airresistance. There are two forces to consider; the gravitational force (conservative) and the drag force (nonconservative).
More informationHOOKE S LAW AND OSCILLATIONS
9 HOOKE S LAW AND OSCILLATIONS OBJECTIVE To measure the effect of amplitude, mass, and spring constant on the period of a springmass oscillator. INTRODUCTION The force which restores a spring to its equilibrium
More informationWork, Power, and Energy: Explaining the causes of motion without Newton. KIN335 Spring 2005
Work, Power, and Energy: Explaining the causes of motion without Newton KIN335 Spring 2005 What you should know Definition of work and its characteristics Definition of energy (including kinetic energy
More information10.1 Quantitative. Answer: A Var: 50+
Chapter 10 Energy and Work 10.1 Quantitative 1) A child does 350 J of work while pulling a box from the ground up to his tree house with a rope. The tree house is 4.8 m above the ground. What is the mass
More informationWork, Energy & Power. AP Physics B
ork, Energy & Power AP Physics B There are many dierent TYPES o Energy. Energy is expressed in JOULES (J) 4.19 J = 1 calorie Energy can be expressed more speciically by using the term ORK() ork = The Scalar
More informationPotential Energy and Equilibrium in 1D
Potential Energy and Equilibrium in 1D Figures 627, 628 and 629 of TiplerMosca. du = F x dx A particle is in equilibrium if the net force acting on it is zero: F x = du dx = 0. In stable equilibrium
More informationPractice Test SHM with Answers
Practice Test SHM with Answers MPC 1) If we double the frequency of a system undergoing simple harmonic motion, which of the following statements about that system are true? (There could be more than one
More informationPhysics 1A Lecture 10C
Physics 1A Lecture 10C "If you neglect to recharge a battery, it dies. And if you run full speed ahead without stopping for water, you lose momentum to finish the race. Oprah Winfrey Static Equilibrium
More informationW i f(x i ) x. i=1. f(x i ) x = i=1
Work Force If an object is moving in a straight line with position function s(t), then the force F on the object at time t is the product of the mass of the object times its acceleration. F = m d2 s dt
More informationMidterm Solutions. mvr = ω f (I wheel + I bullet ) = ω f 2 MR2 + mr 2 ) ω f = v R. 1 + M 2m
Midterm Solutions I) A bullet of mass m moving at horizontal velocity v strikes and sticks to the rim of a wheel a solid disc) of mass M, radius R, anchored at its center but free to rotate i) Which of
More informationPHY231 Section 1, Form B March 22, 2012
1. A car enters a horizontal, curved roadbed of radius 50 m. The coefficient of static friction between the tires and the roadbed is 0.20. What is the maximum speed with which the car can safely negotiate
More informationPhysics 201 Homework 8
Physics 201 Homework 8 Feb 27, 2013 1. A ceiling fan is turned on and a net torque of 1.8 Nm is applied to the blades. 8.2 rad/s 2 The blades have a total moment of inertia of 0.22 kgm 2. What is the
More informationv v ax v a x a v a v = = = Since F = ma, it follows that a = F/m. The mass of the arrow is unchanged, and ( )
Week 3 homework IMPORTANT NOTE ABOUT WEBASSIGN: In the WebAssign versions of these problems, various details have been changed, so that the answers will come out differently. The method to find the solution
More informationFigure 1.1 Vector A and Vector F
CHAPTER I VECTOR QUANTITIES Quantities are anything which can be measured, and stated with number. Quantities in physics are divided into two types; scalar and vector quantities. Scalar quantities have
More information2After completing this chapter you should be able to
After completing this chapter you should be able to solve problems involving motion in a straight line with constant acceleration model an object moving vertically under gravity understand distance time
More informationSupplemental Questions
Supplemental Questions The fastest of all fishes is the sailfish. If a sailfish accelerates at a rate of 14 (km/hr)/sec [fwd] for 4.7 s from its initial velocity of 42 km/h [fwd], what is its final velocity?
More informationPreview of Period 2: Forms of Energy
Preview of Period 2: Forms of Energy 2.1 Forms of Energy How are forms of energy defined? 2.2 Energy Conversions What happens when energy is converted from one form into another form? 2.3 Efficiency of
More informationUnit 2 Force and Motion
Force and Motion Unit 2 Force and Motion Learning Goal (TEKS): Identify and describe the changes in position, direction, and speed of an object when acted upon by unbalanced forces. This means: We are
More information