Chapter 7 Energy of a System
|
|
- Joleen Bishop
- 5 years ago
- Views:
Transcription
1 Chapter 7 Energy of a System Course Outline : Work Done by a Constant Force Work Done by avarying Force Kinetic Energy and thework-kinetic EnergyTheorem Power Potential Energy of a System (Will be discussed in Chapter 8) Conservative and Non-conservative Forces (Will be discussed in Chapter 8)
2 What is Systems? A valid system: May be a single object or particle May be a collection of objects or particles May be a region of space May vary with time in size and shape A force applied to an object in empty space System is the object Its surface is the system boundary The force is an influence on the system from its environment that acts across the system boundary.
3 7.2 Work The work, W, done on a system by an agent exerting a constant force on the system is the product of the magnitude F of the force, the magnitude Dr of the displacement of the point of application of the force, and cos q, where q is the angle between the force and the displacement vectors. W = F Dr cos q The meaning of the term work is distinctly different in physics than in everyday meaning. Work is done by some part of the environment that is interacting directly with the system. Work is done on the system. Section 7.2
4 W = F Dr cos q The displacement is that of the point of application of the force. A force does no work on the object if the force does not move through a displacement. The work done by a force on a moving object is zero when the force applied is perpendicular to the displacement of its point of application. Section 7.2
5 Work Example The normal force and the gravitational force do no work on the object. cos q = cos 90 = 0 (perpendicular) The force is the only force that does work on the object. F Section 7.2
6 The sign of the work depends on the direction of the force relative to the displacement. F Work is positive when projection of onto Dr is in the same direction as the displacement. Work is negative when the projection is in the opposite direction. The work done by a force can be calculated, but that force is not necessarily the cause of the displacement. Work is a scalar quantity. The unit of work is a joule (J) 1 joule = 1 newton. 1 meter = kg m² / s² J = N m Section 7.2
7 Work Is An Energy Transfer This is important for a system approach to solving a problem. If the work is done on a system and it is positive, energy is transferred to the system. If the work done on the system is negative, energy is transferred from the system. If a system interacts with its environment, this interaction can be described as a transfer of energy across the system boundary. This will result in a change in the amount of energy stored in the system. Section 7.2
8 Example (7.1) : Mr. Clean A man cleaning a floor pulls a vacuum cleaner with a force of magnitude F = 50.0 N at an angle of 30.0 o with the horizontal (Fig. (7.4a)). Calculate the work done by the force on the vacuum cleaner as the vacuum cleaner is displaced 3.00 m to the right.
9 Example (7.2) : The Scalar Product The vector A and B are given by A =2i + 3j and B =-i + 2j. (a) Determine the scalar product A B.b) Find the angle between A and B Example (7.3) : Work Done by a Constant Force A particle moving in the xy plane undergoes a displacement d = (2.0i + 3.0j) m as a constant force F = (5.0i + 2.0j) N acts on the particle. Calculate the work done by force.
10 7.3 Work Done By Varying Force
11 Example (7.4) : Calculating Total Work Done from a Graph A force acting on a particle varies with x, as shown in Figure (7.8). Calculate the work done by the force as the particle moves from x = 0 to x = 6.0 m.
12 Work Done By A Spring A model of a common physical system for which the force varies with position. The block is on a horizontal, frictionless surface. Observe the motion of the block with various values of the spring constant. Section 7.4
13 Spring Force (Hooke s Law) The force exerted by the spring is F s = - kx x is the position of the block with respect to the equilibrium position (x = 0). k is called the spring constant or force constant and measures the stiffness of the spring. k measures the stiffness of the spring. This is called Hooke s Law. Section 7.4
14 The vector form of Hooke s Law is F = F x i kx i When x is positive (spring is stretched), F is negative When x is 0 (at the equilibrium position), F is 0 When x is negative (spring is compressed), F is positive Section 7.4
15 Hooke s Law, final The force exerted by the spring is always directed opposite to the displacement from equilibrium. The spring force is sometimes called the restoring force. If the block is released it will oscillate back and forth between x and x. Section 7.4
16 Work Done by a Spring Identify the block as the system. Calculate the work as the block moves from x i = - x max to x f = 0. The net work done as the block moves from -x max to x max is zero Section 7.4
17 Assume the block undergoes an arbitrary displacement from x = x i to x = x f. The work done by the spring on the block is xf 1 1 W kx dx kx kx xi s i f If the motion ends where it begins, W = 0 Section 7.4
18 Spring with an Applied Force Suppose an external agent, F app, stretches the spring. The applied force is equal and opposite to the spring force. F app F 垐 appi Fs kxi kx? i Work done by F app as the block moves from x max to x = 0 is equal to -½kx 2 max For any displacement, the work done by the applied force is xf 1 1 W kx dx kx kx xi app f i Section 7.4
19 E7.5a)If a spring is stretch 2.0 cm by a suspended object having a mass of 0.55kg, what is the force constant of the spring? b)how much work is done by the spring on the object as it stretches through this distance
20 7.5 Kinetic Energy One possible result of work acting as an influence on a system is that the system changes its speed. The system could possess kinetic energy. Kinetic Energy is the energy of a particle due to its motion. K = ½mv 2 K is the kinetic energy m is the mass of the particle v is the speed of the particle A change in kinetic energy is one possible result of doing work to transfer energy into a system. Section 7.5
21 Calculating the work: x f f Wext F dx ma dx xi xi W ext v v i f mv dv 1 1 W mv mv 2 2 W K K DK 2 2 ext f i ext f i x Section 7.5
22 Work-Kinetic Energy Theorem The Work-Kinetic Energy Theorem states W ext = K f K i = ΔK When work is done on a system and the only change in the system is in its speed, the net work done on the system equals the change in kinetic energy of the system. The speed of the system increases if the work done on it is positive. The speed of the system decreases if the net work is negative. Also valid for changes in rotational speed The work-kinetic energy theorem is not valid if other changes (besides its speed) occur in the system or if there are other interactions with the environment besides work. The work-kinetic energy theorem applies to the speed of the system, not its velocity. Section 7.5
23 Example (7.6) : A Block Pulled on a Frictionless Surface A 6.0-kg block initially at rest is pulled to the right along a horizontal, frictionless surface by a constant horizontal force of 12 N. Find the speed of the block after it has moved 3.0 m. n v f n v f F f k F mg d mg d (a) (b) Figure (7.16)
24 7.5 Power Power is the time rate of doing work. Practically, it is important to know that how much work the vehicles do, but also how rapidly the work is done. For example, There is two types of automobile engine which are the normal engine and the optional engine. Both of them do the same amount of work, but the optional engine with highest-priced take less time to complete the work.
25
26
27 Example An elevator car has a mass of 1000kg and is carrying passengers having combined mass of 800 kg. A constant frictional force of 4000N retards its motion upward. a) What must be the minimum delivered by the motor to lift the elevator at a constant speed of 3.00 m/s? b) What power must the motor deliver at the instant its speed is v if it is designed to provide an upward acceleration of 1.00 m/s 2?
W = F x W = Fx cosθ W = Fx. Work
Ch 7 Energy & Work Work Work is a quantity that is useful in describing how objects interact with other objects. Work done by an agent exerting a constant force on an object is the product of the component
More informationWork and Kinetic Energy I
Work and Kinetic Energy I Scalar Product The scalar product of any two vectors A and B is a scalar quantity equal to the product of the magnitudes of the two vectors and the cosine of the angle φ between
More informationChapter 13. Simple Harmonic Motion
Chapter 13 Simple Harmonic Motion Hooke s Law F s = - k x F s is the spring force k is the spring constant It is a measure of the stiffness of the spring A large k indicates a stiff spring and a small
More informationMechanics and Heat. Chapter 5: Work and Energy. Dr. Rashid Hamdan
Mechanics and Heat Chapter 5: Work and Energy Dr. Rashid Hamdan 5.1 Work Done by a Constant Force Work Done by a Constant Force A force is said to do work if, when acting on a body, there is a displacement
More informationChapter 6 Work and Energy
Chapter 6 Work and Energy Midterm exams will be available next Thursday. Assignment 6 Textbook (Giancoli, 6 th edition), Chapter 6: Due on Thursday, November 5 1. On page 162 of Giancoli, problem 4. 2.
More informationEnergy of a System. chapter
chapter 7 Energy of a ystem 7.1 ystems and Environments 7.2 Work Done by a Constant Force 7.3 The calar Product of Two Vectors 7.4 Work Done by a Varying Force 7.5 Kinetic Energy and the Work Kinetic Energy
More informationRecall: Gravitational Potential Energy
Welcome back to Physics 15 Today s agenda: Work Power Physics 15 Spring 017 Lecture 10-1 1 Recall: Gravitational Potential Energy For an object of mass m near the surface of the earth: U g = mgh h is height
More informationChapter 7 Kinetic Energy and Work
Prof. Dr. I. Nasser Chapter7_I 14/11/017 Chapter 7 Kinetic Energy and Work Energy: Measure of the ability of a body or system to do work or produce a change, expressed usually in joules or kilowatt hours
More informationLesson 5. Luis Anchordoqui. Physics 168. Tuesday, September 26, 17
Lesson 5 Physics 168 1 C. B.-Champagne Luis Anchordoqui 2 2 Work Done by a Constant Force distance moved times component of force in direction of displacement W = Fd cos 3 Work Done by a Constant Force
More informationPSI AP Physics B Dynamics
PSI AP Physics B Dynamics Multiple-Choice questions 1. After firing a cannon ball, the cannon moves in the opposite direction from the ball. This an example of: A. Newton s First Law B. Newton s Second
More informationChapter 12 Vibrations and Waves Simple Harmonic Motion page
Chapter 2 Vibrations and Waves 2- Simple Harmonic Motion page 438-45 Hooke s Law Periodic motion the object has a repeated motion that follows the same path, the object swings to and fro. Examples: a pendulum
More informationPHY 101. Work and Kinetic Energy 7.1 Work Done by a Constant Force
PHY 101 DR M. A. ELERUJA KINETIC ENERGY AND WORK POTENTIAL ENERGY AND CONSERVATION OF ENERGY CENTRE OF MASS AND LINEAR MOMENTUM Work is done by a force acting on an object when the point of application
More informationPower: Sources of Energy
Chapter 7: Energy Power: Sources of Energy Tidal Power SF Bay Tidal Power Project Main Ideas (Encyclopedia of Physics) Energy is an abstract quantity that an object is said to possess. It is not something
More informationGeneral Physics I. Lecture 4: Work and Kinetic Energy
General Physics I Lecture 4: Work and Kinetic Energy What Have We Learned? Motion of a particle in any dimensions. For constant acceleration, we derived a set of kinematic equations. We can generalized
More informationWork Done by a Constant Force
Work and Energy Work Done by a Constant Force In physics, work is described by what is accomplished when a force acts on an object, and the object moves through a distance. The work done by a constant
More informationWork and Kinetic Energy. Chapter Outline
P U Z Z L E R Chum salmon climbing a ladder in the McNeil River in Alaska. Why are fish ladders like this often built around dams? Do the ladders reduce the amount of work that the fish must do to get
More informationChapter 14 Oscillations. Copyright 2009 Pearson Education, Inc.
Chapter 14 Oscillations 14-1 Oscillations of a Spring If an object vibrates or oscillates back and forth over the same path, each cycle taking the same amount of time, the motion is called periodic. The
More informationPhysics Test 9: Work and Energy page 1
Name Physics Test 9: Work and Energy page 1 Multiple Choice Read each question and choose the best answer by putting the corresponding letter in the blank to the left. 1. Which of the following is a unit
More informationKinetic Energy and Work
Chapter 7 Kinetic Energy and Work Copyright 7.2 What is Energy? Question: What is energy? Answer: Energy is a scalar quantity associated with the state (or condition) of one or more objects. Energy is
More informationChapter 14 Oscillations
Chapter 14 Oscillations If an object vibrates or oscillates back and forth over the same path, each cycle taking the same amount of time, the motion is called periodic. The mass and spring system is a
More information(35+70) 35 g (m 1+m 2)a=m1g a = 35 a= =3.27 g 105
Coordinator: Dr. W. L-Basheer Monday, March 16, 2015 Page: 1 Q1. 70 N block and a 35 N block are connected by a massless inextendable string which is wrapped over a frictionless pulley as shown in Figure
More informationEssentially, the amount of work accomplished can be determined two ways:
1 Work and Energy Work is done on an object that can exert a resisting force and is only accomplished if that object will move. In particular, we can describe work done by a specific object (where a force
More informationChapter 5 Oscillatory Motion
Chapter 5 Oscillatory Motion Simple Harmonic Motion An object moves with simple harmonic motion whenever its acceleration is proportional to its displacement from some equilibrium position and is oppositely
More informationWORK, POWER & ENERGY
WORK, POWER & ENERGY Work An applied force acting over a displacement. The force being applied must be parallel to the displacement for work to be occurring. Work Force displacement Units: Newton meter
More informationChapter 7. Work and Kinetic Energy
Chapter 7 Work and Kinetic Energy P. Lam 7_16_2018 Learning Goals for Chapter 7 To understand the concept of kinetic energy (energy of motion) To understand the meaning of work done by a force. To apply
More informationName Lesson 7. Homework Work and Energy Problem Solving Outcomes
Physics 1 Name Lesson 7. Homework Work and Energy Problem Solving Outcomes Date 1. Define work. 2. Define energy. 3. Determine the work done by a constant force. Period 4. Determine the work done by a
More informationPHYS 101 Previous Exam Problems. Kinetic Energy and
PHYS 101 Previous Exam Problems CHAPTER 7 Kinetic Energy and Work Kinetic energy Work Work-energy theorem Gravitational work Work of spring forces Power 1. A single force acts on a 5.0-kg object in such
More informationWork and kinetic energy. LA info session today at 5pm in UMC235 CAPA homework due tomorrow night.
Work and kinetic energy LA info session today at 5pm in UMC235 CAPA homework due tomorrow night. 1 Work I apply a force of 2N in the x direction to an object that moves 5m in x. How much work have I done
More informationAnother Method to get a Sine Wave. X = A cos θ V = Acc =
LAST NAME FIRST NAME DATE PER CJ Wave Assignment 10.3 Energy & Simple Harmonic Motion Conceptual Questions 3, 4, 6, 7, 9 page 313 6, 7, 33, 34 page 314-316 Tracing the movement of the mass on the end of
More informationMomentum & Energy Review Checklist
Momentum & Energy Review Checklist Impulse and Momentum 3.1.1 Use equations to calculate impulse; momentum; initial speed; final speed; force; or time. An object with a mass of 5 kilograms is moving at
More informationChapter 14 Oscillations. Copyright 2009 Pearson Education, Inc.
Chapter 14 Oscillations Oscillations of a Spring Simple Harmonic Motion Energy in the Simple Harmonic Oscillator Simple Harmonic Motion Related to Uniform Circular Motion The Simple Pendulum The Physical
More informationWORK, ENERGY & POWER Work scalar W = F S Cosθ Unit of work in SI system Work done by a constant force
WORK, ENERGY & POWER Work Let a force be applied on a body so that the body gets displaced. Then work is said to be done. So work is said to be done if the point of application of force gets displaced.
More informationElastic Potential Energy
Elastic Potential Energy If you pull on a spring and stretch it, then you do work. That is because you are applying a force over a displacement. Your pull is the force and the amount that you stretch the
More informationPotential Energy. Uo = mgh. Apply the Work-Kinetic Energy Theorem: F = - mg x = - (h - ho) ΔK = W = Fx ½ mv 2 - ½ mvo 2 = (-mg ) [- (ho - h)]
Physics 17 Part F Potential Energy U = mgh Apply the Work-Kinetic Energy Theorem: F = - mg x = - (h - ho) ΔK = W = Fx ½ mv 2 - ½ mvo 2 = (-mg ) [- (ho - h)] Re-written: ½ mv 2 + mgh = ½ mvo 2 + mgho Ko
More informationConservation of Energy and Momentum
Conservation of Energy and Momentum Three criteria for Work There must be a force. There must be a displacement, d. The force must have a component parallel to the displacement. Work, W = F x d, W = Fd
More informationA. B. C. D. E. v x. ΣF x
Q4.3 The graph to the right shows the velocity of an object as a function of time. Which of the graphs below best shows the net force versus time for this object? 0 v x t ΣF x ΣF x ΣF x ΣF x ΣF x 0 t 0
More informationWork changes Energy. Do Work Son!
1 Work changes Energy Do Work Son! 2 Do Work Son! 3 Work Energy Relationship 2 types of energy kinetic : energy of an object in motion potential: stored energy due to position or stored in a spring Work
More informationa. Determine the potential energy of the spring as a function of displacement.
PSI AP Physics C Work and Energy (With Calculus) Free Response Problems Use g = 10 m/s 2 1. A spring is found with a force that doesn t obey Hooke s Law: F = -kx 2. This spring is placed on a horizontal
More informationOld Exam. Question Chapter 7 072
Old Exam. Question Chapter 7 072 Q1.Fig 1 shows a simple pendulum, consisting of a ball of mass M = 0.50 kg, attached to one end of a massless string of length L = 1.5 m. The other end is fixed. If the
More informationENERGY. Conservative Forces Non-Conservative Forces Conservation of Mechanical Energy Power
ENERGY Conservative Forces Non-Conservative Forces Conservation of Mechanical Energy Power Conservative Forces A force is conservative if the work it does on an object moving between two points is independent
More informationl1, l2, l3, ln l1 + l2 + l3 + ln
Work done by a constant force: Consider an object undergoes a displacement S along a straight line while acted on a force F that makes an angle θ with S as shown The work done W by the agent is the product
More informationMass on a Horizontal Spring
Course- B.Sc. Applied Physical Science (Computer Science) Year- IInd, Sem- IVth Subject Physics Paper- XIVth, Electromagnetic Theory Lecture No. 22, Simple Harmonic Motion Introduction Hello friends in
More informationLecture 9: Kinetic Energy and Work 1
Lecture 9: Kinetic Energy and Work 1 CHAPTER 6: Work and Kinetic Energy The concept of WORK has a very precise definition in physics. Work is a physical quantity produced when a Force moves an object through
More informationPotential Energy and Conservation of Energy Chap. 7 & 8
Level : AP Physics Potential Energy and Conservation of Energy Chap. 7 & 8 Potential Energy of a System see p.191 in the textbook - Potential energy is the energy associated with the arrangement of a system
More informationWork and kinetic energy. If a net force is applied on an object, the object may
Work and kinetic energy If a net force is applied on an object, the object may CHAPTER 6 WORK AND ENERGY experience a change in position, i.e., a displacement. When a net force is applied over a distance,
More informationChapter 6 Work and Kinetic Energy
Chapter 6 Work and Kinetic Energy Up until now, we have assumed that the force is constant and thus, the acceleration is constant. Is there a simple technique for dealing with non-constant forces? Fortunately,
More informationPeriodic Motion. Periodic motion is motion of an object that. regularly repeats
Periodic Motion Periodic motion is motion of an object that regularly repeats The object returns to a given position after a fixed time interval A special kind of periodic motion occurs in mechanical systems
More informationMomentum & Energy Review Checklist
Momentum & Energy Review Checklist Impulse and Momentum 3.1.1 Use equations to calculate impulse; momentum; initial speed; final speed; force; or time. An object with a mass of 5 kilograms is moving at
More informationWork and Energy. Work and Energy
1. Work as Energy Transfer Work done by a constant force (scalar product) Work done by a varying force (scalar product & integrals). Kinetic Energy Work-Energy Theorem Work by a Baseball Pitcher A baseball
More informationOscillations. Oscillations and Simple Harmonic Motion
Oscillations AP Physics C Oscillations and Simple Harmonic Motion 1 Equilibrium and Oscillations A marble that is free to roll inside a spherical bowl has an equilibrium position at the bottom of the bowl
More information40 N 40 N. Direction of travel
1 Two ropes are attached to a box. Each rope is pulled with a force of 40 N at an angle of 35 to the direction of travel. 40 N 35 35 40 N irection of travel The work done, in joules, is found using 2 Which
More information4. What is the equation for the Work-Kinetic Energy theorem and what does it mean?
Bell Ringer: 1. What is a force? 2. What is Newton s 2 nd Law? 3. What is work? 4. What is the equation for the Work-Kinetic Energy theorem and what does it mean? Notes 6.1: Work done by a Spring Force
More information14.4 Change in Potential Energy and Zero Point for Potential Energy
14.4 Change in Potential Energy and Zero Point for Potential Energy We already calculated the work done by different conservative forces: constant gravity near the surface of the earth, the spring force,
More informationWORK AND ENERGY PRINCIPLE
WORK AND ENERGY PRINCIPLE Work and Kinetic Energy In the previous article we applied Newton s second law F ma to various problems of particle motion to establish the instantaneous relationship between
More informationUnit V: Mechanical Energy
Unit V: Mechanical Energy Work In physics, we have two definitions of work. 1) Work is a transfer of energy. This means that energy changes forms or energy is transferred from one object to another object.
More informationAP Physics C Mechanics
1 AP Physics C Mechanics Work and Energy 2015 12 03 www.njctl.org 2 Table of Contents Click on the topic to go to that section Energy and Work Conservative and Non Conservative Forces Conservation of Total
More informationQuiz Samples for Chapter 7 Kinetic Energy and Work
Name: Department: Student ID #: Notice ˆ + ( 1) points per correct (incorrect) answer ˆ No penalty for an unanswered question ˆ Fill the lank ( ) with ( ) if the statement is correct (incorrect) ˆ : corrections
More informationMULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
PH105-007 Exam 2 VERSION A Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) A 1.0-kg block and a 2.0-kg block are pressed together on a horizontal
More informationthe spring is compressed and x is the compression
Lecture 4 Spring problem and conservation of mechanical energy Hooke's Law The restoring force exerted by the spring is directly proportional to its displacement. The restoring force acts in a direction
More informationChapter 11 Vibrations and Waves
Chapter 11 Vibrations and Waves If an object vibrates or oscillates back and forth over the same path, each cycle taking the same amount of time, the motion is called periodic. The mass and spring system
More informationSometimes (like on AP test) you will see the equation like this:
Work, Energy & Momentum Notes Chapter 5 & 6 The two types of energy we will be working with in this unit are: (K in book KE): Energy associated with of an object. (U in book PE): Energy associated with
More informationThe work-energy theorem
The work-energy theorem Objectives Investigate quantities using the work-energy theorem in various situations. Calculate quantities using the work-energy theorem in various situations. Design and implement
More informationPhysics 2414 Group Exercise 8. Conservation of Energy
Physics 244 Group Exercise 8 Name : OUID : Name 2: OUID 2: Name 3: OUID 3: Name 4: OUID 4: Section Number: Solutions Solutions Conservation of Energy A mass m moves from point i to point f under the action
More informationWelcome back to Physics 211
Welcome back to Physics 211 Today s agenda: Work Power Physics 211 Fall 2012 Lecture 09-2 1 Current assignments HW#9 due this Friday at 5 pm. Short assignment SAGE (Thanks for the feedback!) I am using
More informationAP Physics C - Mechanics
Slide 1 / 125 Slide 2 / 125 AP Physics C - Mechanics Work and Energy 2015-12-03 www.njctl.org Table of Contents Slide 3 / 125 Click on the topic to go to that section Energy and Work Conservative and Non-Conservative
More informationPhysics 101: Lecture 9 Work and Kinetic Energy
Exam II Physics 101: Lecture 9 Work and Kinetic Energy Today s lecture will be on Textbook Sections 6.1-6.4 Physics 101: Lecture 9, Pg 1 Forms Energy Kinetic Energy Motion (Today) Potential Energy Stored
More informationChapter 5: Energy. Energy is one of the most important concepts in the world of science. Common forms of Energy
Chapter 5: Energy Energy is one of the most important concepts in the world of science. Common forms of Energy Mechanical Chemical Thermal Electromagnetic Nuclear One form of energy can be converted to
More informationChapter 07: Kinetic Energy and Work
Chapter 07: Kinetic Energy and Work Conservation of Energy is one of Nature s fundamental laws that is not violated. Energy can take on different forms in a given system. This chapter we will discuss work
More informationAP Physics C - Mechanics. Energy and Work. Slide 1 / 125 Slide 2 / 125. Slide 4 / 125. Slide 3 / 125. Slide 6 / 125. Slide 5 / 125.
Slide 1 / 125 Slide 2 / 125 AP Physics C - Mechanics Work and nergy 2015-12-03 www.njctl.org Slide 3 / 125 Slide 4 / 125 Table of Contents Click on the topic to go to that section nergy and Work Conservative
More informationPower: Sources of Energy
Chapter 5 Energy Power: Sources of Energy Tidal Power SF Bay Tidal Power Project Main Ideas (Encyclopedia of Physics) Energy is an abstract quantity that an object is said to possess. It is not something
More informationWork done on an object = energy gained by the object Work done by an object = energy lost by the object
Energy Energy can be defined as the capacity for doing work, or the property of a system that diminishes when the system does work on any other system by an amount equal to the work done. 1) When work
More informationChapter 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 informationConcept of Force Challenge Problem Solutions
Concept of Force Challenge Problem Solutions Problem 1: Force Applied to Two Blocks Two blocks sitting on a frictionless table are pushed from the left by a horizontal force F, as shown below. a) Draw
More information4.2. The Normal Force, Apparent Weight and Hooke s Law
4.2. The Normal Force, Apparent Weight and Hooke s Law Weight The weight of an object on the Earth s surface is the gravitational force exerted on it by the Earth. When you weigh yourself, the scale gives
More informationKing Fahd University of Petroleum and Minerals Physics Department Physics 101 Recitation Term 131 Fall 013 Quiz # 4 Section 10 A 1.50-kg block slides down a frictionless 30.0 incline, starting from rest.
More informationCh 5 Work and Energy
Ch 5 Work and Energy Energy Provide a different (scalar) approach to solving some physics problems. Work Links the energy approach to the force (Newton s Laws) approach. Mechanical energy Kinetic energy
More informationChapter 7 Work and Energy
8/04/0 Lecture PowerPoints 009 Pearson Education, Inc. This work is protected by United States copyright laws and is provided solely for the use of instructors in teaching their courses and assessing student
More informationDynamics 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- 1 -APPH_MidTerm. Mid - Term Exam. Part 1: Write your answers to all multiple choice questions in this space. A B C D E A B C D E
Name - 1 -APPH_MidTerm AP Physics Date Mid - Term Exam Part 1: Write your answers to all multiple choice questions in this space. 1) 2) 3) 10) 11) 19) 20) 4) 12) 21) 5) 13) 22) 6) 7) 14) 15) 23) 24) 8)
More informationAP Physics C: Work, Energy, and Power Practice
AP Physics C: Work, Energy, and Power Practice 1981M2. A swing seat of mass M is connected to a fixed point P by a massless cord of length L. A child also of mass M sits on the seat and begins to swing
More informationUse the following to answer question 1:
Use the following to answer question 1: On an amusement park ride, passengers are seated in a horizontal circle of radius 7.5 m. The seats begin from rest and are uniformly accelerated for 21 seconds to
More informationis acting on a body of mass m = 3.0 kg and changes its velocity from an initial
PHYS 101 second major Exam Term 102 (Zero Version) Q1. A 15.0-kg block is pulled over a rough, horizontal surface by a constant force of 70.0 N acting at an angle of 20.0 above the horizontal. The block
More informationEnergy Work Kinetic Energy Potential Energy
Energy Work Kinetic Energy Potential Energy Lana Sheridan De Anza College Oct 25, 2017 Last time energy work Overview Work as an integral Kinetic energy Work-Kinetic energy theorem Potential energy N through
More information(a) On the dots below that represent the students, draw and label free-body diagrams showing the forces on Student A and on Student B.
2003 B1. (15 points) A rope of negligible mass passes over a pulley of negligible mass attached to the ceiling, as shown above. One end of the rope is held by Student A of mass 70 kg, who is at rest on
More informationIn-Class Problems 20-21: Work and Kinetic Energy Solutions
MASSACHUSETTS INSTITUTE OF TECHNOLOGY Department of Physics Physics 8.01T Fall Term 2004 In-Class Problems 20-21: Work and Kinetic Energy Solutions In-Class-Problem 20 Calculating Work Integrals a) Work
More information1. A sphere with a radius of 1.7 cm has a volume of: A) m 3 B) m 3 C) m 3 D) 0.11 m 3 E) 21 m 3
1. A sphere with a radius of 1.7 cm has a volume of: A) 2.1 10 5 m 3 B) 9.1 10 4 m 3 C) 3.6 10 3 m 3 D) 0.11 m 3 E) 21 m 3 2. A 25-N crate slides down a frictionless incline that is 25 above the horizontal.
More information4.) A baseball that weighs 1.6 N leaves a bat with a speed of 40.0 m/s. Calculate the kinetic energy of the ball. 130 J
AP Physics-B Energy And Its Conservation Introduction: Energy is a term that most of us take for granted and use quite freely. We assume we know what we are talking about when speaking of energy. In truth,
More informationThe content contained in all sections of chapter 6 of the textbook is included on the AP Physics B exam.
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 is always
More informationChapter 8. Conservation of Energy
Chapter 8 Conservation of Energy Energy Review Kinetic Energy Associated with movement of members of a system Potential Energy Determined by the configuration of the system Gravitational and Elastic Potential
More information3. Kinetics of Particles
3. Kinetics of Particles 3.1 Force, Mass and Acceleration 3.3 Impulse and Momentum 3.4 Impact 1 3.1 Force, Mass and Acceleration We draw two important conclusions from the results of the experiments. First,
More informationa. Change of object s motion is related to both force and how long the force acts.
0. Concept of Energy 1. Work. Power a. Energy is the most central concept underlying all sciences. Concept of energy is unknown to Isaac Newton. Its existence was still debated in the 1850s. Concept of
More informationMechanics II. Which of the following relations among the forces W, k, N, and F must be true?
Mechanics II 1. By applying a force F on a block, a person pulls a block along a rough surface at constant velocity v (see Figure below; directions, but not necessarily magnitudes, are indicated). Which
More informationAP Physics 1: MIDTERM REVIEW OVER UNITS 2-4: KINEMATICS, DYNAMICS, FORCE & MOTION, WORK & POWER
MIDTERM REVIEW AP Physics 1 McNutt Name: Date: Period: AP Physics 1: MIDTERM REVIEW OVER UNITS 2-4: KINEMATICS, DYNAMICS, FORCE & MOTION, WORK & POWER 1.) A car starts from rest and uniformly accelerates
More informationOscillations. Phys101 Lectures 28, 29. Key points: Simple Harmonic Motion (SHM) SHM Related to Uniform Circular Motion The Simple Pendulum
Phys101 Lectures 8, 9 Oscillations Key points: Simple Harmonic Motion (SHM) SHM Related to Uniform Circular Motion The Simple Pendulum Ref: 11-1,,3,4. Page 1 Oscillations of a Spring If an object oscillates
More informationChapter 14. Oscillations. Oscillations Introductory Terminology Simple Harmonic Motion:
Chapter 14 Oscillations Oscillations Introductory Terminology Simple Harmonic Motion: Kinematics Energy Examples of Simple Harmonic Oscillators Damped and Forced Oscillations. Resonance. Periodic Motion
More informationChapter 15. Oscillatory Motion
Chapter 15 Oscillatory Motion Part 2 Oscillations and Mechanical Waves Periodic motion is the repeating motion of an object in which it continues to return to a given position after a fixed time interval.
More informationChapter 7. Kinetic Energy and Work
Chapter 7 Kinetic Energy and Work 7.3 Kinetic Energy Kinetic energy K is energy associated with the state of motion of an object. The faster the object moves, the greater is its kinetic energy. For an
More informationDynamics 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 informationPhysics 23 Notes Chapter 6 Part Two
Physics 23 Notes Chapter 6 Part Two Dr. Alward Conservation of Energy Object moves freely upward under the influence of Earth only. Its acceleration is a = -g. v 2 = vo 2 + 2ax = vo 2-2g (h-ho) = vo 2-2gh
More informationPHYSICS 149: Lecture 17
PHYSICS 149: Lecture 17 Chapter 6: Conservation of Energy 6.7 Elastic Potential Energy 6.8 Power Chapter 7: Linear Momentum 7.1 A Vector Conservation Law 7. Momentum Lecture 17 Purdue University, Physics
More information