Lecture 10. Potential energy and conservation of energy
|
|
- Francine Cobb
- 6 years ago
- Views:
Transcription
1 Lecture 10 Potential energy and conservation of energy
2 Today s Topics: Potential Energy and work done by conservative forces Work done by nonconservative forces Conservation of mechanical energy Potential energy curves and equipotentials
3 Potential Energy Potential Energy has the potential to do work! A change in Potential Energy arises from the work done by a conservative force. The work done by gravity when a ball is lifted to height Δh does work on the ball when it is released. If the work done by gravity in lifting the ball a height Δh is (-mgδh), ΔPE -W conservative mgδh
4 Example Δh θ m A box of mass m is pushed to the top of a rough board of length L, that is inclined by θ to the horizontal. What is the change in potential energy of the box? F F N mg Same change in potential as raising the box by Δh f Identify the forces acting on the box Identify the conservative forces that do work F N and mgcosθ are perpendicular to the displacement, so they do no work. F and f are not conservative forces, so they can not change the potential energy W mg - mgsinθ L - mgδh ΔPE - W mg mgδh
5 ACT: Up the Hill Two paths lead to the top of a big hill. One is steep and direct, while the other is twice as long but less steep. How much more potential energy would you gain if you take the longer path? a) the same b) twice as much c) four times as much d) half as much e) you gain no PE in either case Because your vertical position (height) changes by the same amount in each case, the gain in potential energy is the same.
6 ACT: Sign of the Energy Is it possible for the gravitational potential energy of an object to a) yes b) no be negative? Gravitational PE is mgh, where height h is measured relative to some arbitrary reference level where PE 0. For example, a book on a table has positive PE if the zero reference level is chosen to be the floor. However, if the ceiling is the zero level, then the book has negative PE on the table. Only differences (or changes) in PE have any physical meaning.
7 Back to the Work-Energy Theorem In normal situations both conservative and nonconservative forces act simultaneously on an object, so the work done by the net external force can be written as W W c + W nc W KE f - KE o DKE W c -DPE DKE -DPE +W nc THE WORK-ENERGY THEOREM W nc DKE + DPE
8 Conservation of Mechanical Energy W nc ( KE - KE ) + ( PE PE ) DKE + DPE - f o f o W nc ( KE + PE )- ( KE + PE ) f f o o W nc Ef - E o If the net work on an object by non-conservative forces is zero, then its energy does not change:
9
10 The Pendulum A simple pendulum consists of a mass m (of negligible size) suspended by a string or rod of length L (and negligible mass). The angle it makes with the vertical varies with time as a sine or cosine. DEMO: Bowling ball pendulum If we displace a pendulum by an angle, q, away from equilibrium, it rises by an amount: Dh L - Lcosq L(1 -cosq ) aboveits initial position. DPE mgdh mgl(1 -cosq )
11 ACT: Down the Hill Three blocks of equal mass start from rest and slide down different frictionless ramps. All ramps have the same height. Which block has the greatest speed at the bottom of its ramp? d) same speed for all blocks a b c All of the blocks have the same initial gravitational PE, because they are all at the same height (PE mgh). Thus, when they get to the bottom, they all have the same final KE, and hence the same speed (KE mv ). 1
12 ACT: Water Slide I Paul and Kathleen start from rest at the same time on frictionless water slides with different shapes. At the bottom, whose velocity is greater? a) Paul b) Kathleen c) both the same Conservation of Energy: E i mgh E f mv 1 1 therefore: gh v Because they both start from the same height, they have the same velocity at the bottom.
13 ACT: Water Slide II Paul and Kathleen start from rest at the same time on frictionless water slides with different shapes (but equal lengths). Who makes it to the bottom first? a) Paul b) Kathleen c) both the same Even though they both have the same final velocity, Kathleen is at a lower height than Paul for most of her ride. Thus, she always has a larger velocity during her ride and therefore arrives earlier!
14 ACT: Runaway Truck A truck, initially at rest, rolls down a frictionless hill and attains a speed of 0 m/s at the bottom. To achieve a speed of 40 m/s at the bottom, how many times higher must the hill be? a) half the height b) the same height c) times the height d) twice the height e) four times the height Use energy conservation: Ø initial energy: E i PE g mgh Ø final energy: E f KE mv Conservation of Energy: E i mgh E f mv 1 therefore: gh v So if v doubles, H quadruples! 1 1
15 Let s continue our Example Δh m θ Now our box is at rest at the top of the inclined plane and we release it. First, let s ignore friction. What is it s initial and final KE? What is its initial and final PE? What is its final velocity? KE 0 0 since box is at rest PE 0 mgδh PE f 0 since box is at bottom KE F mgδh since we are ignoring friction and, so, the total mechanical energy is conserved PE 0 + KE 0 mgdh + 0 mgdh v PE F 1 mv + mv gdh KE F
16 If we included friction: f m Δh θ Then work is done by friction, and the final velocity is smaller W W NC NC E 1 F - mv E 0 - mgdh
17 Storing potential energy in a spring: PE spring 1 kx
18
19 ACT: Elastic Potential Energy How does the work required to stretch a spring cm compare with the work required to stretch it 1 cm? a) same amount of work b) twice the work c) four times the work d) eight times the work The elastic potential energy is kx. So in the second case, the elastic PE is four times greater than in the first case. Thus, the work required to stretch the spring is also four times greater. 1
20 ACT: Springs and Gravity A mass attached to a vertical spring causes the spring to stretch and the mass to move downwards. What can you say about the spring s potential energy (PE s ) and the gravitational potential energy (PE g ) of the mass? a) both PE s and PE g decrease b) PE s increases and PE g decreases c) both PE s and PE g increase d) PE s decreases and PE g increases e) PE s increases and PE g is constant The spring is stretched, so its elastic PE increases, because PE s 1 kx. The mass moves down to a lower position, so its gravitational PE decreases, because PE g mgh.
21 Potential Energy Curves and Equipotentials The curve of a hill or a roller coaster is itself essentially a plot of the gravitational potential energy: DEMO: Wavy track
22 The potential energy curve for a spring:
23 Contour maps are also a form of potential energy curve:
Question 8.1 Sign of the Energy II
Question 8. Sign of the Energy II Is it possible for the gravitational potential energy of an object to be negative? a) yes b) no Question 8. Sign of the Energy II Is it possible for the gravitational
More informationConcepTest PowerPoints
ConcepTest PowerPoints Chapter 6 Physics: Principles with Applications, 6 th edition Giancoli 2005 Pearson Prentice Hall This work is protected by United States copyright laws and is provided solely for
More informationLecture 10 Mechanical Energy Conservation; Power
Potential energy Basic energy Lecture 10 Mechanical Energy Conservation; Power ACT: Zero net work The system of pulleys shown below is used to lift a bag of mass M at constant speed a distance h from the
More informationReview. Kinetic Energy Work Hooke s s Law Potential Energy Conservation of Energy Power 1/91
Review Kinetic Energy Work Hooke s s Law Potential Energy Conservation of Energy Power 1/91 The unit of work is the A. Newton B. Watt C. Joule D. Meter E. Second 2/91 The unit of work is the A. Newton
More informationConservation of Energy
Lecture 3 Chapter 8 Physics I 03.0.04 Conservation of Energy Course website: http://faculty.uml.edu/andriy_danylov/teaching/physicsi Lecture Capture: http://echo360.uml.edu/danylov03/physicsspring.html
More information5.3. Conservation of Energy
5.3. Conservation of Energy Conservation of Energy Energy is never created or destroyed. Any time work is done, it is only transformed from one form to another: Kinetic Energy Potential Energy Gravitational,
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 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 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 information= 1 2 kx2 dw =! F! d! r = Fdr cosθ. T.E. initial. = T.E. Final. = P.E. final. + K.E. initial. + P.E. initial. K.E. initial =
Practice Template K.E. = 1 2 mv2 P.E. height = mgh P.E. spring = 1 2 kx2 dw =! F! d! r = Fdr cosθ Energy Conservation T.E. initial = T.E. Final (1) Isolated system P.E. initial (2) Energy added E added
More informationCHAPTER 6 WORK AND ENERGY
CHAPTER 6 WORK AND ENERGY ANSWERS TO FOCUS ON CONCEPTS QUESTIONS (e) When the force is perpendicular to the displacement, as in C, there is no work When the force points in the same direction as the displacement,
More informationChapter 6 Energy and Oscillations
Chapter 6 Energy and Oscillations Conservation of Energy In this chapter we will discuss one of the most important and fundamental principles in the universe. Energy is conserved. This means that in any
More informationWork and energy. 15 m. c. Find the work done by the normal force exerted by the incline on the crate.
Work and energy 1. A 10.0-kg crate is pulled 15.0 m up along a frictionless incline as shown in the figure below. The crate starts at rest and has a final speed of 6.00 m/s. motor 15 m 5 a. Draw the free-body
More informationPotential Energy & Conservation of Energy
PHYS 101 Previous Exam Problems CHAPTER 8 Potential Energy & Conservation of Energy Potential energy Conservation of energy conservative forces Conservation of energy friction Conservation of energy external
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 informationPhysics 1A, Summer 2011, Summer Session 1 Quiz 3, Version A 1
Physics 1A, Summer 2011, Summer Session 1 Quiz 3, Version A 1 Closed book and closed notes. No work needs to be shown. 1. Three rocks are thrown with identical speeds from the top of the same building.
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 informationPhys101 Lectures 9 and 10 Conservation of Mechanical Energy
Phys101 Lectures 9 and 10 Conservation of Mechanical Energy Key points: Conservative and Nonconservative Forces Potential Energy Generalized work-energy principle Mechanical Energy and Its Conservation
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 informationMECHANICAL (TOTAL) ENERGY
DO NOW: 1/19 If you haven t already, please take the short google form survey posted on Edmodo Please turn in your Work done by friction Lab in the top tray POTENTIAL ENERGY Stored energy An object that
More informationP = dw dt. P = F net. = W Δt. Conservative Force: P ave. Net work done by a conservative force on an object moving around every closed path is zero
Power Forces Conservative Force: P ave = W Δt P = dw dt P = F net v Net work done by a conservative force on an object moving around every closed path is zero Non-conservative Force: Net work done by a
More information(A) 10 m (B) 20 m (C) 25 m (D) 30 m (E) 40 m
Work/nergy 1. student throws a ball upward where the initial potential energy is 0. t a height of 15 meters the ball has a potential energy of 60 joules and is moving upward with a kinetic energy of 40
More informationCPS lesson Work and Energy ANSWER KEY
CPS lesson Work and Energy ANSWER KEY 1. A ball feeder slowly pushes a bowling ball up a 1-m ramp to a height of 0.5 m above the floor. Neglecting friction, what constant force must be exerted on the 5-kg
More informationChapters 10 & 11: Energy
Chapters 10 & 11: 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
More informationName 09-MAR-04. Work Power and Energy
Page 1 of 16 Work Power and Energy Name 09-MAR-04 1. A spring has a spring constant of 120 newtons/meter. How much potential energy is stored in the spring as it is stretched 0.20 meter? 1. 2.4 J 3. 12
More information1 1. A spring has a spring constant of 120 newtons/meter. How much potential energy is stored in the spring as it is stretched 0.20 meter?
Page of 3 Work Power And Energy TEACHER ANSWER KEY March 09, 200. A spring has a spring constant of 20 newtons/meter. How much potential energy is stored in the spring as it is stretched 0.20 meter?. 2.
More information1) To Work or Not to Work
1) To Work or Not to Work Is it possible to do work on an object that remains at rest? 1) yes 2) no 1) To Work or Not to Work Is it possible to do work on an object that remains at rest? 1) yes 2) no Work
More information2 possibilities. 2.) Work is done and... 1.) Work is done and... *** The function of work is to change energy ***
Work-Energy Theorem and Energy Conservation *** The function of work is to change energy *** 2 possibilities 1.) Work is done and... or 2.) Work is done and... 1 EX: A 100 N box is 10 m above the ground
More informationWEP-Energy. 2. If the speed of a car is doubled, the kinetic energy of the car is 1. quadrupled 2. quartered 3. doubled 4. halved
1. A 1-kilogram rock is dropped from a cliff 90 meters high. After falling 20 meters, the kinetic energy of the rock is approximately 1. 20 J 2. 200 J 3. 700 J 4. 900 J 2. If the speed of a car is doubled,
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 informationConservative vs. Non-conservative forces Gravitational Potential Energy. Conservation of Mechanical energy
Next topic Conservative vs. Non-conservative forces Gravitational Potential Energy Mechanical Energy Conservation of Mechanical energy Work done by non-conservative forces and changes in mechanical energy
More informationMomentum, Impulse, Work, Energy, Power, and Conservation Laws
Momentum, Impulse, Work, Energy, Power, and Conservation Laws 1. Cart A has a mass of 2 kilograms and a speed of 3 meters per second. Cart B has a mass of 3 kilograms and a speed of 2 meters per second.
More informationEnergy present in a variety of forms. Energy can be transformed form one form to another Energy is conserved (isolated system) ENERGY
ENERGY Energy present in a variety of forms Mechanical energy Chemical energy Nuclear energy Electromagnetic energy Energy can be transformed form one form to another Energy is conserved (isolated system)
More information(A) 10 m (B) 20 m (C) 25 m (D) 30 m (E) 40 m
PSI AP Physics C Work and Energy (Algebra Based) Multiple Choice Questions (use g = 10 m/s 2 ) 1. A student throws a ball upwards from the ground level where gravitational potential energy is zero. At
More informationChapter 6: Work and Kinetic Energy
Chapter 6: Work and Kinetic Energy Suppose you want to find the final velocity of an object being acted on by a variable force. Newton s 2 nd law gives the differential equation (for 1D motion) dv dt =
More informationPhys101 Lectures 9 and 10 Conservation of Mechanical Energy
Phys101 Lectures 9 and 10 Conservation of Mechanical Energy Key points: Conservative and Nonconservative Forces Potential Energy Generalized work-energy principle Mechanical Energy and Its Conservation
More informationPotential energy functions used in Chapter 7
Potential energy functions used in Chapter 7 CHAPTER 7 CONSERVATION OF ENERGY Conservation of mechanical energy Conservation of total energy of a system Examples Origin of friction Gravitational potential
More informationUnit 4 Work, Power & Conservation of Energy Workbook
Name: Per: AP Physics C Semester 1 - Mechanics Unit 4 Work, Power & Conservation of Energy Workbook Unit 4 - Work, Power, & Conservation of Energy Supplements to Text Readings from Fundamentals of Physics
More informationD) No, because of the way work is defined D) remains constant at zero. D) 0 J D) zero
CHAPTER 6 REVIEW NAME 1) Can work be done on a system if there is no motion? A) Yes, if an outside force is provided. B) Yes, since motion is only relative. C) No, since a system which is not moving has
More informationChapters 10 & 11: Energy
Chapters 10 & 11: 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
More informationPhysics 201, Review 2
Physics 201, Review 2 Important Notes: v This review does not replace your own preparation efforts v The review is not meant to be complete. v Exercises used in this review do not form a test problem pool.
More informations_3x03 Page 1 Physics Samples
Physics Samples KE, PE, Springs 1. A 1.0-kilogram rubber ball traveling east at 4.0 meters per second hits a wall and bounces back toward the west at 2.0 meters per second. Compared to the kinetic energy
More informationLecture 18: Work and Energy. Today s Agenda
Lecture 18: Work and Energy Work and Energy Definition of work Examples Today s Agenda Definition of Mechanical Energy Conservation of Mechanical Energy Conservative forces Physics 201: Lecture 10, Pg
More informationPhysics 231. Topic 5: Energy and Work. Alex Brown October 2, MSU Physics 231 Fall
Physics 231 Topic 5: Energy and Work Alex Brown October 2, 2015 MSU Physics 231 Fall 2015 1 What s up? (Friday Sept 26) 1) The correction exam is now open. The exam grades will be sent out after that on
More informationHealy/DiMurro. Vibrations 2016
Name Vibrations 2016 Healy/DiMurro 1. In the diagram below, an ideal pendulum released from point A swings freely through point B. 4. As the pendulum swings freely from A to B as shown in the diagram to
More informationDEVIL PHYSICS THE BADDEST CLASS ON CAMPUS IB PHYSICS
DEVIL PHYSICS THE BADDEST CLASS ON CAMPUS IB PHYSICS LSN -3: WORK, ENERGY AND POWER Questions From Reading Activity? Essential Idea: The fundamental concept of energy lays the basis upon which much of
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 informationWork Energy Review. 1. Base your answer to the following question on the information and diagram below and on your knowledge of physics.
Name: ate: 1. ase your answer to the following question on the information and diagram below and on your knowledge of physics. student pushes a box, weighing 50. newtons, 6.0 meters up an incline at a
More informationPhysics 201, Review 2
Physics 01, Review Important Notes: v This review does not replace your own preparation efforts v The review is not meant to be complete. v Exercises used in this review do not form a test problem pool.
More informationPSI AP Physics I Work and Energy
PSI AP Physics I Work and Energy Multiple-Choice questions 1. A driver in a 2000 kg Porsche wishes to pass a slow moving school bus on a 4 lane road. What is the average power in watts required to accelerate
More informationWEP-Energy. 2. If the speed of a car is doubled, the kinetic energy of the car is 1. quadrupled 2. quartered 3. doubled 4. halved
1. A 1-kilogram rock is dropped from a cliff 90 meters high. After falling 20 meters, the kinetic energy of the rock is approximately 1. 20 J 2. 200 J 3. 700 J 4. 900 J 2. If the speed of a car is doubled,
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 8. Potential Energy & Conservation of Energy
Chapter 8 Potential Energy & Conservation of Energy 8.1 Potential Energy Technically, potential energy is energy that can be associated with the configuration (arrangement) of a system of objects that
More informationHomework #5. Ph 231 Introductory Physics, Sp-03 Page 1 of 4
Homework #. Ph Introductory Physics, Sp-0 Page of -A. A 7 kg block moves in a straight line under the influence of a force that varies with position as shown in the figure at the right. If the force is
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. K = K f K i = 1 2 mv 2 f rf = v v F dr Consider a vertical spring oscillating with mass m attached
More information5. A car moves with a constant speed in a clockwise direction around a circular path of radius r, as represented in the diagram above.
1. The magnitude of the gravitational force between two objects is 20. Newtons. If the mass of each object were doubled, the magnitude of the gravitational force between the objects would be A) 5.0 N B)
More informationLectures Chapter 6 (Cutnell & Johnson, Physics 7 th edition)
PH 201-4A spring 2007 Work and Energy Lectures 16-17 Chapter 6 (Cutnell & Johnson, Physics 7 th edition) 1 Work and Energy: Work done by a constant force Constant pushing force F pointing in the same direction
More informationPhysics 201, Midterm Exam 2, Fall Answer Key
Physics 201, Midterm Exam 2, Fall 2006 Answer Key 1) A constant force is applied to a body that is already moving. The force is directed at an angle of 60 degrees to the direction of the body s velocity.
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 informationW = 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 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 informationWhat is Energy? Which has more energy? Who has more energy? 1/24/2017
What is Energy? Energy is a measure of an object s ability to cause a change in itself and/or its surroundings Read pages 61-7 Which has more energy? Who has more energy? Mississippi River Cargo Barge
More information- Conservation of Energy Notes Teacher Key -
NAME: DATE: PERIOD: PHYSICS - Conservation of Energy Notes Teacher Key - - Is Energy Conserved? - Determine the max height that a 5kg cannonball will reach if fired vertically with an initial velocity
More informationPhysics Unit 4:Work & Energy Name:
Name: Review and Preview We have come a long way in our study of mechanics. We started with the concepts of displacement and time, and built up to the more complex quantities of velocity and acceleration.
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 informationPotential Energy. Serway 7.6, 7.7;
Potential Energy Conservative and non-conservative forces Gravitational and elastic potential energy Mechanical Energy Serway 7.6, 7.7; 8.1 8.2 Practice problems: Serway chapter 7, problems 41, 43 chapter
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 informationChapter 7 Potential Energy and Energy Conservation
Chapter 7 Potential Energy and Energy Conservation We saw in the previous chapter the relationship between work and kinetic energy. We also saw that the relationship was the same whether the net external
More informationPhysics 1A Lecture 6B. "If the only tool you have is a hammer, every problem looks like a nail. --Abraham Maslow
Physics 1A Lecture 6B "If the only tool you have is a hammer, every problem looks like a nail. --Abraham Maslow Work Let s assume a constant force F acts on a rolling ball in a trough at an angle θ over
More informationUniversity of Colorado, Boulder, 2004 CT8-3
University of Colorado, Boulder, 2004 CT8-3 A hockey puck slides without friction along a frozen lake toward an ice ramp and plateau as shown. The speed of the puck is 4m/s and the height of the plateau
More informationExam #2, Chapters 5-7 PHYS 101-4M MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
Exam #2, Chapters 5-7 Name PHYS 101-4M MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) The quantity 1/2 mv2 is A) the potential energy of the object.
More informationGeneral Physics I Work & Energy
General Physics I Work & Energy Forms of Energy Kinetic: Energy of motion. A car on the highway has kinetic energy. We have to remove this energy to stop it. The brakes of a car get HOT! This is an example
More informationPage 1. Name:
Name: 3834-1 - Page 1 1) If a woman runs 100 meters north and then 70 meters south, her total displacement is A) 170 m south B) 170 m north C) 30 m south D) 30 m north 2) The graph below represents the
More informationExtra credit assignment #4 It can be handed in up until one class before Test 4 (check your course outline). It will NOT be accepted after that.
Extra credit assignment #4 It can be handed in up until one class before Test 4 (check your course outline). It will NOT be accepted after that. NAME: 4. Units of power include which of the following?
More informationPhysics 201 Lecture 16
Physics 01 Lecture 16 Agenda: l Review for exam Lecture 16 Newton s Laws Three blocks are connected on the table as shown. The table has a coefficient of kinetic friction of 0.350, the masses are m 1 =
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 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 informationEnergy Problem Solving Techniques.
1 Energy Problem Solving Techniques www.njctl.org 2 Table of Contents Introduction Gravitational Potential Energy Problem Solving GPE, KE and EPE Problem Solving Conservation of Energy Problem Solving
More informationChapter 7: Energy. Consider dropping a ball. Why does the ball s speed increase as it falls?
Chapter 7: Energy Consider dropping a ball. Why does the ball s speed increase as it falls? Viewpoint #1: Force of gravity causes acceleration which causes velocity to change. Viewpoint #2: Force of gravity
More informationWork and the Work-Energy Theorem
Work and Energy Click on the topic to go to that section Energy and the Work-Energy Theorem Work and Energy 2009 by Goodman & Zavorotniy Forces and Potential Energy Conservation of Energy Power Conservation
More information= y(x, t) =A cos (!t + kx)
A harmonic wave propagates horizontally along a taut string of length L = 8.0 m and mass M = 0.23 kg. The vertical displacement of the string along its length is given by y(x, t) = 0. m cos(.5 t + 0.8
More informationOld Exams Questions Ch. 8 T072 Q2.: Q5. Q7.
Old Exams Questions Ch. 8 T072 Q2.: A ball slides without friction around a loop-the-loop (see Fig 2). A ball is released, from rest, at a height h from the left side of the loop of radius R. What is the
More informationPotential Energy & Energy Conservation
Physics 101: Lecture 10 Potential Potential Energy & Energy Conservation Today s lecture will cover Textbook Sections 6.5-6.8 Hour Exam 1: Next Monday! -7 pm, see course site for room assignments -5:15
More informationLectures 11-13: From Work to Energy Energy Conservation
Physics 218: sect.513-517 Lectures 11-13: From Work to Energy Energy Conservation Prof. Ricardo Eusebi for Igor Roshchin 1 Physics 218: sect.513-517 Energy and Work-Energy relationship Prof. Ricardo Eusebi
More informationHomework 6. problems: 8.-, 8.38, 8.63
Homework 6 problems: 8.-, 8.38, 8.63 Problem A circus trapeze consists of a bar suspended by two parallel ropes, each of length l. allowing performers to swing in a vertical circular arc. Suppose a performer
More informationReview for Exam 2 S 2019
Review for Exam 2 S 2019 R1. Work W = F.d (in N m =Joules = J If we know the angle between vectors, q F.d = F d cos q F = (1, 2, 3) F =sqrt(1+4+9)=~4 d = (4, 5, 6) d =sqrt(16+25+36)~9 q=10; W=F d cos(60)
More informationHarmonic Motion: Exercises
Harmonic Motion: Exercises 1. The following is a list of forces, each of which is the net external force acting on an object with mass number m that is free to move in onedimension only. Assume that s
More informationPotential Energy, Conservation of Energy, and Energy Diagrams. Announcements. Review: Conservative Forces. (path independent) 8.
Potential Energy, Conservation of Energy, and Energy Diagrams 8.01 W06D Today s Reading ssignment: Chapter 14 Potential Energy and Conservation of Energy, Sections 14.1-14.7 nnouncements Problem Set 5
More informationHonor Physics Final Exam Review. What is the difference between series, parallel, and combination circuits?
Name Period Date Honor Physics Final Exam Review Circuits You should be able to: Calculate the total (net) resistance of a circuit. Calculate current in individual resistors and the total circuit current.
More informationConcept of Force Concept Questions
Concept of Force Concept Questions Question 1: You are pushing a wooden crate across the floor at constant speed. You decide to turn the crate on end, reducing by half the surface area in contact with
More informationP8.14. m 1 > m 2. m 1 gh = 1 ( 2 m 1 + m 2 )v 2 + m 2 gh. 2( m 1. v = m 1 + m 2. 2 m 2v 2 Δh determined from. m 2 g Δh = 1 2 m 2v 2.
. Two objects are connected by a light string passing over a light frictionless pulley as in Figure P8.3. The object of mass m is released from rest at height h. Using the principle of conservation of
More informationCh 11 ENERGY and its CONSERVATION. work causes a change in the energy of a system KE (an increase or decrease in KE) ket.
Ch 11 ENERGY and its CONSERVATION 11.1 The Many Forms of Energy work causes a change in the energy of a system W = KE (an increase or decrease in KE) work energy theorem object + work object work increase
More informationPotential energy and conservation of energy
Chapter 8 Potential energy and conservation of energy Copyright 8.1_2 Potential Energy and Work Potential energy U is energy that can be associated with the configuration (arrangement) of a system of objects
More informationUnit 08 Work and Kinetic Energy. Stuff you asked about:
Unit 08 Work and Kinetic Energy Today s Concepts: Work & Kinetic Energy Work in a non-constant direction Work by springs Mechanics Lecture 7, Slide 1 Stuff you asked about: Can we go over the falling,
More informationPHYSICS 231 INTRODUCTORY PHYSICS I
PHYSICS 231 INTRODUCTORY PHYSICS I Lecture 6 Last Lecture: Gravity Normal forces Strings, ropes and Pulleys Today: Friction Work and Kinetic Energy Potential Energy Conservation of Energy Frictional Forces
More informationLecture 18. Newton s Laws
Agenda: l Review for exam Lecture 18 l Assignment: For Monday, Read chapter 14 Physics 207: Lecture 18, Pg 1 Newton s Laws Three blocks are connected on the table as shown. The table has a coefficient
More informationWelcome to: Physics I. I m Dr Alex Pettitt, and I ll be your guide!
Welcome to: Physics I I m Dr Alex Pettitt, and I ll be your guide! Physics I: E Conservation of energy Lecture 7: 20-10-2017 Last lecture: review Work: W = F r F = F r cos = F x r x + F y r y + F z r z
More information0J2 - Mechanics Lecture Notes 2
0J2 - Mechanics Lecture Notes 2 Work, Power, Energy Work If a force is applied to a body, which then moves, we say the force does work. In 1D, if the force is constant with magnitude F, and the body moves
More informationGravitational Potential
Gravitational Potential Energy Bởi: OpenStaxCollege Work Done Against Gravity Climbing stairs and lifting objects is work in both the scientific and everyday sense it is work done against the gravitational
More information