Work, Energy, Conservation of Energy


 Ursula French
 2 years ago
 Views:
Transcription
1 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 probles requiring a knowledge of basic calculus. Part I. Multiple Choice F Ø. A force F is exerted at an angle Ø on a box of ass as it is dragged across the floor at constant velocity. If the box travels a distance x, then the work done by the force F on the box is a. Fx b. Fx cos Ø c. gx cos Ø d. Fx sin Ø e. Fx tan Ø 2. A block of wood, initially oving along a rough surface, is pushed with an applied horizontal force F applied that is less than the friction force F friction. Which of the following stateents is false? a. The Work being done by the applied force is negative. b. The net Work being done on the block is negative. c. The block is slowing down. d. The net Work being done on the box decreases its kinetic energy K. e. There is an increase in internal energy due to friction. 3. A 300Watt electric wheelchair has a ass of 50kg, and carries its 50kg occupant at constant velocity up a long rap. About how uch tie does it take the wheelchair to reach the top of the 0eter high rap? a. 3 s b. 7 s c. 0 s d. 333 s e. 33 s
2 U(r) 3U0 2U0 U0 0 r0 2r0 3r0 4r0 r 4. The graph above represents the potential energy U as a function of position r for a particle of ass. If the particle is released fro rest at position r o, what will its speed be at position 3r 0? a. 8U 0 b. c. 4U 0 2U 0 d. 6U 0 e. The particle will never reach position 3r The behavior of a nonlinear spring is described by the relationship F = 2kx 3, where x is the displaceent fro the equlibriu position and F is the force exerted by the spring. How uch potential energy is stored in the spring when it is displaced a distance x fro equilibriu? a. 2 kx 4 b. c. d. e. 6kx 2 3 kx 4 3 kx kx 2
3 Part II. Free Response anchor 0 d 2d anchor 0 6. A block of ass rests on a rough surface, and has a light spring of spring constant k and unstretched length d attached to one side as shown, with the other end of the spring attached to an anchor. There is a static coefficient of friction µ s between the surface and the block, and when the block is placed to the right at position 2d, it reains stationary on the surface. Express answers in ters of, k, d, and fundaental constants. a. Draw a freebody diagra of the block at the tie when it is located at position 2d. d 2d b. Deterine the friction force acting on the block when it is located at position 2d.
4 anchor 0 d 2d 3d c. The block is now oved to position 3d and released, where it reains at rest. When the block is oved slightly past this position, the block begins to slide along the surface with a kinetic coefficient of friction µ k. i. In ters of the variables given, what is the value of µ s? ii. How uch potential energy is stored in the assspring syste just before the block begins to ove? iii. The block slides a total distance of d before coing to a halt again. Deterine the coefficient of kinetic friction µ k.
5 iv. At what position does the block have its axiu velocity as it slides? v. What is the axiu velocity of the block as it slides?
6 A r = 20 D h = 60 C E B 7. A roller coaster car of ass = 200 kg is released fro rest at the top of a 60 high hill (position A), and rolls with negligible friction down the hill, through a circular loop of radius 20 (positions B, C, and D), and along a horizontal track (to position E). a. What is the velocity of the car at position B? b. Deterine the velocity of the car at position C. c. Draw a freebody diagra of the car at position C.
7 d. Deterine the velocity of the car at position D. e. Deterine the force (agnitude and direction) of the track on the car at position D. f. After copleting the loop, the rollercoaster car is travelling horizontally at velocity v 0 and subjected to a braking force F braking = kv, where k is a constant, v is the instantaneous velocity of the car, and tie t is the aount of tie that the braking force has been applied. i. Develop a definite integral expressed in ters of initial velocity v 0, k,, and tie t that could be used to evaluate the velocity of the car along the horizontal track. ii. Solve the integral to deterine an equation that could be used to calculate the horizontal velocity of the car as a function of initial velocity v 0, k,, and tie t.
8 8. A conservative force acts in the xdirection on a particle of ass = 2.0 kg to produce a potential energy curve as shown above. a. A particle is released fro rest at the 0.5 eter position. i. What is the potential energy of the particle at this position? ii. What is the velocity of this particle at x = 2 eters? iii. Describe the point on the U curve at x = 4 briefly, and what happens when the released particle reaches this position. iv. Does the released particle reach x = 7? If not, explain why not. If so, describe the particle s behavior.
9 b. A second particle, also of ass, is released fro rest at x = 8. Briefly describe the behavior of this particle. c. Sketch a graph of the conservative force that produces this potential energy curve.
10 Practice Test Solutions:. The correct answer is b. Work done by an object is calculated according to the Work forula W=F x, or W=Fx cos Ø. There are a couple of distractors in this proble: the ass of the box is not needed in the solution, and the box s constant velocity isn t required. The fact that the box is traveling at constant velocity iplies that there is friction ipeding its otion, but evidently the energy lost to friction is equal to the work being done by the force F, so that the net Work done on the box by F and F friction = 0. None of this inforation is necessary, though, to solve the proble. 2. The correct answer is a. Stateent a is false because the work done by any single agent is W = Fx cosθ. Here, with the applied Force and the displaceent of the box being in the sae direction (or cosθ = cos(0) =), the Work being done by the applied force is positive, and goes toward increasing the box's kinetic energy. Of course, the net, or overall, Work being done on the box has to include the force of Friction, which is acting in a direction opposite that of the box's displaceent. Thus, Work done by friction is negative, which has the effect of converting soe of the box's kinetic energy to internal energy via heat. 3. The correct answer is e. The wheelchair carries a total ass of 00kg up to a height of 0, with 300J of Work being done by the wheelchair each second. The tie for the total Work does is calculated as follows: P = Work tie tie = Work Power = gh P tie = (00kg)(0 /s2 )(0) 300J /s = = 33s 4. The correct answer is c. This is a conservation of energy proble, in which we exaine the relationship between the particle s potential and kinetic energies. U i + K i = U f + K f 3U = 2U 0 + v 2 2 U 0 = v 2 2 v = 2U 0 5. The correct answer is a. The potential energy stored in the spring is calculated using the Work integral: U = U = x f x i x 0 U = 2k x 4 F dx 2kx 3 dx x 4 0 = 2 kx 4
11 Practice Test Solutions: 6. a. The block isn t oving yet, so the force exerted by the spring to the left equals the force exerted by friction to the right. Vectors should be labeled and drawn with lengths proportional to their agnitude. Soe instructors wish for vectors to be drawn with their point of origin beginning at the location where that force is applied, and soe instructors prefer that force vectors be drawn originating fro the center of the (point) ass. FNoral Fspring Ffriction Fgravity b. The friction force acting on the block at this point is equal in agnitude to the force applied by the spring: F net = a c. F spring F friction = 0 F friction = kx = kd i. The coefficient of static friction is based on the axiu force of static friction that the blocksurface can support. In this case: µ static = F friction F Noral = kx g = k(2d) g ii. The potential energy stored in the spring is siply based on U spring = 2 kx 2 : U spring = 2 kx 2 U spring = 2 k(2d)2 = 2kd 2 iii. The coefficient of kinetic friction can be deterined by using a Conservation of Energy analysis, taking into account the potential energy of the assspring syste at the beginning and end, as well as the energy lost to heat in the block s slide: U spring initial ΔE internal = U spring final 2 kx 2 i F friction d = 2 kx 2 f 2 kx 2 i µ k gd = 2 kx 2 f 2 k(2d)2 µ k gd = 2 kd 2 µ k = 3kd 2g 20, Richard White
12 Practice Test Solutions: Note that this result reveals that µ k = 3 " 2kd% $ ' = 3 4 # g & 4 µ x, which is consistent with the principal that coefficients of kinetic friction are less than coefficients of static friction. iv. The block has its axiu velocity where the slope of the velocitytie curve is 0, ie. where acceleration is 0. At that position, the force fro the spring and the force of friction are equal to each other: F net = a F spring F friction = 0 kx µ k F Noral = kx µ k g = 0 where x is the displaceent of the spring fro its unstretched length at d. Substituting in µ k fro the proble before: kx µ k g = 0 " kx 3kd % $ 'g = 0 # 2g & kx 3 2 kd = 0 7. x = 3d, relative to unstretched length at d 2 Relative to the origin: 3d 2 + d = 5 2 d v. Now that we know the position of the axiu velocity, we can use Conservation of Energy again to calculate that velocity: U s initial ΔE int = K +U s final 2 kx 2 i F friction x = 2 v2 + 2 kx 2 f # 2 k(2d)2 µ k g d & % $ 2 ' ( = 2 v2 + 2 k # % 3 $ 2 d & ( ' # 2 k(2d)2 3kd & % $ 2g ' (g # d & % $ 2 ' ( = 2 v2 + 2 k # % 3 $ 2 d & ( ' Solve to get v = d 2 k a. This is a conservation of energy proble, with the gravitational potential energy of the car U being converted to kinetic energy K as the car rolls down the hill. U = K 2 2 gh = 2 v 2 v = 2gh = = 34.3 /s
13 Practice Test Solutions: b. At position C, soe of the car s K has converted back to U. U i = K +U f gh A = 2 v 2 C + gh C v C = 2g(h A h C ) = 2 9.8(60 20) = 28 /s c. The freebody diagra for the car includes the only two forces acting on the car: the force of gravity, and the force of the track which is providing the centripetal force that keeps the car oving in a circle (usually considered as a Noral force). FNoral Fgravity d. The velocity of the car at position D is deterined using the sae technique as in (b): U i = K +U f gh A = 2 v 2 D + gh D v D = 2g(h A h D ) = 2 9.8(60 40) =9.8 /s e. The force of the track on the car at D can be deterined by using Newton s 2nd Law of Motion to the circular otion: F c = v 2 r F track + F g = v 2 r F track = v 2 F r g Here we re considering down (toward the iddle of the circle) to be in the positive direction, and we re assuing that the force of the track and the force of gravity are both pointing down: the force of gravity is providing soe of the force to keep the car oving in a circle, and the force of the track will provide the reaining. In soe cases, however if the car is traveling very slowly, for exaple a uch saller centripetal force will required, to the point that the track has to provide an upwards force. We would realize that this was the case if we calculated a Force for the track that was negative. Continuing with our calculation: F track = v 2 F r g F track = (200)(9.8)2 20 (200)(9.8) =960N
14 Practice Test Solutions: f. i. The horizontal braking force causes the velocity of the car to decrease as a function of tie t. The integral describing the car s otion is based on applying Newton s 2nd Law of Motion: F net = a kv = dv dt dv dt = k v dv v = k dt v dv t k = v 0 v dt 0 ii. Now solve the integral for v: v dv t k = v 0 v dt 0 v lnv v0 = k t lnv lnv 0 = k t $ ln v ' & ) = k % v 0 ( t v = e v 0 k t k v = v 0 e t 8. Potential energy can be defined only for conservative forces, and diagras are one way of describing those forces. The relationship between the conservative force acting on a particle, its displaceent, and the potential energy associated with the force is described by the equation ΔU = F x dx, or F x = du dx. a. i. By exaining the graph, the potential energy U is about 5 Joules. ii. Using Conservation of Energy: U i + K i = U f + K f 5J + 0 = 3J + 2 v 2 v = 6 = 6 2 = 2.8 /s iii. At x = 4 there is a position of unstable equilibriu. At this point, based on F x = du, there is dx no acceleration applied by the conservative force (the slope of the U curve is 0), but here, the particle will continue oving past that position, based on the fact that it has 4 Joules of K energy.
15 Practice Test Solutions: iv. The particle does reach the position x = 7, and because it still has 2 Joules of K energy, it will continue to ove to the right, even though the conservative force is no longer causing any acceleration. b. A particle released fro rest at position x = 8 will not experience any conservative force, and so will not accelerate. It will reain at that location. c. The graph of the conservative force is effectively a graph of the negative slopes of the Ux graph. Key points to ake sure are included in the Force graph are positions where U graph inflects. The Force curve should cross the xaxis at equilibriu points (at x =, 3, and 5 eters, as well as for x > 7 ). Sketch in the rest of the curve based on your interpretation of the U graph.
Answer, 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 informationLecture L9  Linear Impulse and Momentum. Collisions
J. Peraire, S. Widnall 16.07 Dynaics Fall 009 Version.0 Lecture L9  Linear Ipulse and Moentu. Collisions In this lecture, we will consider the equations that result fro integrating Newton s second law,
More informationVersion 001 test 1 review tubman (IBII201516) 1
Version 001 test 1 review tuban (IBII01516) 1 This printout should have 44 questions. Multiplechoice questions ay continue on the next colun or page find all choices before answering. Crossbow Experient
More informationChapter 13 Simple Harmonic Motion
We are to adit no ore causes of natural things than such as are both true and sufficient to explain their appearances. Isaac Newton 13.1 Introduction to Periodic Motion Periodic otion is any otion that
More informationChapter 8: Newton s Third law
Warning: My approach is a soewhat abbreviated and siplified version of what is in the text, yet just as coplete. Both y treatent and the text s will prepare you to solve the sae probles. Restating Newton
More informationMh1: Simple Harmonic Motion. Chapter 15. Motion of a SpringMass System. Periodic Motion. Oscillatory Motion
Mh1: Siple Haronic Motion Chapter 15 Siple block and spring Oscillatory Motion Exaple: the tides, a swing Professor Michael Burton School of Physics, UNSW Periodic Motion! Periodic otion is otion of an
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 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 informationLesson 44: Acceleration, Velocity, and Period in SHM
Lesson 44: Acceleration, Velocity, and Period in SHM Since there is a restoring force acting on objects in SHM it akes sense that the object will accelerate. In Physics 20 you are only required to explain
More informationSimple Harmonic Motion
SHM1 Siple Haronic Motion A pendulu, a ass on a spring, and any other kinds of oscillators ehibit a special kind of oscillatory otion called Siple Haronic Motion (SHM). SHM occurs whenever : i. there
More informationcharge is detonated, causing the smaller glider with mass M, to move off to the right at 5 m/s. What is the
This test covers momentum, impulse, conservation of momentum, elastic collisions, inelastic collisions, perfectly inelastic collisions, 2D collisions, and centerofmass, with some problems requiring
More informationAnswer: Same magnitude total momentum in both situations.
Page 1 of 9 CTP1. In which situation is the agnitude of the total oentu the largest? A) Situation I has larger total oentu B) Situation II C) Sae agnitude total oentu in both situations. I: v 2 (rest)
More informationPhysics 211: Lab Oscillations. Simple Harmonic Motion.
Physics 11: Lab Oscillations. Siple Haronic Motion. Reading Assignent: Chapter 15 Introduction: As we learned in class, physical systes will undergo an oscillatory otion, when displaced fro a stable equilibriu.
More informationConcepTest 4.6 Force and Two Masses
ConcepTest 4.6 Force and Two Masses A force F acts on ass 1 giving acceleration a 1. The sae force acts on a different ass 2 giving acceleration a 2 = 2a 1. If 1 and 2 are glued together and the sae force
More informationHomework 8. problems: 10.40, 10.73, 11.55, 12.43
Hoework 8 probles: 0.0, 0.7,.55,. Proble 0.0 A block of ass kg an a block of ass 6 kg are connecte by a assless strint over a pulley in the shape of a soli isk having raius R0.5 an ass M0 kg. These blocks
More informationVersion 001 Summer Review #04 tubman (IBII ) 1
Version 001 Suer Review #04 tuban (IBII20142015) 1 This printout should have 20 questions. Multiplechoice questions ay continue on the next colun or page find all choices before answering. Conceptual
More informationChapter 7 WORK, ENERGY, AND Power Work Done by a Constant Force Kinetic Energy and the WorkEnergy Theorem Work Done by a Variable Force Power
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
More informationAll you wanted to know about Formulae and Graphs (but were afraid to ask!)
All you wanted to know about Forulae and Graphs (but were afraid to ask!) o be able to carry out practical investigations in Physics you ust understand the following: 1. What variables are you investigating
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 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 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 information7. Kinetic Energy and Work
Kinetic Energy: 7. Kinetic Energy and Work The kinetic energy of a moving object: k = 1 2 mv 2 Kinetic energy is proportional to the square of the velocity. If the velocity of an object doubles, the kinetic
More informationAP1 WEP. Answer: E. The final velocities of the balls are given by v = 2gh.
1. Bowling Ball A is dropped from a point halfway up a cliff. A second identical bowling ball, B, is dropped simultaneously from the top of the cliff. Comparing the bowling balls at the instant they reach
More informationE k = ½ m v 2. (J) (kg) (m s 1 ) FXA KINETIC ENERGY (E k ) 1. Candidates should be able to : This is the energy possessed by a moving object.
KINETIC ENERGY (E k ) 1 Candidates should be able to : This is the energy possessed by a oing object. Select and apply the equation for kinetic energy : E k = ½ 2 KINETIC ENERGY = ½ x MASS x SPEED 2 E
More informationAP Physics. Chapter 9 Review. Momentum et. al.
AP Physics Chapter 9 Review Moentu et. al. 1. A 2000kg truck traveling at a speed of 3.0 akes a 90 turn in a tie of 4.0 onds and eerges fro this turn with a speed of 4.0. What is the agnitude of the average
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 informationWORK 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 informationPhys 207. Announcements. Hwk 6 is posted online; submission deadline = April 4 Exam 2 on Friday, April 8th. Today s Agenda
Phys 07 Announceents Hwk 6 is posted online; subission deadline = April 4 Ea on Friday, April 8th Today s Agenda Review of Work & Energy (Chapter 7) Work of ultiple constant forces Work done by gravity
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 information2.1 Force and Motion Kinematics looks at velocity and acceleration without reference to the cause of the acceleration.
2.1 Force and Motion Kinematics looks at velocity and acceleration without reference to the cause of the acceleration. Dynamics looks at the cause of acceleration: an unbalanced force. Isaac Newton was
More informationExplaining Motion:Forces
Explaining Motion:Forces Chapter Overview (Fall 2002) A. Newton s Laws of Motion B. Free Body Diagrams C. Analyzing the Forces and Resulting Motion D. Fundamental Forces E. Macroscopic Forces F. Application
More informationF=ma From Problems and Solutions in Introductory Mechanics (Draft version, August 2014) David Morin, morin@physics.harvard.edu
Chapter 4 F=a Fro Probles and Solutions in Introductory Mechanics (Draft version, August 2014) David Morin, orin@physics.harvard.edu 4.1 Introduction Newton s laws In the preceding two chapters, we dealt
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 informationConcept Review. Physics 1
Concept Review Physics 1 Speed and Velocity Speed is a measure of how much distance is covered divided by the time it takes. Sometimes it is referred to as the rate of motion. Common units for speed or
More informationHonors Physics. Momentum Review
Honors Physics Moentu Review Nae Date. A freight car of ass 0,000 kg oves along a frictionless level railroad track with a constant speed of 5 /s. What is the oentu of the car A. 30,000 kg /s B. 3,000
More informationPhysics 201 Homework 5
Physics 201 Homework 5 Feb 6, 2013 1. The (nonconservative) force propelling a 1500kilogram car up a mountain 1.21 10 6 joules road does 4.70 10 6 joules of work on the car. The car starts from rest
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 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 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 informationWork and Direction. Work and Direction. Work and Direction. Work and Direction
Calculate the net gravitational force on the shaded ball. Be sure to include the magnitude and direction. Each ball has a mass of 20,000 kg. (0.79N, 22.5 o N of E) Chapter Six Work = Force X distance W
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 informationMULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
Exam Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) The following four forces act on a 4.00 kg object: 1) F 1 = 300 N east F 2 = 700 N north
More informationLAWS OF MOTION PROBLEM AND THEIR SOLUTION
http://www.rpauryascienceblog.co/ LWS OF OIO PROBLE D HEIR SOLUIO. What is the axiu value of the force F such that the F block shown in the arrangeent, does not ove? 60 = =3kg 3. particle of ass 3 kg oves
More informationPhysics 2101, First Exam, Fall 2007
Physics 2101, First Exam, Fall 2007 September 4, 2007 Please turn OFF your cell phone and MP3 player! Write down your name and section number in the scantron form. Make sure to mark your answers in the
More 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 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 informationChapter 5: Work, Power & Energy
Chapter 5: Work, Power & Energy Abition is like a vector; it needs agnitude and direction. Otherwise, it s just energy. Grace Lindsay Objectives 1. Define work and calculate the work done by a force..
More informationPHYSICS 151 Notes for Online Lecture 2.2
PHYSICS 151 otes for Online Lecture. A freebod diagra is a wa to represent all of the forces that act on a bod. A freebod diagra akes solving ewton s second law for a given situation easier, because
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 informationPhys101 Lectures 14, 15, 16 Momentum and Collisions
Phs0 Lectures 4, 5, 6 Moentu and ollisions Ke points: Moentu and ipulse ondition for conservation of oentu and wh How to solve collision probles entre of ass Ref: 9,,3,4,5,6,7,8,9. Page Moentu is a vector:
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 informationUniversity Physics 226N/231N Old Dominion University. Newton s Laws and Forces Examples
University Physics 226N/231N Old Dominion University Newton s Laws and Forces Examples Dr. Todd Satogata (ODU/Jefferson Lab) satogata@jlab.org http://www.toddsatogata.net/2012odu Wednesday, September
More informationCh 6 Forces. Question: 9 Problems: 3, 5, 13, 23, 29, 31, 37, 41, 45, 47, 55, 79
Ch 6 Forces Question: 9 Problems: 3, 5, 13, 23, 29, 31, 37, 41, 45, 47, 55, 79 Friction When is friction present in ordinary life?  car brakes  driving around a turn  walking  rubbing your hands together
More 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 informationF = ma. F = mg. Forces. Forces. Free Body Diagrams. Find the unknown forces!! Ex. 1 Ex N. Newton s First Law. Newton s Second Law
Forces Free Body Diagrams Push or pull on an object Causes acceleration Measured in Newtons N = Kg m s Shows all forces as vectors acting on an object Vectors always point away from object Used to help
More 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 informationKEY NNHS Introductory Physics: MCAS Review Packet #1 Introductory Physics, High School Learning Standards for a Full FirstYear Course
Introductory Physics, High School Learning Standards for a Full FirstYear Course I. C O N T E N T S T A N D A R D S Central Concept: Newton s laws of motion and gravitation describe and predict the motion
More informationAssignment Work (Physics) Class :Xi Chapter :04: Motion In PLANE
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. Assignment Work (Physics) Class :Xi Chapter :04: Motion In PLANE State law of parallelogram of vector addition and derive expression for resultant of two vectors
More informationB Answer: neither of these. Mass A is accelerating, so the net force on A must be nonzero Likewise for mass B.
CTA1. An Atwood's machine is a pulley with two masses connected by a string as shown. The mass of object A, m A, is twice the mass of object B, m B. The tension T in the string on the left, above mass
More 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 informationExperiment: Static and Kinetic Friction
PHY 201: General Physics I Lab page 1 of 6 OBJECTIVES Experiment: Static and Kinetic Friction Use a Force Sensor to measure the force of static friction. Determine the relationship between force of static
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 informationQUESTIONS : CHAPTER5: LAWS OF MOTION
QUESTIONS : CHAPTER5: LAWS OF MOTION 1. What is Aristotle s fallacy? 2. State Aristotlean law of motion 3. Why uniformly moving body comes to rest? 4. What is uniform motion? 5. Who discovered Aristotlean
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 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 informationImagine that a wall of your house is hit on one occasion by a boy on a skateboard and on another by a large juggernaut.
A Resource for Freestanding Matheatics Qualifications Iagine that a wall of your house is hit on one occasion by a boy on a skateboard and on another by a large juggernaut. Suppose both had a speed of
More informationWork, Kinetic Energy and Potential Energy
Chapter 6 Work, Kinetic Energy and Potential Energy 6.1 The Important Stuff 6.1.1 Kinetic Energy For an object with mass m and speed v, the kinetic energy is defined as K = 1 2 mv2 (6.1) Kinetic energy
More informationThe Mathematics of Pumping Water
The Matheatics of Puping Water AECOM Design Build Civil, Mechanical Engineering INTRODUCTION Please observe the conversion of units in calculations throughout this exeplar. In any puping syste, the role
More informationChapter 5 Using Newton s Laws: Friction, Circular Motion, Drag Forces. Copyright 2009 Pearson Education, Inc.
Chapter 5 Using Newton s Laws: Friction, Circular Motion, Drag Forces Units of Chapter 5 Applications of Newton s Laws Involving Friction Uniform Circular Motion Kinematics Dynamics of Uniform Circular
More informationChapter 5 Newton s Laws of Motion
Chapter 5 Newton s Laws of Motion Sir Isaac Newton (1642 1727) Developed a picture of the universe as a subtle, elaborate clockwork slowly unwinding according to welldefined rules. The book Philosophiae
More informationPhys 111 Fall P111 Syllabus
Phys 111 Fall 2012 Course structure Five sections lecture time 150 minutes per week Textbook Physics by James S. Walker fourth edition (Pearson) Clickers recommended Coursework Complete assignments from
More informationChapter 4. Motion in two & three dimensions
Chapter 4 Motion in two & three dimensions 4.2 Position and Displacement Position The position of a particle can be described by a position vector, with respect to a reference origin. Displacement The
More information1 of 9 10/27/2009 7:46 PM
1 of 9 10/27/2009 7:46 PM Chapter 11 Homework Due: 9:00am on Tuesday, October 27, 2009 Note: To understand how points are awarded, read your instructor's Grading Policy [Return to Standard Assignment View]
More informationPhysics 2A, Sec B00: Mechanics  Winter 2011 Instructor: B. Grinstein Final Exam
Physics 2A, Sec B00: Mechanics  Winter 2011 Instructor: B. Grinstein Final Exam INSTRUCTIONS: Use a pencil #2 to fill your scantron. Write your code number and bubble it in under "EXAM NUMBER;" an entry
More informationGround Rules. PC1221 Fundamentals of Physics I. Force. Zero Net Force. Lectures 9 and 10 The Laws of Motion. Dr Tay Seng Chuan
PC1221 Fundamentals of Physics I Lectures 9 and 10 he Laws of Motion Dr ay Seng Chuan 1 Ground Rules Switch off your handphone and pager Switch off your laptop computer and keep it No talking while lecture
More informationPeople s Physics book 3e Ch 251
The Big Idea: In most realistic situations forces and accelerations are not fixed quantities but vary with time or displacement. In these situations algebraic formulas cannot do better than approximate
More informationSTATIC AND KINETIC FRICTION
STATIC AND KINETIC FRICTION LAB MECH 3.COMP From Physics with Computers, Vernier Software & Technology, 2000. INTRODUCTION If you try to slide a heavy box resting on the floor, you may find it difficult
More informationRotational Mechanics  1
Rotational Mechanics  1 The Radian The radian is a unit of angular measure. The radian can be defined as the arc length s along a circle divided by the radius r. s r Comparing degrees and radians 360
More informationThe car is pulled up a long hill. 2. Does the roller coaster ever get higher than the first hill? No.
Roller Coaster Physics Answer Key Vocabulary: friction, gravitational potential energy, kinetic energy, momentum, velocity Prior Knowledge Questions (Do these BEFORE using the Gizmo.) [Note: The purpose
More informationDISPLACEMENT AND FORCE IN TWO DIMENSIONS
DISPLACEMENT AND FORCE IN TWO DIMENSIONS Vocabulary Review Write the term that correctly completes the statement. Use each term once. coefficient of kinetic friction equilibrant static friction coefficient
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 informationA Review of Vector Addition
Motion and Forces in Two Dimensions Sec. 7.1 Forces in Two Dimensions 1. A Review of Vector Addition. Forces on an Inclined Plane 3. How to find an Equilibrant Vector 4. Projectile Motion Objectives Determine
More informationWork and Kinetic Energy
Chapter 6 Work and Kinetic Energy PowerPoint Lectures for University Physics, Thirteenth Edition Hugh D. Young and Roger A. Freedman Lectures by Wayne Anderson Goals for Chapter 6 To understand and calculate
More informationHow to calculate work done by a varying force along a curved path. The meaning and calculation of power in a physical situation
Chapter 6: Work and Kinetic Energy What is work done by a force What is kinetic energy workenergy theorem How to calculate work done by a varying force along a curved path The meaning and calculation
More informationDiscussion Session 4 Projectile Motion Week 05. The Plan
PHYS Dicuion Seion 4 Projectile Motion Week 5 The Plan Thi week your group will practice analyzing projectile otion ituation. Why do we pend a whole eion on thi topic? The anwer i that projectile otion
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 informationIf I have seen further than others, it is by standing upon the shoulders of giants.
Chapter 4: Dynaics If I have seen further than others, it is by standing upon the shoulders of giants. Sir Isaac Newton Objectives 1. Define ass and inertia and explain the eaning of Newton s 1st Law.
More informationFORCES AND MOTION UNIT TEST. Multiple Choice: Draw a Circle Completely around the ONE BEST answer.
FORCES AND MOTION UNIT TEST Multiple Choice: Draw a Circle Completely around the ONE BEST answer. 1. A force acting on an object does no work if a. a machine is used to move the object. b. the force is
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 informationSimple Harmonic Motion. Simple Harmonic Motion
Siple Haronic Motion Basic oscillations are siple haronic otion (SHM) where the position as a function of tie is given by a sign or cosine Eaples of actual otion: asses on springs vibration of atos in
More information6: Applications of Newton's Laws
6: Applications of Newton's Laws Friction opposes motion due to surfaces sticking together Kinetic Friction: surfaces are moving relative to each other a.k.a. Sliding Friction Static Friction: surfaces
More informationPlane Trusses. Section 7: Flexibility Method  Trusses. A plane truss is defined as a twodimensional
lane Trusses A plane truss is defined as a twodiensional fraework of straight prisatic ebers connected at their ends by frictionless hinged joints, and subjected to loads and reactions that act only at
More informationCOEFFICIENT OF KINETIC FRICTION
COEFFICIENT OF KINETIC FRICTION LAB MECH 5.COMP From Physics with Computers, Vernier Software & Technology, 2000. INTRODUCTION If you try to slide a heavy box resting on the floor, you may find it difficult
More 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 informationPhysics 101 Prof. Ekey. Chapter 5 Force and motion (Newton, vectors and causing commotion)
Physics 101 Prof. Ekey Chapter 5 Force and motion (Newton, vectors and causing commotion) Goal of chapter 5 is to establish a connection between force and motion This should feel like chapter 1 Questions
More informationNewton s Laws PreTest
Newton s Laws PreTest 1.) Consider the following two statements and then select the option below that is correct. (i) It is possible for an object move in the absence of forces acting on the object. (ii)
More 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 informationAP Physics Energy and Springs
AP Physics Energy and Springs Another major potential energy area that AP Physics is enamored of is the spring (the wire coil deals, not the ones that produce water for thirsty humanoids). Now you ve seen
More informationChapter 8: Conservation of Energy
Chapter 8: Conservation of Energy This chapter actually completes the argument established in the previous chapter and outlines the standing concepts of energy and conservative rules of total energy. I
More information