Chapter 7. Newton’s Third LawChapter 7. Reading QuizzesSlide 3Slide 4Slide 5Slide 6Interacting ObjectsSlide 8Slide 9Slide 10Applications: Acceleration ConstraintsAcceleration Constraint in ActionApplications: Strings and PulleysTension- another lookSlide 15Slide 16The Massless String ApproximationSlide 18Slide 19Tactics: Analyzing interacting objectsSlide 21Slide 22What’s in your system vs the environment?Slide 24Problem-Solving Strategy: Interacting-Objects ProblemsSlide 26Slide 27Slide 28EXAMPLE 7.3 The forces on accelerating boxesSlide 30Slide 31Slide 32Slide 33EXAMPLE 7.6 Comparing two tensionsSlide 35Slide 36Slide 37Slide 38EXAMPLE 7.7 Mountain climbingSlide 40Slide 41Slide 42Slide 43Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.Topics:•Interacting Objects•Analyzing Interacting Objects •Newton’s Third Law •Ropes and Pulleys •Examples of Interacting-Object ProblemsChapter 7. Newton’s Third LawChapter 7. Newton’s Third LawCopyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.Chapter 7. Reading QuizzesChapter 7. Reading QuizzesCopyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.The propulsion force on a car is due toA. static friction.B. kinetic friction. C. the car engine.D. elastic energy.Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.Is the tension in rope 2 greater than, less than, or equal to the tension in rope 1?A. greater than rope 2B. less than rope 2 C. equal to rope 2Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.A. the acceleration of an object has to be positive.B. two objects have to accelerate in the same.C. the magnitude of the accelerations of two objects have to be equal.D. an object is prevented from accelerating.E. Acceleration constraints were not discussed in this chapter.An acceleration constraint says that in some circumstancesCopyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.Interacting ObjectsIf object A exerts a force on object B, then object B exerts a force on object A. The pair of forces, as shown, is called an action/reaction pair.Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.Interactions through Contact & at a DistanceCopyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.Car B is stopped for a red light. Car A, which has the same mass as car B, doesn’t see the red light and runs into the back of B. Which of the following statements is true?A. A exerts a larger force on B than B exerts on A.B. A exerts a force on B but B doesn’t exert a force on A.C. B exerts a force on A but A doesn’t exert a force on B.D. B exerts a larger force on A than A exerts on B.E. B exerts the same amount of force on A as A exerts on B.Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.A small car is pushing a larger truck that has a dead battery. The mass of the truck is larger than the mass of thecar. Which of the following statements is true?A. The truck exerts a larger force on the car than the car exerts on the truck.B. The truck exerts a force on the car but the car doesn’t exert a force on the truck.C. The car exerts a force on the truck but the truck doesn’t exert a force on the car.D. The car exerts a larger force on the truck than the truck exerts on the car.E. The car exerts the same amount of force on the truck as the truck exerts on the car.Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.Applications: Acceleration ConstraintsCopyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.Acceleration Constraint in ActionIf the rope is pulled down10 cm, how far up does the 10.2 kg mass move?Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.Applications: Strings and PulleysCopyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.Tension- another lookCopyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.The Massless String ApproximationOften in physics and engineering problems the mass of the string or rope is much less than the masses of the objects that it connects. In such cases, we can adopt the following massless string approximation:Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.A. Equal to B. Greater thanC. Less thanAll three 50 kg blocks are at rest. Is the tension in rope 2 greater than, less than, or equal to the tension in rope 1?Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.Tactics: Analyzing interacting objectsCopyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.Tactics: Analyzing interacting objectsCopyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.Tactics: Analyzing interacting objectsCopyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.What’s in your system vs the environment?Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.INTERACTION DIAGRAMS &FREE BODY DIAGRAMSCopyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.Problem-Solving Strategy: Interacting-Objects ProblemsCopyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.Problem-Solving Strategy: Interacting-Objects ProblemsCopyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.A fishing line of negligible mass lifts a fishupward at constant speed. The line and the fish are the system, the fishing pole is part of the environment. What, if anything, is wrong with the free-body diagrams?A. The force of the pole on the fish is missing.B. The force of gravity on the line is missing.C. The gravitational force and the tension force are incorrectly identified as an action/reaction pair.D. There should be only one force on the fish.E. There is nothing wrong with the free-body diagrams.Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.Copyright