General Physics I Forces
|
|
- Neal Davidson
- 5 years ago
- Views:
Transcription
1 General Physics I Forces
2 Dynamics Isaac Newton ( ) published Principia Mathematica in In this work, he proposed three laws of motion based on the concept of FORCE. A force is a push or a pull. A force has magnitude & direction (vector). Law 1: An object subject to no external forces is at rest or moves with a constant velocity.» If no forces act, there is no acceleration. Law 2: For any object, F NET = F = ma Law 3: Forces occur in pairs: F A,B = - F B,A (For every action there is an equal and opposite reaction.)
3 Newton s Second Law For any object, F NET = F = ma. The acceleration a of an object is proportional to the net force F NET acting on it. The constant of proportionality is called mass, denoted m. This is the definition of mass. The mass of an object is a constant property of that object, and is independent of external influences. Force has units of [kg m/s 2 ] = N (Newton)
4 Newton s Second Law Components of F = ma : F X = ma X F Y = ma Y Adding forces is like adding vectors a NET F 1 F 2 F NET = ma NET Suppose we know m and F X, we can solve for a X and apply the result to the things we learned about kinematics over the last few weeks: v x 2 x v 0x 1 x x0 v0xt axt 2 v v 2a ( x x 2 ox a x t x 2 o )
5 Example: Pushing a Box on Ice. A girl is pushing a heavy box (mass m) across a sheet of ice (horizontal & frictionless). She applies a force in the x direction. If the box starts at rest, what is its speed v after being pushed a distance d? v F m a d x
6 Example: Pushing a Box on Ice... Where do we start? v F m a d x
7 Forces We will consider two kinds of forces: Contact force: This is the most familiar kind. I push on the desk (Applied Force). The ground pushes on the chair (Normal Force). Resistance to Motion (Frictional Force) Action at a distance (Non-Contact Forces): Gravity (a little bit in this lecture) Electricity (next semester) Magnetism (next semester)
8 Contact Forces & Newton's Third Law: Objects in contact exert forces. Convention: F a,b means the force acting on a due to b. F m,w F w,m So F w,m means the force on the wall due to the man. F A, B = - F B, A is true for all forces F f,m F m,f
9 Example of Good Thinking Consider only the box as the system! F on box = ma box = F b,m Free Body Diagram (more on this soon ) a box F m,b F b,m ice
10 Newton s 3rd Law Two blocks are stacked on the ground. How many action-reaction pairs of forces are present in this system? a (a) 2 (b) 3 b (c) 4
11 The Free Body Diagram Newton s 2nd Law says that for an object F = ma. Key phrase here is for an object. So before we can apply F = ma to any given object we isolate the forces acting on this object. Consider the following case: What are the forces acting on the plank? P = Plank F = Floor W = Wall E = Earth
12 The Free Body Diagram... Isolate the plank from the rest of the world.
13 The Free Body Diagram... The forces acting on the plank should reveal themselves... F P,W From Newton s Second Law: F P,E = ma = mg F P,F F P,E Where: g 9.81 m / s 2
14 More... In this example the plank is not moving... It is certainly not accelerating! So F NET = ma becomes F NET = 0 F P,W F P,W + F P,F + F P,E = 0 F P,F F P,E This is the basic idea behind statics (F NET = 0 cases) We ll hit some of this here but will see more when we cover torque!
15 Free-Body Diagram & The Normal Indicate the forces acting on the block. Is the block moving? m The NORMAL is ALWAYS perpendicular to the surface doing the pushing No Surface = No Normal Multiple Surfaces = Multiple Normals
16 More Free-Body Diagram Examples ΣF x : ΣF y :
17 Normal Force A block of mass m rests on the floor of an elevator that is accelerating upward. What is the relationship between the force due to gravity and the normal force on the block? (a) N > mg (b) N = mg (c) N < mg a m
18 New Topic: Friction What does it do? It opposes relative motion! How do we characterize this in terms we have learned? Friction results in a force in the direction opposite to the direction of relative motion! Parallel to surface. Perpendicular to Normal force. y x
19 Surface Friction... Friction is caused by the microscopic interactions between the two surfaces:
20 Model for Sliding Friction The direction of the frictional force vector is perpendicular to the normal force vector N. The magnitude of the frictional force vector f F is proportional to the magnitude of the normal force N. f F = K N ( = K mg in the previous example) The heavier something is, the greater the friction will be...makes sense! The constant K is called the coefficient of kinetic friction. These relations are all useful APPROXIMATIONS to messy reality.
21 Model... Dynamics: x : Recall from Newton s 2 nd Law: F x m = a x y : so N y F ma x f K N mg
22 Static Friction... So far we have considered friction acting when the two surfaces move relative to each other- I.e. when they slide.. We also know that it acts in when they move together: the static case. In these cases, the force provided by friction will depend on the OTHER forces on the parts of the system. The maximum possible force that the friction between two objects can provide is f MAX = S N, where s is the coefficient of static friction. So f F S N. As one increases F, f F gets bigger until f F = S N and the object starts to move. N y F x f F mg *** Just like in the sliding case except a = 0 ***
23 Additional comments on Friction: Since f F = N, the force of friction does not depend on the area of the surfaces in contact. This is a surprisingly good rule of thumb, but not an exact relation By definition, it must be true that S K for any system (think about it...).
24 Springs Springs are objects that exhibit elastic behavior An ideal spring is: Massless = the mass of the spring is negligible. The applied force (F applied ) required to compress/stretch is proportional to the displacement of the spring from its unstrained length (x) or F applied = kx. Where k is called the spring constant (or stiffness of the spring) To stretch/compress a spring, the spring exerts a restoring force of equal & opposite magnitude (reaction force, F) against the stretching/compressing force or F s = -kx {this is referred to as Hooke s Law!}
25 The (Elastic) Restoring Force (& Newton s 3 rd Law) Action: Applied force is proportional to displacement of the spring: F applied = kx Reaction: Restoring force is equal/opposite to applied force: F s = -F applied = -kx
26 Tools: Ropes & Strings Can be used to pull from a distance. Tension (T) at a certain position in a rope is the magnitude of the force acting across a cross-section of the rope at that position. The force you would feel if you cut the rope and grabbed the ends. An action-reaction pair. T cut T T
27 Tools: Ropes & Strings... An ideal (massless) rope has constant tension along the rope. T T If a rope has mass, the tension can vary along the rope For example, a heavy rope hanging from the ceiling... T = T g T = 0 We will deal mostly with ideal massless ropes.
28 Tools: Ropes & Strings... The direction of the force provided by a rope is along the direction of the rope: a y = 0 (box not moving) m
29 Problem: Two strings & Two Masses on horizontal frictionless floor: Given T 1, m 1 and m 2, what are a and T 2? a x T 2 m 2 m 1 T 1
30 Problem: Tension and Angles --Statics-- A box is suspended from the ceiling by two ropes making an angle with the horizontal. What is the tension in each rope? 1 2 m Hint: How many dimensions are in play for this diagram?
31 1 2 m
32 Tools: Pegs & Pulleys Used to change the direction of forces An ideal massless pulley or ideal smooth peg will change the direction of an applied force without altering the magnitude: F 1 ideal peg or pulley F 1 = F 2 F 2
33 Tools: Pegs & Pulleys Used to change the direction of forces An ideal massless pulley or ideal smooth peg will change the direction of an applied force without altering the magnitude...so let s illustrate the free-body diagram below to see how this works: m
34 Horizontal Mass and a Hanging Mass Given M 1 and M 2, what are a and T? NOTE (New Rule): Direction of Motion = Positive Direction!!
35 The Inclined plane Consider a block of mass m that slides down a frictionless ramp that makes angle with respect to the horizontal having an acceleration a. Illustrate the free-body diagram in order to solve for a? Define convenient axes parallel and perpendicular to the plane: Ex: Acceleration a is in x direction only. a m
36 a m
37 Inclined Plane with Friction: m a
38 Two inclined planes - Dynamics Illustrate the Free-Body Diagram m 1 m 2 1 2
39 End of Forces Lecture
Physics 100: Lecture 4b Chapter 4
Physics 100: Lecture 4b Chapter 4 Today s Agenda More discussion of dynamics Recap The Free Body Diagram The tools we have for making & solving problems:» Ropes & Pulleys (tension)» Hooke s Law (springs)
More informationLECTURE 12 FRICTION, STRINGS & SPRINGS. Instructor: Kazumi Tolich
LECTURE 12 FRICTION, STRINGS & SPRINGS Instructor: Kazumi Tolich Lecture 12 2! Reading chapter 6-1 to 6-4! Friction " Static friction " Kinetic friction! Strings! Pulleys! Springs Origin of friction 3!!
More informationWebreview practice test. Forces (again)
Please do not write on test. ID A Webreview 4.3 - practice test. Forces (again) Multiple Choice Identify the choice that best completes the statement or answers the question. 1. A 5.0-kg mass is suspended
More informationChapter 4: Newton s Second Law F = m a. F = m a (4.2)
Lecture 7: Newton s Laws and Their Applications 1 Chapter 4: Newton s Second Law F = m a First Law: The Law of Inertia An object at rest will remain at rest unless, until acted upon by an external force.
More informationLecture 5. Dynamics. Forces: Newton s First and Second
Lecture 5 Dynamics. Forces: Newton s First and Second What is a force? It s a pull or a push: F F Force is a quantitative description of the interaction between two physical bodies that causes them to
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 informationIsaac Newton ( ) 1687 Published Principia Invented Calculus 3 Laws of Motion Universal Law of Gravity
Isaac Newton (1642-1727) 1687 Published Principia Invented Calculus 3 Laws of Motion Universal Law of Gravity Newton s First Law (Law of Inertia) An object will remain at rest or in a constant state of
More informationPHYSICS 220 Lecture 04 Forces and Motion in 1 D Textbook Sections
PHYSICS 220 Lecture 04 Forces and Motion in 1 D Textbook Sections 3.2 3.6 Lecture 4 Purdue University, Physics 220 1 Last Lecture Constant Acceleration x = x 0 + v 0 t + ½ at 2 v = v 0 + at Overview v
More informationPhys 1401: General Physics I
1. (0 Points) What course is this? a. PHYS 1401 b. PHYS 1402 c. PHYS 2425 d. PHYS 2426 2. (0 Points) Which exam is this? a. Exam 1 b. Exam 2 c. Final Exam 3. (0 Points) What version of the exam is this?
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 informationDynamics: Forces and Newton s Laws of Motion
Lecture 7 Chapter 5 Physics I Dynamics: Forces and Newton s Laws of Motion Course website: http://faculty.uml.edu/andriy_danylov/teaching/physicsi Today we are going to discuss: Chapter 5: Force, Mass:
More informationReview: Advanced Applications of Newton's Laws
Review: Advanced Applications of Newton's Laws 1. The free-body diagram of a wagon being pulled along a horizontal surface is best represented by a. A d. D b. B e. E c. C 2. The free-body diagram of a
More informationCHAPTER 4 NEWTON S LAWS OF MOTION
62 CHAPTER 4 NEWTON S LAWS O MOTION CHAPTER 4 NEWTON S LAWS O MOTION 63 Up to now we have described the motion of particles using quantities like displacement, velocity and acceleration. These quantities
More informationChapter 4. Forces and Newton s Laws of Motion. continued
Chapter 4 Forces and Newton s Laws of Motion continued Quiz 3 4.7 The Gravitational Force Newton s Law of Universal Gravitation Every particle in the universe exerts an attractive force on every other
More informationYou may use g = 10 m/s 2, sin 60 = 0.87, and cos 60 = 0.50.
1. A child pulls a 15kg sled containing a 5kg dog along a straight path on a horizontal surface. He exerts a force of a 55N on the sled at an angle of 20º above the horizontal. The coefficient of friction
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 information24/06/13 Forces ( F.Robilliard) 1
R Fr F W 24/06/13 Forces ( F.Robilliard) 1 Mass: So far, in our studies of mechanics, we have considered the motion of idealised particles moving geometrically through space. Why a particular particle
More informationDynamics: Forces and Newton s Laws of Motion
Lecture 7 Chapter 5 Dynamics: Forces and Newton s Laws of Motion Course website: http://faculty.uml.edu/andriy_danylov/teaching/physicsi Today we are going to discuss: Chapter 5: Force, Mass: Section 5.1
More informationHelp Desk: 9:00-5:00 Monday-Thursday, 9:00-noon Friday, in the lobby of MPHY.
Help Desk: 9:00-5:00 Monday-Thursday, 9:00-noon Friday, in the lobby of MPHY. SI (Supplemental Instructor): Thomas Leyden (thomasleyden@tamu.edu) 7:00-8:00pm, Sunday/Tuesday/Thursday, MPHY 333 Chapter
More informationStudent AP Physics 1 Date. Newton s Laws B FR
Student AP Physics 1 Date Newton s Laws B FR #1 A block is at rest on a rough inclined plane and is connected to an object with the same mass as shown. The rope may be considered massless; and the pulley
More informationPhysics 101 Lecture 5 Newton`s Laws
Physics 101 Lecture 5 Newton`s Laws Dr. Ali ÖVGÜN EMU Physics Department The Laws of Motion q Newton s first law q Force q Mass q Newton s second law q Newton s third law qfrictional forces q Examples
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 informationPhysics B Newton s Laws AP Review Packet
Force A force is a push or pull on an object. Forces cause an object to accelerate To speed up To slow down To change direction Unit: Newton (SI system) Newton s First Law The Law of Inertia. A body in
More informationHATZIC SECONDARY SCHOOL
HATZIC SECONDARY SCHOOL PROVINCIAL EXAMINATION ASSIGNMENT VECTOR DYNAMICS MULTIPLE CHOICE / 45 OPEN ENDED / 75 TOTAL / 120 NAME: 1. Unless acted on by an external net force, an object will stay at rest
More informationPhys 1401: General Physics I
1. (0 Points) What course is this? a. PHYS 1401 b. PHYS 1402 c. PHYS 2425 d. PHYS 2426 2. (0 Points) Which exam is this? a. Exam 1 b. Exam 2 c. Final Exam 3. (0 Points) What version of the exam is this?
More informationNewton s 3 Laws of Motion
Newton s 3 Laws of Motion 1. If F = 0 No change in motion 2. = ma Change in motion Fnet 3. F = F 1 on 2 2 on 1 Newton s First Law (Law of Inertia) An object will remain at rest or in a constant state of
More informationfor any object. Note that we use letter, m g, meaning gravitational
Lecture 4. orces, Newton's Second Law Last time we have started our discussion of Newtonian Mechanics and formulated Newton s laws. Today we shall closely look at the statement of the second law and consider
More informationCHAPTER 4 TEST REVIEW -- Answer Key
AP PHYSICS Name: Period: Date: DEVIL PHYSICS BADDEST CLASS ON CAMPUS 50 Multiple Choice 45 Single Response 5 Multi-Response Free Response 3 Short Free Response 2 Long Free Response AP EXAM CHAPTER TEST
More informationConcept of Force and Newton s Laws of Motion
Concept of Force and Newton s Laws of Motion 8.01 W02D2 Chapter 7 Newton s Laws of Motion, Sections 7.1-7.4 Chapter 8 Applications of Newton s Second Law, Sections 8.1-8.4.1 Announcements W02D3 Reading
More informationThe Laws of Motion. Newton s first law Force Mass Newton s second law Gravitational Force Newton s third law Examples
The Laws of Motion Newton s first law Force Mass Newton s second law Gravitational Force Newton s third law Examples Gravitational Force Gravitational force is a vector Expressed by Newton s Law of Universal
More informationPhysics Mechanics. Lecture 11 Newton s Laws - part 2
Physics 170 - Mechanics Lecture 11 Newton s Laws - part 2 Newton s Second Law of Motion An object may have several forces acting on it; the acceleration is due to the net force: Newton s Second Law of
More informationChapter 4 Force and Motion
Chapter 4 Force and Motion Units of Chapter 4 The Concepts of Force and Net Force Inertia and Newton s First Law of Motion Newton s Second Law of Motion Newton s Third Law of Motion More on Newton s Laws:
More informationChapter 5. The Laws of Motion
Chapter 5 The Laws of Motion The Laws of Motion The description of an object in motion included its position, velocity, and acceleration. There was no consideration of what might influence that motion.
More informationBell Ringer: What is Newton s 3 rd Law? Which force acts downward? Which force acts upward when two bodies are in contact?
Bell Ringer: What is Newton s 3 rd Law? Which force acts downward? Which force acts upward when two bodies are in contact? Does the moon attract the Earth with the same force that the Earth attracts the
More informationLecture 6 Force and Motion. Identifying Forces Free-body Diagram Newton s Second Law
Lecture 6 Force and Motion Identifying Forces Free-body Diagram Newton s Second Law We are now moving on from the study of motion to studying what causes motion. Forces are what cause motion. Forces are
More informationDiscussion Session 6 Newton s Second & Third Laws Week 07. The Plan
PHYS 100 Discussion Session 6 Newton s Second & Third Laws Week 07 The Plan This week we use Newton s Third Law ( F A on B = F B on A ) to relate the forces between two different objects. We can use this
More informationNewton s Laws and Free-Body Diagrams General Physics I
Newton s Laws and Free-Body Diagrams In the next few sections, we will be exploring some of the most fundamental laws of our universe, laws that govern the relationship actions and motion. These laws are
More informationChapter Four Holt Physics. Forces and the Laws of Motion
Chapter Four Holt Physics Forces and the Laws of Motion Physics Force and the study of dynamics 1.Forces - a. Force - a push or a pull. It can change the motion of an object; start or stop movement; and,
More informationPractice. Newton s 3 Laws of Motion. Recall. Forces a push or pull acting on an object; a vector quantity measured in Newtons (kg m/s²)
Practice A car starts from rest and travels upwards along a straight road inclined at an angle of 5 from the horizontal. The length of the road is 450 m and the mass of the car is 800 kg. The speed of
More information8.01x Classical Mechanics, Fall 2016 Massachusetts Institute of Technology. Problem Set 2
8.01x Classical Mechanics, Fall 2016 Massachusetts Institute of Technology 1. Stacked Blocks Problem Set 2 Consider two blocks that are resting one on top of the other. The lower block has mass m 2 = 4.8
More informationPHYS 101 Previous Exam Problems. Force & Motion I
PHYS 101 Previous Exam Problems CHAPTER 5 Force & Motion I Newton s Laws Vertical motion Horizontal motion Mixed forces Contact forces Inclines General problems 1. A 5.0-kg block is lowered with a downward
More informationTopic: Force PHYSICS 231
Topic: Force PHYSICS 231 Current Assignments Homework Set 2 due this Thursday, Jan 27, 11 pm Reading for next week: Chapters 10.1-6,10.10,8.3 2/1/11 Physics 231 Spring 2011 2 Key Concepts: Force Free body
More informationUniversity Physics (Prof. David Flory) Chapt_06 Saturday, October 06, 2007 Page 1
University Physics (Prof. David Flory) Chapt_06 Saturday, October 06, 2007 Page 1 Name: Date: 1. A crate resting on a rough horizontal floor is to be moved horizontally. The coefficient of static friction
More information5. Forces and Free-Body Diagrams
5. Forces and Free-Body Diagrams A) Overview We will begin by introducing the bulk of the new forces we will use in this course. We will start with the weight of an object, the gravitational force near
More informationNewton s Law of Motion
Newton s Law of Motion Physics 211 Syracuse University, Physics 211 Spring 2017 Walter Freeman February 13, 2017 W. Freeman Newton s Law of Motion February 13, 2017 1 / 21 Announcements Homework 3 due
More information第 1 頁, 共 7 頁 Chap5 1. Test Bank, Question 9 The term "mass" refers to the same physical concept as: weight inertia force acceleration volume 2. Test Bank, Question 17 Acceleration is always in the direction:
More informationChapter 3 The Laws of motion. The Laws of motion
Chapter 3 The Laws of motion The Laws of motion The Concept of Force. Newton s First Law. Newton s Second Law. Newton s Third Law. Some Applications of Newton s Laws. 1 5.1 The Concept of Force Force:
More informationThursday February 8. Write these equations in your notes if they re not already there. You will want them for Exam 1 & the Final.
Assignment 4 due Friday like almost every Friday Pre-class due 15min before class like every class Help Room: Here, 6-9pm Wed/Thurs SI: Morton 222, M&W 7:15-8:45pm Office Hours: 204 EAL, 10-11am Wed or
More informationChapter 4. Dynamics: Newton s Laws of Motion. That is, describing why objects move
Chapter 4 Dynamics: Newton s Laws of Motion That is, describing why objects move orces Newton s 1 st Law Newton s 2 nd Law Newton s 3 rd Law Examples of orces: Weight, Normal orce, Tension, riction ree-body
More informationNewton s Laws. A force is simply a push or a pull. Forces are vectors; they have both size and direction.
Newton s Laws Newton s first law: An object will stay at rest or in a state of uniform motion with constant velocity, in a straight line, unless acted upon by an external force. In other words, the bodies
More informationAP Physics 1 Review. On the axes below draw the horizontal force acting on this object as a function of time.
P Physics Review. Shown is the velocity versus time graph for an object that is moving in one dimension under the (perhaps intermittent) action of a single horizontal force. Velocity, m/s Time, s On the
More informationFigure 5.1a, b IDENTIFY: Apply to the car. EXECUTE: gives.. EVALUATE: The force required is less than the weight of the car by the factor.
51 IDENTIFY: for each object Apply to each weight and to the pulley SET UP: Take upward The pulley has negligible mass Let be the tension in the rope and let be the tension in the chain EXECUTE: (a) The
More informationOscillations! (Today: Springs)
Oscillations! (Today: Springs) Extra Practice: 5.34, 5.35, C13.1, C13.3, C13.11, 13.1, 13.3, 13.5, 13.9, 13.11, 13.17, 13.19, 13.21, 13.23, 13.25, 13.27, 13.31 Test #3 is this Wednesday! April 12, 7-10pm,
More informationLecture Outline Chapter 6. Physics, 4 th Edition James S. Walker. Copyright 2010 Pearson Education, Inc.
Lecture Outline Chapter 6 Physics, 4 th Edition James S. Walker Chapter 6 Applications of Newton s Laws Units of Chapter 6 Frictional Forces Strings and Springs Translational Equilibrium Connected Objects
More informationThe Concept of Force Newton s First Law and Inertial Frames Mass Newton s Second Law The Gravitational Force and Weight Newton s Third Law Analysis
The Laws of Motion The Concept of Force Newton s First Law and Inertial Frames Mass Newton s Second Law The Gravitational Force and Weight Newton s Third Law Analysis Models using Newton s Second Law Forces
More informationPhysics 111 Lecture 4 Newton`s Laws
Physics 111 Lecture 4 Newton`s Laws Dr. Ali ÖVGÜN EMU Physics Department www.aovgun.com he Laws of Motion q Newton s first law q Force q Mass q Newton s second law q Newton s third law q Examples Isaac
More informationNewton s First Law and IRFs
Goals: Physics 207, Lecture 6, Sept. 22 Recognize different types of forces and know how they act on an object in a particle representation Identify forces and draw a Free Body Diagram Solve 1D and 2D
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 informationQ16.: A 5.0 kg block is lowered with a downward acceleration of 2.8 m/s 2 by means of a rope. The force of the block on the rope is:(35 N, down)
Old Exam Question Ch. 5 T072 Q13.Two blocks of mass m 1 = 24.0 kg and m 2, respectively, are connected by a light string that passes over a massless pulley as shown in Fig. 2. If the tension in the string
More informationChapter 4. Dynamics: Newton s Laws of Motion
Chapter 4 Dynamics: Newton s Laws of Motion Types of Forces: An Overview Examples of Nonfundamental Forces -- All of these are derived from the electroweak force: normal or support forces friction tension
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 informationPhys101 Lecture 5 Dynamics: Newton s Laws of Motion
Phys101 Lecture 5 Dynamics: Newton s Laws of Motion Key points: Newton s second law is a vector equation Action and reaction are acting on different objects Free-Body Diagrams Ref: 4-1,2,3,4,5,6,7. Page
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 informationF on stone by rope F on box by rope. F on stone by Earth
B3-SCT70: HANGING STONE CONNECTED TO BOX FREE-BODY DIAGRAS A massless rope connects a box on a horizontal surface and a hanging stone as shown below. The rope passes over a massless, frictionless pulley.
More informationDynamics; Newton s Laws of Motion
Dynamics; Newton s Laws of Motion Force A force is any kind of push or pull on an object. An object at rest needs a force to get it moving; a moving object needs a force to change its velocity. The magnitude
More informationForces and Newton s Laws Notes
Forces and Newton s Laws Notes Force An action exerted on an object which can change the motion of the object. The SI unit for force is the Newton (N) o N = (kg m)/s 2 o Pound is also a measure of force
More informationChapter 5. Force and Motion-I
Chapter 5 Force and Motion-I 5.3 Newton s First Law Newton s First Law: If no force acts on a body, the body s velocity cannot change The purpose of Newton s First Law is to introduce the special frames
More informationTuesday February 7. Topics for this Lecture: Forces: Friction on Planes, Tension With Pulleys
Tuesday February 7 Topics for this Lecture: Forces: Friction on Planes, Tension With Pulleys Write these equations in your notes if they re not already there. You will want them for Exam 1 & the Final.
More informationChapter 4. The Laws of Motion
Chapter 4 The Laws of Motion Classical Mechanics Describes the relationship between the motion of objects in our everyday world and the forces acting on them Conditions when Classical Mechanics does not
More informationDynamic equilibrium: object moves with constant velocity in a straight line. = 0, a x = i
Dynamic equilibrium: object moves with constant velocity in a straight line. We note that F net a s are both vector quantities, so in terms of their components, (F net ) x = i (F i ) x = 0, a x = i (a
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 informationBig Questions. Physics 201, Lecture 7. Newton s First Law. What Did the Big Guys Say. Today s Topics. What does it take to maintain a motion?
Big Questions Physics 201, Lecture 7 oday s opics n n What does it take to maintain a motion? ewton s Laws of Motion (Chap. 5) n First Law, Force and Inertia Forces n Second Law, F=ma Mass n hird Law,
More informationAP Physics 1 - Test 05 - Force and Motion
P Physics 1 - Test 05 - Force and Motion Score: 1. brick slides on a horizontal surface. Which of the following will increase the magnitude of the frictional force on it? Putting a second brick on top
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 informationChapter 5. Force and Motion I
Chapter 5. Force and Motion I Newton s Laws Concepts of Mass and Force Newton s Three Laws But first, let s review the last lecture.. Physics, Page 1 Summary of the last lecture 1. Projectile Motion x
More informationName: Unit 4 Newton s 1 st & 3 rd Law
Name: Period: Table #: Unit 4 Newton s 1 st & 3 rd Law 1 UNIT IV: Reading - Force Diagrams The analysis of a problem in dynamics usually involves the selection and analysis of the relevant forces acting
More information7.1 Interacting Systems p Action/reaction pairs p Newton s Third Law p Ropes and Pulleys p.
7.1 Interacting Systems p. 183-185 7.2 Action/reaction pairs p. 185-189 7.3 Newton s Third Law p. 189-194 7.4 Ropes and Pulleys p. 194-198 7.5 Interacting-system Problems p. 198-202 1 7.1 Interacting Systems
More informationChapters 5-6. Dynamics: Forces and Newton s Laws of Motion. Applications
Chapters 5-6 Dynamics: orces and Newton s Laws of Motion. Applications That is, describing why objects move orces Newton s 1 st Law Newton s 2 nd Law Newton s 3 rd Law Examples of orces: Weight, Normal,
More informationDynamics Notes 1 Newton s Laws
Dynamics Notes 1 Newton s Laws In 1665 Sir Isaac Newton formulated three laws that dictate the motion of objects. These three laws are universal and apply to all forces in the universe. Newton s 1 st Law:
More informationMain points of today s lecture: Normal force Newton s 3 d Law Frictional forces: kinetic friction: static friction Examples. Physic 231 Lecture 9
Main points of today s lecture: Normal force Newton s 3 d Law Frictional forces: kinetic friction: static friction Examples. Physic 3 Lecture 9 f N k = µ k f N s < µ s Atwood s machine Consider the Atwood
More informationUnit 2 Part 2: Forces Note 1: Newton`s Universal Law of Gravitation. Newton`s Law of Universal Gravitation states: Gravity. Where: G = M = r =
Unit 2 Part 2: Forces Note 1: Newton`s Universal Law of Gravitation Gravity Newton`s Law of Universal Gravitation states: Where: G = = M = m = r = Ex 1: What is the force of gravity exerted on a 70.0 kg
More informationPhysics 2210 Fall Review for Midterm Exam 2 10/07/2015
Physics 2210 Fall 2015 Review for Midterm Exam 2 10/07/2015 Problem 1 (1/3) A spring of force constant k = 800 N/m and a relaxed length L 0 = 1.10 m has its upper end fixed/attached to a pivot in the ceiling.
More informationPHYSICS. Chapter 5 Lecture FOR SCIENTISTS AND ENGINEERS A STRATEGIC APPROACH 4/E RANDALL D. KNIGHT Pearson Education, Inc.
PHYSICS FOR SCIENTISTS AND ENGINEERS A STRATEGIC APPROACH 4/E Chapter 5 Lecture RANDALL D. KNIGHT Chapter 5 Force and Motion IN THIS CHAPTER, you will learn about the connection between force and motion.
More informationWhat is a Force? Free-Body diagrams. Contact vs. At-a-Distance 11/28/2016. Forces and Newton s Laws of Motion
Forces and Newton s Laws of Motion What is a Force? In generic terms: a force is a push or a pull exerted on an object that could cause one of the following to occur: A linear acceleration of the object
More informationLecture 7. Forces. Important note: First Exam is next Tuesday, Feb. 6, 8:15-9:45 pm (see link on Canvas for locations)
Lecture 7 Forces Important note: First Exam is next Tuesday, Feb. 6, 8:15-9:45 pm (see link on Canvas for locations) Today s Topics: Forces The gravitational force The normal force Frictional Forces Next
More informationPhysics 2211 ABC Quiz #3 Solutions Spring 2017
Physics 2211 ABC Quiz #3 Solutions Spring 2017 I. (16 points) A block of mass m b is suspended vertically on a ideal cord that then passes through a frictionless hole and is attached to a sphere of mass
More informationChapter 5 Force and Motion
Chapter 5 Force and Motion Chapter Goal: To establish a connection between force and motion. Slide 5-2 Chapter 5 Preview Slide 5-3 Chapter 5 Preview Slide 5-4 Chapter 5 Preview Slide 5-5 Chapter 5 Preview
More informationForce mediated by a field - long range: action at a distance: The attractive or repulsion between two stationary charged objects.
VISUAL PHYSICS ONLINE DYNAMICS TYPES O ORCES 1 Electrostatic force orce mediated by a field - long range: action at a distance: The attractive or repulsion between two stationary charged objects. AB A
More informationFraser Heights Secondary Physics 11 Mr. Wu Practice Test (Dynamics)
Fraser Heights Secondary Physics 11 Mr. Wu Practice Test (Dynamics) Instructions: Pick the best answer available for Part A. Show all your work for each question in Part B Part A: Multiple-Choice 1. Inertia
More informationPHYSICS 231 Laws of motion PHY 231
PHYSICS 231 Laws of motion 1 Newton s Laws First Law: If the net force exerted on an object is zero the object continues in its original state of motion; if it was at rest, it remains at rest. If it was
More information3/10/2019. What Is a Force? What Is a Force? Tactics: Drawing Force Vectors
What Is a Force? A force acts on an object. A force requires an agent, something that acts on the object. If you throw a ball, your hand is the agent or cause of the force exerted on the ball. A force
More informationPHYSICS. Chapter 7 Lecture FOR SCIENTISTS AND ENGINEERS A STRATEGIC APPROACH 4/E RANDALL D. KNIGHT Pearson Education, Inc.
PHYSICS FOR SCIENTISTS AND ENGINEERS A STRATEGIC APPROACH 4/E Chapter 7 Lecture RANDALL D. KNIGHT Chapter 7 Newton s Third Law IN THIS CHAPTER, you will use Newton s third law to understand how objects
More informationChapter 5 Lecture. Pearson Physics. Newton's Laws of Motion. Prepared by Chris Chiaverina Pearson Education, Inc.
Chapter 5 Lecture Pearson Physics Newton's Laws of Motion Prepared by Chris Chiaverina Chapter Contents Newton's Laws of Motion Applying Newton's Laws Friction Newton's Laws of Motion Two of the most important
More information1. Draw a FBD of the toy plane if it is suspended from a string while you hold the string and move across the room at a constant velocity.
1. Draw a FBD of the toy plane if it is suspended from a string while you hold the string and move across the room at a constant velocity. 2. A 15 kg bag of bananas hangs from a taunt line strung between
More informationWelcome to Forces an anticipation guide A force is defined as a push or a pull When answering the following true or false statements, offer a
Welcome to Forces an anticipation guide A force is defined as a push or a pull When answering the following true or false statements, offer a real-life example that justifies your answer. You haven t answered
More informationUnit 06 Examples. Stuff you asked about:
Unit 06 Examples Today s Concepts: 1. Force due to gravity 2. Force due to strings 3. Force due to springs (just a little bit) Mechanics Lecture 5, Slide 1 Stuff you asked about: Can you go over all of
More informationPHYSICS - CLUTCH CH 04: INTRO TO FORCES (DYNAMICS)
!! www.clutchprep.com FORCE, APPLIED FORCE, TENSION A force is either a push or a pull. Unit = ( ) - We ll represent all forces as a We ll refer to generic forces as forces. - Usually on an object by a
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 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 informationPhys101 Second Major-131 Zero Version Coordinator: Dr. A. A. Naqvi Sunday, November 03, 2013 Page: 1
Coordinator: Dr. A. A. Naqvi Sunday, November 03, 2013 Page: 1 Q1. Two forces are acting on a 2.00 kg box. In the overhead view of Figure 1 only one force F 1 and the acceleration of the box are shown.
More information