Section 12.1 Forces - Weebly
NameChapter L2ClassDateForcesand MotionSection 12.1 Forces(pages nshowfarcesffict themotionof aariousobjects.Reading Strategy (pageos6)Relating Text and Visuals As you read about forces, look carefullyat Figures2,3, and 5 in your textbook. Then complete the table bydescribing the forces and motion shown in each figure. For moreinformation on this Reading Strategy,seethe Reading and StudySkitls in the Skilts and Reference Handbook at the end ofyour textbook.What is a Force? (pages356-osz)ott6'e:g, rEictL. A force is defined as a(n)or a(n)that acts on an object.2. Is the following sentencetrue or false?A force can act to cause anobject at rest to move or it can acceleratean object that is alreadymoving.3. How can a force change the motion of an object that is already rnoving?o,g,ct-ot!EqitEl(t, oBEoctdtct6j\v4. Circle the letter of the best answer. \ /hat force causesa L-kg mass toaccelerateat a rate of L meter per second each second?a. Ikg/m.s'b. 1 kglsc. L kg.6d. L newtonCombiningForceS (pases3E?-358)5. The overall force acting on an object after all the forces are combinedis the5. How do balanced and unbalanced forces affect the motion of an object?PhysicalScienceReading and Study workbook'Chapter'l-,2 1.g7
CIassNameDateChapter12 Forcesand MotionFriCtiOh (pages3E 360)7. Is the following sentencetrue or false?Friction is a force that helpsobjectsthat are touchi.g move past eachother rnore easily.8. Circle the letters that identify types of friction.a. rollingb. gravityc. staticd. sliding9. The friction force that acts on objects that are at rest isL0. Why is less force needed to keep an object moving than to startthe object in motion?1"L.Complete the table below about friction forces.Typesof FrlcilonForcesFrictionForceExampleStaticPushinga bookalongyourdeskRolling12. Is the following sentencetrue or false? Fluid friction is a force thatopposes the motion of an object through a fluid such as water.v- DEIoGravitV (pagesollL3. Gravity is a(n)force that pulls objects together.L4. Is the following sentencetrue or false? Earth's gravity actsdownward toward the center of Earth.15. Describe how gravity and air resistance affect the motion of afalling object. Tcoonpg '()-,cel(Dt,ctL5. Is the following sentencetrue or false?Terminal velocity is theconstant velocity of a falling object when the force of air resistanceequals the force of gravity.(oct l ;(crProiectile Motioh (pages62)1-7.The curved path caused by the combination of an initial forwardvelocity and the downward force of gravity is known asmotion.138 PhysicalscienceReading and Study workbookECD.Chapter lZ6 D
NameChapter 12ClassDateForcesand MotionSection 12.2 Newton's First andSecond Laws of Motion(pages cceleration.Theaccelerationdueta grauityis defined,andmassandwei{htarecompared.Reading Strategy (pages6olBuilding Vocabulary As you read this section, write a definition inthe table for each vocabulary word you encounter. use your ownwords in the definitions. Foi more information on this Readingltrgtegy, see the Reading and study skills in the skills andReference Handbook at the end of your le, 'cl)eqtEct)4-ict(l,.s:tt-( t!g4'clECtJ"Eua .9gUoe,d,ct-/,\vDelinltionGalileo, and Nevytoh (pases363-0641Match eachscientistwith his accomplishment.AccomplishmentL. Italian scientist who did experimentstlrat helped correct misconCeptionsabout force and motion2. Scientist who studied in England andintroduced several laws describingforce and motion3. An ancient Greek philosopher whomade many scientific discoveriesthrough observation and logical reasoningScientista. Aristotleb. Galileoc. NewtonNewtonts Finst Law of Motion (pases3g{-s6s;4' Is the following sentencetrue or false?According to Newton,s firstlaw of motion, an object's state of motion does rr6t .hur,ge as long asthe net force acting on it is zero.J . What is inertia?PhysicalscienceReadingand Study workbook.Chapter 12 1g9
NameDateClassChapter 1.2 Forcesand Motion6. Is the following sentence true or false? The law of inertia statesthat an object in motion will eventually slow down and come to acomplete stop if it travels far enough in the salne direction.Newton's Second Law ofMOtiOh(pases 365-368)7. According to Newton's second law of motion, acceleration of anobject depends upon theof the object andtheacting on it.Match eachterm with its description.DescriptionTerm8. A measure of the inertia of an objecta. mass9. Net force/Massb. net force1-0.Causes an object's velocity to changec. accelerationL1.Is the following sentencetrue or false?The acceleration of anobject is always in the same direction as the net force acting onthe object.L2. Is the following seirtencetrue or false?If the same force acts upontwo obfectswith different masses,the accelerationwill be greaterfor the object with greater mass.soa-goe)Weight and Mass (pases13. What is weight?6r14. Write the formula used to calculate the weight of an object.-,CDctct15. Is the following sentencetrue or false? Becausethe weight formulashows that rnass and weight are proportional, doubling the massof an object will not affect its weight.16. Complete the table below by describing the difference betweenmass and weight.Eg 'roct- c)MassandWeightMassrFlecr orcCDWeightCD tc6'd(D17. Onthe moon, the acceleration due to gravity is only about one sixththat on Earth. Thus, an object will weighon the moon than it weighs on Earth.140 PhysicalScienceReading and Study Workbook .Chapter rZCD CDct-
Chapter L2DateClassNameForcesand MotionSection 12.3 Newton's Third Law ofMotion and Momentum(pages g72 77laction-reactionThis sectiondescribesforcesand how the mamentuffiofabjectsis detsrmined.Reading Strategy (pase3721Sumriarizing As you read about momentum in this section, completethe concept map to organize what you learn. For more information onthis Readi"g Stiategy, see the Reading and Study Skills in the Skillsand Reference Handbook at the end of your textbook.@bYiscalculatedismeasuremultiplying- -Newtonts Third Law (page373)1. According to Newton's third law of motion, what happens wheneverone object exerts a force on a second object?"Edtatt(l)E t: ;,Ito,(ltctoett6,:tctEED :.aeoB 2. The equal and opposite forces described by Newton's third law areforces.andcalled3. Circle the letters that identify each sentencethat is true aboutaction-reaction forces.a. Newton's second law describesaction-reactionforces.b. ForceSalways exist in pairs.c. Action-reaction forces never cancel.d. All action-reaction forces produce motion.4. Is the following statement true or false?Action-reaction forces donot cancel each other because the action force is always greater thanthe reaction force.Momentum (pasess7 s751G'ottq,ar-@5. Circle the letter of each factor that affects the momentum of amoving object.d. velocityb. volumec. shapea. mass6. It two identical objects are moving at different velocities, the objectmomentum.that is moving faster will havePhysicalScienceReading and Study Workbook .Chapter 12 141
Chapter L2DateClassNameForcesand Motion7. Your in-line skates are sitting in a box on a shelf in the closet. \Atrhat'is their momenftrrn?8. Is the following sentence true or false?An object with a small masscan have a large momentum if the object is traveling at a highspeed.9. Write the momentum formula, including the correct units.10. Circle the letter of the object that has the greatest momentum.a. a7}}-grarn bird flyirg at a velocity of 2.5 m/ sb. a L000-kilogram car traveling at 5 m/sc. a 4Gkilogram shopping cart rolling along at 0.5 m/ sd. a 3O0-kilogram roller coaster car traveling at ?-5m/ sGonseruation of Momentum (pasessre,gr7l1.1.What does conservation of momentum mean?L2. Is the following sentence true or false? Objects within a closedsystem can exert forces on one another, but other objects and forcescannot leave or enter the system. 13. According to the law of conservation of momentum, what happensto the total momentum of a systern if no net force acts on the systern?L4. Is the following sentence true or false? In a closed system with twoobjects, the loss of momentum of one object equals the gain inmomentum of the other object.@-t(Dclaomct- ForquestionsL5andL6,referto thegrnphbelow, toEcrnctcl-,CDETaod(D(a (ctaCD(D(tt15. The momentum of the ball at one second is16. What is the speed of the ball at 0.5 seconds?Show yourcalculation. Hint: Solve the momentum formula for velocity.142 PhvsicalScienceReading and Study Workbook .Chapter 12
Chapter 12DateClassNameForcesand MotionSection 12.4 Univen alForces\--l(pages 378F982)Thissectisndefinesfour foreesthat existthroughouttheuniverce.Eachforceis discussed.anditssignificanceis describedReading Strategy (paseszs)Comparing and Contrasting As you read this section/comParetwouniversalforcesby cornpletingthe table.For more information on thisReadingStrategy,seethe Reading and Study Skilts in the Skills andReferenceHandbook at the end of your ailicles?RelallveAc'tsOverWhatDistance? StengrthnuclearStrongWeaknuclear1. What are the four universalforces?b.a.d.c.Electromagnetic Foncesbaseesze-sze)-iqt at)e:.9 -i2. Is the following sentence true or false? Electromagnetic force isassociated with charged particles.3. Name the only two forces that can both attract and repel.ec)cttEl-5Eo)ctEE '. -aa-:.;oB 4. Objects with like chargesobjectswith oppositechargesone another, andone another.5. Circle the letters of the sentencesthat correctly describemagnets or magnetic forces.a. Magnetic forces act on certain rnetals.b. Magnets have two poles, north and south.c. TWo poles that are alike attract each other.d. Magnetic forces can both attract and repel.' toe attct-oFofceS (pagee379-38o)Nuclear6, The force that holds particles in the nucleus together is the7. What evidencesuggeststhat nuclearforceshave a powerfulforce of attraction?PhysicalSeienceReading and Study Workbook .Chapter 12 143
NameDateClassChapterL2 Forcesand Motion8. Circle the letter of the best answer.Over extremelyshort distances,approximatelyhow many tirnesstrongeris the strong nuclearforcethan the electricforce of repulsion?d. 10,000c. L000b. 100a. 109. Compare and contrast the strong and weak nuclear forces.sgo-se2)Gravitational Forc (pages10. State Newton's law of universal gravitation.11. Circle the letter of each sentencethat is tme about gravitational force.a. The closer two objects are to one anotheq,the weaker thegravitational force.b. The farther apart two objects are, the weaker the gravitational force.c. The greater the rnass of an object, the stronger its gravitational force.d. Earth's gravitational force is stronger than the gravitationalforce of the sun.12. The gravitational force of attraction between two objects dependsand13. Is the following sentence true or false? Gravity is the weakestuniversal force, but it is the most effective force over longdistances.14. The sun's mass is much greater than the mass of Earth, so thesun's gravitational force is muchthan thatof Earth.15. Why does the moon orbit Earth in a nearly circular path?@-tCDclact oe(:oi E!16. Is the following sentence true or false? The gravitational pull of themoon is the primary cause of Earth's ocean tides. 'icle-GloIto17, Is the following sentence true or false?An artificial satellite in ahigh orbit will slow down and lose altitude due to the pull ofEarth's gravity.-,aCDcl 18. List four uses of artificial satellites.(Eta(DCD3ct-lMPhysicalScienceReading and Study Workbook .Chapter L2
NarneClassDateChapter L2 Forcesand Motion ection 12.2 Nevyton'sFirst andSecond Laws of Motion(pages 863-371)Using Nevvton'ssecon d LawContent and Uocabulary upportNewtan's FrnstLaw of MationNewton's first law of motion states that the motion of an object doesnot change as long as the net force acting on the object is zero. Inother words, an object at rest tends to remain at rest, and an object inmotion tends to remain in motion. For example, a soccer ball lying onthe ground does not move until a force, such as a kick, causes it tomove. Once in motion, it will continue to rnove until another force,such as friction or a wall, causesit to slow down or stop. Newton's ,first law is also called the law of inertia. Inertia is the tendency of anobject to resist a change in its motion.Newton'sSecond Law of MotionObjects change their motion, or accelerate,when unbalancecl forcesare applied to them. For example, if a rolling soccer ball starts to rolllp 1 s,lope,it will decreasein velocify until it stops. Then, it will rollback down the slope at an increasing velocity. Two forces-inertia andacting on the ball. They are acting together when the balltravlf-areis rolling down the slope and against each other when the ball isrolling up the slope. Their combined force on the ball is the net force.Newton's second law of motion states that the acceleration of anobjectis equalto the net force acting on it divided by the object'smass. Mass is a measure of the inertia of an object and depends onthe amqunt of matter the obiect contains. Newton's second law can beexpressedby the equation::AccelerationW,or a: #An object with less mass or greater net force has greater acceleration.- Dct6oFFIat (5.ctg:!ccrer.E,(Dctao"EcoWeightWeight is the force of gravity acting on an object. The equation forweight is:CD:ct ta6Weight : Mass X Acceleration due to gravity,or W : rngAcceleration due to gravify (g) is 9.8 m/ s2.42PhysicalscienceMath skills and problem Solving WorkbookCD DCDF-:
DateClassNameSection 12.2 Newtonts First and Second Laws of MotionSolved Examples\.--".lExample 1:Erin threw a 3.0-kilogram ball with a net force ofration?a*'saccere1T#Hl#. il,1"lll",f:3.0Mass (m)kgUnlcttoutn:Acceleration (a)a: #Equation:a : ? 9#: ToN/kgSolution:The answer,; ;?-, can alsobe expressedas 70 m/ s2,becausethe unit N/kg equalsm/ s2.Exanrple 2:A L,200-kilogram car acceleratesat 4.5 m/*.the net force of the car?What isGiuen:ffi;i3;"tl3i1Y sm/s2:45N/ksUnknown:Net force(F)Equation:a : #Solution:Solvethe equationfor I, and substitutethegiven values:-do,b6gF: aXm;F:4.SN/kgX 1 , 2 0 0 k 9* 5 , 4 0 0 NE.9 EgESoe )6Example3:Find the massof a personwhoseweight is 490N.Giaen:Weight (Itr) : 490Nj Accelerationdue to gravity (g) : 9.8m/sz : 9.8N/kgUnknoutrc;Mass (rn)4!-EIEDEquation: W : mg-aa:.;.oSolution: Solve the equation far m, and substitute thegiven values:a:poE6)ct-mw4'v\ 1\r: t;m:ffitk: soks@PhysicalScienceMath Skills and Problem Solving Workbook49
NameClassDateChapter 12 Forcesand Motion ection 12.3 Neuyton'sThird Law ofMotion and Momentum(pages gn72-3771Analyzing MomentumGontent and Vocabulary SupportMomentumMomentum is the product of an object's mas and velocity. The largerthe mass of an object or the faster it is moving, the larger itsmomentum. If an object has large momentum, it is hard to stop.Imagine trying to stop a car rolling very slowly down a slope. Itwould be hard to do becauseof the large mass of the car, not becauseof the car's velocity. It would also be hard to stop an object with asmall mass but great velocity, such as a baseball traveling more thanL00 kilometers per hour. The baseball's speed would give it largemomentum.Mamentum FormulaThe formula for calculating the momentum of an object is:Momentum : Mass x Velocityo.'e(t,qtMomentum is measured in units of kilograrn-meters per second,written kg.*/r. For example, the momentum of a golf ball with amass of 0.0,5kilograms and a speed of 58 meters per second is:g: ctot6'Et-Mornentum : 0.05kg X 58 m/s : 2.9 kg.rt /tThe equation for momentum can be rewritten to find mass orvelocity if momentum is known:ctEIo,clEIEDE-.c:Mass :Velocity:Yffi*eoct-t:)ocl6:ta-@Law of Conservationaf MomentumAccording to the law of conservation of momentum, within a systemtotal momenfum does not change. If one obiect loses momentum,another object gains momentum. Thus, momentum is conserved. Forexample, a baseball bat loses velocity and rnomentum when it hits aball. However, the ball gains velocity and momentum when the batstrikes it.PhysicalScienceMath skills and Problem Solving Workbookqs
ClassNameDateSection 12.3 Newton' Third Law of Motion and MomentumData\-'A teacher is demonstrating the relationship between velocity andrnomentum. She drops a O.O3-kilogramobject from the school roof tothe lawn below. The graph shows the momentum of the obiect fromthe time it leaves the roof until it lands on the lawn.Momentum of O.O3-kgObiect in Free Fafl1.00E 0.e0f; 0.80:d o.7oE o.oo; o.st)E o.4oE o,soE o,zoE o.1o01,00.51,52,42.53.0Iime (s)The table shows the momentum of several cars. Each has a differentmass/ but all are traveling at the ame constant velocity'of Carswith a Ueloci of 20 CDao(: .:lo2n21,000-cte.: ct3ct"oCD6c)5-tCD(Dct aa6DCDCDcl-46PhysicalScienceMath Skills and Problem Solving Workbook
NarneClassDatePractice Exercises1: ercise 2:A runner with a mass of 60 kilograms acceleratesat2.2 m/ s2.What is the ruruler's net force?Exercise3:Find the mass of a flying discus that has a net force of1.05newtons and acceleratesat 3.5 m/s2.r \v-Ecl)elac,Exercise 4:Ian has a mass of 58.0 kilograms. What is his weight?CLecrota-t3cg(crctat(DQExoE D Exercise 5:Find the mass of a book that has a weight of1,4.7newtons.CDe ;cotD(D Dct-44PhysicalScienceMath Skills and Problem Solving workbook
ClassNameDateQuestions'1. a. Describing Based on the graph, describe how momentumchanges with time for an object in free fall.b. Calculating Use the object's momentum and mass to calculateits velocity at 1.0 second and 3.0 seconds.c. Relating Cause and Effect What causesthe momentum of theobject to change as it falls?2. a. Identifying IdentiSr the car with the smallest momenfum andthe car with the largest momentum. What is the mass of each ofthese cars?-c,6'eo)6.:t: Eb. Calculating Based on its momentum and velocity, calculate thernassof car B. Based on its mass and velocify, calculate themomentum of car D.ct( ,AC'EdtclEET, o-.J (tControlling Variables How could you increasethe momentumof car E to equal the momenfum of car A?g'EoeCJ(ItE-@Physical ScienceMath Skills and Problem Solving Workbook47
Section 12.1 Forces (pages 356-362) This section describes what forces are and explains how farces ffict the motion of aarious objects. Reading Strategy (page os6) Relating Text and Visuals As you read about forces, look carefully at Figures2,3, and 5 in your textbook. Then complete the table by describing
2 A. The forces shown above are PUSHING / PULLING forces. B. The forces shown above are WORKING TOGETHER / OPPOSITE FORCES. C. The forces are EQUAL / NOT EQUAL. D. The forces DO / DO NOT balance each other. E. The stronger force is pulling to the RIGHT / LEFT. F. The weaker force is pulling to the RIGHT / LEFT. G. Motion is to the RIGHT / LEFT. Circle the best answer on the line provided.
Forces Jacob Israelachvili ch 3,4 L6 Interaction forces- II Binnig, Quate, Gerber (reader) Intermolecular & Surface Forces Jacob Israelachvili ch 4,5 L5 Interaction forces-III Intermolecular & Surface Forces Jacob Israelachvili ch 5,6 Interaction forces-IV Intermolecular & Surface Forces Jacob Israelachvili ch 6,7 L7 F-Z, F-d curves – I
CHAPITRE I : STATIQUE DU SOLIDE 4. Bilan de forces 3.2. Forces concentrées forces réparties notion de centre de masse 3.3. Forces d’action forces de réaction 3.1. Forces extérieures forces intérieures 2. Conditions d’équilibre d’un solide 1. Définitions : force, solide, corps libre,
Hydrostatic Forces on Plane Surfaces Static Surface Forces Forces on plane areas Forces on curved surfaces Buoyant force Stability of floating and submerged bodies Forces on Plane Areas Two types of problems – Horizontal surfaces (pressure is
meaningful, and competitive. A marketing environmental scan looks at demographic forces, socio-cultural forces, economic forces, technological forces, competitive forces, and regulatory forces. A. Demographic Forces The statistical study of populations is referred to as demographics. It looks at age, gender, ethnicity, income, and occupation.
intermolecular forces. Intermolecular Force (IMF): between molecules. This is the force that holds molecules together. It is a form of “stickiness” between molecules. Examples of intermolecular forces are London dispersion forces (LDF), dipole-dipole forces (DDF), and hydrogen bridging forces (HBF).File Size: 832KB
properties of biological substances. All intermolecular forces are Van der Waals forces; that is, they are not true bonds in the sense of sharing or transferring electrons, but are weaker attractive forces. These forces include dipole-dipole forces, hyd
Pile designers therefore looked at calculation based on theoretical soil mechanics. 16 Geotechnical Design to EC7 13 January 2017 Layer 1 Layer 2 Layer 3 L 1 L 2 L 3 Q s1 Q s2 Q s3 Q b Ultimate pile resistance Q u Q s Q b Traditional Pile Design to BS 8004. 17 Geotechnical Design to EC7 13 January 2017 Traditional Pile Design to BS 8004 The usual approach is to divide the ground into .
