FORCE AND MOTION UNIT OVERVIEW THE BIG IDEA. Other topics SPARK

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1 FORCE AND MOTION UNIT OVERVIEW Force ad motio are fudametal to all matter i the uiverse. A force is aythig that ca push or pull a object. Forces ifluece objects that are at rest or that are already i motio. The Force ad Motio uit acquaits studets with Isaac Newto s three laws of motio, which describe how forces iteract with objects to ifluece motio. These laws ivolve iertia, mass, velocity, ad mometum. Studets will lear about several key forces, icludig gravity, frictio, ad magetism. A force is required to do work, ad geeratig a force requires eergy. Eergy ca be stored as potetial eergy, or it ca have kietic eergy the eergy of motio. Eergy ca also be coverted ad exchaged through eergy trasfer. Certai readig resources are provided at three readig levels withi the uit to support differetiated istructio. Other resources are provided as a set, with differet titles offered at each readig level. Dots o studet resources idicate the readig level as follows: low readig level middle readig level high readig level THE BIG IDEA SPARK Forces ad motio are itegral parts of our daily lives. From kickig a soccer ball to pickig up a sadwich to droppig a pecil, force ad motio are always at play. Eve the blood flowig through our bodies moves due to the pumpig force of the heart muscle. Objects move i predictable ways, as described by the uiversally accepted priciples of force ad motio. Everythig is i costat motio because forces are always at work. Eve somethig that is at rest o Earth is orbitig the Su ad beig acted upo by gravity. By learig about force ad motio, studets will come to uderstad how they ca use forces to produce motios that allow them to be safe ad to ejoy themselves. Other topics This uit also addresses topics such as: force ad motio i sports, weightlessess, potetial ad kietic eergy of rubber bads, how gravity affects the motio of objects i the solar system, perpetual motio, the forces that move a roller coaster, ad how racecars are built to maximize acceleratio. The spark is desiged to get studets thikig about the uit s topics ad to geerate curiosity ad discussio. Learig A Z All rights reserved. 1

2 Force ad Motio Materials ucooked eggs hard-boiled eggs paper towels Activity Place studets i small groups. Give each group oe ucooked egg ad oe hard-boiled egg without revealig which egg is which. Istruct studets to carefully place the two eggs o a table ad to getly spi them without lettig either egg fall off the table. Have studets observe the motio of the eggs util they evetually come to rest. Studets may otice that it is more difficult to spi oe of the eggs (the ucooked egg). Now ask studets to spi each egg agai. Oce both eggs are spiig, have studets quickly yet getly touch the top of each egg to stop it from spiig ad the let go. Direct studets to cotiue watchig the eggs ad observe what happes. The hard-boiled egg should remai statioary, but the ucooked egg should begi to spi agai after it is stopped. Below are questios to spark discussio. What made the eggs start spiig? Why did both spiig eggs evetually come to rest, eve whe left utouched? Was oe egg more difficult to spi tha the other? Why? Did oe of the eggs start spiig agai after it was stopped? If so, why? What would have happeed if oe of the eggs had moved past the edge of the table? Why? Usig this experimet, how ca you distiguish betwee ucooked ad hard-boiled eggs i the future? Use this activity to begi a itroductory discussio about force ad motio. Explai that iertia is the tedecy for a object at rest to remai at rest ad the tedecy for a object i motio to remai i motio. I this spark, the liquid parts of the ucooked egg had more iertia tha the solid, hard-boiled egg. Because of iertia, the ucooked egg resisted spiig ad also resisted stoppig oce it was i motio. Whe the two eggs were forced to stop, the iertia of the liquid egg started the egg spiig agai. Evetually, though, both eggs lost their mometum, stopped spiig, ad came to rest. This was due to a force called frictio actig agaist the motio of the eggs. Throughout the uit, studets will lear more about forces ad motio. May of the uit s vocabulary terms are related to the spark activity ad ca be itroduced durig the spark. For vocabulary work, see the Vocabulary sectio i this Uit Guide. Learig A Z All rights reserved. 2

3 Force ad Motio Force ad Motio Force ad Motio (verb) WORD CARD (adjective) WORD CARD (ou) WORD CARD Cut or Fold Force ad Motio Force ad Motio Force ad Motio DEFINITION CARD DEFINITION CARD DEFINITION CARD Learig A Z All rights reserved. UNIT GUIDE PRIOR KNOWLEDGE Force ad Motio Ivite studets to explai their uderstadig of force ad motio. Also ask them to share what they kow about frictio, iertia, mometum, ad mass. Discuss how our world would be differet without forces actig o objects. Probig Questios to Thik About Use the followig questios to have studets begi thikig of what they kow about force ad motio. What is a example of a force? Ca ature act as a force to move objects? If so, what are some examples? Why do objects fall to the groud? Is it possible to make a machie that cotiues to ru forever (perpetual motio machie)? Why is it harder to pick up a brick tha a pecil? Why do objects you throw always seem to fly i a arch? Why does a bicycle speed up as it rolls dowhill? Is it harder to tur a corer at a slow or a fast speed? Why? Why is it easier to pull a wago o a sidewalk tha o grass? Why do you sometimes feel a floatig sesatio o a roller coaster? Would your weight be the same o the Moo as o Earth? Tell studets they will lear more about these topics soo. UNIT MATERIALS Each uit provides a wide variety of resources related to the uit topic. Studets may read books ad other passages, work i groups to complete hads-o experimets ad ivestigatios, discuss sciece ideas as a class, watch videos, complete writig tasks, ad take assessmets. Resources are available for pritig or projectig, ad may studet resources are also available for studets to access digitally o. Selected uit resources are available i more tha oe laguage. For a complete list of materials provided with the uit, see the Force ad Motio uit page o the Sciece A Z website. VOCABULARY $ attract balaced to pull toward i a state i which equal ad opposite forces cacel each other out Use the terms below for vocabulary developmet throughout the uit. They ca be foud i boldface i the Nofictio Book, the Quick Reads, ad/or other uit resources. These terms ad defiitios are available o Vocabulary Cards for studet practice. Additioal vocabulary lists are provided i the teachig tips for Ivestigatio Packs ad FOCUS Books. $ chemical eergy eergy made by a chage i a substace or a combiatio of substaces Learig A Z All rights reserved. 3

4 Force ad Motio Core Sciece Terms These terms are crucial to uderstadig the uit. directio distace electromagetism eergy trasfer force frictio gravity iertia kietic eergy magetism mass mometum motio potetial eergy speed weight work the way or course toward which somethig moves or faces the amout of space betwee thigs the combied force of electricity ad magetism the movemet of eergy from oe object to aother or the chage of eergy from oe form to aother the stregth or eergy that moves a object a force that slows dow movig thigs the force that pulls thigs toward the ceter of Earth or ay other object that has mass the tedecy of a object to resist chage i the directio or speed of its motio the eergy that a movig body has because of its motio a force that pushes ad pulls certai metals the amout of matter, measured o Earth by its weight the stregth or force that keeps somethig movig the act of goig from oe place to aother; movemet the eergy a body has because of its positio, electrical charge, or structure; stored eergy the rate of movemet how heavy somethig is, determied by the pull of gravity o the object s mass the act of usig force to move somethig over a certai distace Other Key Sciece Terms The followig vocabulary is ot essetial for comprehedig the uit but may erich studets vocabulary. attract balaced chemical eergy electricity to pull toward i a state i which equal ad opposite forces cacel each other out eergy made by a chage i a substace or a combiatio of substaces eergy created by movig charged particles Learig A Z All rights reserved. 4

5 has mass Credit: ariahabich/123rf mass gametsmieetcrol 3 14 UNIT GUIDE Force ad Motio eergy egie geerator heat eergy law light eergy lies of force magetic field reactio repel rest soud eergy velocity weightless the power to do work, make a chage, or move objects a machie with movig parts that uses power to create motio; a motor a machie that turs potetial ad kietic eergy ito electricity a form of eergy that is trasferred from a object with a higher temperature to a object with a lower temperature a statemet about results that always occur uder certai circumstaces a form of radiat eergy that allows us to see ivisible lies of magetic force that flow through ad aroud a maget a area aroud a maget or a movig electrical charge withi which a magetic force acts a equal, opposite respose to a force beig applied to force or push away a pause durig which o force is movig a object a form of eergy that allows us to hear the rate of movemet i a certai directio experiecig little or o oticeable gravitatioal pull Name Date Learig A Z All rights reserved. Credit: Igram Publishig/Thikstock FORCE AND MOTION Word Search Directios: Below are defiitios of vocabulary terms. Figure out each term ad the fid ad circle it i the puzzle. Words may appear horizotally, vertically, or diagoally. R B M A G N E T I S M U A N R K J Y I C F J Y L W G P Y H J C H O B S W Q X P I R F F B J V R E Z L M M O T I O N J K Z H C H G D O L A J P M U T N E M O M X O P G O N W R I E V N A I O S K C S Y B R N X Z O X Z J T M I O L H Q K E C P F M P J A I F A O Y T D T I L D Y N Y P E F J B V T I G N V M D F Y T C Y U B T Q E O M T C I G B J E O G W D C T F J R N N D W O E F J I G I V Q Z M O I I N E R T I A E R Q M S F Z X F H Z E P R H Y B Z J B N I M P M T R C R O T R T R F K L M B C E D S B Z D G W X J Q A L D I S T A N C E E D B T F N M V Y W 1. the tedecy of a object to resist chage i the directio or speed of its motio 2. the way or course toward which somethig moves or faces 3. the act of usig force to move somethig over a certai distace 4. a force that slows dow movig thigs 5. the amout of space betwee thigs FORCE AND MOTION Fill i the Blak Name Date Directios: Fill i each blak with the correct word from the list. Use each word oce. distace frictio kietic eergy mometum speed force iertia mass potetial eergy work I did a lot of work today, but ot the kid of work you may be thikig of. First, I stretched a rubber bad tight, givig it a lot of. Whe I let it go, the rubber bad flew across the room. Sice it was movig, it ow had. I used to move somethig over a certai, so I kow that I did. 6. a force that pushes ad pulls certai metals 7. the rate of movemet 8. the force that pulls thigs toward the ceter of Earth or ay other object that has mass 9. the stregth or force that keeps somethig movig 10. the act of goig from oe place to aother; movemet Next, I rode my bike to the library. I had to overcome my bike s i order to make it move. The, I had to keep pedalig so betwee the tires ad the road would t slow my bike dow. I was movig at a fast, so I got there quickly. I had built up a lot of, though, ad it took me a few extra secods to stop. Maybe it was the of all those extra books i my backpack! I thik I did a lot of work today. But my mom does t agree. She says I still have to clea my room! 3 Name Date Learig A Z All rights reserved. FORCE AND MOTION Directios: To aswer the riddle, uscramble each word ad write i the squares. The write the circled letters i order o the umbered spaces below. 1 sasm the amout of matter, measured o Earth by its weight viragty the force that pulls thigs toward the ceter of Earth or ay other object that 2 steaicd the amout of space betwee thigs 4 hwiget Uscramble Vocabulary Activities You may choose to itroduce all the terms that will be ecoutered i the uit before assigig ay of the readig compoets. Vocabulary Cards with the key sciece terms ad defiitios are provided. Dots o the cards idicate the readig levels of the Nofictio Book or the Quick Reads i which each term ca be foud. If all level dots appear, the term may come from aother resource i the uit. Studets ca use these cards to review ad practice the terms i small groups or pairs. The cards ca also be used for ceter activity games such as Cocetratio. The Word Work activity sheets offer fu puzzles ad practice with key vocabulary terms from the uit. For further vocabulary practice ad reiforcemet, you ca choose from the vocabulary Graphic Orgaizers. To build customized vocabulary lessos with terms related to the topic, see. 5 how heavy somethig is, determied by the pull of gravity o the object s the combied force of electricity ad magetism Riddle: Why was the girl uhappy about pullig the heavy wago that had o wheels? Aswer:! Learig A Z All rights reserved. Learig A Z All rights reserved. 5

6 A Sciece A Z Physical Series Word Cout: 2,299 Visit Writte by Ned Jese UNIT GUIDE Force ad Motio Studets ca use the Word Smart vocabulary Graphic Orgaizer to orgaize iformatio o the sciece terms. You may wat to assig each studet oe to three words to share his or her Word Smart kowledge with classmates. Studets who have the same word should first compare their Word Smart sheets with each other ad the report to the larger group. The sciece terms ca be used i oral practice. Have studets use each term i a spoke setece. As studets read, ecourage them to create a sciece dictioary by recordig ew vocabulary terms ad defiitios i their SAZ Joural. BACKGROUND ad MISCONCEPTIONS Force ad Motio Use this sectio as a resource for more backgroud kowledge o uit cotet ad to clarify the cotet for studets if miscoceptios arise. Refer to Usig the Iteret below for more ways to exted the learig. Q: If a body i motio remais i motio util a force acts o it, why do thigs evetually stop? Is it because they used up all their eergy? A: Objects evetually stop because a force such as frictio or gravity acts agaist the object s motio. Oce a object is i motio, the eergy that was used to iitiate the motio is irrelevat. I the absece of forces actig agaist that motio, a movig object would, i fact, cotiue to move forever! This is true of a boucig ball, a speedig car, a gallopig horse, ad a shootig star. Q: If I wat to keep a object movig, do I eed to keep applyig a force? A: I theory, o. Accordig to Newto s first law, a body i motio will remai i motio. A object will keep movig at the same velocity as log as it does t receive ay additioal pushes or pulls. Objects do ot stop because of a lack of force; they stop because a differet force is beig applied. For example, frictio is a force that acts agaist a object s motio. If you slide a book across a table, it will evetually come to rest because frictio is pushig o it i the opposite directio of its motio. Reducig frictio by applyig oil or flour to the table would allow the book to travel farther give the same amout of force. Q: Are speed, velocity, ad acceleratio the same thig? A: No. They are related but are ot exactly the same. Speed measures the rate of motio how fast somethig is goig. Velocity is the speed a object is movig i a certai directio. Acceleratio is the measuremet of the chage i velocity over time. A chage i acceleratio ca be a chage i a object s speed or directio. Accordig to Newto s secod law, a force is required to accelerate a object. Learig A Z All rights reserved. 6

7 Force ad Motio Q: Whe a object is at rest, are ay forces actig o it? A: Yes. Eve whe a object is statioary, the force of gravity is pullig it toward Earth s ceter. Frictio is helpig to hold it i place agaist a surface. At the same time, whatever the object is sittig o opposes the force of gravity ad holds the object up. This force is called the ormal force. I additio, other forces, such as air movemet, could be actig o the object but are ot strog eough to overcome the object s iertia. Q: Do heavier objects fall to the groud faster tha lighter object? A: No ad yes. I the absece of air resistace, objects of all sizes ad weights, whe dropped from the same height, will hit the groud at the same time. Without air resistace, objects experiece free fall. Durig free fall, objects with more mass experiece greater force due to gravity, but this greater force is offset by the icreased iertia of the larger mass. Because of this tradeoff, the objects hit the groud at the same time. I the presece of a appreciable amout of air resistace, more massive objects will fall faster tha smaller objects. I this case, air resistace is strog eough to slow dow smaller objects, whereas the larger, more massive objects cotiue to accelerate. Also, objects of similar mass will fall at differet rates if oe ecouters more air resistace tha the other due to its shape. This is the case whe comparig the drop rate of a crumpled paper ad a paper airplae. Q: Why do astroauts o a space statio orbitig Earth float? A: Astroauts look as though they are floatig, but they are actually fallig. Free fall occurs whe gravity is the oly force actig o objects. I free fall, o cotact forces are actig to oppose the force of gravity. The space statio, the astroauts, ad all the objects withi the space statio are fallig together at the same rate i a curved patter, or orbit, so the people are ot held dow as they would be o Earth. This is why astroauts feel weightless i space. Q: Is there gravity i outer space? A: Yes, defiitely! There is some amout of gravity everywhere i outer space. Gravity is what keeps plaets i orbit aroud the Su ad what keeps the Moo i orbit aroud Earth. Gravity is a attractio betwee two objects. Larger masses have stroger gravitatioal pulls. The Moo s gravity is strog eough to create ocea tides o Earth. The Su is so large that its gravitatioal pull reaches beyod our ow solar system. Eve etire galaxies exert gravity o oe aother. However, this pull decreases as the distace betwee two masses icreases. Learig A Z All rights reserved. 7

8 Force ad Motio Q: Is it true that I would weigh less if I were stadig o the Moo? A: Yes. Weight is a measuremet of the amout of force a object exerts because of gravity. The more massive somethig is, the more gravitatioal pull it exerts. If you step o a scale, you are basically squeezig the sprigs i the scale betwee yourself ad the floor, gravity is pullig you dow, while the force of the floor is pushig you up (ormal force). The more mass you have, the more you squeeze the sprigs of the scale, so the more you weigh. O the Moo, the force of gravity is oe-sixth as strog as the force of gravity o Earth. Sice the force of gravity is weaker o the Moo, it would pull dow o you much less tha the force of gravity o Earth. If you were to step o the same scale o the Moo, you would squeeze the sprigs less ad therefore weigh less. Your mass would ot chage, but your weight would. If you could stad o Jupiter, you would weigh much more tha o Earth. Jupiterimages Corporatio EXTENSION ACTIVITIES Usig the Iteret Most search egies will yield may results whe the term force or motio is etered. You ca also perform a more specific search, such as for iformatio o Isaac Newto ad his three laws of motio. Be aware that some sites may ot be educatioal or iteded for the elemetary classroom. More specific iquiries are recommeded, such as: force ad motio i sports iertia ad mometum Galileo s theories of motio physics for kids law of uiversal gravity frictio i shoes electricity ad magetism weightlessess eergy ad work kietic vs. potetial eergy Below are some liks with excellet resources for studets ad/or teachers. Rader s Physics4Kids website is writte for childre ad cotais explaatios of force, acceleratio, motio, eergy, work, ad mass. The site also cotais quizzes for studets to assess their kowledge of force ad motio. Physics i Sports Coectio uses athlete video clips to explai ad illustrate Newto s law of uiversal gravity ad his three laws of motio. The site icludes questios about the video clips that will stimulate studet thikig about force ad motio. Learig A Z All rights reserved. 8

9 Force ad Motio Read all about Newto s laws o the NASA website desiged for educators ad studets. This site icludes grade-specific liks to suggested force ad motio activities ad demostratios, plus a page for studets at a lower readig level. Kids will ejoy learig about the physics of skateboardig o this website published by the Exploratorium i Sa Fracisco. Like all other objects, Newto s Laws as well as frictio ad mometum apply to skateboards. The UCLA Physics & Astroomy K 6 Coectio is published by two scietists with the goal of brigig astroomy ad physics ito elemetary classrooms. It supplies teachers with the kowledge they eed to teach studets. Click o the Physics Table of Cotets lik to reach cotet about force ad motio. The site icludes teachig tips ad classroom activities. The Physics Classroom website presets tutorials that explai force ad motio with helpful illustrated diagrams. The site also cotais worksheets ad activities that ca be used i the classroom. Some cotet may be too advaced for elemetary school studets or may require additioal istructio. Projects ad Activities Iquiry Sciece/Project: Take studets outside to the school playgroud. Ask them to observe commo playgroud equipmet such as a swig set, a teeter-totter, ad a slide. Have studets choose oe piece of playgroud equipmet ad desig a hypothetical experimet o force ad motio that improves the way the equipmet works. For example, icreasig the legth of the chais o a swig will icrease the maximum height a rider ca reach. Addig a lubricat to a slide will reduce frictio ad allow the rider to go faster. Iquiry Sciece/Project: Experimet with the relatioship betwee force, mass, ad acceleratio (refer to Isaac Newto s famous equatio, F = m a). Use balls of various sizes ad weights (for example, Pig- Pog, golf, teis, ad baseball). Drop the balls from various heights ito smoothed sad, such as from the top of a play structure i a playgroud. Balls with more mass will cause larger impact craters i the sad tha balls with smaller mass. I additio, droppig balls from a greater height will cause them to accelerate more ad will cause larger impact craters i compariso to balls dropped closer to the groud. Measurig the width ad depth of the impact craters will give studets a meas of comparig the amout of force that was applied to the groud whe each ball struck it. Learig A Z All rights reserved. 9

10 Force ad Motio Writig: Have studets write a brief biography of Isaac Newto. Ecourage them to iclude dates of his importat discoveries ad evets i his life that may have iflueced his thikig o force ad motio. For more iformatio o writig biographies, visit. Guest: Ivite a physicist or egieer to the classroom to discuss force ad motio ad how it impacts our daily lives. Ask the speaker to focus o a everyday item, such as a car, ad how egieers work to reduce frictio ad drag so that cars ca do more work usig less fuel for eergy. Arts: Have studets view paitigs related to forces ad motio, such as The Hammer ad the Feather by Ala Bea ( hammerfeather-ew.html). Ask them to describe what is happeig i each paitig ad what cocept(s) of force ad motio each paitig is illustratig. Supply studets with colored pecils, markers, pait, ad costructio paper so they ca make their ow versio of a famous paitig. Techology: Ivite studets to explore the followig website: This simulatio allows studets to lauch various projectiles at a target. Studets ca experimet with chagig variables such as iitial speed, mass, ad diameter of the object as well as whether or ot wid resistace is preset durig the simulatio. Field Trip: Atted a sportig evet, such as a soccer game or a gymastics competitio. Have studets take otes ad record sketches of forces ad motio they observe. Back i class, ecourage them to share ad explai their examples usig Newto s laws of motio. Research/Home Coectio: Studets ca coduct research as a family/home project or i the library/ media ceter to exted the learig about a topic i oe of the Quick Reads or other uit resources. Learig A Z All rights reserved. 10