Announcements. Formulas Review. Exam format

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Daniel Reed
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1 Annuncemens 1. N hmewrk due mrrw! a. Wuld be an ecellen eening sud fr and/r ake he eam. Eam 1 sars da! a. Aailable in Tesing Cener frm Tues, Sep :15 am, up Mnda, Sep, clsing ime i. If u pick up ur eam afer 5 pm, u ll hae a lae fee. b. Cers Ch.,3 (hmewrks 1-3) c. There s a 3 hur ime limi i. Las ear s Eam 1: 1. Sudens k an aerage f 1.5 hurs. Sme k less han 1 hur 3. Sme k he full 3 hurs ii. This ear s Eam 1 will be a lile harder d. Adice: i. Take ime and space draw diagrams. ii. Shw all ur wrk n he eam papers iii. Wrie ur numerical answers in he blanks i. Circle he crrec chice. Then ransfer ur answers n ur bubble shee. e. Ne card: i. I will n gie u an frmulas n he eam ii. I will gie an cnsans (like g = 9.8 m/s ) r cnersin facrs ha u need. iii. Wrie anhing else u wan n a 3 5 ne card, frn & back. Handwrien nl! f. Calculars: i. The are allwed, an pe. ii. Be sure ur calcular has a leas basic scienific funcins such as rig, epnens, ec. g. Las ear s Eam 1 is psed n he web sie, alng wih sluins. i. Dn lk a he sluins unil u e wrked he eam...r u wn find u where u are weak. I s eas fl urself! h. Things sud i. HW prblems ii. In-class prblems (clicker quizzes & prblems) iii. Las ear s eam i. Cnceps frm lecures & dems. Oher prblems! (ebk, her bks, ec) Cln Lecure 5-9/16/08 - pg 1 Cln Lecure 5-9/16/08 - pg Eam frma The fllwing graph is f elci s ime () f a car ming alng a rad, and righ is psiie. The graph shws ha he car is [1?] a) speeding up b) slwing dwn c) saing a cnsan speed, and ming he [?] a) righ b) lef, wih accelerain he [3?] a) righ b) lef, and he accelerain is [4?] a) increasing in magniude b) decreasing in magniude c) cnsan. A je plane lands wih a speed f 50 m/s and can decelerae (slw dwn) a a maimum accelerain magniude f 7 m/s as i cmes res. Frm he insan he plane uches he runwa, wha is he minimum ime needed befre i can cme res? [11?] a) less han 7.0 s b) beween 7.0 and 7.1 s c) beween 7.1 and 7. s d) beween 7. and 7.3 s e) beween 7.3 and 7.4 s f) beween 7.4 and 7.5 s g) beween 7.5 and 7.6 s h) mre han 7.6 s These bubble shees hae 10 bubbles per quesin. + is he righ Frmulas Reiew Definiins Final eam: u will be epeced knw hese ae =< >= (insanan.) = slpe f angen line f s graph a ae =< a >= a (insanan.) = slpe f angen line f s graph Trignmer definiins Final eam: u will be epeced knw hese ppsie sinθ = hpenuse adjacen csθ = hpenuse ppsie anθ = adjacen Quadraic frmula Final eam: I will gie u his ± 4 If a + b + c = 0, = b b ac a Cln Lecure 5-9/16/08 - pg 3 Cln Lecure 5-9/16/08 - pg 4

2 Kinemaic frmulas fr cnsan a Final eam: I will gie u hese i + f ae = = + a 1 = + + a = + a f Kinemaic frmulas, applied prjeciles Final eam: I will n gie u hese; jus plug in a = 0 and a = -g he regular kinemaic frmulas which I will gie u -direcin = = + -direcin = g 1 = + g = g Cnceps Reiew 1. Trig: need knw hw sin, cs, and an wrk. Min: a. Displacemen b. Velci and speed c. Accelerain (alwas in direcin f frce) d. Hw inerpre (), () and a() graphs: i. slpes cnnec hem e. Aerage s. Insananeus 3. Kinemaic equains a. Take ur ime: i. Draw picures, chse + direcin 1. Wrie gien inf n picure, prperl labeled (eample: f = 10 m/s). Wrie missing inf n picure, als labeled (eample: =?) ii. Think abu which equains describe he min iii. Wrie dwn he ms relean equains smblicall i. Plug numbers in ur equains, see wha he ell u Cln Lecure 5-9/16/08 - pg 5 Cln Lecure 5-9/16/08 - pg 6. D algebra, carefull i. Plug numbers in calcular wice! b. Prblems can be dne mre han ne wa i desn hur check ur wrk wih her eqns 4. Adding Vecrs a. Graphicall alwas d! b. Wih cmpnens i. Use cs, sin ge -and - shadws ii. Add - and -cmpnens separael ge cmpnens f final ecr iii. Magniude f final ecr: Phagrean hm i. Angle f final ecr: angen 6. Relaie min: a. One-dimensin: i s eas figure u, jus add r subrac speeds b. -dimensins: draw ecrs, and wrie he ecr equain: ac = ab + bc wih a, b, and c being bjecs frm he prblem. Then be sure ur wrk (cmpnens) agrees wih i. 5. Free-fall/prjeciles a. Tw ses f kinemaic equains ( and ) i. a = 0 ii. If up = psiie, hen a = -g = -9.8 m/s b. If iniial elci a an angle: diide 0 in - and -cmpnens c. If range -pe prblem: hink abu which crdinae ses he ime. i. Sle fr ime ii. Plug in her crdinae s equain(s) Cln Lecure 5-9/16/08 - pg 7 Cln Lecure 5-9/16/08 - pg 8

3 Sme cnceps frm las lecure Sall and Bb each hrw a rck hriznall frm a cliff. Sall hrws her rck hard. Bb hrws his mre easil. Clicker quiz: Which spends he lnges ime falling? a. Sall s b. Bb s Clicker quiz: Which rck is ging fases (ecr magniude) jus befre i his he grund? a. Sall s b. Bb s Sall hrws a rck hriznall frm a cliff. Bb hrws his a an angle abe hriznal. The hrw he same speed. Maimum range Warmup: Neglecing air resisance, a wha angle shuld u hrw a ball n a fla field in rder ge he maimum range? a. 30 b. 45 c. 60 d. I depends n he iniial speed We re als neglecing heigh f persn ha culd hae a sligh effec. Wha if u d wrr abu air resisance? Simulain: hp://phe.clrad.edu/new/simulains/sims.php?sim=prjecile_min Clicker quiz: Which his firs? a. Sall s b. Bb s Cln Lecure 5-9/16/08 - pg 9 Cln Lecure 5-9/16/08 - pg 10 Sme HW prblems (missed b man): HW, Prblem 3 Using a rcke pack wih full hrle, a lunar asrnau acceleraes upward frm he Mn s surface wih a cnsan accelerain f.03 m/s. A a heigh f 9.76 m, a bl cmes lse. (The free-fall accelerain n he Mn s surface is abu 1.67 m/s.) (a) Hw fas is he asrnau ming a ha ime? (b) Hw lng afer he bl cmes lse will i hi he Mn s surface? (c) Hw fas will i be ming hen? (d) Hw high will he asrnau be when he bl his? (e) Hw fas will he asrnau be raeling hen? HW 3, Prblem 3 A hme run is hi in such a wa ha he baseball jus clears a wall 1 m high, lcaed 130 m frm hme plae. The ball is hi a an angle f 3.6 he hriznal, and air resisance is negligible. Find (a) he iniial speed f he ball, (b) he ime i akes he ball reach he wall, and (c) he speed f he ball when i reaches he wall. (Assume he ball is hi a a heigh f 1.0 m abe he grund.) Cln Lecure 5-9/16/08 - pg 11 Cln Lecure 5-9/16/08 - pg 1

4 Mre cncepual quizzes The cure is elci s ime fr an bjec, psiie means he righ. Clicker quiz: The cure represens an bjec: a. ming righ b. ming lef c. ming righ hen ming lef d. ming lef hen ming righ e. n ming Clicker quiz: The accelerain f his bjec is: a. he righ b. he lef c. he righ hen he lef d. he lef hen he righ e. zer Fr he () cure A shwn he righ, he clses () cure ha describes is elci is clses cure (chse 1-6 frm cures belw). Fr he () cure B shwn he righ, he clses () cure ha describes is elci is clses (chse 1-6 frm cures belw). Fr cure 1 in he () graphs belw, he accelerain is 1) alwas psiie ) alwas negaie 3) psiie hen negaie 4) negaie hen psiie Cln Lecure 5-9/16/08 - pg 13 Cln Lecure 5-9/16/08 - pg 14 Clicker quiz: If A and B are ecrs, which is rue fr A B and B A? a. he pin in he same direcin b. he hae he same cmpnens c. he pin in ppsie direcins d. he lk he same when drawn Mre wrked prblems A mris dries nrh fr 30 minues a 85 km/h and hen sps fr 15 minues. He hen urns suh, raeling 130 km in 50 min. His aerage elci was km/hr in he direcin 1) nrh ) suh Clicker quiz: The hriznal () cmpnen f he elci f a fball while in he air is: (neglec air resisance) b. increasing c. decreasing d. saing he same e. speeding up hen slwing dwn f. nne f he abe Cln Lecure 5-9/16/08 - pg 15 Cln Lecure 5-9/16/08 - pg 16

5 A baseball hi sraigh up akes 5 secnds reach is maimum heigh. The iniial elci f he ball was m/s. The maimum heigh he ball reached was m. Cliff diers a Acapulc jump in he sea frm a cliff 40 m high. A he leel f he sea, a rck sicks u a hriznal disance f 5.5 m. If he diers jump ff hriznall, he mus hae a hriznal iniial elci greaer han m/s jus miss he er edge f he rck (if he use he elci u calculae he wuld jus hi he edge f he rck ). The diers are in he air fr hw lng? s Cln Lecure 5-9/16/08 - pg 17 Cln Lecure 5-9/16/08 - pg 18 A place kicker kicks a + A + fball frm a pin 50 m frm he galpss, frm he B grund. When kicked, he ball leaes he grund wih a speed f 35 m/s a an angle f 5 abe he hriznal. When i crsses he plane f he galps i is m abe he grund. The iniial hriznal cmpnen f he elci is m/s. Cln Lecure 5-9/16/08 - pg 19

Lecture 4 ( ) Some points of vertical motion: Here we assumed t 0 =0 and the y axis to be vertical.

Lecture 4 ( ) Some points of vertical motion: Here we assumed t 0 =0 and the y axis to be vertical. Sme pins f erical min: Here we assumed and he y axis be erical. ( ) y g g y y y y g dwnwards 9.8 m/s g Lecure 4 Accelerain The aerage accelerain is defined by he change f elciy wih ime: a ; In analgy,