Pre-AP/IB Physics. 1. The total amount of momentum in a closed, isolated system a. is constantly increasing b. is constantly decreasing

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1 Nae: Pre-AP/IB Physs Reew: Work, Energy, & Moentu Please Note soe addtonal noraton n robles 5,6, & & Objetes/oabulary: Use the work energy theore to sole robles. Understand the onet o oste and negate work Use law o onseraton o energy to sole robles. Dene oentu and ulse and use the ulse-oentu theore Use law o onseraton o oentu to sole robles. Understand the derene between elast and nelast ollsons. Multle Choe Identy the letter o the hoe that best oletes the stateentor answers the queston. 1. he total aount o oentu n a losed, solated syste a. s onstantly nreasng b. s onstantly dereasng. s onsered d. s radal. A hange n the knet energy durng a ollson eans that. a. the ollson s nelast b. the ollson s elast. onseraton o oentu s not true d. none o these 3. When a net ore not equal to zero ats on a body. a. the eloty o the body s onstant b. the body s aeleratng. the oentu o the body s zero d. the oentu s nreasng 4. he sallest hange n oentu wll be rodued by. a. a large ore oer a short te b. a sall ore oer a short te. a sall ore oer a long te d. a large ore oer a long te 5. I an objet wth a eloty o 40 /s has the sae oentu as that o a 10 kg ass hang a eloty o 0 /s, the ass o the objet s. a. 10 kg. 5 kg b. 8 kg d. 1 kg 6. Iulse an be reresented by. a. hange n eloty dded by te b. ore tes te ore s aled. ass tes eloty d. none o the aboe 7. When a bat hts a baseball, the ore exerted by the bat on the ball s that exerted by the ball on the bat.. less than 8. When a bat hts a baseball, the hange n oentu o the ball s that o the bat.. less than

2 Nae: Pre-AP/IB Physs 9. When a bat hts a baseball, the hange n eloty o the ball s that o the bat.. less than 10. What s the oon orula or work? a. W Fd(sn θ) b. W Fd. W Fd d. W F d 11. A 1.00 x 10 3 kg sorts ar aelerates ro rest to 5.0 /s n 7.50 s. What s the aerage ower outut o the autooble engne? a. 0.8 kw kw b kw d. 5.4 kw 1. A worker ushes a wheelbarrow wth a horzontal ore o 50.0 N oer a leel dstane o 5.0. I a rtonal ore o 43 N ats on the wheelbarrow n a dreton ooste to that o the worker, what net work s done on the wheelbarrow? a. 50 J b. 0J. 35 J d J 13. A lght attendant ulls a 50.0 N lght bag a dstane o 50.0 along a leel arort loor at a onstant seed. A 30.0 N ore s exerted on the bag at an angle o 50.0 aboe the horzontal. How uh work s done on the lght bag? a J b J. 480 J d J 14. Whh o the ollowng energy ors s n a enl allng ro a desk? a. knet energy b. non-ehanal energy. gratatonal otental energy d. elast otental energy and knet energy 15. Whh o the ollowng energy ors s assoated wth an objet n oton? a. otental energy. non-ehanal energy b. elast otental energy d. knet energy 16. Whh o the ollowng energy ors s assoated wth an objet due to ts oston relate to Earth? a. otental energy. gratatonal otental energy b. elast otental energy d. knet energy 17. Whh o the ollowng araeters does not exress how resstant a srng s to beng oressed or strethed? a. oresson dstane b. relaxed length. srng onstant d. strethng dstane 18. A 40.0 N rate s ulled u a 5.0 nlned lane at a onstant eloty. I the lane s nlned at an angle o 37 o to the horzontal and there s a onstant ore o rton o 10.0 N between the rate and the surae, what s the net gan n otental energy by the rate? a. 90 J b. 10 J. 10 J d. 10 J

3 Nae: Pre-AP/IB Physs 19. A 5.00 x 10 N rate s at the to o a 5.00 ra, whh s nlned at 0.0 wth the horzontal. What s ts otental energy? (g 9.81 /s.) a. 855 J. 815 J b. 350 J d J 0. Why doesn t the rnle o ehanal energy onseraton hold n stuatons when rtonal ores are resent? a. Knet energy s not sly onerted to a or o otental energy. b. Potental energy s sly onerted to a or o gratatonal energy.. Cheal energy s not sly onerted to eletral energy. d. Knet energy s sly onerted to a or o gratatonal energy. 1. A ole aulter lears Wth what eloty does the aulter strke the at n the landng area? (Dsregard ar resstane. g 9.81 /s.) a..70 /s /s b /s d. 1.6 /s. A 15.0 kg rate, ntally at rest, sldes down a ra.0 long and nlned at an angle o 0.0 o wth the horzontal. Usng the work knet energy theore and dsregardng rton, nd the eloty o the rate at the botto o the ra. (g 9.81 /s.) a. 6.1 /s b. 3.7 /s. 9.7 /s d. 8.3 /s 3. A hld rdng a byle has a total ass o 40.0 kg. he hld aroahes the to o a hll that s 10.0 hgh and long at 5.0 /s. I the ore o rton between the byle and the hll s 0.0 N, what s the hld s eloty at the botto o the hll? (Dsregard ar resstane. g 9.81 /s.) a. 5.0 /s b /s. 11 /s d. She stos beore the botto. 4. What s the aerage ower suled by a 60.0 kg seretary runnng u a lght o stars rsng ertally 4.0 n 4. s? a. 380 W. 610 W b. 560 W d. 670 W Short Answer An exlanaton n olete sentenes ust be gen to reee redt. hs ay nlude orula, and substtutons nto the orulas. 5. In the ollowng sentene, s the eeryday or the sent eanng o work ntended? A oah does work on the bleahers by ong the nto lae beore the basketball gae. Yes, W Fd 6. Is onseraton o ehanal energy lkely to hold n the ollowng stuaton? A skateboard rolls aross a sewer grate. No, soe knet energy wll be lost due to rton 7. Is onseraton o ehanal energy lkely to hold n ths stuaton? An e skater gldes aross reshly ade e. Yes, we assue e s rtonless whh we do. 8. What ours when a ahne does work on an objet? It hanges the aount o energy the objet has

4 Nae: Pre-AP/IB Physs Free Resonse All work ust be shown to reee redt. hs nludes gens, orulas, and substtutons nto the orulas. 1. A sker wth a ass o 88 kg hts a ra o snow at 16 /s and beoes arborne. At the hghest ont o lght, the sker s 3.7 aboe the ground. What s the sker s gratatonal otental energy at ths ont? PE gh J. A ar wth a ass o 1500 kg hts a arked 18 wheeler wth a ass o 10,000 kg and stks to t. I the ar s ong at 0 /s, how ast s the 18 wheeler-ar syste ong ater the ollson? / s 0 ( ) 3. I the two ehles had ontnued traelng at 4.0 /s. How ast was the ar ong at the oent o at? / s 0 ( ) 4. he.0 kg head o an axe s ong at a eloty o 5.0 /s when t strkes a log and enetrates 0.0 nto the log. a. What was the ulse arted on the axe? ( 0 5.0) N s F t.0 10 b. What s the aerage ore exerted on the log? a x s F a N. How uh work was done on the axe blade, assue the aeleraton o the blade s unor? W Fd J 1 1 Alternate: W KE 1 0 (.0)(5) 5J 5. wo arts, one o ass M and the other o ass 3M, ollde head-on elastally. I ass 3M s ong wth a eloty V beore the ollson and at V aterward, what was the ntal eloty o ass M t s eloty was V aterwards? P 3 3V - 3V -3V P -V - V thereore M eloty ust be -V 6. What was the hange n oentu o art M n #5 M equals 10 kg and V equals /s?

5 Nae: Pre-AP/IB Physs -60 kg/s 7. A roket s shot u and reahes a seed o 50 /s just beore t exlodes nto two dental ees. Pee A goes o at 45 o to ertal and 40 /s, what are the x and y oonents o ee B s oentu n ters o M (ass)? x y osθ sn θ (40) os(45) 8.3 (40)sn(45) 8.3