a v2 r a' (4v) 2 16 v2 mg mg (2.4kg)(9.8m / s 2 ) 23.52N 23.52N N

Transcription

1 Conceptual ewton s Law Applcaton Test Revew 1. What s the decton o centpetal acceleaton? see unom ccula moton notes 2. What aects the magntude o a ctonal oce? see cton notes 3. What s the deence between netc and statc cton? see cton notes 4. When s a ctonal oce the geatest when someone st stats pushng on an object, just beoe t moves, o ate t moves? see cton notes 5. What s the decton o the netc cton oce? see cton notes 6. What s the decton o the statc cton oce? see cton notes 7. What s the decton o the nomal oce? see cton notes 8. Is the cente o mass always located at the cente o an object? Why o why not? see cente o mass eadng questons 9. Gve an example o a cente o mass that s not even located wthn the actual object. see cente o mass eadng questons 10. What s specal about the moton o the cente o mass? see cente o mass eadng questons 11. Gve thee examples o thngs that can supply centpetal oce. see unom ccula moton notes 12. Why s t moe dcult to stop you ca when you baes loc? see unom ccula moton notes 13. What s momentum? see momentum notes 14. What s the deence n an elastc and nelastc collson? see momentum notes 15. What s mpulse? see momentum notes 16. How ae mpulse and change n momentum elated? see momentum notes 17. What equaton do consevaton o momentum poblems stat wth? see momentum notes Poblems 18. Tammy s unnng aound a ccula tac at a constant speed. I she nceases he speed by a acto o ou, by what acto wll he centpetal acceleaton ncease? (16) a v2 a' (4v) 2 16 v2 19. Magaet holds a 2.40 g bloc o wood aganst a vetcal suace by pessng aganst t pependculaly, s = 0.32, what s the oce she exets to eep t thee? (73.5 ) y 0 s P s 0 s (2.4g)(9.8m / s 2 ) s s x 73.5 P 0 P 73.5

2 20. A hocey puc movng wth an ntal speed o 6.00 m/s sldes acoss a concete loo and comes to est ate gong 9.00 m. Detemne the coecent o netc cton. (0.204) v 2 v 2 2ax a v 2 2x 0 y (6m / s)2 2(9m) x ma ma 2.0m / s 2 a 2m / s2 g 9.8m / s A man exets a constant hozontal oce o 30.0 to gve a 5.00 g bloc an acceleaton o 5.00 m/s 2 along a hozontal suace. What s the cton oce? (5.00 ) ma x P ma P P ma 30 5g(5m / s 2 ) A 36.0 g cate sldes down a amp nclned at angle o 25º wth a constant speed o m/s. Detemne the coecent o netc cton. (0.466) 0 y cos cos x 0 sn cos 0 sn cos tan tan 25º 0.466

3 23. A 25.0 g pacage sldes down a 2.40 m long amp that s nclned at an angle o 28º. I the ntal speed down the amp was 1.40 m/s and = 0.160, what s the speed o the pacage at the bottom o the amp? (4.17 m/s) 0 y cos cos x ma sn cos ma a g(sn cos) (9.8m / s 2 )(sn28º 0.16cos 28º) 3.21m / s 2 v 2 v 2 2ax v (1.4m / s) 2 2(3.21m / s 2 )(2.4m) 4.17m / s 24. A 24.3 g mass and a 45.8 g mass ae placed so that the centes o mass ae sepaated by 4.60 m. How a s the cente o mass o the two objects om the cente o the 24.3 g mass? (3.00m) 24.3g(0) 45.8g(4.6m) m 45.8 g x cm 3.00m g 24.3g 45.8g x=0 x=4.6m 25. ou masses ae placed at vaous postons n the xy plane. Detemne the coodnates o the cente o mass a 1.00 g mass s placed at (8.0,0)m, a 1.50 g mass s placed at (0,-5.0)m, a 2.00 g mass s placed at (-2.0, 3.0)m and a 2.50 g mass s placed at (-8.0, 8)m. (-2.3, 2.6) m. x cm 1g(8m) 1.5g(0m) 2g(2m) 2.5g(8m) 1g 1.5g 2g 2.5g 2.3m 1g(0m) 1.5g(5m) 2g(3m) 2.5g(8m) y cm 2.6m 1g 1.5g 2g 2.5g 26. A boy whls a stone aound n a ccula hozontal path by applyng a oce o I the speed o the stone s nceased by a acto o 1.40, what wll the necessay oce be? (78.4 ) mv2 ' m1.4v mv2 ' 1.96(40 ) A 40.0 g gl s sttng on the outsde edge o a mey-go-ound that has a damete o 2.60 m. I she s movng wth a speed o 2.10 m/s, what s the oce necessay to hold on? (136 ) mv2 (40g) 2.1m / s 2 1.3m 136

4 28. What s the maxmum speed a 2500 g ca can go aound a level ccula tac o adus 20.0 m wthout slppng s=0.500? (9.9 m/s) 0 y s s ma x s mv2 v s g 0.5(9.8m / s 2 )(20m) 9.9m / s 29. A 200 g cannon at est contans a 10 g cannon ball. When ed, the cannon ball leaves the cannon wth a speed o 105 m/s. What s the ecol speed o the cannon? (v=5.25 m/s) p p 0 (10 g)(105 m / s) (200 g) v v 5.25 m / s 30. A 5.00 gam bullet tavelng hozontally at 850 m/s stes a statonay taget and stops ate penetatng 24.5 cm nto the taget. What s the aveage oce o the taget on the bullet? (=7372 ) v v 2ax 2 0 (850 m / s) 2 a(.245 m) a 1.47x10 m / s ma (0.005 g)(1.47x10 m / s ) A g lump o clay movng hozontally at 15.0 m/s stes and stcs to a statonay 0.25 g cat that can move on a ctonless tac. Detemne the speed o the cat and clay ate the collson. (v=5.625 m/s) p p (0.15 g)(15 m / s) (0.4 g) v v m / s 32. A mothe s holdng he 5.5 g baby n he ams whle dng n a ca movng at 32.0 m/s. The ca s nvolved n a head-on collson and stops wthn 0.5 seconds. What s the magntude o the oce exeted by the baby on hs mothe s ams? (=-352 ) J t mv mv (5.5 g)(0 32 m / s) 352 t 0.5s

5 Use ths dagam o the emanng questons: The box has a mass o 2.00 g. A 15 m 8 m 3.5m D E 45º B 15 m C 63º 33. The box s ntally statonay. I the nclne s ctonless, calculate the speed o the box at the bottom o the hll,.e., pont B. (v=14.4 m/s) ma sn ma a g sn (9.8 m / s ) sn m / s v v 2ax v m s m 2 2(6.93 / )(15 ) 14.4 m/ s 34. Consde the staght away poton o the dagam om ponts B-C. I the coecent o cton on the staght away s 0.18, what s the speed o the box ate t moved 15.0 m? (v=12.4 m/s) y x 0 a g.18(9.8 m / s ) 1.76 m / s v v 2ax ma ma v m s m s m (14.4 / ) 2( 1.76 / )(15 ) 12.4 m/ s

6 35. I the box then sldes up the next hll whee the coecent o cton on the hll s 0.04, what s the speed o the box at the top o the second hll? (v=9.75 m/s) 0 y cos cos x sn cos ma a g(sn cos ) (9.8 m / s )(sn 63º 0.04 cos 63º ) 8.9 m / s v v 2ax ma v (12.4 m / s) 2( 8.9 m / s )(3.5 m) 9.62 m / s 36. I ths box sldes along the second staght-away o a dstance o 8 m, what s the speed o the box ate ths dstance? ote, the suace om pont D to pont E s ctonless. (9.62 m/s) Speed doesn t change on hozontal ctonless nclne. 37. The box stes a wall and stops. What s the oce o the wall on the box the box stops n 1.20 seconds? (=-16.3 ) J t mv mv (2 g)( m / s) 16.0 t 1.2s 38. What s the oce o the box on the wall? (=16.0 ) ewton s 3 d law 39. What change n momentum does the box expeence? (Δp=-19.2s) p mv (2 g)( m / s) 19.2 s 40. What mpulse does the box expeence because o the oce? (J=-19.2s) Impulse = change n momentum