Mr. Kepple. Motion at Constant Acceleration 1D Kinematics HW#5. Name: Date: Period: (b) Distance traveled. (a) Acceleration.

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1 Moion Consn Accelerion 1D Kinemics HW#5 Mr. Kepple Nme: De: Period: 1. A cr cceleres from 1 m/s o 1 m/s in 6.0 s. () Wh ws is ccelerion? (b) How fr did i rel in his ime? Assume consn ccelerion. () Accelerion (b) Disnce reled = = = 5 m/s 6 x x 0 = x = ( )(6) + 1 ( 5)(6) x = 99 m. Suppose rocke ship in deep spce moes wih consn ccelerion equl o 9.8 m/s², which gies he illusion of norml gri during he fligh. () If i srs from res, how long will i ke o cquire speed one-enh h of ligh, which rels m/s? (b) How fr will i rel in doing so? () Time unil = c (b) Disnce reled = 0 + = 0 x x 0 = x = + 1 (9 8)( 6 ) = ( )( ) 9 8 x = m = 6 s 3. A world-clss spriner cn rech op speed (of bou 11.5 m/s) in he firs 15.0 m of he rce. () Wh is he erge ccelerion of his spriner nd (b) how long does i ke her o rech h speed? () Aerge Accelerion = 0 + (x x 0 ) = 0 (x x 0 ) (b) Time = 0 + = 0 = ( 5) ( 5) = 4 4 m/s² = = 6 s

2 4. In coming o sop, cr lees ski mrks 85 m long on he highw. Assuming decelerion of 4.00 m/s², esime he speed of he cr jus before brking. = 0 + (x x 0 ) 0 = (x x 0 ) 0 = ( 4)(85) = 6 m/s 5. An inenie drier is reling 18.0 m/s when he noices red ligh hed. His cr is cpble of decelering re of 3.65 m/s². If i kes him 0.00 s o ge he brkes on nd he is 45.0 m from he inersecion when he sees he ligh, will he be ble o sop in ime? (4 poins) Disnce during recion ime x = x = ( 8)( ) = 6 m Tol disnce d = = 48 m The drier will NOT sop in ime. Disnce o sop = 0 + (x x 0 ) x = 0 x = ( 8) ( 65) = 44 4 m 6. An elecric ehicle srs from res nd cceleres re of.0 m/s² in srigh line unil i reches speed of 0 m/s. The ehicle hen slows consn re of 1.0 m/s² unil i sops. () How much ime elpses from sr o sop? (b) How fr does he ehicle rel from sr o sop? (6 poins) () Time elpsed = = ( ) () = s = ( ) ( ) = s = 0 = 1 + = + = s () Disnce reled = 0 + (x x 0 ) x 1 = ( ) () = m x = 0 x = ( ) ( ) = m x = x 1 + x = + = m

3 Freel Flling Objecs 1D Kinemics HW#6 Mr. Kepple Nme: De: Period: 1. A sone is dropped from he op of cliff. I is seen o hi he ground below fer 3.75 s. How high is he cliff? Tke downwrd o be he posiie direcion. Choose he op of he cliff m. If cr rolls genl ( off ericl cliff, how long does i ke o rech 55 km/h? (3 poins) Tke downwrd o be he posiie direcion. 55 km 1 h 1 3 m 1 km 1 h 36 s 15.8 m/s s 3. A bll pler cches bll 3. s fer hrowing i ericll upwrd. () Wih wh speed did he hrow i, nd (b) wh heigh did i rech? Tke upwrd o be he posiie direcion. Choose he heigh he bll ws hrown. () Iniil Speed + 1 g + 1 g m/s 16 m/s () Mx Heigh g m 13 m

4 4. A helicoper is scending ericll wih speed of 5.10 m/s. A heigh of 105 m boe he Erh, pckge is dropped from window. How much ime does i ke for he pcke o rech he ground? Tke downwrd o be he posiie direcion. Choose he heigh he pckge ws relesed such h 1 5 m g ± s 5. A rocke rises ericll, from res, wih n ccelerion of 3. m/s² unil i runs ou of fuel n liude of 950 m. Afer his poin, is ccelerion is h of gri, downwrd. () Wh is he eloci of he rocke when i runs ou of fuel? (b) How long does i ke o rech his poin? (c) Wh mximum liude does he rocke rech? (d) How much ime (ol) does i ke o rech mximum liude? () Veloci when ou of fuel (b) Time o run ou of fuel m/s 78 m/s s 4 s (c) Mx heigh (d) Time o mx heigh g g g 7.96 s Tol Time: m s 3 s

5 Kinemics Problems 1D Kinemics HW#7 Mr. Kepple Nme: De: Period: The problems on his pge re more chllenging hn simpl plugging ino he kinemics equions. You will he o do ddiionl hinking nd follow muliple logicl seps o he find he soluions. 1. A flling sone kes 0.33 s o rel ps window. m ll. From wh heigh boe he op of he window did he sone fll? Speed he op of he window, ke downwrd o be posiie nd 0 = 0 he op of he window. = g 0 = 0 1 g = 0.33 = 5.05 m/s The heigh boe he op of he window is he disnce required o rech his speed when dropped from res. = 0 g 0 0 = = 0 g 0 = 1.3 m. A rock is dropped from se cliff nd he sound of i sriking he ocen is herd 3.4 s ler. If he speed of sound is 340 m/s, how high is he cliff? ol ime T = + s = T s Combine equions nd elimine : h = g T s rock = g h = g T h s 0 = h + 0 g h = g h = g T Th s + h s sound = h = 0 + s s + 0 g h Tg h + gt s s = h 1.098h = 0 s = h s From qudric formul: h = 5 m

6 3. A bll is dropped from he op of 50.0-m high cliff. A he sme ime, crefull imed sone is hrown srigh up from he boom of he cliff wih speed of 4.0 m/s. The sone nd bll collide pr w up. How fr boe he bse of he cliff does his hppen? bll = g = Se equions equion o ech oher nd sole for ime: = = 4 sone = = = 50 4 =.083 s Use ime o find he posiion: = = 8.7 m 4. A rock is hrown ericll upwrd wih speed of 1.0 m/s. Excl 1.00 s ler, bll is hrown up ericll long he sme ph wih speed of 18.0 m/s. () A wh ime will he srike ech oher? (b) A wh heigh will he collision occur? ime b = 1 rock = g = () Time unil collision = = =.9 bll = g = b 4.9 b = = = = = 1.45 s (b) Heigh of collision = = = 7.10 m