Suppose that an object travels from one point in sp ;iwk 2g, g/fneso34ybace to another. Make a comparisygig;k n3obw / ,s4ef2on between the displacement and the distance traveled.

  When is the average velocity of x+js+zcj d.7hb*z np) ejx(qi4 xn4-yan object equal to the instantaneous velocity?

  A new car manufacturer advertises tmiw0 .jbop /*p8 ncn(that their car can go "from zero to sixty in 8 s". p8.m(/o j*incwnt pb0 This is a description of

  An object moving in the +x axis experiences an acceleratijiecf)lvp:. a9(n ar p)u t+q7on of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x dpi4db :6g1htwe l4o:a 8yg(ygirection) begins to slow down as it approaches a traffic light. Make a statement concerning its acceiaelh64 :pw (by gt4g18dy o:gleration.

  Suppose that a car traveling to the Wesc)5 qseqidv6rmr ,;-i t (-x direction) begins to slow down as it approaches a traffic light. Make a statement cq-,sr i ireqv5;6)mdc oncerning its acceleration.

  Suppose that an objecc:ql:iyom6s kg)fu 9;b5bgk /t is moving with a constant velocity. Make a statement concerlk;:: youk/)sfic6 bq 5bgg 9mning its acceleration.

  If the velocity of an ob+ivo2bju0f3krq .l 1y / r m)gga4qj9rject is zero, does it mean that the acceleration is zero? Support your answe/r y ju4q )iv grgofaqm9kb32+r.1jl0 r with an example.

  Can an object's velocity change direction when its acceleri.wkvxz:8iy r0 zc/)jl1f 1ld ation is constant? Support your answer wi fl)i:zykc xlr d1iz8w1 /0v.jth an example.

  Suppose that an object i;rv. o33:eh4yg: g-t:ls e8otm nvxxsm/ yfo3s moving with constant acceleration. Make a statement conc-r 3g;tlxofxo o ve:8mv:t g43eys hm:3/ns y.erning its motion with respect to time.

  Can an object have increasing speed while ki) x:n, gz4.+t3cclryy; ydoits acceleration is decreasing? Support your answer wit: +x yoyc,rkgn43y lcd ).zit;h an example.

  Suppose a can, after an initial kick, moves up a*3ii tpyf) he7xseg+l18o l+rlong a smooth hill of ice. Make a statement concernifx gyi+8 3irt+l poh*7se1) leng its acceleration.

  Under what condition is average velocity equal to the averag 6+h6uz flhvltbh-alj) n(*s cv 3k0u6e of the object's initial and final velocit-vfhklb*a6 vh6uhl+ 0 (6z 3lc)snjtu y?

  Objects A and B both start at rest. They both accelerate at the same rate.s a(gv(y 9uc1 kabz3/z However, object A v/za1 a((ckz bysg u39accelerates for twice the time as object B. What is the final speed of object A compared to that of object B?

  Objects A and B both start from rest. They both accelerate at the 1b*r9 5twghwz same rate. However, object A accelerates for twice thewwgz 1b9rh*5t time as object B. What is the distance traveled by object A compared to that of object B?

  When an object is released from r3 ayt1u.pb1n9q5fq emest and falls in the absence of friction, which of the following is tru9na1 1umy 5febqt.3p qe concerning its motion?

  When an object is released from rest anba r7 x 6-u66htdmf.al23okmueb :u azog/*k 1d falls in the absence of friction, whichm6az6uu2k63lo1 :er bu /a k7h-fb*mogdtxa. of the following is true concerning its motion?

  Suppose a ball is thrown sth /4qg/fnu/we3kmz*7 zy-a wtraight up. Make a statement about the velocity and the acceleration when the bal7zg-z 4//fqt mwk/aeyn*h u3wl reaches the highest point.

  Suppose a ball is thrown straight up. What is its acceleration just befor/h55,lg wbkewe it reaches it lw/gb kehw55,s highest point?

  Suppose a ball is thrown straight up, reaches a maximum height, then falls to x1h9 ctdsh5ch*)y (qiits initial height. Make a statement about the direct hyxqh(9dc5th*)i1 csion of the velocity and acceleration as the ball is going up.

  A ball is thrown straight up, reaches a maximum height, th6y/s30 n o9b 0dzfxcet8va;waen falls to its initial height. Make a statement about the direction of the velocity and accelerati; vectsxd89fboz n/63 0aaw0y on as the ball is coming down.

  Suppose a ball is thrown downward in the absence of air resistance. Make a state6r ryo: pmo079q4;fm sdqor;x ment concerning its ac0o: 4;d7ps ro;r9mqf oq xry6mceleration.

  Suppose a skydiver jumps from a high-flying plane. What is her 0gldh6f:wgu-e (p ) ft1zdw2 oacceleration when shw 0w- h1(g)6 f g2plotdfu:zdee she reaches terminal velocity?

  A ball is thrown vertically upward with a spedc+a fnngg7vc6 (o *c)ed v. An identical second ball is thrown upward with a speed 2v (twice as fast). What is the ratio of the maximum height of the second ball to 6c7n+a cv)gog n*d(fc that of the first ball? (How many times higher does the second ball go than the first ball?)

  Ball A is dropped from the top of a buildinmp1cj:echf3vp+j7 n1 g. One second later, ball B is dropped from the same building.e1 p:j+3 pnhv17m jccf As time progresses, the distance between them

  Ball A is dropped from the top of a bui s5n dp/-ekaj 0/rcpu;lding. One second later, ball B is dropped from the same building. As time progresses, th -;ed0/p5puc jrn/aske difference in their speeds

  Two objects are thrown from the top of a tall building. cvtzoz0hlo 64b:2 i3 z iuj3-oOne is thrown up, and the other is thrown down, both with the same initial6i3o :t0ozb2ovhcu z3i- l4z j speed. What are their speeds when they hit the street?

  A brick is dropped from the top of a building. A second brickj/p2- )olza ;*e /o giz3sitet is thrown straight down frgpe 32;)ziji/o ltt ze -as/o*om the same building. They are released at the same time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with constant non-zero velocity in tkc7qz7f+6 lsc)ehh;r he +x axis. The position versus time graph of thi hr 6qlkszefhcc) +77;s object is

  An object is moving with co yrdt 5w;f,9omnstant non-zero acceleration in the +x axis. The position versufy d;5owt9rm ,s time graph of this object is

  An object is moving with constant non-zero velocity inq4q73 m5w 7wtptih m: ,dvw j8y0mr0jc the +x axis. The velocity versus time graph of this objeyhwjd8rt ,3m j5t 77cwpmvmq0qw0:4 ict is

  An object is moving with constant non-ze cgoj(-3cw.t5vz tn* xqa07e dro acceleration in the +x axis. The velo5z3tdeacn07txj.cwqg*o - ( vcity versus time graph of this object is

  The slope of a position versus time grapjg olpn(fb0 //h gives

  The slope of a veloci us5ffxitrh) e+ps yf5.ev*0+/7tnf dty versus time graph gives

  The area under a curve in an acceleration versusagj.)aa+f9d en bw9j/ time graph gives

  The area under a curve oz:l1 gkwd l l((90qqdin a velocity versus time graph gives

  If the position versus time graph of an object is a horiziloac5q- j (xzsj 928ay8 6rrzontal line, the object ziaz88 cj 9r2ql5 (o ajrxy-6sis

  If the position versus time graph of an object is a vertical line, thehfcm (3 t.m,k*gtsle 3(2jo)tji+jnm object isj3)h fcmem , ( .mjng*2ji(o+tk3ttls

  If the velocity versus time gqjx jv7cj:;g 7raph of an object is a horizontal line, the object jcx:7 ;j7jgqvis

  If the velocity versus time grapplrw3.-rksv3ggk+* m jp + )kvh of an object is a straight line making an angle of 30 degrees with the time axis, kkl *sg+ g-v p3)v.+r3rkmpwjthe object is

  An object moves 15.0 m north f, rnrwb9;qg 6and then 11.0 m south. Find both the distance traveled and the,f w b;9qgnrr6 magnitude of the displacement vector.

  A boat can move at 30 km/h in still water. How uf +pdby9 yxe5f p28e+long will it take to move 12 km upstready yff9+exub5p+e2p 8m in a river flowing 6.0 km/h?

  55 mi/h is how many m/s? (1 mi = 1gu g ay (b7,ebirypo3wa*;z49 609 m)

  What must be your average speed in order to travel 350 km in 5.15 hcyj eefq.v/ ).8;r:7kn4j( b pd ivqmg?

  A runner ran the marathr/jhzg uk ; 3,7wklp2ron (approximately 42.0 km) in 2 hours and 57 min. What i/gpr 3u wlhjk 2,zk7;rs the average speed of the runner in m/s?

  A car travels 90 km/h. How long does it tak)wq xh3t/zftk2k.w d 0e for it to travel 400 km?

  A ly (light year) is the distance that light travels in one year. The s f44fgu-. dz q.nktol8peed of lighto 4uq.zfkl -g8d.4f nt is $3.00 \times 10^8 \; m/s$. How many miles are there in a light year? (1 mi = 1609 m, 1 yr = 365 d.)

  If you are driving 7j; i5la6 (hnwzh)+tu ,q)bhhp 2 km/h along a straight road and you look to the side for 4.0 s, how far do yohuij w;hqtpl(5hn 6h +b )),zau travel during this inattentive period?

  If you run a complete loop arou/.nda9 8hdj* 9oxhub*/n nyxcnd an outdoor track (400 m), in 100 s, your average velocit*/h*a cnnh bxuo.dn89j9y/ dxy is

  A polar bear starts aobfenj) 9g2u o+h5xy6t the North Pole. It travels 1.0 km south, then 1.0 km east, then 1.0 km north, then 1.0 km west to return to its starting point. This trip takes jybexo6on9h 2+)uf5g45 min. What was the bear's average speed?

  A polar bear starts at the North Pol: im57om p)ej3weuw y(e. It travels 1.0 km south, then 1.0 km east, then 1.0 km north, iwy(pje)5o mwe 37mu: then 1.0 km west to return to its starting point. This trip takes 45 min. What was the bear's average velocity?

  You are driving home on a weekend from school at 55 me8 xvlrv1hbby(;3- s2s1iabwi/h for 110 miles. It then starts to snow and you slow to 35 mi/h. You ver(8yi1wb sal; hs3-v1 xb 2barrive home after driving 4 hours and 15 minutes. How far is your hometown from school?

  A motorist travels 16xk di409jgy.wi6q3fb.t ntk - 0 km at 80 km/h and 160 km at 100 km/h. What is the averagegnfwk kb.yd9t3x-q 4it 6.j 0i speed of the motorist for this trip?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 (ypka1o) g+nm,esd9s km/h. What is her average speed for the tm+eap1go s(k) 9ys,ndrip?

  An airplane travels apo zv4(9x b: kzkge-w 3g(*oggt 300 mi/h south for 2.00 h and then at 250 mi/h north for 750 miles. What is the average spego-(k 3zzg:pek9 gog4* x( wbved for the trip?

  In a 400-m relay race the anchorman (the person who runs the last 100 m) fr /rf0n1te; wmor team A can run 100 m in 9.8 s. His rival, the anchorman for team B, can cover 100 m in 10.1 s. What is the largest lead the team B runner can have when the team A runner starts the final leg of the race, in orderem1w r0f;/tn r that the team A runner not lose the race?

  A car decelerates uniformly and comes to a stop after 8 s. The car'aw5 5ccpf/4q4 c.awaas average velocity during deceleration was 55 km/h. What was the car's decelerationac.awc45a wca4 /pf5 q while slowing down?

  An airplane increases its speed from 100 m/s to 160 m/s, at th;pclb. dl v0qdx;bf:bl(6) qge average rate of b) fc (bld6qpdvx.g: l;b0ql ;$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerates at th:(hq8q0s.t vk1 ruyhxpi:)d he rate of $2.0 \; m/s^2$. How much time is required for the car to reach a speed of 90 km/h?

  A cart starts from rest and wlbgydb o6iqox6x**; bn;: +kaccelerates at $4.0 \; m/s^2$ for 5.0 s, then maintain that velocity for 10 s, and then decelerates at the rate of $2.0 \; m/s^2$ for 4.0 s. What is the final speed of the car?

  A car travels at 15 m/s for 10 s.+d81o fw 4:excivxqr oafi 6:( It then speeds up with a constant acceleration a:r6wdqef418o( +i xv cfoix: of $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity ofnf05zbu1haipt7y jq 3)by o45 7.4 m/s experiences a constant acceleration of yy1oba4bqtuz 5p)nj7 0hf5i3 $2.9 \; m/s^2$. What is the cart's displacement during the first 4.7 s of its motion?

  A bullet moving horizontally to the right (+x dir iv p d6k.nxst)89 fg8zd;9azwection) with a speed of 542 m/s strikes a sandbag and penetraz ;68a. )fsp9i9znk8 dtxvgwd tes a distance of 20.13 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is lojr(nj z3n05k 9xyjxkgg5mn3 ys2x. +h0o px(aunched from a catapult on an aircraft carrier. It reaches a speed of 42 m/s at the end of the catapult, and th5+xnjj yxg x0g3j p35. skm h(oy29rx z(nonk0is requires 2.0 s. Assuming the acceleration is constant, what is the length of the catapult?

  A car starting from rest moves wi; o x6eb9 ea)rftxd-j+th constant acceleration of $2.0 \; m/s^2$ for 10 s, then travels with constant speed for another 10 s, and then finally slows to a stop with constant acceleration of
-$2.0 \; m/s^2$. How far does it travel?

  A car goes from 40 m/s to 80 m/s in a distance of 20w9afpf+-t pd ;0 m. What is its average acceleration? ;t9fwap-d +fp

  An object starts from rest and undergoes uniform accelerati l9 mylw6 no+oydttt9 *+cc2t2on. During the first secot lm9*yt+nwdc 6 l+ 2ctt2o9oynd it travels 9.6 m. How far will it travel during the third second?

  An object is moving in a straight line with constant acceleration. Initia* cfh)bqf2r1blly it r b*bc2)1qhff is traveling at 16 m/s. Three seconds later it is traveling at 10 m/s. How far does it move during this time?

  A car starts from rest and acceleratesdy(6,+ 6whmqj wp i8tc uniformly at $3.0 \; m/s^2$. A second car starts from rest 6.0 s later at the same point and accelerates uniformly at $5.0 \; m/s^2$. How long does it take the second car to overtake the first car?

  A car with good tires on a dry road can decelerate k)0 0mtwmv+noh d;3 u a)yz(bs4dtgx-at about $5.0 \; m/s^2$ when braking. Suppose a car is initially traveling at 55 mi/h.
(a.) How much time does it take the car to stop?    $s$ (only input numerical values)
(b.) What is the stopping distance?    $m$ ((only input numerical values)

  At the instant a traffic livvq(;xpxx-m99a 3lfg2 h-we yght turns green, a car that has been waiting at the intersection sl(ywe2x9h 9a-;f x 3p v-vqxmgtarts ahead with a constant acceleration of $2.00 \; m/s^2$. At that moment a truck traveling with a constant velocity of 15.0 m/s overtakes and passes the car.
(a.) Calculate the time necessary for the car to reach the truck.    $s$ (only fill in numerical values)
(b.) Calculate the distance beyond the traffic light that the car will pass the truck.    $m$ (only fill in numerical values)
(c.) Determine the speed of the car when it passes the truck.    $m/s$ (only fill in numerical values)

  An object is thrown upward with a speed of 12 m/s on the surface of planet l zd6j dz;cy.(cvao8 kn-u*y2X where the acceleration due t.yjdlyco2(cua86kvn - z; d*z o gravity is $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown upward with a speed of 12 m/s on the surface of planet Xu9zpaxinu 8mh8 ;fnd,od98- v where the accelerau ipndx88f 9ndu8 voazm;,9h-tion due to gravity is $1.5 \; m/s^2$. How long does it take for the object to reach the maximum height?

  An object is thrown upward with a speed of 15 m/s on the s6j6bya1x g(w9)gf x a:bzjz6curface of planet X where the acceleration db)1jg6xa6za(w x9 j6bfcy:zgue to gravity is $2.5 \; m/s^2$. How long does it take for the object to return to where it is thrown?

  An object is thrown upward with a speed of 14 m/s on the surface of plan*c/6yhfy/m,c nyq bg 1et X where thynh//cm yc gy,6fb*1qe acceleration due to gravity is $3.5 \; m/s^2$. What is the speed of the object after 8.0 s?

  Human reaction time is usually greater v3thj, .4fw2nd 1 zg)xjrpd9b than 0.10 s. If your friend holds a ruler between your fingers and releases it witr 24 xtwgpjnzfh9v.)1, ddj3bhout warning, how far can you expect the ruler to fall before you catch it?

  A ball is thrown upward at a velocitrvw4( boapr; a /)sz:j :;v.iefv;tam y of 19.6 m/s. What is its velocity after 3. tvarj4 v a:efw :zb)ims.o/;pvar; ;(00 s?

  A bullet shot straight up returns to its starting point in 16 s. What is t z 6mno0cfkg0,p,h(kyhe initial speed of the bul,h06gy o pkf k(cm,zn0let?

  A ball is thrown straight up with a speed of 36.0 m/s. How long doksj; v m3i;2ihes it take to return to its starting p2 ij3sm;;ivh koint?

  A ball is thrown downward from the top of a building9m0sca-un0t.-s j-pg y :ieyf+rqbb 0 with an initial speed of 28 m/s. It strikes the ground after 1.1 s+0ag b r- f9c-ep. jy:sum0n-btsy0qi. How high is the building?

  A ball is thrown straight up with a speed oi l4s x zu sueg7)* rpe.czj;t25qqd4:f 30 m/s. (only fill in numerical value in the blanks)eqz zx.dps4;5*c)g2lq t4u:ueis r7j
(a.) How long does it take the ball to reach the maximum height?    $s$
(b.) What is the maximum height reached by the ball?    $m$
(c.) What is its speed after 4.2 s?    $m/s$

  A foul ball is hit straight up into thefl5 j:p3ugvv.ogs vpr6f4r(8d jfj5* air with a speed of 40.6 m/s. (use $g=10 \; m/s^2$, only fill in numerical value in the blank)
(a.) Calculate the time required for the ball to rise to its maximum height.  (数值)  $s$
(b.) Calculate the time for the ball to fall back to the height at which it was hit.  (数值)  $s$
(c.) Calculate the maximum height reached by the ball.  (数值)  $m$
(d.) Calculate the ball's speed 3 seconds later.  (数值)  $m/s$
(e.) Determine the time at which the ball pass a point 9 m above the point of contact between the bat and ball for the first time.  (数值)  $s$
(f.) Determine the time at which the ball pass a point 9.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is t5z mqytu m7o-8t-ebs5he velocity at t = 1.0 s?

  In Fig. below, what is theadqg b3i01t oj166(pp fz; vlx velocity at t = 2.5 s?

  In Fig. below, what is the velocity at t = m9o2+rrlv5n b 4.0 s?

  In Fig. below, what is the velocity atw8m:g, fj/t ec t = 5.5 s?

  In Fig. below, what is th61lya4z9pfhbvl c3xtnw/;qx o 1l2(xe average velocity from 0 to 4.0 s?

  In Fig. below, what is the average velocity from ;fcc,f3vmbd l 8dvo4; 0 to 6.0 s?

  In Fig. below, what is the acceleration at 1.0 v(y9+1f um(7d vkatsjk;)fsc s?

  In Fig. below, what is z;/mqvl*+jt ,s l pfz/the acceleration at 3.0 s?

  In Fig. below, what is the average acceleration from 0 to 53 h5nv tgmh on4+t pl.ww4yq- 8;nks.o.0 s?

  In Fig. below, what is the fjc*2z;qlq xvp9.izp++e7vp g,f6oy average acceleration from 0 to 8.0 s?

  In Fig. below, what is the do(jn4spwny h:i33u/ u isplacement from 0 to 8.0 s?

Does a car speedometer measure speed, velocity? {speev2( ai:w ms :7xmadsodf;;(c h te2qb.d|velocity}

  An object can have a varying speed if its veu m+m6u) iognss ds-;6locity is constant.

  The velocity of an obj; e l1vjru ;6ogoo7(adect can be negative when its acceleration is positive.

  If one object has a greater speed than a second object, the fir ikb*1l r fhw(p2.mz:kst must have a greater accelera lp2i.mkk zwrb:*f1( htion.

  Two cars emerge side by side from a bg vph438 1;6jgygiybtunnel. Car A is traveling with a speed of $60 \; km/h$ and has an acceleration of $40 \; km/h/min$ Car B has a speed of $40 \; km/h$ and has an acceleration of $60 \; km/h/min$ . Can A will pass car B at the instant they come out of the tunnel.

  An object can be incredrclvwne0 ) +,8i zia3asing in speed as its acceleration decreases.

  A baseball player hits a foul ball straight up into the 5kyyh ij 0;:1wq jabc1air. It leaves the bat with a speed o jyjq0hc:; y15kiwb1af $120 \; km/h$. In the absence of air resistance, how fast will the ball be traveling when the catcher catches it?    $km/h$ (please only fill in numerical value in the blank)

  As a freely falling object speeds up, what is happening to its accelerat*8/2ih ;b18 jcgt7nm kk urnkl(dsca.ion, how doeumb;i8gd8nrk*c lk 1(k c2 /sjn7ha. ts it change if air friction is ignored?

  As a freely falling object speeds up, what is happeninhxta6 wtw g0bhi1jf6 n.4 j)oz0 w;1wag to its acceleration, how does it chant16a0zwf4nh1w bj .x0aw;gw6o tjih )ge if air friction CAN NOT be ignored?

  An object that is thrown vertical(mc4wpxl.7nib)c +*lw vli3qly upward will return to its original position with the same speed as it had initially if air resispiw(.v4 *nlwmcl b 3lxcq)7 +itance is negligible. If air resistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzero acceleration at the same tjx. nymdeb/n/av 0l*0ime.

  An object can have nonzero velocity and zero accelerat74yahys6vu )/ yiopv. t+yf( tion at the same time.

  An elevator moving from the second floor to the fifth floor makip+6 d szb 9y9/bj)h8pjpic/hh ng no stops along the way has zero acceleration pi6 8dbcp/sy z+/hph b9jh9j)all the time.

  A rolling ball moves fr6gvyxq8w ,t0iom $x_1=1.7 \mathrm{~cm}$ to $x_2=-5.4 \mathrm{~cm}$ during the time from $t_1=2.4 \mathrm{~s}$ to $t_2=5.7 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-3.0 \mathrm{~s}$ is at $x_1=2.6 \mathrm{~cm}$ and at $t_2=3.5 \mathrm{~s}$ is at $x_2=7.8 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps around ag;3fh f(8 aacm quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 7.9 min. Calculate (a) the average speed  (数值)  $m/s$ and (b) the average velocity    $m/s$

  A horse canters away from its trainer in a straight line, moving 104o+/iiu /dcck 7 m away in 10.3 s. It then turc 4 //uokid+icns abruptly and gallops halfway back in 4.7 s. Calculate (a) its average speed  (数值)  $m/s$ and (b) its average velocity  (数值)  $m/s$ for the entire trip, using “away from the trainer” as the positive direction.

  A car accelerates fr/2y5c*p zh9ll 1ve l,o0cjw twom $12 \; m/s$ to $24 \; m/s$ in 5.3 s. What was its acceleration?  (数值)  $m/s^2$ How far did it travel in this time?  (数值)  $m$ Assume constant acceleration.

  A car slows down from vo4n* n8:aaxe $20 \; m/s$ to rest in a distance of 83 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a speen5- blcy0pmf 04 )an cg0gev1ev)btt2 d of $29 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.3 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of thdvff8+8e qemh* ym.6o e blocks to essentially top speed abou68 ymqmod8efe* v f+.ht $11.5 \; m/s$ in the first 11.2 m of the race. What is the average acceleration of this sprinter?  (数值)  $m/s^2$ and how long does it take her to reach that speed?  (数值)  $s$

  A car slows down uniformly.yqzt4vj.zf8u 42 wdodakv1 //)ixl a from a speed of $21 \; m/s$ to rest in 5.03 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves skid marks 92 m long on the highway. A23 eq5 mx:h+r.uoucl ym rrk;j5vpe-( ssuming a decelerato:r.(rjk rm -3 u255uqxveye clp+;mhion of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truc- ht s2 a2yk9igd4ak7qk going $25 \; m/s$ on the highway. The car’s driver looks for an opportunity to pass, guessing that his car can accelerate at $1.0 \; m/s^2$. He gauges that he has to cover the 20-m length of the truck, plus 10 m clear room at the rear of the truck and 10 m more at the front of it. In the oncoming lane, he sees a car approaching, probably also traveling at $25 \; m/s$. What is the closest distance of the approaching car that he can still sately make the attempt to pass the truck? (without hitting the approaching car).    $m$

  A runner hopes to complete th 0lxl,rb8 gxyyb5d- *zq h5m-/wc -rcse 10,000-m run in less than 30.0 min. After exactly 27.0 min, there are still 1100 m to go. The ru8c5rbg0*,b -lc yy - /- lh5xmzdrqwsxnner must then accelerate at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$