Suppose that an object trave cpesy+ 9403d4 z29jyyt eyxwgls from one point in space to another. Make a comparison between the displacement and the distan 4zcy+wtg y2p0y9y4d ese3j9x ce traveled.

  When is the average velocity of akoqf r mrsx+v66kttum69) m:my4q0,gn object equal to the instantaneous velocity?

  A new car manufacturer advertises that their car can go "from zern)- mu8k,xcss o to sixty in 8 s8x -num)s cks,". This is a description of

  An object moving in the +x axis experiences an acceleratios kjjh (p+7s)g:oe tu.n of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East4 wr-fgh l4hen,35hm4r gl1et (+x direction) begins to slow down as it approaches a traffi 3n15r44lmehtr w lheh 4,gg-fc light. Make a statement concerning its acceleration.

  Suppose that a car traveling to the West (-x direction) begins to slow downxs:d auo utr ,e5lg f6814hfi) as it approaches a traffi4lr5ffd1 x8)e uuhat6i ,gs:o c light. Make a statement concerning its acceleration.

  Suppose that an object is moving wit zgmf9az*:h/n, r9hc eh a constant velocity. Make a statement concerning its accelerati/ :afm9c 9rh ng*ze,hzon.

  If the velocity of an ob5atd. o v2nn1 jtr/1pclm4: mlject is zero, does it mean that the acceleration is zero? Support4 t. c5t2vl loja1rm:n1dmnp/ your answer with an example.

  Can an object's velocity change direction when its a+m(.4h qe6lej t awlu8cceleration is constant? Support your answer with an el+.l86 qet 4ewamjh (uxample.

  Suppose that an object is moving yw; 1/e mcqejdqe2zz/f4ndb:e81 ud7 with constant acceleration. Make a statement concerning its motion wit ze8fw:em7ze1e1jdb dnqu q 4cyd/2;/h respect to time.

  Can an object have increasing speed while its acceleration is dbs6 ;lrua8tvu;kc:s 9b71 bmf ecreasing? Support your answer t b;s: avbfsk ubl97mr816c ;uwith an example.

  Suppose a can, after an initial kick, moves up along 9sud-n-kz++bok 5 snr a smooth hill of ice. Make a statement concerning its accelerationz+b-o -skn+rsduk n5 9.

  Under what condition is average velocity equal to the average oz cp8utw 68x. ev2h wz47pbg1rf the object's initial a8x2wghw7 btpu81rev4p z . cz6nd final velocity?

  Objects A and B both start at rest/g0gnzqqei 1x(zr e 3h6;o,sq. They both accelerate at the same rate. However, object A accelerates for twice the time as object B. What is theg /6(13g ien;zr0z xqoshqe, q final speed of object A compared to that of object B?

  Objects A and B both start from rest. They both accelerat 8(ji) ht32txtd+ 6lbo-f *z,cqzojoc e at the same rate. Howev)djcftt,2-x+t*qooo6 hzl zicj8 b3 ( er, object A accelerates for twice the time as object B. What is the distance traveled by object A compared to that of object B?

  When an object is released from rest and falls in the absenv0 rfq(oq: 5y f3a* wr0ixm8wyce of friction, which of the following is true concernin w(qay rw*vimf rfxy3oq085: 0g its motion?

  When an object is released from rest and falls in the abpg cu. s+wasw77-ww /cw;ij(bsence of friction, which of the following is true concerning its m+wwaw(. p cssjuwb cwi 7-7/;gotion?

  Suppose a ball is thrown straight up. iu xbm46ok 4;d Make a statement about the velocity and the acceleration when the ball reaches the high46 kmx;u4odib est point.

  Suppose a ball is thr)a5 gijo (n8(eysu5m nown straight up. What is its acceleration just before it reaches is)5 gj(noe iany 8m(5uts highest point?

  Suppose a ball is thrown straight up, reaches a maximum height, then fai t.o*sn hho09lls to its initial height. Make a statement about oh oths.i*9n0the direction of the velocity and acceleration as the ball is going up.

  A ball is thrown straight up, reaches a maximum h :y( c0o0jtzj/uzw tm-eight, then falls to its initial height. Make a sta :coz t0jmyt 0(wzj-/utement about the direction of the velocity and acceleration as the ball is coming down.

  Suppose a ball is thrown downward in the absence of air resistance. Make a stattu(uht 16 *sdeement concerningds1tu*he ( 6ut its acceleration.

  Suppose a skydiver jumps from a high-flying plane. What is her aywfzu s a0vx yg +z6;qwo4/xu;y;*xl:cceleration when she she reaches terminal velocityy s y xza4vuwgfzqx6lwxu; :/+y;o*;0?

  A ball is thrown vertically upward with a speed v. Aacl .b38eklf(n identical second ball is thrown upward with a speed 2v (twice as fast). What is the ratio of the maximum height ofll3a(kcbf 8.e the second ball to 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 building. One second later, ball B 0hf7rjxb lh42 is dropped from 4fhjr7x b lh02the same building. As time progresses, the distance between them

  Ball A is dropped from the toptvc7 y/ij0 ckemf,wj 1jz (r)1 of a building. One second later, ball B is dropped from the same building. As time progresses, the dif /v m1)jrw1jeyki(f tj,0z7ccference in their speeds

  Two objects are thrown from the top of a tall building. n5 ; 3gs1 diwb,y;dj ,ibci)wzOne is thrown up, and the 3i ,)gz nj5yi;c bw1d;wid sb,other is thrown down, both with the same initial speed. What are their speeds when they hit the street?

  A brick is dropped from d 592moin 0 4h9dlfbtcy72cw tthe top of a building. A second brick is thrown straighthtdni702my9 ccd5tbl9 2owf 4 down from 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 consz hm.2xgsk;hz 5w lfdr ;06sfh :z;:ojtant non-zero velocity in the +x axis. The position versus time grap6zo .2w;::5;g 0rhxmdsz ;hkz hsfljfh of this object is

  An object is moving with constant non-zero acceueu 5u-3z: rcs.dzj rx28nd*q qea .y)leration in the +x axis. The position versus time graph of this object id5nr *uz8use2.:c e )j q3a.rqxyuzd- s

  An object is moving with constant non-zero veloc6+ u;qdgtnq5y7 +q m:miyela(ity in the +x axis. The velocity versus time graph of this obj y:iueqm7n6 agqlmy(+q5t + ;dect is

  An object is moving with constant non-ze3pd-9s swumqmk ,3vvn-hx0 ip6 u7 u.aro acceleration in the +x axis. The velocity versus iaqku mu.37w v-,s6uh x vm9sp-n3d0p time graph of this object is

  The slope of a position0ql9 z(5s8tjzj.ojb8+pxi(a;d azc c versus time graph gives

  The slope of a velocity versus time gra (s,abidi0 a)hph gives

  The area under a curve in an acceleration versus time gra; 8+kx -a)pyax*rgv 9b1kn ecmcb gc3:ph gives

  The area under a curve in a v3)nw mcwqw1 4relocity versus time graph gives

  If the position versus time graph of an object is a horizontxmkg* 0myh(i * wocec:-ti*9nv)pq 2bal line, the object isi-vxk9 t0 *me( cbq2wy n *:om)pch*gi

  If the position versus time-rlk/ y2jihfi,6:ktk graph of an object is a vertical line, the object islj kr-k,k2it6:/hif y

  If the velocity versus l-obr89: x/ku4v lw entime graph of an object is a horizontal line, the object is wxk89r o-v4ln:/bue l

  If the velocity versus time graph of an obje:tfs 3 h)yobtb +7 ;:lu2tqztxct is a straight line making an angle of 30 degrees witho )qbzy:ubx2ttf:s t7+;3tl h the time axis, the object is

  An object moves 15.0 m north and then 11.0 m south. Find both the distance uw 9ou5/eyfq )iekzahdmp40 :av57a / traveled and the magni4 u5kw5aadmv ehip/q )9o/zau7fy0: etude of the displacement vector.

  A boat can move at 30 km/h in still water. How long will it take to move 2c7mj y4kgp.r12 km upstream in a river flowing k.2mg7p rcjy 46.0 km/h?

  55 mi/h is how many m/cukz1gak+ ,:jjc6v5tq 4+ atls? (1 mi = 1609 m)

  What must be your average speed inx(ai3.ct aevs +pfq-r)x 9ql4 order to travel 350 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 6bf59p/f i lcso9qmo24d,iinc gl)8bkm) in 2 hours and 57 min. What is the averagc4 nidoplbs9)2 fgq65ib/ 89,ifoclme speed of the runner in m/s?

  A car travels 90 km/h. How long does it take forxgnk mywsks 7.0m)f+6 it to travel 400 km?

  A ly (light year) is the distance that light tr1 zz6( 3vfzw-ig0p zpjavels in one year. The speed of ligp-zz(vz0 1 z ji3wg6fpht 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 72 km/h along a straight road and you look4d72q(sx vba8zq id- ;red9 zr to the side for 4.0 s, how f vaq94xre z;2-b(dsqd 7r8zidar do you travel during this inattentive period?

  If you run a complete loop around an outdoor track (400 m), in 100 s, yof9nlm mtx,x3qge7 57/:gnd v nur averagem 7 mnexd/g37 xntvn:f9lqg5, velocity is

  A polar bear starts at thets10ycor /g7f North Pole. It travels 1.0 km south, then 1.0 km east, then 1.0 km north, th csfr7/tyg1 o0en 1.0 km west to return to its starting point. This trip takes 45 min. What was the bear's average speed?

  A polar bear starts at the North Pole6ptq1kz rmo0q0 enq /s b;p i4-a,c7ar. 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. Th c q4rbrosapi6 kq -,pmn1qe7 ;0t0z/ais trip takes 45 min. What was the bear's average velocity?

  You are driving home on a weekend from school at 55 mi/h for 1y ;qgvx +92y0esw. llh10 miles. It then starts to snow and you slow to 35 mi/h. You arrive home af; gv2.+qyy e 9xls0whlter driving 4 hours and 15 minutes. How far is your hometown from school?

  A motorist travels 160 km at 80 km/h an4c ksv k37s0yzd 160 km at 100 km/h. What is the average speed of the motorist for this tripsv7k 03s4c kyz?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h. What is her a-k1jo8jh-i; hxw; xnhvera 8 ;hxjhkx1j;nwh-o-i ge speed for the trip?

  An airplane travels at 300 mi/h south for 2.00 h and then at qhh w8uz3c6.f1 eo2pc c,u9yi 250 mi/h north for 750 miles. What is the average speed for the trquefhz y96c, oci1cw32h8.pu ip?

  In a 400-m relay race the anchorman (the persou;m(bol 4 x* gz+hfud+n who runs the last 100 m) for 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 teaum+f; zo*b (+xhg4lud m A runner starts the final leg of the race, in order that the team A runner not lose the race?

  A car decelerates uniformly anc pxq8cl) 8 kllgwu2 a+n7;xd4d comes to a stop after 12 s. The car's average velocity during deceleration was 58 km/h. What was the caw4klc l+ )x8 2lcqdu8g;7 pxanr's deceleration while slowing down?

  An airplane increases its speed from 100 m/s to 160 m/su z7s)(k*ws-vgjqk)) pp fp(iaj0 d5 i, at the average rate of apj *70 fd )pgpw) q(ik vikusz)-js(5$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerates a. jmvw8ei3wc *t the 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 accelerates atv;z3/ l6 qolcw $4.0 \; m/s^2$ 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. It then speeds up with a constant acce qf9kn2zww 5j1leration o59fk12 zwqwjnf $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initia *9os;wdxv71qt w;fj: fzvfgky* p/7 zl velocity of 5.8 m/s experiences a constant acceleration off qgpotsd7wfzwzy /vk:j9;x1* f v7;* $3.4 \; m/s^2$. What is the cart's displacement during the first 8.2 s of its motion?

  A bullet moving horizontally to the right (+x direction) with a spegag cjy 78.7kued of 328 m/s strikes a sandbag and penetrates a distance of 86.01 cm. What is the average accelerationc8ygg77uj ka., in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on an aircraft carrier. I)zel3i2hbg.*y 7w,kcbmja e f-7r+ws t reaches a speed of 42 m/s at tham y)glb-3.s k7h2czwwre ji7b f+,*ee end of the catapult, and this requires 2.0 s. Assuming the acceleration is constant, what is the length of the catapult?

  A car starting from rest moves with constant accedt ;i f)v z31yj)qu,7f6o akgeleration 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 200 m. What io0v- icuor2h6. jez,vs its average acceleratio6cu j.zov ,i2er v0h-on?

  An object starts from rest and undergoes uniform accelerati +e1 v4vzullv/q:nj5pon. During the first second it travels 4.3 m. How fa /pq5e 1:vllzj4v+vnur will it travel during the third second?

  An object is moving in a straightjfdeb:b3be-sb4h2;j-mga k s b)f-/ z line with constant acceleration. Initially it is travelihegs/j-mfbb4sb: 2z k3b- d j)b ea;-fng 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 acc j, cc8yj .1xh*mpoqz8elerates 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 at abo y+vueo +hqtr7ix)7-y ut $5.0 \; m/s^2$ 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 light turns green, a car that hk a:(ou/;sia0uwv0ql as been waiting at the intersection starts:q; voil 00kua(a/u ws 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 planemqg;yh *oba1h4(-pn at X wher(a;p-oq1n*4g mahh bye the acceleration due to 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 f*k 6o-u+bkg 3 kxhpo112 m/s on the surface of planet X where thhb- kkg 3xp1u6 fo+k*oe acceleration 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 wi0e 1 r3sa6v/c mdrr)iffg2r3cth a speed of 15 m/s on the surface of planet X where ivc2rec1 6/3fasfr0r g3m)rd the acceleration due 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 s gi:e8:ulqx:h4sp obfr0x ; uxe-c9:lpeed of 14 m/s on the surface of planet X where the accelerp: e;4 r euuxx0s-:cx qi:9gl:ohf bl8ation 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 than 0.10 s. If your friend) (qu ckha+)gyaeb5w0 holds a ruler between your fingeraq )ywb0gh +)e caku(5s and releases it without warning, how far can you expect the ruler to fall before you catch it?

  A ball is thrown upward at a velocity of 19.6 m/s. What )q(t gxxnyc;/ is its velocity after 3.00tyxqgn/x ;)c( s?

  A bullet shot straight up returns to its starm3 m( l6gspv6sb j/pm-u-m/b wting point in 12 s. What is the initial speed of the bulletup -63bmmswsl(6-m //vgmbj p ?

  A ball is thrown straight up withkf;og jk 2uwgb1 l(//qhq tj.1 a speed of 36.0 m/s. How long does it take to return t11 gq2jfot qukh . bkjlw(//g;o its starting point?

  A ball is thrown downward from the top of a building with an initial speed of 1at 9f gnyf7j:+7 m/s. It strikes the groff: ty7n9gja +und after 5.0 s. How high is the building?

  A ball is thrown strajrum s7 n4z5-oight up with a speed of 30 m/s. (only fill in numerical value in ts7n -zomu5 r4jhe blanks)
(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 w8 z w,gfmem(9 lbf3s+into the air with a speed of 40.9 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 7 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 7.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is the ve. h8*g bssln*(enc5 pdlocity at t = 1.0 s?

  In Fig. below, what is the velocity atfsjgzmdvx 27g+n4 2ukw7q;2 k t = 2.5 s?

  In Fig. below, what is thd+5 dkrh e*)zte velocity at t = 4.0 s?

  In Fig. below, what is the velocity at t = 5.5 5 zxili/(0tmkvt,+i ,i rzmr+ s?

  In Fig. below, what is w: 0) dbq jbz*emfl+2y /1yunqk*k0 nvthe average velocity from 0 to 4.0 s?

  In Fig. below, what is the average velocity from 0 to 6.0 s?sl c;cup7t.0h djt-8v1/ qpfczb w1:i

  In Fig. below, what is the azh .:g: +nyf, jr,cqvycceleration at 1.0 s?

  In Fig. below, what is the acceleration at 3.0 s?z6j -cp7v0zdq

  In Fig. below, what is the average acauhp wy 4 :2c)vbaodvluh9 /58celeration from 0 to 5.0 s?

  In Fig. below, what is the average accel: f3(,+k p,lcaruhs;kbcl t3qeration from 0 to 8.0 s?

  In Fig. below, what is the displacement from 0 to 8.0 s? 8:g2jxmxytj; bq,y9z

Does a car speedometer measure speedekh (b;r 8p,*ap wsv,kvb3a/e , velocity? {speed|velocity}

  An object can have a vary7kz9ebis,aft x w2u p8 v;+fq;ing speed if its velocity is constant.

  The velocity of an object can be negative when its accel-(2pw 0 n2kgabc hbbn7nzv3 g,eration is positive.

  If one object has a greater speed than a second object, the first m5l(.dg+w po- zy dbkdjbf7: -tust have a greater acceleo7- (gzjfk- wb5+d:db yp .dltration.

  Two cars emerge side by side from a tunnel. Car A is traveling wi gd u,g 6sn::m-eb4- m5tw14xhairh zoth 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 increasing in speed as its acceleration decreiy,c. p8h4bij ases.

  A baseball player hits a foul ball straight up into the air. It leaves thr :l:r: wlyv-we bat with a slw:w:: rvylr- peed of $120 \; km/h$. 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 acceleration,uk+rm7k/qo;l*8hij / ,5z(we wqkb zi how does it change if air fii eohk( / ,k5bk /uq*8;7r+wjqzlwmzriction is ignored?

  As a freely falling object speeds up, what is happening to its accelera63+tj sz+gsf ktion, how does it chanf6ktgs+z 3s +jge if air friction CAN NOT be ignored?

  An object that is thrown ver cd 6q * dc/ij(:uitx4my+3ob/kq3zcrtically upward will return to its original position with the same speed as it had initially if air resistance is negligible. If air resistance is appreciable, how wi(: rb i3 d+ tzikcc/uj4dcym6* x3/qqoll this result be altered?

  An object can have zero vel./:3gicwqkf9wqsgf sa, u7r. ocity and nonzero acceleration at the same time.

  An object can have nonzervcoj *6(xz9p 2 v z.a6pm;vnzeo velocity and zero acceleration at the same time.

  An elevator moving from the gf3 yi/v0je- f2* tjausecond floor to the fifth floor making no stops along the way has zero a e-yfju03fig 2ajt*/vcceleration all the time.

  A rolling ball moves frombd ttbgev(;hl6( v.u5* gmr m2 $x_1=2.3 \mathrm{~cm}$ to $x_2=-8.2 \mathrm{~cm}$ during the time from $t_1=2.1 \mathrm{~s}$ to $t_2=5.6 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-4.8 \mathrm{~s}$ is at $x_1=2.8 \mathrm{~cm}$ and at $t_2=3.3 \mathrm{~s}$ is at $x_2=7.7 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete lanxs4axc 59e; iv30xm *q7owmlps around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 12.4 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 straixyp*l9xye8fqdi t i+ 7z19(abght line, moving 87 m away in 10.3 s. It then turns abruptly and gallops halfway back in 4.qi8f(x a ze 97ylp+t xd*i19yb5 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 fro stf;hla,tnj;7 ki5h. xdj d4)m $11 \; m/s$ to $22 \; m/s$ in 4.0 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 +fou76sfx6/rb.nuq0c (dcgdvgbp ;3 $21 \; m/s$ to rest in a distance of 66 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a speed o7wpfx89dcf m.f $29 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.7 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of the blocks to essentially top speed aboo *hrfgjh -xwas7;6;mut 67 ;gfrh- ;h*sjxmaow$10.1 \; m/s$ in the first 13.0 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 uni2h1 2wsk y4n 8wvjhi9iformly from a speed of $18 \; m/s$ to rest in 5.05 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. A qx ieutt/8c/dg)5sh)ssuming a d8qu5e)x thgcs) //td ieceleration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck *11fhfcdmcrt1e w*z. +t yp-dgoing $25 \; m/s$ 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).    $m$