Suppose that an object travec,2ysr.x9/ zdtqs/fcls from one point in space to another. Make a comparison between the r/fxcsqct,s2d.zy /9 displacement and the distance traveled.

  When is the average velocity of gijz07c bxh2 5an object equal to the instantaneous velocity?

  A new car manufacturer aj bgi2/t ss(.kri/ pd 6rb)l;rdvertises that their car can go "from zero to sixty in 8 srj irl( sb;/b)st r/.id2g6pk ". This is a description of

  An object moving in the +x axis experiences an accelerati sujby-:f3(5bc 4 ydnton of $2.0 \; m/s^2$. This means the object is

  Suppose that a car travel7 * cbcxf1:drbing to the East (+x direction) begins to slow down as it approaches a traffic light. Make a stated:*cf cx1bbr7ment concerning its acceleration.

  Suppose that a car traveling to the West (-x d9-td*k r,fmn*imbk,o qd . 2wwirection) begins to slow down as it approaches a traffic light. Make a statement concerning its accelerationktm9.,brn*wwm*fiqd2 k do- ,.

  Suppose that an object is moving with a constant velocity. Make a statement coi34*c+fce kay ncerning its accelerae fka43c*yc+i tion.

  If the velocity of an object is zerop5y j(af m6of+, does it mean that the acceleration is zero? Support your answer with a+yf 56japfo m(n example.

  Can an object's velocity change direction when its acceleratou:y) ggewkj hgl*8732 jm8 j:xd p 6pz(pm5wsion is constant? Support your answer with an examp35)(zuggp d :8o 62swhxj:p g*jl7mpmjkw8eyle.

  Suppose that an object is moving with constant accelerationalkf/+2hlu0j6kvg g 4 56n(extwzq so, xx1/r. Make a statement concerning its motion with re+/r6f/2x (gw0nvs ,lzxkoleg4ju 156xhqk atspect to time.

  Can an object have increasing speed while kd-gf wof*rlgx(1z6f 9,f 0loits acceleration is decreasing? Support your anrl 1o0f wdf6gz(f k9gox*, l-fswer with an example.

  Suppose a can, after an initial ki+mag 7)m c63kw1z 95e gpnjkotck, moves up along a smooth hill of ice. Make a statement concerningpc9ega37+wn mz)1t5km 6 ko jg its acceleration.

  Under what condition is averzo pa9- c.-a6ovl6p rtd )a/hjage velocity equal to the average of the object's initial and fio/a 6r-6 h9ppvd z-a.ao clj)tnal velocity?

  Objects A and B both sta.z gm:bp6/3*7b sd drjp* kqifrt at rest. They both accelerate at the same rate. However, object A accelerates for twice the time as object B. What is the final speed of object A comrpb7*d6 mzdgpf s3b qi/ j:k*.pared to that of object B?

  Objects A and B both start from rest. They both accelerate at th4 m rowb7cyhk c*++hp)z :(x: 1cwlprde same rate. However, object A accelerates for twice the time as object B. What is the distance traveled by object A compared to that of objopcc+rkmcz:*ww71y )b hpr +4 :hxd(l ect B?

  When an object is released fromgtxe xb5p*b z84)e:wr rest and falls in the absence of friction, which of the following is true concerning its mot 4 wbb*xz)58grx:pe etion?

  When an object is released from rest and falls in the absence u +loyb,4ir6aof friction, which of the following is true concerning its mol, i6uo r+ayb4tion?

  Suppose a ball is thrown straight up. Make a state7 l9zid;ga /bm)od4r5juu;mb ment about the velocity and the acceleratirg5bbdm9 u4/m) ; jlai7 oz;udon when the ball reaches the highest point.

  Suppose a ball is thrown s + jua9 thavkk dw2*dzsg+o7)zs*7ml7 traight up. What is its acceleration just before it reaches its highe7gu v 7+m7stowz )aa9hk*2ksz+djl* dst point?

  Suppose a ball is thrown straight up, reaches a maximum height, then falls to z ,u0caj.6wcqits initial height. Make a statement about the direction of the velocity and accelerat .j,cuw0qz ac6ion as the ball is going up.

  A ball is thrown straight up, reach5p(+5rec qgcsed6 px3es a maximum height, then falls to its initial height. Make a statement about the directi +(c6qx55degcse prp3 on of the velocity and acceleration as the ball is coming down.

  Suppose a ball is thrown downward in the absence of air x;y;-(6wj ec e5lvn4cgiv( xgresistance. Make a statement concerninlx 6-(icnw;v;e4x5 ggejv(c yg its acceleration.

  Suppose a skydiver ju-3bcmoeye88 bmps from a high-flying plane. What is her acceleration when she she reaches terminal vel8co8y -bm3e beocity?

  A ball is thrown vertically upward with a -yfu uzs 4+8gmspeed v. An identical second ball is thrown upward with a speed 2v (twice as fast). What is the ratmy-guz usf84 +io of the maximum height of 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,ntmq9k ;;vya. ball B is dropped from the ;anyv;t m .qk9same building. As time progresses, the distance between them

  Ball A is dropped from the top of a building. One second 2fznpq g,g x89later, ball B is dropped from the saqp2fx gz9n,8g me building. As time progresses, the difference in their speeds

  Two objects are thrown from the top gta 2hu7ld0r, of a tall building. One is thrown up, and the other is thrown 0hd7 r, 2taulgdown, both with the same initial speed. What are their speeds when they hit the street?

  A brick is dropped from the top of a building. A ssoe k;ia3iy6/jqi qhjdff8-.2es +n 3econd brick is thrown straight down from the same building. They are released at the same time. Neglect air resistance. Compare the accelerationsfo f2kh jsdq/e- as.i63i+8q nejiy;3 of the two bricks.

  An object is moving with constant non-zero velb9v yf.l 5e2hzz-ecj 0x qec,*ocity in the +x axis. The position versus time graph of this object 9h-ez j*2q5vexzclcyb.,f e0is

  An object is moving wi.:2s eof qhg0bth constant non-zero acceleration in the +x axis. The position verbe2:s0fgh.qo sus time graph of this object is

  An object is moving with constant non-zero velocity in the +x axis. The velj:3grs /f;qvcs)tb9db;u 4kv ocity versusqbvu: ;sb)/d4fj; c3v tk rsg9 time graph of this object is

  An object is moving with constan5;h2+z; j bkpipadti-/ . bkfgt non-zero acceleration in the +x axis. The velocity versus time graphg;z25bpkt.iibaf p/ +jk d- h; of this object is

  The slope of a position versus timerv uikdon, oj7)a5(*t graph gives

  The slope of a velocity versus time v kqkn ua-d*9. aea66ograph gives

  The area under a curve in an acceleration versus timefz djl(s20-jacbrj 1- graph gives

  The area under a curve in a vel8*zg blw. jyo)4dgzsk * bz+g0ocity versus time graph gives

  If the position versus time graph of an object isu(b0abm5 9vwl wtkuxr yn,qm*-0 wb8, a horizontal line, the object is-,uluv*brk xw 0n 0q(, b9bw8twa5mm y

  If the position versus time graph of an object is a vertical l*+1/ iahi4r6vs y 3km 6twgaobine, the object ism ika6/ait4v61ryb 3w*oh+g s

  If the velocity versus time grap 8ai- kv**mdd6qq/tno h of an object is a horizontal line, the object is*a8 q 6/dt vd*mnoqk-i

  If the velocity versus time graph of anq l,r4lihby6k) ;jas / object is a straight line making an angle of 30 degrees with the time axilrjh4sa ;y/k6lb,)qis, the object is

  An object moves 15.0 m nor4e p(d2*+e es cqjns 5t2:rt mpjy7+azth and then 11.0 m south. Find both the distance traveled and the magnitude of the di7m( jenys4 p+rtsz:e2 +j*d5tqca pe 2splacement vector.

  A boat can move at 30 km/h in still water. How long w3x 94alt,vwnr ozmm1;ill it take to move 12 km upstream in a river flow ,3 4 omxrzv91am;wlnting 6.0 km/h?

  55 mi/h is how many m/s? (1 migsvie e5 ldf m4*-f-a5/3gyd f = 1609 m)

  What must be your average speed in order to travel 350ob v .7l6y+jvo km in 5.15 h?

  A runner ran the marathon (approximately 42.0 km) inp g8t jdmm4hw z hq*al8r2i/f,11z+iu 2 hours and 57 min. What is the average speed of the ruq8/hz tirz8 m*m2 jglia f41, uhd1wp+nner in m/s?

  A car travels 90 km/h. How long does it take for it to x/.w+ a vq3ez6 cm.lattravel 400 km?

  A ly (light year) is the distanqkj qoeaze* (cf7 -1*qce that light travels in one year. The speed of light is *ze* c71o-qekajq qf($3.00 \times 10^8 \; m/s$. 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 yo .vti *;lqh,bmpd7t7kj j)q3*(xo dzzu look to the side for 4.0 s, how far do you travel during this inattentopq( q *j3,dt7hmz bizk7 j*lx)d;v.tive period?

  If you run a complete lk - stp;9g7r3n1bnf+d 0d cvnqoop around an outdoor track (400 m), in 100 s, your average vel3t-bd 1n9 c 0gqfr;7s+kpvnn docity is

  A polar bear starts at the North Pole. It t+,tpjl 8jdpce/f:0 xgravels 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 4:/f,jxpe0+8dl p gt cj5 min. What was the bear's average speed?

  A polar bear starts at the North Pole. It travels 1.0 km sok+z8n6 t 5 v:ahk4abicuth, then 1.0 km east, then 1.0 km north, then 1.0 km west to return to its starting point. This trip takes 45 min. Wh+6i5b 4z tnak:akcv8 hat was the bear's average velocity?

  You are driving home on a weekend from school atp *yi w*)oexd :dihz4q, gdv.: 55 mi/h for 110 miles. It then starts to snow and you slow to 35 mi/h. You arrive home after driving 4 hours and 15 minutes. How far isve*g4px wqi .,yi:d:h dodz *) your hometown from school?

  A motorist travels 160 km at 80 km/h and 160 km at 100 km/h. W ;5* y9uey.lgpib;mdd hat is the average speed of d5y bu9e pymi.;;lgd* the motorist for this trip?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h. f:9 m .4pppv b*:vc.sptf 4bko What is her average spee4 mp .:bpb9op.4pvs *f c:fktvd for the trip?

  An airplane travels at 300 mr12f)wq:voai i/h south for 2.00 h and then at 250 mi/h north for 750 miles. What is the average srfow2i qv 1a):peed for the trip?

  In a 400-m relay race+el/;i4wv 5ib *hcwjv the anchorman (the person 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 runnh/ji;viww+*4vc el b5 er can have when the team A runner starts the final leg of the race, in order that the team A runner not lose the race?

  A car decelerates uniformly 85xc i;fh1t 3zjegue( and comes to a stop after 9 s. The car's average velo (j 1fxtzgu8i ;35ehcecity during deceleration was 63 km/h. What was the car's deceleration while slowing down?

  An airplane increases its speed from 100 m/s to 160 m/s2bz wc+tlvr,8 , at the average rate of b82zc,wtl rv+$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/1z1tb 5b4zzdo, q 2igmh accelerates at 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 d,7iiue k*qzj/5o+ kcma-w e *and accelerates 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 d6 o6v53hxp 8 wr*nytjt-gya7 s. It then speeds up with a constant acceleration 7x66 tw3p*8r n-ag5tjyd oyv hof $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 1 c. 8h+y;z* twzvehl58du jvu5.6 m/s experiences a constant acceleration of8le; zuy. v5thh1+8 zwucvdj* $2.8 \; m/s^2$. What is the cart's displacement during the first 9.0 s of its motion?

  A bullet moving horizontally to the right (+x directmh2* p+)lggq0yb f x8oion) with a speed of 203 m/s strikes a sandbag and penetrates a distance of 77.73 cm. What is the aoh2mqf*0 lp )gg8xb+ yverage acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is q0)wgrxyst ; 1launched from a catapult on an aircraft carrier. It reaches a speed of 42 m/s at the end of the catapult, and this requires 2.0 s. Assuming the acce;xw0s) q1yrtg leration is constant, what is the length of the catapult?

  A car starting from rest moves with con, udquv0qe/l.r+ :ycdj4x1scstant 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 d)vpfitg8yy) bkv- +;s istance of 200 m. What is its average accelerati ks +); gvbti)fvpyy8-on?

  An object starts from rest and undergoes uniform acceleration. During the 6vj,s/0 g,9)c2s b bfs omjcyuha8iz* first second f hb 2j96 )scvy,bic */ao8zj0s,g msuit travels 5.7 m. How far will it travel during the third second?

  An object is moving in a straight line with constant acceleration. ikxcv8k 9x*au z +5szazb)o4/Initially it is traveling at+ z/4 kkzx vx5aoci*uz9)8sba 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 accelerates uniformly at sqy.bt 0 r4/*k uoepv1$3.0 \; m/s^2$. 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 aboutgef/ze0 aerl- :wwuxq0r 9*:e $5.0 \; m/s^2$ 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 has been xxsck8p ).x-6zve :wvwaiting at the intersection starts ahx ev6k8v -.xzp) xc:swead 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)0blfyjm53r0neel0:mae9 8coj ze s - of planet X where the acceleration due to gravity issl)a9:elz ej cojm-0rme n0508y bf3e $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown upward with a speed of 12 m/s on theupbs ocn:ox9hu rt:401 *rq kw+bjb5 3 surface of planet X where the accelera4x ok cbohwr9q1:bnu u*:50+jbprt 3stion 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 mz*wedw arn+*76twd n5 /s on the surface of planet X where the wd57 +dr* * anwweztn6acceleration 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 speed of 14/ v. ydi.o3x6ps1 y8g4xaktyx m/s on the surface of planet X where the acceleration due to grixo8g3atskd /y1 .v y y.46pxxavity is $3.5 \; m/s^2$. What is the speed of the object after 8.0 s?

  Human reaction time is usually gr2-jqgj3xh ) koeater than 0.10 s. If your friend holds a ruler between your fingers and releases g -2o3qxk)hj jit 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 is itso*75vzm pa87hm 0ncjr velocity after 3.*mo7prmh085 vnajc 7 z00 s?

  A bullet shot straightjq wd jv)7 r+tq( +m8u0rie)zp up returns to its starting point in 15 s. What is the initial speed of the bul8d) +i zuj7et0mjqwv (qr)p r+let?

  A ball is thrown straight up with a speed of 36.0 m/s. How long does it take to/ hcn9zsj ;p4kyc*l)+np m5vw return to its startin )pjcncsv9/4wk+zy *5nhp;m lg point?

  A ball is thrown downward from the top of a building with an initial spe5k/q.dqaf vz)ju0u+qed of 17 m/s. It strikes the ground after 3.3 s. How high is the bu ujqkd5qf+q au0v /z.)ilding?

  A ball is thrown straight up with a speed of 30 m/s.q udvxkjk2ny8k :2 -g. (only fill in numerical value in the blaydx g-8jk: .qkk22un vnks)
(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 the air with a speed of 44.9 m/s+y 9 ko(zv1x1c5dnjw t. (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 6 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 6.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is the velocitymng kfe47y(sn 7jz d/7 at t = 1.0 s?

  In Fig. below, what is the velocity at t = apq 9-v+ ouj5c2.5 s?

  In Fig. below, what is the velocity at t = 4.0qko : .ikjk uk0iv8-n2 s?

  In Fig. below, what is the velocity at t = 5.5 s?c f,uznl -jy7u:9gy* c

  In Fig. below, what is the averagw l3 qvkb:awvqq9+x.8e velocity from 0 to 4.0 s?

  In Fig. below, what is the average velocity from 0 to 6.pq w5ymf9br5 rv/o mo vo t.dzj+a:2710 s?

  In Fig. below, what is the acceleration at 1.0 eqwgvdg ioso25*// p0 s?

  In Fig. below, what is the accelerationdk3le0s f xgf90b05ht at 3.0 s?

  In Fig. below, what is the averagefjrbl1q:1/,* kx nukc u 1s+ji acceleration from 0 to 5.0 s?

  In Fig. below, what is the average acceleration from 0 to wvypata*6z 2xk)1a4 t 8.0 s?

  In Fig. below, what is-kxu( 1 qyu(e3ov ,/uj ejwk.x the displacement from 0 to 8.0 s?

Does a car speedometesyij)t0 d(eb6r measure speed, velocity? {speed|velocity}

  An object can have a oxtslf/1fz,l 9t:+zhvarying speed if its velocity is constant.

  The velocity of an object can be negative when lxnjftf2ell:-8q9y5k hk3x f:l kc+(its acceleration is positive.

  If one object has a greater speed than a secon4 y2mnw0 u0ykty8iag 1d object, the first must have a greater acceler14 umyt2g0 naiwky80yation.

  Two cars emerge side by side from av4hho4 zb/v(obfk y22 tunnel. 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 increasing in speed as its acczpf766y b;pl keleration decreases.

  A baseball player hits a foul ball straiga1tyq ajta;7j k;* 1d2z ws2 qs,5cwmsht up into the air. It leaves the bat with a speedskt2;25mjdsc*7 tqa zw1, ;j w aq1ysa 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 isl ;8 nh-mojqvr:ewz 5))ry: ike*dyx9 happening to its acceleration, how d*e):n:h5j wkri lrdqy-)oz9e vy ; x8moes it change if air friction is ignored?

  As a freely falling object speeds up, what is happening to i 0tqfja)zj3)vr5q j v*dvi .d;ts acceleration, how does it change if air fricrf3q5;za*v i 0)t ).vj jdjdvqtion CAN NOT be ignored?

  An object that is thrown vertically upward will return to it5 es4rq9cdgvz:l:f: g;fd 6 trs original position with th rqgt:vc 5;grf4::ed9sd l6fze same speed as it had initially if air resistance 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 gokgm* nh33 8-oop*oatime.

  An object can have nonzero velocity and zero acceleration at the same time.evu q7d5lh-7 p

  An elevator moving from the second floorb*h eh)+e*/(yh d iu o,.dcgpo to the fifth floor making no stops along the way hashduoy g*).c *o(bdi/ee h, ph+ zero acceleration all the time.

  A rolling ball moves n8 n l0+(a zwr b-l9.dc p7pa7;autkdyfrom $x_1=2.5 \mathrm{~cm}$ to $x_2=-5.1 \mathrm{~cm}$ during the time from $t_1=1.5 \mathrm{~s}$ to $t_2=5.9 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-2.2 \mathrm{~s}$ is at $x_1=2.7 \mathrm{~cm}$ and at $t_2=4.3 \mathrm{~s}$ is at $x_2=8.4 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps around a quarter-,m mtcmiq* ql*9)0d0 kgzv h:nmile ($1 \; mile = 1609 \; m$) track in a total time of 9.5 min. Calculate (a) the average speed  (数值)  $m/s$ and (b) the average velocity    $m/s$

  A horse canters away f e3ph-0dw+ 2fw vc5diirom its trainer in a straight line, moving 98 m away in 13.2wpiw-h3c f d5e0vdi +8 s. It then turns abruptly and gallops halfway back in 4.5 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 frw+zpk7 yob/.wom $13 \; m/s$ to $23 \; m/s$ in 4.2 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 fromu eaubr:47wlf-,5cpp $18 \; m/s$ to rest in a distance of 78 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must re3)lbdtlwr c - vcq,.sz207ptm ach a speed of $27 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.1 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of the blocks to essentially top spw:wu d:5u8n;upywfyi x8y z9( eed abouf8(xpz89;:y nwiuywu:u w y5 dt $11.4 \; m/s$ in the first 10.3 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 uni2urhhb0 y/1xu , -cz0) ik +y(ebdpncaformly from a speed of $20 \; m/s$ to rest in 4.17 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a.fhp- 2aeqf*/ /t goif car leaves skid marks 92 m long on the highway. Assuming a deceleration ofg*o pffqi/ .fe h-at/2 $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck goil/1z(bfxe fe* ng $25 \; m/s$ 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 the 10,000-m run e +plar h)m/ n15fkgb:in less than 30.0 min. After exactly 27.0 min, there are still 1100 l1mf pe/k+n:b) rh5 agm to go. The runner must then accelerate at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$