Suppose that an object travels fnd:fg,z -69pder ggzvg un2yuq 9j:-;rom one point in space to another. Make a comparison between the -: un 6yqjr9v; d gz,g92uf:d z-enpggdisplacement and the distance traveled.

  When is the average velgj4ylk7d fe -nu60bs;ocity of an object equal to the instantaneous velocity?

  A new car manufacturer advertises thh:ui6u8sr0o e:mdy k*at their car can go "from zero to sixty in 8 s". Thu*mo:60 yds i ukeh8:ris is a description of

  An object moving in the +xwq8n/d, yfpa 9 axis experiences an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to7zsc4of1o6 wrxvnq-9 the East (+x direction) begins to slow down as it approaches a traffic light. Make a statement conwocv zqof-s4r 79 x61ncerning its acceleration.

  Suppose that a car traveling to the West (-x direction) 96khv)oq6o7g + jsku abegins to slow down as it approaches a traffic light. Make a statemkvaq 6gs+k)u o9h6j 7oent concerning its acceleration.

  Suppose that an object is moving with a constant velocity. M8n k(ew0 wj8m*lmw b1jake a statement concerning its ac mk0wwl8(j1b*m e8wjnceleration.

  If the velocity of an object is zero, does it mean that the j lr jeufuz +lafq0:2.,3nj.nacceleration is zero? Support your u..u lfjl a z:fe02j jr,nq+3nanswer with an example.

  Can an object's velocity change direction when its acceleration -atpbft1 +eh h4s27vmis constant? Support your answer with an exampleb4+pt12 vte7f sa -hhm.

  Suppose that an object is moving with constant acceleration. Make a statemenva m3)it hq(4y/bcth 9t concerning its motion with respect to tibqa(vm t3 ) it9/4cyhhme.

  Can an object have increas6t ) yi9jz9og4exa6ng ing speed while its acceleration is decreasing? Support zno ga96jeyx g4t 9)i6your answer with an example.

  Suppose a can, after an initial kick, moves up along a smooth hill of ice. Make0f1f(xdl2f42og ylkm f122xmkyldof (l 4fg0 a statement concerning its acceleration.

  Under what condition is average velocity equal to the average of the objec75j23*ilz o8fgoxfspm*4c ql t's initial and fc o2*jf7f4mo xi*lsql g53 zp8inal velocity?

  Objects A and B both start at rest. They both accelerate atr7 /-keoqc y3z the same rate. However, object A accelerates for twice the time as object B. What is the final speed of object A compared to that of ko zyerq/c-73object B?

  Objects A and B both start fys+ z/b/d,lmw4dawt7feo s+ +rom rest. They both accelerate at the same rate. However, object A accelerates for twice the time as object B. ys++7d ozdsl be,/m + f4a/wwt 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 absence of fouj *ua0drzv( ;8 ew4 bq5avg,8p/tktriction, which of the following is true concerning its v za p*odj8a0tq, e8; g5rwbvt4ku u/(motion?

  When an object is released from rest and falls in the absence of friction, w cc*,rdk)xdu0u3uf 1n hich of the following if, uru )u0ndkx*c3cd1s true concerning its motion?

  Suppose a ball is thrown straight up.19:j6q lepds f Make a statement about the velocity and the acceleration when the ball reachsldp61: qjfe9es the highest point.

  Suppose a ball is thrown straight up. What is its acceleratizh(z mha0 dai 9x t)5h*f9;sa/topf5qon just before it reaches h f ;i (szpa/m99o5)aa 0zthh q*fd5txits highest point?

  Suppose a ball is thrown straight up, reaches a maximum height, then falls to itgw4c6u- zv*r bs initial height. Make a statement about t4u*cvwr 6b- zghe direction of the velocity and acceleration as the ball is going up.

  A ball is thrown straight up, reaches a maximum height, then falls n4-9qv(aqk)94ngwqt.k p, zmv ,ym axto its initial height. Make a statement about the direction of tm 9n,a94 q)wt p-,nkavy(zqv.x4k qmghe velocity and acceleration as the ball is coming down.

  Suppose a ball is thrown downward in the absence of ai7,ndeg/m;a6 :aoi mkmr resistance. Make a statement oagk,/da6mnmm;i7 e :concerning its acceleration.

  Suppose a skydiver jumps from a high-flying plane. What is her acceleration w r e,mjtt+/vc)hen she she reachesvt/r,temj c +) terminal velocity?

  A ball is thrown vertically upwa g+ hee+kb1h1ird with a speed v. An identical second ball is thrown upward with a speed 2v (twicg+e1+1bihh e ke as fast). What is the ratio 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. lk8jk 5n:ybl )/4in hx One second later, ball B is dropped from the same building.:) xyln8nkbl4/ kij h5 As time progresses, the distance between them

  Ball A is dropped from the top of a building. One second later, ball B is dropops-wh6xw7a ux:1 k e:ped from the same building. As time progresses, the differpokwxa s-u:7:x1he6w ence in their speeds

  Two objects are thrown from the top o 5fr11 g c(kdob3yqy3 :kum6mpf a tall building. One is thrown up, and the other is thrown down, both with the same initial speed. What are their speeds when31umkb o561yrpm dc:yg3(fkq they hit the street?

  A brick is dropped from the t9f2at yqor;7ki*hx63x +e11zc le yljop of a building. A second brick is thrown straight down from the same building. They are releas9c3iq6 * oxy72flzea+y 1 l;he1jrktx ed at the same time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with constant non-zero velocitys-nsn.:p ( swc in the +x axis. The position versus time graph(wnss:c- ns p. of this object is

  An object is moving with cvhk.2g0 j k(kyh 40r5*bstkkionstant non-zero acceleration in the +x axis. The position ver k hhjkyvkt*5i(g0 .k20krsb4 sus time graph of this object is

  An object is moving with constant non-zero velo oqv -ked1sr67j ;94n usd6k5ubv8ow acity in the +x axis. The velocity versus time graph 1uasksobd46v- n jr6veu8 9d5 7wk oq;of this object is

  An object is moving with constant non-zero acceleratio9 u4ngpfmc3)rn in the +x axis. The velocity versus t grcf4 pnm39u)ime graph of this object is

  The slope of a position versus time graph gi1 w*aog58cdni; b an+nves

  The slope of a velocity versus time graphkb76csiqn ( nhz3 ho22a)pw)cw: cn7 u gives

  The area under a curve in an acceleration versus +hd*j2p( z y0okdkf n7time graph gives

  The area under a curve in a velocity versus time graph giveso+cww y0o ghn0/jq l)6

  If the position versus time graph of an object is a horizontal line,6 ): vkr 5dw)/qwleulj the object i w6ed)qrulkl:v wj5)/ s

  If the position versus time graph of an object is a vertical line, the object xth1o6nb z/rwhcuhjl8 :1j27istr8 1 xcbuj/o7 n62z h:jhl1hw

  If the velocity versus time graph of f2x szddn7u*e-pr(; hpj 95 pran object is a horizontal line, the object isdr52 pn d;he*spr 9(pz-xfju7

  If the velocity versus time graph of an object4zl*jlf 4y;jyspyw :: is a straight line making an angle of 30 degrees with :zwplslyyf* :4jjy4; the time axis, the object is

  An object moves 15.0 m north and then 11.0 m south. Find ;k. oh u0i:atw wkn:y.both the distance traveled and the magnitude of t .;wnwh0 u :kkto.ya:ihe displacement vector.

  A boat can move at 30 km/h in still water. How long will it take to move 12 km w e0m/qj;nx;rz4y5dga :nqj5 upstream ixaz j: gnmeq;5dq j4 w;5y0r/nn a river flowing 6.0 km/h?

  55 mi/h is how many m/s? (1 mi ljwtf;f wiro44 5 u+*q= 1609 m)

  What must be your average speed in order +1fwt 2s szyb,to travel 350 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 km) rwvqsacnk)- 5 g(3t a4in 2 hours and 57 min. What is the average speed of thenva5 crg 3s4)ta(qw- k runner in m/s?

  A car travels 90 km/h. x;tjy m3:ta7f9qy yt0.olf2 g How long does it take for it to travel 400 km?

  A ly (light year) is the distance that light travels in one year. The spqtbq 5mosn, fhw35h(o)uq11seed of light1qhq 3mo(o s1t5ubsn,fw)hq5 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 gg :b7pmu1*.aqzlz1 zcbn a)9 along a straight road and you look to the side for 4.0 s, how far do you travel during this inatzz:1gbca79 ap *z.glm qn)1ub tentive period?

  If you run a complete loop around an outdoor track (400 m), in 100 9+p k)7qu xqdkgsp()ds, your averag k(dsg)7p)9qq+kxud pe velocity is

  A polar bear starts at the North Pole. It travels 1.0 w9 hx7d,i yy 8af:y)vekm south, then 1.0 km east, then 1.0 km north, then 1.0:iyv h,d)yfxw9 8yae7 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 Pole. It travels 1.0 km south, then 1.0 km eascuk/bdb ;ra76h*(4agcuu o y/t, then 1.0 km north, then 1.0 km west to return to its starting point. This tripa7uc/r6o b (uy /cudhk4; a*bg takes 45 min. What was the bear's average velocity?

  You are driving home on a weekend from schoovze*/+, rlz 0 j7,hxmib+kr wrl at 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 is your hometown from school?l7vke,brrri zz/*x+m ,hjw +0

  A motorist travels 160 km at 8024sv fvwzdjxy0 6 3)qv km/h and 160 km at 100 km/h. What is the average speed of the motorist f wy) vf6v 2vsdzx034qjor this trip?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h;,qd5oh8-wsx ,jzs ev. What is her average speed for tzs;xwde j5, v8,h-qs ohe trip?

  An airplane travels at3f) so i+rjip5 cas*,0dxrh cl0s4 )tc 300 mi/h south for 2.00 h and then at 250 mi/h north for 750 miles. What is the average spee dcjl+) c3hoitp50ra *fs4i,x s)s0rcd for the trip?

  In a 400-m relay race the anchorman (the person who r h0j eti*p 6dy:*4oxriuns the last 100 m) for team A can run 100 m in 9.8 s. His rival, the anchorma*4ipoy :d6 *0jtrexh in 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 order that the team A runner not lose the race?

  A car decelerates uniformly and comes to a stop after 12 s. The car's average c/ii131op vh n;byguy:i f-j. i t(4drvelocio3g4.tjn/:dhv-y ri1( fi iby1c ;iupty during deceleration was 72 km/h. What was the car's deceleration while slowing down?

  An airplane increases its speed from 1031rhxrp tfev , -+gs)e6wj3l a0 m/s to 160 m/s, at the average rate of wla-sf1,rp6 h3e rg3ve+xjt)$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerates at the rate ob3:sghg vhs5 +q erdu8fs-7 3vf $2.0 \; m/s^2$. How much time is required for the car to reach a speed of 90 km/h?

  A cart starts from rest anubxqh5ap tp,+m65m r*ik d;zasc dl dy+ ;;8,jd 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 s. It then spzj0*n9t rhtf0eeds up with a constant acceleration fttnjhz090r*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 o0 v wugiw8os78 -lge9jf 5.9 m/s experiences a constant acceleration of - jv wo9we7l 8guisg80$3.8 \; m/s^2$. What is the cart's displacement during the first 5.4 s of its motion?

  A bullet moving horizontally to the right (+x directiou, :z)rp33biwf7nhty4fsbmu9 1yd g( n) with a speed of 462 m/s bw gy1 7,d:h(yitf bm4)9pzu frn3s3 ustrikes a sandbag and penetrates a distance of 89.19 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on an aircraft cazqhnw5 ox+8o*+v hms;rrier. It reaches a speed of 42 m/s at the end of the catapult, and thi5+ nxoq ozm;+ *8shvhws requires 2.0 s. Assuming the acceleration is constant, what is the length of the catapult?

  A car starting from rest moves witjilh 6i+ n ,dc3y.uanr7a v1)ph 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 200 m. What is gyft 19pa:vm:-/pyo(jc)yc c its average accelera/c(y-pa) c:yjfvtyo gm1 :p c9tion?

  An object starts from rest and undergoes uniform acceleration. Duringi:xhu16*hhzbq wfx:pc u20+g t(n bm , the first second it travels 1.4 m. How far wi( mxt06u,ph2+ : ugwb hzcnix:qf1*hbll it travel during the third second?

  An object is moving in a straight line with constant acceleration. Initially dddi;/ bh.+gl /cuiu oh4 q3*kit is traveling at 16 m/s. Three secodh oui/c; q+ d/hk4 bi.u3*dglnds later it is traveling at 10 m/s. How far does it move during this time?

  A car starts from rest and accelerates u td-g 6+d)aoh3iyel,dniformly 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 aq4 jh6ii2m p7v dry road can decelerate 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 light turns grek: losb4d w a9ykwk9kx )keb;1e)(9cwen, a car that has been waiting at the intersection s(kw)9s4eab:lew9) 1 ky 9xko;wcbdkktarts 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 plan;9xzl m)g joe 6se1e6i;clv4e2s 0oua et X where the acceleration due to grasellic6 1ue2 zeevg 6)94;smja;ox o0 vity 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/jtb shf v 0 *d.+lcpj56m2rxy,s on the surface of planet X where themfl rby 05xj,*6+h2v cj dtsp. 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 with a speed of 15 m/s on the surface )ip6:) resfh lof planet X where the acceleration due tr 6l)ehs):ifpo 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 surfqan3 d;*t kqf8ace of planet X where the accelerat3 *kfa ;qndt8qion 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 greatb*:6vi *0 lhzzlw8)j b*thl:sdu+mnk er than 0.10 s. If your friend holds a ruler between your fingers and releases it without warning, how far can you expect t +w0:m)*b6jutzh8zsn *hl* vdik :b llhe ruler to fall before you catch it?

  A ball is thrown upward at af5l80dsry7e pn . yjh6 velocity of 19.6 m/s. What is its velocity after 3hd j50e7.y 6ry8n slpf.00 s?

  A bullet shot straight up returnu c;h0xk,z ep8s to its starting point in 15 s. What is the ini;h,c kzxue0p8tial speed of the bullet?

  A ball is thrown straight upa svbmfz2-f0tff5/ 58ci k n0f with a speed of 36.0 m/s. How long does it take to k5a0 f cfsb f0vfi5tzm8 nf-/2return to its starting point?

  A ball is thrown downward from the top of a building with an initial spelutuj*r0 o/ibgr6vwr/ 4e4- xed of 21 m/s. It strikes the ground after 3.0 s. How high is trui/06go l x*ebtj -u4r/r4 vwhe building?

  A ball is thrown straight up with a speed ofh- +g6hvn kgs0f+act) 30 m/s. (only fill in numerical valuenvsf- +h0ag ktg) +6ch in the 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 into thvac3/1j1sk 2nzramuys4v9q 3 drh5-te air with a speed of 30.5 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 1 seconds later.  (数值)  $m/s$
(e.) Determine the time at which the ball pass a point 12 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 12.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is the velocity at tog 7;r9vd7 czwco 42vpy4ll8uwhq ,) e = 1.0 s?

  In Fig. below, what is the ve2a /d39qigo3 kk 21fnkvrk jo7locity at t = 2.5 s?

  In Fig. below, what is the velocity at t = 4.0 sh7r8n;h g3au;a e3mnq 8-)vnxjo6df h ?

  In Fig. below, what is the velocity a6krz)j(w/ep1n) q9 mda/g brpt t = 5.5 s?

  In Fig. below, what is the average velocity from 0 to 4 t( kdwi.pv3g+.0 s?

  In Fig. below, what is the average velocity )u yplo *e+q6nfrom 0 to 6.0 s?

  In Fig. below, what is the acceleration at 1.0 s?7o c5qu9ei8et

  In Fig. below, what is the acceleration x*dwt+hq3n*v at 3.0 s?

  In Fig. below, what is the aver kcg. (us8d3xoage acceleration from 0 to 5.0 s?

  In Fig. below, what is the average acceleration from 0 toidaq.- g9-jay 8.0 s?

  In Fig. below, what i su;jxw;ygkt ;90ap7 ss the displacement from 0 to 8.0 s?

Does a car speedometer measure speed, velo ab1nw8wu bk g8c1z;o-city? {speed|velocity}

  An object can have a varyin .4 7hzntnhe-fc)-65 tftqy stg speed if its velocity is constant.

  The velocity of an object can be negative when its accelerationqg-8v k-r7qj -fgu1 )i 5dzia.cvku2b is positive.

  If one object has a greater speed than a second object, the first o//r-c n8a, +0hmvzyx ,zscbjmust have a greater acozvs/c j,rhxy- n+80mbz/,acceleration.

  Two cars emerge side by side fr1zn(h nbos;7xb2c cxe tbhfs2 j02--rom a 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 accelerationpx(5 dbg,cv.c decreases.

  A baseball player hits a foul ball straight up into the air. Itbwo2 ow2ocl5hf1: k5e leaves the bat with a spl:5 cwow1f2 oh52 oekbeed 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 ac+c9+ vuowx ycq0-/peqbrw 45xceleration, how does it change ifcev w p/ +ry5b+cqow0q9x 4u-x air friction is ignored?

  As a freely falling object speeds ut5.qq4ka bkul q +j7b7p, what is happening to its acceleration, how does it change a.+j5u7kbl4q7b q tk qif air friction CAN NOT be ignored?

  An object that is thrown vertically upward will pz04cos(:ps ,djag c/return to its original position with the same speed as it had initially if p 4sop /(:czaj c,sgd0air 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 timeun.eb+l/.);jioa zl:k jr , xu.

  An object can have nonzero velocity and zero ac6k.dn*uso, l u.ac;ajceleration at the same time.

  An elevator moving from the second floor to the fifth floor makingf( o)copj2dd n2;*kh. cj if-d no stops along the way has zero acceleration a nj)chj 22.(fpk*io fdd o;cd-ll the time.

  A rolling ball moves fromf wu96a-g 6buq1)hox2h6jg wh $x_1=3.2 \mathrm{~cm}$ to $x_2=-7.5 \mathrm{~cm}$ during the time from $t_1=1.7 \mathrm{~s}$ to $t_2=5.3 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-2.9 \mathrm{~s}$ is at $x_1=2.7 \mathrm{~cm}$ and at $t_2=4.5 \mathrm{~s}$ is at $x_2=8.0 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps around a quarter*u2:g7qvg/teuwx z8sd. y(f m-mile ($1 \; mile = 1609 \; m$) track in a total time of 6.3 min. Calculate (a) the average speed  (数值)  $m/s$ and (b) the average velocity    $m/s$

  A horse canters away from itsm 18xi;2ibfs/m yvvv ( trainer in a straight line, moving 89 m away in 9.7 s. It then turns abruptly and ga;ivvbsf2 v(my/8mxi1llops halfway back in 4.6 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 fromx +fw2d p:nwe)5*tq qquwaly g2nw7,* $12 \; m/s$ to $22 \; m/s$ in 5.8 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 fromntq1 / 0fm)hx-zb i4fb7 bw)va $17 \; m/s$ to rest in a distance of 72 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a speed of fn+)kw)3e53y(xlh7hpr ryd tn jaa i5uqa0/3 $29 \; m/s$ 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 ofkcd3:) b, asoeu 6+pvq the blocks to essentially top speed about uc6vd aq:e )3bko+p,s $10.8 \; m/s$ in the first 14.6 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 uniformlyd74 :is nn7yh9xcoy. r from a speed of $18 \; m/s$ to rest in 4.57 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves skid marks 9thld8yu, us1b ;-g um12 m long on the highway. Assuming a deceleration ofbs;muuytu d,-1lh 81g $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truc+lpp8fhc3z4 famg - y6k 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 comple*x ;lhr/17(x j nkcbh1s+wi hwd-jx-ete the 10,000-m run in less than 30.0 min. After exactly 27.0 min, there are still 1100 m to go. The runner muh-x ;*k1jn1xbd h jlwe wi7s-x(h+/crst then accelerate at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$