Suppose that an object travels from one point in space to another. Make a c92 1a1od v/ 7-iqajv-uos enqjomparison betwo 7 2 vqij nu1a-dq-j9aos/e1veen the displacement and the distance traveled.

  When is the average velocity of an object equal gf, k k ssmam77xzh,8*ozig85 to the instantaneous velocity?

  A new car manufacturer advertisaawj.n03)hm) vf+/j d;6f 8rqnqs qgwes that their car can go "from zero to sixty in 8 s". This is a descripg3;amhqj8fq.) a w0svj)nd+wnqf/r6tion of

  An object moving in the +x axis experiencq(galj/h ohve,02 ehoz0s ek h* j(s.3es an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x direction) begins to s ky.vglf2e c02low down as it approaches a traffic liyefk2c0 .l2vgght. Make a statement concerning its acceleration.

  Suppose that a car traveling to the West (-x d4s jb5)0vgeait/ q.tb4w 78sjmd l/ssirection) begins to slow down as it approaches a traffic light. Make a statement concerning its accelerati54tjsv/bdsseq0abt g8) /.wm sij 4l7on.

  Suppose that an objectd7/)i9v(umol vn5z.o6ks t sd is moving with a constant velocity. Make a statement concerning its accelerati5tvs 7/k)d9snd zioo. (v6mul on.

  If the velocity of an object is zero, does it l1ufujr+p (d,ywk 9*5 d-wyj tmean that the acceleration is zero? Support u( *j1wyd,ptfjrld5+-w k9yuyour answer with an example.

  Can an object's velocity change direction when its accelerath2ji 2m3yhj -fion is constant? Support your ajhi 2yjm32hf- nswer with an example.

  Suppose that an object is movinsu: be6uou3 aw0v rd)9g with constant acceleration. Make a statement concerning i)bu 3069uds raeo vu:wts motion with respect to time.

  Can an object have increasing speed while its acceleration is decreasing? Suppo hd+i/ cuma .o,;nam jis4i;b)rt your answer with an exampl.+;)mbsaimd /h o,iuaj4cn;i e.

  Suppose a can, after an initial kick, mr2nkf0: n q5pkoves up along a smooth hill of ice. Make a statement concernin05qfr 2k:np kng its acceleration.

  Under what conditionmo (pguh93 o 8bz:ty8aeph 1)u is average velocity equal to the average of the object's initial opy ho uagh 3b81mtu p)e9z(8:and final velocity?

  Objects A and B both start at rest. They both ach yvktsb9,*j 0uso0w1 celerate at the same rate. However, object A accelerates for twice the s s9 wythj,v0o1ub k*0time 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 samn*-6lp-dg e kxe rate. However, object A accelerates for twice the time as object B. What is the distance traveled by object A compared to that of objec-*l-d ex6kgpnt B?

  When an object is released from rest and falls in the absence of frict c-zgjqu6 -:- q5+.nra gxwt k-kepzk(ion, whichj6.+5gc kezz-u-x(qag pk--nw :qk t r of the following is true concerning its motion?

  When an object is released from rest and falls in then en1zyx d8jz 64(spf/(ko. or absence of friction, which of tz18kp.odesfn4(o nryj z(/6xhe following is true concerning its motion?

  Suppose a ball is thrown straight up. Make a to+ vmfe)s.w * statement about the velocity and the acceleration when the baltvo+s .*w efm)l reaches the highest point.

  Suppose a ball is thrown straight up. What is :k2c0* w gbnflits acceleration just before it reaches its highe w*2cb:0gf nlkst point?

  Suppose a ball is thrown straight up, reaches a ma1/czjps,0j bz/i d./.yv axl tximum height, then falls to its initial height. Make a statemej/, 0.lyd ct/zp.bzx vjai1s/nt about the direction of the velocity and acceleration as the ball is going up.

  A ball is thrown straight up, reaches a maximum heig6pvvphx7kpu c 0q5c,t g ,;vq4ht, then falls to its initial height. Make a statement about the direction of the velocity and acceleration as the ball ;kc ,v4vqqvhp, puxt g675 p0cis coming down.

  Suppose a ball is thrko )5ac*.1x,e*i +hsb4przy5evbm ej own downward in the absence of air resistance. Make a statement vojxce i,me.)+rb5h 54yas1 *ep*bkzconcerning its acceleration.

  Suppose a skydiver jumps from a high-flying plane. Whs (fpp5r-l . ,imteex7at is her acceleration when she sh,5 .peps- txlif (m7ere reaches terminal velocity?

  A ball is thrown vertically upward with a speed v. An identical secr *kg4 bf-ly x.fn;;nej cx-:e6o9agdond ball is thrown upward with a speed 2v (twice 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 thae94-*do reff; gcx- ankxny j6. g:;bln the first ball?)

  Ball A is dropped from the top of a building. One secg0hb5jix/ygq0s od0- ond later, ball B is dropped from0gh/jqo is0 5 y0bgdx- the same building. As time progresses, the distance between them

  Ball A is dropped from the top of a building. One second later, baldm,f( +ox,jna l B is dropped from th(,on ,jf+dm axe same building. As time progresses, the difference in their speeds

  Two objects are thrown from the top ;jawgzr+ z :20mjixb. of a tall building. One is thrown up, and the other is thrown down, both with the same initial spe.x 2 z0mgr+:zi bw;jjaed. What are their speeds when they hit the street?

  A brick is dropped from the top of a building. A+b,ryzp5flj9 n8h ax c da zaqi*3o384 second brick is thrown straight down from the saxlpa39oz* 583j z4 fbd+ryq cin8a,h ame building. They are released at the same time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with le5kkf(qv: -l(xp( zyconstant non-zero velocity in the +x axis. The position versus time :xq(yz -5((k e klpflvgraph of this object is

  An object is moving with cok red8 +k6iwqv5 )gei5nstant non-zero acceleration in the +x axis. The position v dwireq)ek8+k556 ivg ersus time graph of this object is

  An object is moving with constant non-zero00dz4sk+/*ntp 9t zn n sb:oaz velocity in the +x axis. The velocity versus time graph od9ns*z zt :4st akz0pnbn +/0of this object is

  An object is moving w z1o qhdqnu03/ith constant non-zero acceleration in the +x axis. The velocity versus time gr3dz/un0 qo 1qhaph of this object is

  The slope of a posit65;z luz7 ua.h ctcv;q0 jwms3ion versus time graph gives

  The slope of a velocity versus time graph givej3fch53 .d mbws

  The area under a curve in ans;ot,mm/ s4lg acceleration versus time graph gives

  The area under a curve in a ve1gw4 jkc)i;(xxej8yf locity versus time graph gives

  If the position versus time graph of an object is a horizontal line, the objectf0c y5qqb. kq: cb qky:0qfq5.is

  If the position versus time graph of an objebb6;io f7 ik ,l1 9pfsda,rdn/ct is a vertical line, the object isf ,6n 1rl;9af kd,ipobsd/7ib

  If the velocity versus timq1ullj-:sb6. ufelh + e graph of an object is a horizontal line, the object lj1+- luu6h :els.fqb is

  If the velocity versus time graph of an object is ac))cysj q/.s-q z9lz a straight line making an angle of 30 degrees with-y scal j s.cqz)/qz)9 the time axis, the object is

  An object moves 15.0 m north and then 11.0 m south. Find both t v2 btb5-/g 9rcqudgl)he distance traveled and the magnitude of thgvq2u)l/rd5bcb 9 -tge displacement vector.

  A boat can move at 30 km/h in still water9ged i eq3 (txo:i8mr9. How long will it take to move 12 km upstream in a 89rd(q eoigix 9em:t3river flowing 6.0 km/h?

  55 mi/h is how many m/s? (1 mi = 1609z.c-02 knsnxhf )p+ bs8 rsk6m m)

  What must be your average speed in order to travel 350u cwelx1g:co-:x /wd, km in 5.15 h?

  A runner ran the marathoe; );m 6kw6k0vlvrdhbljst,; n (approximately 42.0 km) in 2 hours and 57 min. What is the average speed of the runn edjm0t6;brlsv v),k;;l6kwh er in m/s?

  A car travels 90 km/h. How long doe vouw1)zgh b)t(2f5bus it take for it to travel 400 km?

  A ly (light year) is the distance that light travels in one year. The8)* ai -hfvyaq q ken9gxwx.:.ol17ry speed of yoevkqh w.an r :8 l*yfx7)a 9g1xq.i-light 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 roay0w z tph-5v1eokiu( j, o7rj7j1w;ymd and you look to the side for 4.0 s, how far do you travel during this inatten y-o,11p mutj0(75j w;rhwekjiy v oz7tive period?

  If you run a complete loop around an outdoor track (400 m), in k,zvb47 :ex 4g3zmnnq 100 s, your average ve3:nxv q47, 4 znkmbzgelocity is

  A polar bear starts at the North Pole. It travels 1.0 km so jwo6v) xz+nd/bwh7. h.gqfx+uth, 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. What was the 7+.w nhhb6x+ qg)/j.dfxoz wvbear's average speed?

  A polar bear starts at the Nortk,zun gkl(a/q-4.;tv1 oupym dr 2,jgh 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 star.1 ;t j4mpz u-ro2qg(dkv,/ ygl naku,ting point. This trip takes 45 min. What was the bear's average velocity?

  You are driving home on a - 9gdyt8:fj 3hi rrvx*weekend from school at 55 mi/h for 110 miles. It then starts to snow and you slow to 35 mi/h. You arrive ho3tr jvh*gd98xr-y:f ime after driving 4 hours and 15 minutes. How far is your hometown from school?

  A motorist travels 160 km at 80 km/h umshqivn/br/m3 mp)5hypp * ,/1 g, gaand 160 km at 100 km/h. What is the average speed of the motorist for this tri *sn5ppp ,v rmmh/i yqmb)uh3,//agg1 p?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h at lp+ u;8 d3 )iewzz),m:byvtdo100 km/h. What is her average speedl)bu ve im+,3z)y pz8d:;to wd for the trip?

  An airplane travels at 300 mi/h south for 2.00 h and then at 250 mi/h norc/sab24 mqn7f jl.1o eth for 750 miles. What is the average speeloac2 m1./j 7q4 fsbend for the trip?

  In a 400-m relay race the anchorman (the person who runs the las538 ek 3bey/aq;fm :w3;gh ys rkt-pgqt 100 m) for team A can run 100 m in 9.8 s. His rival, the anchorman for team B, ch- ;35kptgq3sfq/am:e r;3 eyby8kwgan 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 a7ui)wecsb.*q pb6xvn -ec1-d nd comes to a stop after 12 s. The car's average veloc qs17 6 .vnx*ceb--epiwb d)ucity during deceleration was 40 km/h. What was the car's deceleration while slowing down?

  An airplane increases its speed from 100 m/s to 160 m/s, at the ;,e7ekiz lbw1average rate of eie,kl ; zb7w1$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerates at the rate ofh,2c7rco, dvy3 e9k gh $2.0 \; m/s^2$. How much time is required for the car to reach a speed of 90 km/h?

  A cart starts from rest and acc9z -naznw9( l3nh,z zoelerates 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 speeds up with a constant accelerat nwkeye2 (34eqion o3y 4n qke(2ewef $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 6. bsqix8x06g tenwte)*m,g7g*4 m/s experiences a constant acceleration o8inb e*0)teqs 7 w6,gxtggx*mf $2.9 \; m/s^2$. What is the cart's displacement during the first 9.6 s of its motion?

  A bullet moving horizontally gxmm5 bz6+yr;*wrdfu5(x/c d to the right (+x direction) with a speed of 418 m/s strikes a sandbag and penetrates a distance of 51.61 cm. What is the average acc/r;x655g(zm umbdcy dr+xwf*eleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on an aircraft carrier.( .yx3liei* px It reaches a speed of 42 m/s at the end of the catapult, and this requires 2.0 s. Assuming the acceleration is constant, yxxp.l( *3ii ewhat is the length of the catapult?

  A car starting from rest moves with constant acceleration / q) )1a)-uqcc) zxtq r/ u0ku2kahxdsof $2.0 \; m/s^2$ 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 its ave)- )xyf2 tw9h/eo2 m 6dblzblqrage acceleratid w-xz /bfh262 y)9ellmqo)tb on?

  An object starts from rest and undergoes uniform acceleration. During t)ctq.5qkp1 du o3e9br he first second it travels 3.9 m. How far will it travel during the third second?tuqeb9 3 k)qc5 opdr1.

  An object is moving in a straight line witp/ora* nsbs 6:h constant acceleration. Initially it is traveling at 16 m/s. Three seconds later it is traveling at 10 m/s. /6sbnpas*o r:How far does it move during this time?

  A car starts from rest and accelerates uniformly at bn8 lx45i3cgz $3.0 \; m/s^2$. 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 q1h ili;ehr-s n7dh6ce:b6k5 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 greero*d i/t 1wff8osf3/t0e ewssp,0e a* n, a car that has been waiting at the interseeso a0si** 0pw3 ,o wdts/ef1f8 rfet/ction starts 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)2liwrjoesa2 e5k +.u a speed of 12 m/s on the surface of planet X where the acceleration due tae5ksieu2+wj ) .2ro lo gravity is $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown upward with a speed of07/zwrmn l:eaks+ vu2 12 m/s on the surface of planet X where the acceleration dul :0/+zvnse2 mwukra7e 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 upw1 w ;xucldd40xphgzzd a .l0.5ard with a speed of 15 m/s on the surface of planet X where the accep.z504ldg 0x1ddah wcuzx.;lleration 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 upw4x42kd62+hj ef c,qamwdx1mt ard with a speed of 14 m/s on the surface of planet X where texa ,c41+6j2fmd mdtqxwk2 h 4he 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 than 0.10 s. If your friend holds a rul,7 ;pp(nttw2q.jnj bupgm4bc- om s o6.ba/6ier between your fin6um jtp.nago7s.jq/tbpbb im wn6p4o- 2c;,( gers 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 ofqoro64 )5b9kjzh ; ryg 19.6 m/s. What is its velocity after 3.06 o)r j9 4bkg5qyro;zh0 s?

  A bullet shot straight up returns to its starting point in 7 s. x /x f6r+sv:ysWhat is the initial spe y+/ rx6sxf:vsed of the bullet?

  A ball is thrown straight -chg)0-q um t/1weyukup with a speed of 36.0 m/s. How long does it take to return to mue)kg-w-q/yh 1ctu 0its starting point?

  A ball is thrown downward from the top of a building wd wgk y+9xh.ew 9(i6xcith an initial speed of 21 m/s. It strikes the9w( 6xhec+iwyx 9gdk. ground after 7.6 s. How high is the building?

  A ball is thrown straight up with a speed of 30 m/s. (only fill in numerical v(w+4kty ap1s3 u 6udbjalue i kw(sy+p ja bdu3461utn 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 the f1f ( uu7;dfytair with a speed of 30.9 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 1 seconds later.  (数值)  $m/s$
(e.) Determine the time at which the ball pass a point 13 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 13.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is the velocity at t = 1.0 s?7s 8zdxg i: 0yijwzo60

  In Fig. below, what is the velocity at t = 2t ys9.hv l9zsv2cp ctxrei s6 *.6r6v2.5 s?

  In Fig. below, what is the vf2m34fn i6to8a -tnda elocity at t = 4.0 s?

  In Fig. below, what is the velocitav 3m;vlr 1/bq .ni7kly at t = 5.5 s?

  In Fig. below, what is the average velocity rcwv:* /fqcs8from 0 to 4.0 s?

  In Fig. below, what is the averas eah).g x+k(my;4amkqfwjv9kzx+ 50ge velocity from 0 to 6.0 s?

  In Fig. below, what inmq6. q4sbjl6vf 3z 5hs the acceleration at 1.0 s?

  In Fig. below, what is the acceleration f55khaqynd s5s683 1nc+qb+j n: yzeoat 3.0 s?

  In Fig. below, what is the average acceleration fv+vlw z mvnz+0u))nk/ (gc .vjrom 0 to 5.0 s?

  In Fig. below, what is the average acceleration .o2d9-die0:sy muz r ifrom 0 to 8.0 s?

  In Fig. below, what is the displacement from 0 to 8.h u if3;gg5iz+0 s?

Does a car speedometer measure speed, velocepm(lk1pjq( 4ity? {speed|velocity}

  An object can have a varying speed if7q 42ev9 b(vyn3d, oq-cubffn its velocity is constant.

  The velocity of an object can be negative when its acceleration is p:2d3 mkbm7bv oositive.

  If one object has a greater speed than a second object, the first must have vfe ln, 3m62no -fam(o3fpud4 a greater ac(faue, nvmodn4mo p-f3l f623 celeration.

  Two cars emerge side by side from a tunnel. Calha: /fz/ l6gkj jl2+zr 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 speedg395g :lb9+b(xckysbc6h zm ft zg52o as its acceleration decreases.

  A baseball player hits a foul ball szjq+yu k1)g f+mh,ynlcu 1s3( traight up into the air. It leaves the bat with a speed hs l1(gy+fm u3+,) y nqcju1zkof $120 \; km/h$. 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 spee 5rreeny,m66uqglcw p/ m4)b6ds up, what is happening to its acceleration, how does it change if air friction i,c r 46/n6bmwrpe6mly )uegq5 s ignored?

  As a freely falling oe dwl.xty5e*wrqn m4:2o4 e8 sbject speeds up, what is happening to its acceleration, how does it .lt r:5*x2y 8qemee 4dnowws4change if air friction CAN NOT be ignored?

  An object that is thrown vertically upward will return to its original pq;np+8nz e8op-w3gdr soi /wa.;2hnkosition with the same speed as it had initially if air resistance is negligible. If air resistance is awq2/n+izo;p8d n.gwe sa h83 ;ornk- pppreciable, how will this result be altered?

  An object can have zero velocit v 4mf8+2c(t qukis7 0jgefi(by and nonzero acceleration at the same time.

  An object can have nonzero velocity and zero acceleration at the sap7 q9 7ulb 21sbabt;xlme time.

  An elevator moving from the second floor to the fifth floor making no stooq 9n7 4s7 ;tf9oyg uuo7b,d(f:euvf wps along the way has zero acceleration all the t7;ebnuoo 7fu 4ywfv, g 7otf9sq( d:9uime.

  A rolling ball moves j17 hyhlq5t u )3*h*8o-cfz0jyq frahfrom $x_1=1.8 \mathrm{~cm}$ to $x_2=-7.3 \mathrm{~cm}$ during the time from $t_1=2.7 \mathrm{~s}$ to $t_2=5.2 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-4.9 \mathrm{~s}$ is at $x_1=2.6 \mathrm{~cm}$ and at $t_2=3.2 \mathrm{~s}$ is at $x_2=8.3 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete lapsbsj+je+bc6g 3 around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 9.9 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, movin up ,tdy2bjl boxwqf-kc-)0( -g 86 m away in 11.1 s. It then turns abruptly and gallops halfway back in 4.5 s. Calculate (a) its average speed f-0w,yjou d(q)ck2pb- tb- lx  (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 from)- 2gvq*)qq (syag idt $11 \; m/s$ to $23 \; m/s$ in 5.0 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 fromctblt/m3 5. rq $16 \; m/s$ 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 speed of3)int+,ics is f0t7sx 8rcmg( $28 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.4 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of the blockl0r 9 b,obus;ge -i(efs to essentially top speed abouefe(ubr 0,lig ;-sob 9t $10.3 \; m/s$ in the first 14.3 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 uniformlf 1k4fdma hx(ac-6.smc .goe- y from a speed of $19 \; m/s$ to rest in 4.66 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves skid marks 92 m lw ei2d (+tyca8ong on the highway. Assuming a deceldc (8a e+wyi2teration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck gqbb 3n(dhl3n x(.jcn (7ukorr187axpoing $25 \; m/s$ 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).    $m$