Suppose that an objectwzb 033 tdgg8ankys; ) travels from one point in space to another. Make a comparison between the displacement and the distance tab;0y)dngz 833tkw sg raveled.

  When is the average velocity of an object equal to the instantaneo9fy e1v3ubh ;az4sgk0us velocity?

  A new car manufacturer add un(md)hapj7;z)/se 6wv0d qvertises that their car can go "from zero to sixty in 8 s". This is a description o;e7js /d0dzn6h)dq(am )wvp u f

  An object moving in the pkx8uceo2wr:brw pme * :93b6+x axis experiences an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x dt(,nonjnox rd)- ;;k mirection) begins to slow down as it approaches a traffic lighto,dmnrnjk;(tnox; -) . Make a statement concerning its acceleration.

  Suppose that a car trav zxpa:0ab.w)peling to the West (-x direction) begins to slow down as it approaches a traffic light. Make a 0wza. pp:a)xb statement concerning its acceleration.

  Suppose that an object is moving with a conhk /4rc pl4vy;stant velocity. Make a statement concerning its accelerathy4/r 4l c;pkvion.

  If the velocity of an object is zero, does it mean that the accelerati r+kh7 zcbk9d3zxg8.won is zero? Support your x krd+bc8.k3hzw z97 ganswer with an example.

  Can an object's velocity change direction when ih7,aqclr e upg z,14s1ts acceleration is constant? Support your answer w7p4 azecgl,,1 qhs r1uith an example.

  Suppose that an object is moving with constant acceleration. Make a ;-zlzwh-0b zd bz8la+ statement concerning its motion wid 0- l-bzzlzw;h+bz8ath respect to time.

  Can an object have increasing speed while its acceleration is decreasing? Suppo v,,+*c 6nnep(+l *cny xpfgsdrt your answer withp,fx 6 yls,++vcpd*e* ngcn(n an example.

  Suppose a can, after an initial kick, moves up along a smooth hill of iceg7m7 s;rft8*rziver -. Make a statement concerv ;7iz7 *t -ergfmsr8rning its acceleration.

  Under what condition is average velocity equal to t;9m; c qym :x.qjdh8mthe average of the object's initial andq; 9qj.hym: 8d mtxc;m final velocity?

  Objects A and B both s hwq8tlq9n)9 : z,+bbbjc(zp etart at rest. They both accelerate at the same rate. However, object A accelerates for twice the time as object B. What is the bn ( ):zl9p,e8t9 wq+bczbj hqfinal speed of object A compared to that of object B?

  Objects A and B both start from rest. They both accelerate at the same rate. v b dzl,0tqn.5)o93 je tpob zd+.ih5q However, object A accelerates for twice the ti io9q pb3vlz,toh.d e5.b) zj0dt5q +nme 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 absence of frictu t/ yfzxgy-2 e5g,:mcn;qj5fion, which of the following is true concerning its moti -gufy x2zeyq m;5jc5n/gft,: on?

  When an object is releasm kp0y, vcrfh7ux1)e 0ed from rest and falls in the absence of friction, which of the following is true hf07ryx1p0e ), vkcumconcerning its motion?

  Suppose a ball is thrown straight up. Ms(x5a9r 6lmwofn,rn *ake a statement about the velocity and the acceleration when the ball reaches the highessl6wra* o,f( nr9 5mxnt point.

  Suppose a ball is thrown q vcic,;p i q+ad(y5 p4da+pc+straight up. What is its acceleration just before it reaches its highesti+q(app q p5+; c,a cdvc+iyd4 point?

  Suppose a ball is thrown straigh;r*ufevw *0 rkt up, reaches a maximum height, then falls to its initial height. Make a statement about the direction of the veve;0*rwf ukr *locity and acceleration as the ball is going up.

  A ball is thrown straight4zbjsxy+4qsl4ir5 7d4it f ud 1y2v;m up, reaches a maximum height, then falls to its initial height. Make a statement about the4d4 ; v2r 4+x1ftsdq7iy4sj bml5yu iz direction of the velocity and acceleration as the ball is coming down.

  Suppose a ball is thrown downward p 1ufcuvyoa09t ih96 8in the absence of air resistance. Make a statement concerning its a8 1 0v99tfipcyuh ou6acceleration.

  Suppose a skydiver jumps from a high-flying plane. What is her accr*:e+qd9m ahh 8:/,lpwei l5fv yfs3d eleration when she she reai s* w/5lvh +,dfmry: fhlpqa9e3:de8 ches terminal velocity?

  A ball is thrown vertically up zw lnu04n;+ajward with a speed 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 that of the first ball? (How many times jlnu +nza0;4whigher does the second ball go than the first ball?)

  Ball A is dropped from th scwpo-1jqd:ih --aq3e top of a building. One second later, ball B is dropped from the same building. As oqpdh -a q3:1--wcijs time progresses, the distance between them

  Ball A is dropped from the top(v;o+7t *l;y sgukd onb7 ty5i of a building. One second later, ball B is dropped from tdvg 57y;u* tn7lky;( ooi +bsthe same building. As time progresses, the difference in their speeds

  Two objects are thrown from the top of a tall building. O c 5gxjuce;umg/y37j *ne is thrown up, and the other is thrown down, both with the same initial speed. What are their speeds when they hit the street? x5cuj y7e*jm;/cug3 g

  A brick is dropped from the top of1zp 1c d.k;4ki8t /faqkois6l a building. A second brick is thrown straight down from the same b1kkic1z dait6;sfp 8qk. 4 l/ouilding. They are released at the same time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with constant nox / f/:hzbay: )be1iqfn-zero velocity in the +x axis. The position versus time graph of this object isey1z)qf a: /fx/bhi:b

  An object is moving with conzk+zvc/l hd li5xp66(stant non-zero acceleration in the +x axis. The position versus time graph of thizh6p/k+l6 x5 dzi(cvls object is

  An object is moving with constant non-zero velocity in the +x axis. Th( 1 rpof ymoy+pb+52.p 1 siuzuv9ne,pe velocity v +b is 1y1,(2 .evo+ypppzfu5rmo p9nuersus time graph of this object is

  An object is moving with constant a o4f4 ky1e404 wdhhbhnon-zero acceleration in the +x axis. The velocity versus time grakhy wobdh40 4hefa414 ph of this object is

  The slope of a position versus time grazpcu l vwa9)+:ms: nt:ph gives

  The slope of a velocity versus tp2/dq8b9 et ryime graph gives

  The area under a curve in an acceleration vodz-8olu h*l9: c( ;smo 9qturersus time graph gives

  The area under a curve in a velocity versus timej +v d pv ;ze2k:*;f)e2k a6+cxrdxtg,(qejku graph gives

  If the position versus time graph of an object is a horizontal l:1s9yir k gnz.ine, the object ig1izrs. n:yk9 s

  If the position versus time graph of an object is a vertical line, the objectzpm0tr8d+hd )bd l (i5 is05 bhitp( r+)dldm8z d

  If the velocity versus time gra.l 00d43a, v/idhzpwxt bcv+8u dby785rrtgf ph of an object is a horizontal line, the object 7rw50gpx l 3 t0d,yihuvr c.+bvtdbd/8af 4 z8is

  If the velocity versus time grapc 6f 1xem*cg.jsob31f h of an object is a straight line making an angle of 30 degrees with the time axis, the objectc*.ff6m3 bcsj1xg oe1 is

  An object moves 15.0 m north m) 31nbk+*;b8 2dfbiu d hidbaand then 11.0 m south. Find both the distance traveim h*2b;8bdb)aik+ b3fud1 dn led and the magnitude of the displacement vector.

  A boat can move at 30 km/h in still water. How long will it it ra.l gmk6z7 f7*8eztake to move 12 km upstream in a river flowing 6.0 zf l8kit7z6m.r *a eg7km/h?

  55 mi/h is how many m/s? (1 mi = 41o8g 66qvf jc leob:h1609 m)

  What must be your average speed in order to zh1qk54d:vpc travel 350 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 k:l,e/,d;coq gcrttd 6m) in 2 hours and 57 min. What is the average speed ofg,tt;6e/ :lq ,cdo drc the runner in m/s?

  A car travels 90 km/h. How long does it take for it to traveft ro+ vgpii b/vpl(61ht( c4 9i36axzl 400 km?

  A ly (light year) is the d u aru*q ej)+yy+kbsauhx*1l*g*8x3xistance that light travels in one year. The speed of light *e)u*3xklba+u axj8y r*q yu 1xhgs*+ 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 look to n7gfr/*s)mq 6q *svwnthe side for 4.0 s, how far do you travel during this inatte) vrq*w*sm/sfnq7 ng 6ntive period?

  If you run a complete loop around an outdoor track (400 m), in 8l sde 0wrxwsfvky1-/ug8 +;r100 s, your averag1 -w8 w0exrsg+ sl k8dyr;vu/fe velocity is

  A polar bear starts at the North 1eefl*1.ca4 u-im op aPole. It travels 1.0 km south, then 1.0 km east, then 1.0 km nampee*o 14c1il.fu a -orth, then 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 Pole. It travels 1.0 km south, then 1.0 km ew :hkv;dh5q8hsqx6,s he l7 4nast, then 1.0 km north, then 1.0 km west to return to its starting point. This trip takes 45 min. What was the bear'l kq n7:d qvw4;ehsh ,6hh5xs8s average velocity?

  You are driving home on a weekend from school at 55 mx75e1qc e-a p, aehr(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 m(e-7apm,ehe r1xqa 5cinutes. How far is your hometown from school?

  A motorist travels 160 km at 80 kmjn: 4q0q41 m4m jk2u5sowb bk v9vej9f/h and 160 km at 100 km/h. What is the average speed of t49 f wnjskjeb vb 0:kommvjq9425u41qhe motorist for this trip?

  A motorist travels for 3.0 h at 80 km/x bcr8)4*s,z.ykmk rj h and 2.0 h at 100 km/h. What is her average speed for the tr8jksy.* xrmr k ,4)bzcip?

  An airplane travels at 300 mi/h south for 2.00 h and then at 250 mi/h north ipi 6lt32ms8kfor 750 miles. What isip6k msi832 lt the average speed for the trip?

  In a 400-m relay race the anc(0 +bw0wyn0l1rxhjd thorman (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 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 rac(lyx10n w0dtrbj 0h+ we?

  A car decelerates uniformly and comes twg5 o woqk *ew0ro4a :,svegj50;xsq0o a stop after 11 s. The car's average velocity during deceleration was 58 km/h. What was the car's deceleration while slowinw;0wsev5go oj o0:*s awg05 qx,4kqreg down?

  An airplane increases its speed from 100 m v;cs:uc;p+ fk1sugw 6/s to 160 m/s, at the average rate of ;vsps cc;: f6ug+ukw1$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerates at the ra y;f .z.gqvhxyw6ra g9 *t75gpte 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 resn4qqva;.,rtx r zs n64t 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 s. It then speeds up with a 5ybjr r 67./ab9mepmw constant acceleration of ab5 7mjbw/9r 6y.re mp$2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity-.re zo 6*o5 puynqaoc1ck0i4 of 5.3 m/s experiences a constant acceleration ofa eruo64-ozn.0c *i 1ckqy po5 $3.7 \; m/s^2$. What is the cart's displacement during the first 4.3 s of its motion?

  A bullet moving horizontally to the right (+x direction) with a speed of 345 mpjdyn40 (q(y n/s strikes a sandbag and penetrates a didjyp((yn4 n0q stance of 85.34 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from de q3 19x*iuj6x8t3q5mcx ed ba 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 acceleratiomx5 dc bdtxxque1i qe*8396 j3n is constant, what is the length of the catapult?

  A car starting from rest moves with constant acceleration o h ;,*v25qpqkenx di,uf $2.0 \; m/s^2$ 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 p:h tkcld9+3tebcs )0is its average accelerab:kpchdt3 csl9+e)0t tion?

  An object starts from resmfprbr 95/w( gt and undergoes uniform acceleration. During the first s(5brr/g m9 pfwecond it travels 1.4 m. How far will it travel during the third second?

  An object is moving in a straight line with constant acceleration. u:)e(en2xr7h: hxwn iInitially it is traveling at 16 m/s. Three seconds later it is traveling at 10 m/s. How far does it move duruehx)hnxw:r( : 72ne iing this time?

  A car starts from re*+w29d;zqbd:f jzjlb st and accelerates 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 dh/jdnd pq a+q+phg64nj /9 6i*wmyr 7hecelerate 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 r ik fb(8;8uixgreen, a car that has been waiting at the intersecfi(u 8 bkxr;8ition 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 a speed of 12 m/s on the surface of plane0jy, e */pdt6/de ljc1noroh*t X where the acceler*6 rld/ o1h*je0n j ,c/depytoation 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 12 m , ;.en0l0 ;ziiklxx4ryw-k+er h0za r/s on the surface of planet X where the acceleration exrx; y.zi0we -raiklr0zk0h;l 4+ ,ndue 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 surfac8ge i44;cd py,iehva7e of planet X where the acceleration due to gravi 4epv ,a dgie;4ihyc87ty 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 g:psv 30s b:hqspeed of 14 m/s on the surface of planet X where the acceleratv0:bgpq h:s3 sion 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 qw6qt ao)*fs/ friend holds a ruler between your fingers and releases it without warning, how far can you expect the rulertq)o* as6/q fw to fall before you catch it?

  A ball is thrown upward at a fmdcuyb3i ,si+9xfl (0(v ;iuvelocity of 19.6 m/s. What is its velocity after 3;x ud 3ucibfml9(i,( f0 vys+i.00 s?

  A bullet shot straight up ) b-q,.iic:v reyz pbh,3vs)n returns to its starting point in 8 s. What is the initial speed os-3b vebq,vn ) riyiczh:.p),f the bullet?

  A ball is thrown straight up wij f v;;9ms zz2p:e.fbxth a speed of 36.0 m/s. How long does it take to rfz 2; x:.evzf;spm jb9eturn to its starting point?

  A ball is thrown downward from the top of a bk7 f( erwudc, /as.4lkuilding with an initial speed of 16 m/s. It strikes the ground a(kclrf/wae4 ,k7ud s.fter 2.6 s. How high is the building?

  A ball is thrown straight up with a speed of 30 m/s. (only fill in numericag qov8 bgk2z:exv 4xvf4h-8c/l valueo /:8cvvzx4be g xg h428fkvq- 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 /b shi5j .qgrz2iqznz1p9 :w3mpo 81m into the air with a speed of 21.0 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 10 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 10.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is the velocity at t = 1.0 s? ((tk* l yamgq+cira9)

  In Fig. below, what is the velocity at t = 2.5uwgoi -/p-wrqz(8 -g r s?

  In Fig. below, what is the velocity at t = ikga-o /0 k/mq4.0 s?

  In Fig. below, what is the velocity at t = 5.5 i (rvd7z dpppw)q tt9n;*05 ldpb-5dos?

  In Fig. below, what is the average velomygj+zp j4bf780 wt*w3q(*8-q pk2vmn urisdcity from 0 to 4.0 s?

  In Fig. below, what is the average velocity fr: lrxewzf-kwo+a- ;yc anz9-(om 0 to 6.0 s?

  In Fig. below, what is the acceleration at 7zt:yb7zhi 7eciph0w-+ws1 tq 4d-rd 1.0 s?

  In Fig. below, what is the acceli 5*/ /fd; hrc;cwsrc5sklus7eration at 3.0 s?

  In Fig. below, what is the average acceleration bn-erbq hf5l;f-*h.u ge1l*afrom 0 to 5.0 s?

  In Fig. below, what is the average accelq 2gego-5: 4)tfxk dkteration from 0 to 8.0 s?

  In Fig. below, what is the diwzgxq 9ot6ep: 1u*r8hu+y3s csplacement from 0 to 8.0 s?

Does a car speedometer measure speed, velocity? {spq0iti zp w:/l1xj7(jueed|velocity}

  An object can have a varying speed if its velocu-myz 9.d wt*vity is constant.

  The velocity of an object can be negative when its acc eicv ysy+)/( j2 yfk--qr.c;t7pjenxeleration is positive.

  If one object has a greater speed than a se vu9t ps2mg+ r e*dt(79-dhnwucond object, the first must have a greater acceler+ 972gvms(ed-ud wtn th*ur9p ation.

  Two cars emerge side by side from a tunnel. Car A is travel ldt 2kpcyqdc)9839tto i49 xring 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 ah j, 0(ebdh/9a3aznw7 4 kptbss its acceleration decreases.

  A baseball player hits a foul ball straight up into the air. It leaves the bat ,th8cj sbjf ,*with a speed,sc fj*t j,bh8 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 happenino o2ivc:q1wf mgk 1.s9g to its acceleration, how does it change 1f:k mo.qi sv1 wgc2o9if air friction is ignored?

  As a freely falling object speeds up, whf4n: c1nu7:gjw+6 sga f 2ysgaat is happening to its acceleration, how does it change if air friction CAN NOT s6 1g s:jcf:+ y74augfg2 nanwbe ignored?

  An object that is thrown vertical.duwzg e8*k l u+jl4tcj(kh--ly upward will return to its original position with the same speed as it had initially if airekjk4c- wtu*lul8(+ d.jg-hz resistance is negligible. If air resistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzero acceleratio9vrk4u r5 l95neq0lf cn at the same time.

  An object can have nonzero velocity and zero acceleration at the sayh(87t 9tfefsb8 c-wome time.

  An elevator moving from the secrxe:*wmuz;o 5r0m s/ig 6u, xxocl1 6oond floor to the fifth floor making no stops along the:uwr6s 5*6mx; reo/m1xou gi,xo lzc0 way has zero acceleration all the time.

  A rolling ball moves gw(vgu/; .; b9rrcrrhfrom $x_1=3.1 \mathrm{~cm}$ to $x_2=-6.9 \mathrm{~cm}$ during the time from $t_1=2.1 \mathrm{~s}$ 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 $x_1=2.2 \mathrm{~cm}$ and at $t_2=3.1 \mathrm{~s}$ is at $x_2=7.7 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps aroundt cghhg2p j .seq;-6x9 a quarter-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 its trainer in a straight line, 5d;ahwwc, ddd 6zn *0m8dy8wamoving 101 m away in 8.2 s. It then turns abruptly and gallops halfway back in 4.6 s. Calculate (a) its average speedd*8hw05,dzcwd aydm 6w; nda8  (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 froma 0 nt;jlehp 5:9cht/u $11 \; m/s$ to $24 \; m/s$ 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 from7csvtuhk2v* r8c -5 6t1nbhkt $19 \; m/s$ to rest in a distance of 74 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a sp;bfb vkk +*ux4ca,9 (h5dtqqmeed of $26 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.5 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of the blocks to esseg(iud w*0hro0b*w 1ibntially top speed abou* 0wd0ih*gr b1wboi( ut $10.1 \; m/s$ in the first 10.5 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 uniformlh;f xpv;bz +le3;a,b sy from a speed of $18 \; m/s$ to rest in 5.04 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. Ass3j)9nna+ra )vbw r,.q wu7i czuming a dec7bw.)vur+a) 3,a riwn 9zqnjceleration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck x11q0upc;j 8ag zt he)oyzl9/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).    $m$