Suppose that an object zj20kexzr0(uzw b88 jtravels from one point in space to another. Make a comparison between the displacement an200z8ju xez8b(jzrk w d the distance traveled.

  When is the average vemmd 6v.17 y95agcw jmtlocity of an object equal to the instantaneous velocity?

  A new car manufacturer advertises that their car can go "frof23/9u9oc4 d jv-e+pank lbowm zero to sixty in 8 s". This is a descriptiodb+ 9kw4coo pnule2jf a3-/9vn of

  An object moving in the +x axis experienu28 t5nb uu,izces an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to thz)b*3i updsb.g n-fh nthm k7*re2d6 4e East (+x direction) begins to slow down as it approaches a traffic light. Make a statement c)r n.2*tnkf7b4h 6h3 -dsugimbpz*deoncerning its acceleration.

  Suppose that a car traveling to the West (-x directionu,tts8y 3)i )ks k -5fhlbxhc6q0tv r() begins to slow down as it approaches a traffic light. Make a statement concerning its acceleratio)skkvyhr,bt 6u (hsf-tit)l 3 q850cxn.

  Suppose that an object is moving with a c:ys kps;5ci j4onstant velocity. Make a statement concerning its acceleration:cj ;54yi spks.

  If the velocity of an object is zero, doe(, v6ajvylf3p s it mean that the acceleration is zero? Support your answer with an exa 6(vf jalp,yv3mple.

  Can an object's velocity c++zfy fhw 5cg.3yzfn: hange direction when its acceleration is constant? Support your answer with an exam.y:h+zf+z gf5f3cwny ple.

  Suppose that an object is moving with constant acceleration. +;4vg 80trh p qkd-gl31hkvmm Make a statement concerning its motion with remkmd-r+0l1 g3vv p4qk; th 8ghspect to time.

  Can an object have increasing speed06zddq 9pq ,m;vcamp7 while its acceleration is decreasing? Support your answer with an exampmm, ;dadcq9qzv p p760le.

  Suppose a can, after an initial kick, moves up along a smooth hill of ice. Make1 x)m.9bt ctrwv,g r*axsnd*/ a statement concerning its accelagr wv*rsdxcx m9 /t1.*,nbt)eration.

  Under what condition is averagextuv::ik 47gz velocity equal to the average of the object's initial and uv::4z tgxk7ifinal velocity?

  Objects A and B both start at rest. They bo hc-o*0q a ewy*+x3jz maum4h1th accelerate at the same rate. However, object A accem*a -40 ey qazh+*hcx m1j3wuolerates for twice the time as object B. What is the final speed of object A compared to that of object B?

  Objects A and B both start from re8x2t hgqgn(-:cnhu ak9g4bo )st. They both accelerate at the same rate. However, obje k)gu 28-nn4 txg9 hbhog:c(aqct 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 r-q gs+jr -wdgg29j)fo est and falls in the absence of friction, which of the following is true conce- s2fggr wq-j )9og+jdrning its motion?

  When an object is released from rpjm*c d93;,jkq 9gsumest and falls in the absence of friction, which of the following is true cm j3s*gu m9 ;9q,kcdjponcerning its motion?

  Suppose a ball is thrown straight5 8djit b,1zt8/ bnznnjyq 1l, up. Make a statement about the velocity and the acceleration when the ban id,byzl1z8t,t nqjb8 5jn/1 ll reaches the highest point.

  Suppose a ball is thrown straight up. What is its acceleration just b t tt93)ljb(drr*qw k5efore it real9b t3t 5 qr)(jrw*ktdches its highest point?

  Suppose a ball is thrown straight up, reaches a maximum heig (2 wz94jkj vb/j il5vsc8gz9rht, then falls to its initial height. Ma bvjs9 i (gw5zj/jz4k9r2lc8v ke a statement about the direction of the velocity and acceleration as the ball is going up.

  A ball is thrown straight up, reaches a maximumc- n/ mtgql:/od 5r+fs2nl8z j height, then falls to its initial height. Make a statement about the direction of the velocity and acceleration as the ball is coming d+tfn 28/q5slm-dn lj:czo g/r own.

  Suppose a ball is thrown downward in thel9 *ju lx+e b9xfa*.krdsuka.s5 3lr( absence of air resistance. Make a statement concerning its accel *e3a aluuf(*99sd5lbkjx+ xrlr. k.s eration.

  Suppose a skydiver jumps from vjl b +uuwcla0w 7;)j0a high-flying plane. What is her acceleration when she she rea+uj0wju )70wallvb c; ches terminal velocity?

  A ball is thrown vertically uplyv+x+go t+p 3fgkx.*ward 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 thatt*g lkf ++x3.y xopg+v 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 buil7/qh.(lpbxzq ncc; p 6ding. One second later, ball B is dropped froq.cq6;/ bclhz 7 ppxn(m the same building. As time progresses, the distance between them

  Ball A is dropped from the top of a building. One second later, ball B is f)qv m n;l3x +t,ff-uhdropped from the same building. As time progresses, the difference ilfm;vnux)h f+-,fq 3t n their speeds

  Two objects are thrown from the top of a tall buildin yoahh)b9 xgl239yx ;wg. One is thrown up, and the other is thrown down, both wha yb 3g)h2wlxx;y o99ith the same initial speed. What are their speeds when they hit the street?

  A brick is dropped from the top of a building. y5gf yh e5im:q+c kh;+,q7usg A second brick is thrown straight down from the sq+ h5 g57;gfy:sykei,+qcu mhame building. They are released at the same time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with constant non-zero velocity in the +x axis. The positil21loiajskq4q8h;aq ;ihe(9 on vers4jk;;aaq lhqs q 2i9(hoe1il 8us time graph of this object is

  An object is moving with constant non- k7 (iycri iut9td8/:xzero acceleration in the +x axis. The position versus (tr8x i9y/d7cktiiu: time graph of this object is

  An object is moving with constant non-zero velocity in ts:gknei9,yexyb mau68v ;xe1w0q- 6l/ yys )xhe +x axis. The velocity )g;6y, sv0y8y:eqnb- s/xwie yxue9 kl6ma 1x versus time graph of this object is

  An object is moving with constant non-zero acceleration inta2 4xv+6 ch6yg 3rlkd the +x axis. The velocity versus time 6ldhx3 k2 cart6v g4y+graph of this object is

  The slope of a position versus time graph giv emr/m(9ltj7u-wr t5 wes

  The slope of a veloc9j+8itam k,bfo0k7h l 99hlysity versus time graph gives

  The area under a curve in an acc(ywnxpz9 r- t4eleration versus time graph gives

  The area under a curve in a velocity verz/d*- vcnzj1rsus time graph gives

  If the position versus time graph of an object is a horizontal-s v .j8nuo(fv line, the object j(n-.8o v uvfsis

  If the position versus time graph of an object is azcr5)sv ,akhu 3g0cxlv -k8)y vertical line, the object is)skc-0 g5uak xvyc 8lzh)3v,r

  If the velocity versus time graph of an object is a horizontal l8qb,ybrj 7p 1vine, the object yp1 8b7brjqv,is

  If the velocity versui uvdbqqe m9* u 0x;h*od455vcs time graph of an object is a straight line making an angle of 30 degrees with the 95xoud eh *q5qic 0;4dv* bvumtime axis, the object is

  An object moves 15.0 m north and then 11.0 m south. Finf)j,2nvx-r,1 op f.fgadip dlbh +-k-d both the distance traveled and the d o2-f jxri n-f,vl)d.-g pp+bhf 1a,kmagnitude of the displacement vector.

  A boat can move at 30 km/h in still water. How long will it take to move ncgx mx(*+( gy12 km upstream in a rivy(xgm n+c(x *ger flowing 6.0 km/h?

  55 mi/h is how many m/s? (1 mi = 160998, dsf qfq)avdg7 h5, qqv24 cjonq;o m)

  What must be your average speed in ozp6pb9 wp6r8 hrder to travel 350 km in 5.15 h?

  A runner ran the marathon (apq 9: qwne8kav,proximately 42.0 km) in 2 hours and 57 min. What is the average speeq, k8a 9env:wqd of the runner in m/s?

  A car travels 90 km/h. How long does it takegzdutum. ,.m9 (8ovwl for it to travel 400 km?

  A ly (light year) is the distance that lighl3) ;sr u-mshyt travels in one year. The speed of light ;uy -)hs 3lrmsis $3.00 \times 10^8 \; m/s$. 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 9 g mm, cr2hg,vjp66cz2vkcg0road and you look to the side for 4.0 s, how far do you travel during this mzvhg2cp k2g 9,gcm66 vc,jr0inattentive period?

  If you run a complete loop around an outdoor track (400 m), in 100 s, x c)3 pmp(tcutmrz9rlq39g- xb8f2p . nvs;o7 your average velocitu93xrlm7p9(nztbvgx3c mr ; 2sopp)q f 8t.c- y is

  A polar bear starts at the North Pole. It travels 1.0 km soututtz.erdvg ,ft ;e;-prt7v8;, : fopnh, then 1.0 km east, then 1.0 km north, then 1.0 km west to return to its starting pointzf; v:8. ptoevr-;dtftt 7u, pr;ng,e. This trip takes 45 min. What was the bear's average speed?

  A polar bear starts at the North Pole. It travels 1.0 fc kjs.vvn+nk593u c +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 45 min. What was the j .cnfvv5k+nk3sc9+ ubear's average velocity?

  You are driving home on a weekend from school at 55 mi/h for 110 miles.erd0n1rz atds2 tyfv- (-,d u: 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 schdz uddat(yf e2,v -r n-01:rtsool?

  A motorist travels 160 km at 80 km/hjm ey4 z 2l3o/qxrl/6o and 160 km at 100 km/h. What is the average speed of the motorist for this tri4l3r/oo/ z6 y2qjemlxp?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h. What is her averqvho tnroqx3 snl91q(6k -r,/ age speed for the tqsntn- ,kxor9rlh3/ o(qv q6 1rip?

  An airplane travels at 300 mi/h south for 2.00 h and then ata (fu n+*7d(biyqcu84ojn0nn 250 mi/h north for 750bdayu o4q7 uncnn 8(+i(fj 0n* miles. What is the average speed for the trip?

  In a 400-m relay race the anchorman (the person who runs the last 100 m) jrmqo-ea 4sb:+jrirgz77 + 9 iv oe;k6for team A can run 1o sq7erzj+mkb 9r-reog4i+;jiav67:00 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 race?

  A car decelerates uniformly and comes to a n7 mq;lajv o4+2+yu ydstop after 11 s. The car's average veloc++yjy24qvn o 7d; uamlity during deceleration was 77 km/h. What was the car's deceleration while slowing down?

  An airplane increases its speed from 100 m/s dj /btn /k.,c(kx 5nkcto 160 m/s, at the average rate of (ck,xnbktjd/ kn 5c./$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerate-c 1xaag) 6hh +ddi(k2l f/:zys :hcays 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 andco;8w kq+*je x 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 1;y a:y1kr*f c3b8wblm 0 s. It then speeds up with a constant accelerationab3ry8 lbw*k1y;:fm c 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 of 6.7 m/s experiences a constant acceleorn(z ,u yz71 6lqc2 2hiyh0xmration o 2z2n (xl0qcym,7yoz1hhrui 6 f $2.3 \; m/s^2$. What is the cart's displacement during the first 8.4 s of its motion?

  A bullet moving horizontally to the rightq 6k4clhozf 6771v xy-5avhdn (+x direction) with a speed of 252 m/s strikes a sandbag and penetrates a distance of 33.96 cm. What is the a6d4ylna z7h1-o5cfqvv 7 hk x6verage acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on an(tupja rxu;4; aircraft carrier. It reaches a speed of 42 m/s at the end of the catapult, and this requires 2.0 s. Assuming the acceleration is cons r aux4;pj(tu;tant, what is the length of the catapult?

  A car starting from rest moves with constan/19gsjrb76i/pa ypzcn 9vy c,t 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 its average qc qwojs2i-0w2)x3eg. y(obwaccelecgo0 i(2 3wbj)we wq2-.oyxsqration?

  An object starts from rest and undergoes uniform acceleration. During the fa/ 7 c;x. c6ir(dyctajirst seati7( /cj6;cxyc.rda cond it travels 7.4 m. How far will it travel during the third second?

  An object is moving in a straight line with constant acceleru0/ ctd:rhti:)ub9 *gri ,lu fation. Initially it is traveling at 16 m/s. Three seconds later it is traveling at 10 m/s. How far does it move during this time?udt c)ru*,br/g l0::9tiiufh

  A car starts from rest and accelerates uniformlyx3(myj,xp u+)fbw (xg yk) g5u 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 wtk+dv ,t8(zd 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 li/xpg8ta fxa3vi8 /x3x ght turns green, a car that has been waiting at the intersection starts ahead wit3if3gxp8vxxxta/ a/8 h 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 sp sdaw-5rc,+ tycc -b 6k/.pyyweed of 12 m/s on the surface of planet X where thew+skdyt 6acr b. w c--yy5pc,/ 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 spej9v-blickj7 n0 m+tthvy(m0 ;ed of 12 m/s on the surface of planet X where the acceleration due9lti mt(y-7 00vkbchvjmj; n + 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 of plane,lhkh qd xa e( ,ybtuyhp,2l34a/8y)qt X where thl ey/ (x p 4qu)k,28l,ybhdahaq ht3,ye 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 speed of 14 m/s on the surface of p 0 i+y/b:xxzxcpd (vnk/l*. urlanet X where the acceleration due to gravity ic x/:nr.b( xu /y*pzl0kdivx+s $3.5 \; m/s^2$. What is the speed of the object after 8.0 s?

  Human reaction time is /+yt:x9da e 5p:ww ijkusually greater than 0.10 s. If your friend holds a ruler between your fingers and releases it without warning, how far can you expect the wtdj+:kp:ywxi/ae 95 ruler to fall before you catch it?

  A ball is thrown upward at * yxprq- vug82 p5ouko*4*f d;paqgi2 a velocity of 19.6 m/s. What is its velocity after 3.00p8xgay45 k -di 2*;rp*o*2voqgup qu f s?

  A bullet shot straight up returns to its starting point u2u81df, tumb9 d7fppin 18 s. What is the initial speed of the bul8umbp 9,dt7 f2p1dfu ulet?

  A ball is thrown straight up with a speed of 36.0 m/s. Ho5pa:ythe )z 1ew long does it take to return to its starting po51ze):hypea tint?

  A ball is thrown downward from th-qmk; sqv:yx+(q ahn jnd66g1e top of a building with an initial speed of 13 m/s. It strikes the ground after 3.8 s. How high is the mav-6s+ qkjg16y;qq:d n(n xhbuilding?

  A ball is thrown straight up w7kil;xgr ,ua9ith a speed of 30 m/s. (only fill in numerical value in the 7xgl air ,;u9kblanks)
(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 wi 1cpld.ott6b *eazi+/th a speed of 45.6 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 9 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 9.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is the 7vx l .z.p3cmk;6weylvelocity at t = 1.0 s?

  In Fig. below, what is the velocity at t = 2. lwen:,tx+/kc uoe,( y5 s?

  In Fig. below, what is the velw h/ywp0m) .nfsu3/fs)qvr2eocity at t = 4.0 s?

  In Fig. below, what is the veloc3+j. 1utwh pg7ny) hzcity at t = 5.5 s?

  In Fig. below, what is the average velocityl q2y1llkh 6qudh4 ;)y from 0 to 4.0 s?

  In Fig. below, what is the average v y9, .n pwx2cm wa/qab.h,dp9c ;vi8bqelocity from 0 to 6.0 s?

  In Fig. below, what is lj (, ott-fg.v:/wigf8v6znfthe acceleration at 1.0 s?

  In Fig. below, what is the ah 3n c+e . .o p6bx-8exu(gnkzdc:dg/pbq+bk: cceleration at 3.0 s?

  In Fig. below, what is the average acceleration from ) jbsllm)v7l* )/ 6zw(h4a1pzvcygab0 to 5.0 s?

  In Fig. below, what is the average acceleratw081k 7vpbkm dion from 0 to 8.0 s?

  In Fig. below, what is the displacement from 0 zatq e9n0e8ilki.f egc7j6/3 to 8.0 s?

Does a car speedometer measure speed, velocity? {speedi6df -1s)q:xewk sa g;aoq 90l|velocity}

  An object can have a varying speed if its velocity mzc+dn4w 0x*xknm:) 4y vt rk;is constant.

  The velocity of an object can be 1oqvcoql5t-+ negative when its acceleration is positive.

  If one object has a greater speed than a second object, thwg ,nst 1b+wh+e first must have a greater acceleration.bgt+nh+w, ws 1

  Two cars emerge side by side from a tunnel. Car A is traveling with eib6p e5uiy eqk(5s8eu5.bm9 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 an,lj2w: ns i; xfwz7./emjl:bs its acceleration decreases.

  A baseball player hit-em;qft a+ w3ls a foul ball straight up into the air. It leaves the bat with amqlf;t we+a -3 speed 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, hat81.1e e7bpna a tdq1dl3p 3uow does it change ifn8el7 aa1p3 3q1d b .tatdp1ue air friction is ignored?

  As a freely falling object speeds up, what is happening to its acceles,l-gyn8y ;l rration, how does it change if air friction CANg;r,ln -syy8l NOT be ignored?

  An object that is thrown ve67t: .y ncioldq)j0og1,ail lrtically upward will return to its original position with the same speed as it had initi7iy:nq,l )0al 6goo.1ljtdically if air resistance is negligible. If air resistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzero mn1 ozjt :i+;ro 2hq+kacceleration at the same time.

  An object can have nonzero velocit6u;b2g v4xri ty and zero acceleration at the same time.

  An elevator moving from the second floor to the fifth floor making no stoi+l3s91wm65 d q cxxxpps along the way has ze9x1q6+xd5 3swlpmci x ro acceleration all the time.

  A rolling ball moves fro) ls-+4mi3xfm z8wkzvm $x_1=3.3 \mathrm{~cm}$ to $x_2=-4.8 \mathrm{~cm}$ during the time from $t_1=2.5 \mathrm{~s}$ 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 $t_1=-3.2 \mathrm{~s}$ is at $x_1=3.3 \mathrm{~cm}$ and at $t_2=3.5 \mathrm{~s}$ is at $x_2=7.4 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight ta5 ):tfs2*-n digb rgcomplete laps around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 9.8 min. Calculate (a) the average speed  (数值)  $m/s$ and (b) the average velocity    $m/s$

  A horse canters away from its trainer cdwr8cm2* u)1z k(psy in a straight line, moving 94 m away in 11.3 s. It then turns abruptly and gallops halfway back in 4.6 s. Calculate (a) its8)sucpdw(1z r2*cky m 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 frod (ynsqo ))rt,m $12 \; m/s$ to $24 \; m/s$ in 5.2 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 fro5jl8mf3 2 retwn*5dhtm $22 \; m/s$ to rest in a distance of 80 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a speed of l fjz8pa( fa8fg s4u0($29 \; m/s$ 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 or ,dk/p5m zh5et o,(*yjy,3rnzhr9vs f the blocks to essentially top speed about d /v, m,yzr*3rn95(kze,yjorhh5ps t$10.7 \; m/s$ in the first 14.1 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 uniformly fr /2pi9jgqhz8e om a speed of $16 \; m/s$ to rest in 5.14 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, r db,*mvu :h4z.v(esealr 7f/a car leaves skid marks 92 m long on the highway. Assuming a decelerasvbdr (ha 7fr4uee/m z:*vl,.tion of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a tru.p);9 s02zm mbf,khhn3vx cly ck 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).    $m$