Suppose that an obje+;4l fkk3 k9h jxbt9rcct travels from one point in space to another. Make a comparison ;hkxk+9lb3 9jcrftk 4between the displacement and the distance traveled.

  When is the average velocity of an object equ11 ;tp tcieq(rc,1 e- s6fecxhal to the instantaneous velocity?

  A new car manufacturer advertises that their car can go ",ixgf i5)ktqgd;j rjlt.72ci6c +8t xfrom zero to sixty in 8 s". This is a 7.t gxd258 t ;kqfi+ri)jxtgc 6ij,cl description of

  An object moving in the +x axis experiences an accelerat4lkxixeiq/ 7.ai, t.b i,x7 tvion of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x direction) begins8g suclx702tg to slow down as it approaches a traffic light. Make a statement concerning its accele2gt lcugs 870xration.

  Suppose that a car traveling to the West (-x direction) begins to slow zhqjcxkzk :o5n8z8 (1.r;gwsdown as it approaches a traffic light. Makegqsr;x n czz1o88:.wkj kzh(5 a statement concerning its acceleration.

  Suppose that an object is moving w1l qo ig2zk)2with a constant velocity. Make a statement concerning its accewio)q k1z22lgleration.

  If the velocity of an object is zero, does it mesh ppo,bj17q+u op3t:n mn+a:an that the acceleration is zero?1 jtpamonu: hbpn+pqos :+73, Support your answer with an example.

  Can an object's velocity change direction 8dk:wqwa ot:, when its acceleration is constant? Support your answer witao:,d: w8q twkh an example.

  Suppose that an object is moving with constant acceleration.s /h7z;az pcz4qt 8q1ijth26ptvm a -: Make a statement concer zp tvcj6t h:zzp84q2 /hm-q;sti71a aning its motion with respect to time.

  Can an object have increasing speed while its acceleration is decreasin /;:u7paua 4h2qsthzog? Support your answer w7o aau hs:q/h zpu;4t2ith an example.

  Suppose a can, after an initial kick, moves up along a smooth hill of ice. wm-. 5 l,nuuisklpv 1;hy ,/qe Make a statement concerning its accelera.wl5emu,uysvlk-ph,; /1in qtion.

  Under what condition is average veloco9 mg afzl0 -p*e7.chgity equal to the average of the object's inpeg.ozm9l 7ha *g 0-cfitial and final velocity?

  Objects A and B both start at rest. x)7z,3d gkt giThey 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 compared to tdgx3tzk i,g) 7hat of object B?

  Objects A and B both start from rest. They both ac wvlkhvgj()78*wx/rw d4;tl i celerate at the same rate. However, object A accelerates for twice the time as object B. j *xl)w8d4gi/whwk7(;t v rvl What is the distance traveled by object A compared to that of object B?

  When an object is released from rifni qfl-,1z/k iv /n,est and falls in the absence of friction, which of the following is true concerning its motfi/n k-vqi 1zl/n,fi ,ion?

  When an object is released from rest and falls in the absence of f6 g /f4hrm8voxriction, which of the followinxm6/8 gvfr4hog is true concerning its motion?

  Suppose a ball is thrown straight up. Make a statement about the velocitym8bcv(r f/pe(r5 :hezuw0l f ) and the acceleration when the ball reaches the hb80pm c():wv(urfrle/e h5 fzighest point.

  Suppose a ball is thrown straight up. What is its acceleration 2b pa0vwmp ;i4nj6rn9just before it reaches ip2a; v9nrin0m 4w6j bpts highest point?

  Suppose a ball is thrown straight up, reaches a maximum height, then falls to i+w+ l crnsu8p,ts initial height. Make a statement about the direction of the velocity and accencl8p, s+ruw+ leration as the ball is going up.

  A ball is thrown straight u+(ecbvki u / ;y9) vgyw: txjk;hl7py7p, reaches a maximum height, then falls to its initial height. Make a statement about the diyyv uxyvgk )79;l(e 7bcw +:hp i/tkj;rection of the velocity and acceleration as the ball is coming down.

  Suppose a ball is thrown downward in the absence of air resistance. Make a2x: ogf88kr p8cgo d 1bh7hs0k statement concerning ihg 1or 8pghb:82koxk 7f 8d0csts acceleration.

  Suppose a skydiver jumps from a high-flying plane. What is her ay.y,b ih3ksaj3 vq u.oxs1v2m.wmz+- cceleration when she she reaches terminalo+-iyjxs1 ymuw 3 khs.zavb 2v. m.3,q velocity?

  A ball is thrown vertically upward with a speed 5 c+:eprh- )onw 0vx ugy3hi 6si05jb3tsq1oev. An identical second ball is thrown upward with a speed 2v (tsio5x 61q3trw-)u:bh0o0 ephg+ s 3eijyvn 5cwice 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 zj -b(ixprbyq4zl(;2a building. One second later, ball B is dropped from the same building. As time progresses, iz2;(4lr(zb yb p jxq-the distance between them

  Ball A is dropped from the top 0r9epzr /-+ pruhkm.n of a building. One second later, ball B is dropped from the same buildinrrz en+/u0hpp9 m-rk.g. As time progresses, the difference in their speeds

  Two objects are thrown from the 2jkyje1k .b0j)x j o;nnur.2ctop of a tall building. One is thrown up, and the other iskj21e k ;y 2jbcx0n)ju .o.njr thrown down, 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 secon75r xh*lh s,gh cj6/eud brick is thrown straight down from the same building. They are released at the same time. Neglect air resistance. Compare the accelerations of the two brick sc*lu5xe/6j 7hrhh ,gs.

  An object is moving witcdi ,kp ;eok*.h constant non-zero velocity in the +x axis. The position versus time gracipo .e, dkk;*ph of this object is

  An object is moving with constant non-zero acceleration in the +x axis. The posnrwjvlj s0x a/ (81i-xd2d9gxya k-u:ition versui/y xrudsa1xd-g2a 8w0(k9x j:jlv n-s time graph of this object is

  An object is moving with constant non-zero velocity in the +x w2 a :qz9ivdx+axis. The velocity versus t9ax iqwz2d: +vime graph of this object is

  An object is moving with constant non-zero acceld orvworb+2i301s 5 yderation in the +x axis. The velocity versus time graph of this irs o5rwdd0 v +3b2o1yobject is

  The slope of a position versu1lx b*iiha:;n7d 1 akas time graph gives

  The slope of a velocity versus time graph gaqrshca1 n0/( fy7(oa +:nbhx ives

  The area under a curve in an acceleration vevqc srx3d) slpp9(c/qz(:d *vrsus time graph gives

  The area under a curve in a velocity versus time graph giveif ):bc; *sq)bjkn4ncpc6, ves

  If the position versus time gz6p.ffcy f3a4raph of an object is a horizontal line, the object is3.ffa4pyc 6z f

  If the position versus time graph of an object is a vertical lip +)+mu yyh7a*gj3 onwhv mz vz;8:87uqa)kpine, the object isz7ymouk3a 8++7 )hp*;wm)piy:nvajz q h gvu8

  If the velocity versus time graph of an object-g73xr2dbk .jae nv l5 is a horizontal line, the object x3k.7v gn-er ljb2d a5is

  If the velocity versus time graph of anvwpy yp*8lweb, eje59njuzi yf90:(9 object is a straight line making an angle of v,en pz05* pewybliy9(9:w fju8jy e930 degrees with the time axis, the object is

  An object moves 15.0 m north and then 11.0 m south. Find both the diswp5cy h , j72q:saohb(u:+t ky(je+yztance traveled and the magnitude of 2ctbpeh+,sk:yy a(57oj:h+wu( yzjq the displacement vector.

  A boat can move at 30 km/h in still water. How long will it take to move.p6fwoe ax*6i 12 km upstream in a river f 6pafiwo*x.e 6lowing 6.0 km/h?

  55 mi/h is how many m/s? (1 mi s.w-r,c h4:dzs4sfrq = 1609 m)

  What must be your average spee/bn( wl(7iusxvl w:2pd in order to travel 350 km in 5.15 h?

  A runner ran the marathon (approximately k;ha9ri6uf8 o 42.0 km) in 2 hours and 57 min. What is the average speed of the rf;i au6oh 9kr8unner in m/s?

  A car travels 90 km/h. Hov4ioc:kg6qr:/ : cu ysw long does it take for it to travel 400 km?

  A ly (light year) is the distance that light travet+g2 ysxj8f-vq e2(hels in one year. The speed of -2fygxjeqve+2 s(8h tlight 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 d2;4s63clwedi htf +ulook to the side for 4.0 s, how far do you travel during this inattentive pe6dd34u;l s+hiw fte 2criod?

  If you run a complete loop around an outdoor track (40g5ske. cis1 c20 m), in 100 s, your average 1s .ec5cskgi2velocity is

  A polar bear starts at the North Pole. It travels 1.0 km south, then 1.0 k8e2k q 52val i(ux+e-nlja8xhm 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 bear's l( +xv8qn5e2u-j2x hlaie8a kaverage speed?

  A polar bear starts at the North Pole. It travels 1.0 km south, then 1.0 km easw),m09n ydd pat, then 1.0 km north, then 1.0 km west to return to its starting point. This trip takes 45 min )yn0pdwmda,9. What was the bear's average velocity?

  You are driving home on nb(g1 ,s,h3w awcvn(,fol,fs. nwro 2um6 x8ea weekend from school at 55 mi/h for 110 miles. It then starts to sw,(sffn2m (swon,6 , agrbl.v 1h8woxe,ncu 3 now and you slow to 35 mi/h. You arrive home after driving 4 hours and 15 minutes. How far is your hometown from school?

  A motorist travels 160 km at 80 km/h and 160 km at 100 km/h. Whaxw/nj ivm ,0x+t is the average speed of the motoris,v+xmxj/w 0in t for this trip?

  A motorist travels fo xzlth7w1 3k064p eqzrr 3.0 h at 80 km/h and 2.0 h at 100 km/h. What is her average speedh0zz pkt 76lwre4q3x1 for the trip?

  An airplane travels at 300 mi/h south for 2.00 h and then at q*my fj po2wosb-oxshux83;zz1 3a5,+m0et o250 mi/h north for 750 miles. What is the average zfeo80tozu xh3w* axos,+5m1;qos- m3 p yb2j speed for the trip?

  In a 400-m relay race the anchorman (the qfcm3 dqr.10dperson 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 dfcd r3q.m1q0 race?

  A car decelerates uniformly and comes to tu6efyj7( 0wl a stop after 12 s. The car's average velocity during deceleration was 60 km/h. What was the car's deceleratiou(7fjy06tel w n while slowing down?

  An airplane increases its speed from 100 m/s to 160 m/s, at the / 8omg.tq;*n.gm*yv ni .g nmae6d3jhaverage rate of n8.i oj.d;thmmnqe*gv gy 6mg/*a 3n.$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km50 1)1ie3wxe 0,eiqrbm peq zo/h 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 2q5wn k a+964wr c vts*y(uwq; gnlh) ;oty/njand 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 constant acceler:gi-ekh*lldj9 nn:2c) vos b ,ation of i9*:),2bndsn: oke hl- vglcj $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 4.1 m/s experiences a constant accn8+ ggwevy9+2s(lun p.z qpl, eleration ofu wgznyp.8lln9s p,+e( vgq2+ $4.4 \; m/s^2$. What is the cart's displacement during the first 9.6 s of its motion?

  A bullet moving horizontally to the right (+x direction) w83.5r,b mls5zdz dfndith a speed of 418 m/s strikesb 8d,l.zsm35dzfnr 5 d a sandbag and penetrates a distance of 37.19 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from* m diblu ql9mh7 to:0r1ywq0r6l;ii+ 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. Assuminimu+idrtq 0 m6bwq7oly0 *1 :r;h ll9ig the acceleration is constant, what is the length of the catapult?

  A car starting from rest moves with constant acceleratiomff;e7kq) taap/5:-roz gi 3 an 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 74. ij ,1rvrel i1frjato 80 m/s in a distance of 200 m. What is its average accele li7,raj4rr.f1 ive 1jration?

  An object starts from rest a7xwnh ucg7; m.nd undergoes uniform acceleration. During the first second it travels 4.4 m. How fau.cn7hwx7 mg ;r will it travel during the third second?

  An object is moving in a straight line with constant acc )s6hd4 ,l(pzwh+nn v 1cehc0feleration. Initially it is traveling at 16 m/s. Three seconds later it is traveling at 10 m/s. How far does it move du hc4psz n( hwn,dv0)l 1fe6ch+ring this time?

  A car starts from rest and akth:/:s +hy bdccelerates 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 decelerate at about9vq4mf mif-,h $5.0 \; m/s^2$ 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 waiting a/ :j6q4jl 2. mfaopjjit the intersection starts ahead j o46 m2fp :qj/il.ajjwith 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 qw6h7h,,)am cofjk t6a speed of 12 m/s on the surface of planet X where the acceleration du)66 , ,whomq tjh7kface 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 jjo2o3. nj3t 7yho p*qof 12 m/s on the surface of planet X where the acceleration due to gqo tjo.3jhp7 on*j2y3 ravity 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 pl)n 5m b: *0lawepoqf3, yqaya(anet X where th5opabw m eq a03(a:ny)lq*fy,e 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 spe2e1zcg ui8sm;ed of 14 m/s on the surface of planet X where the acceleration due to gravity es;g21 8uzi mcis $3.5 \; m/s^2$. What is the speed of the object after 8.0 s?

  Human reaction time is usually greater thanq-w0)u5ce9s gk 9pzvt 0.10 s. If your friend holds a ruler between your fingers and releases it wiq0t)5e zpvcu9 -kgs9wthout warning, how far can you expect the ruler to fall before you catch it?

  A ball is thrown upward at a vela q8i; s( .lv xsmbz1;8bphxc4ocity of 19.6 m/s. What is its velocity after 3.czpb8 x.;;l 1s( ah8 q4mxbsvi00 s?

  A bullet shot straight up returns to its starting point in 1mjeliasmo5+ 2b22c(w7b y hv32 s. What is the initial speed o(mh2slem32 w 72+byjbo viac5f the bullet?

  A ball is thrown straight up with a s e t(dh(p:gj+ppeed of 36.0 m/s. How long does it take to re( h+g d:j(epptturn to its starting point?

  A ball is thrown downward from the to, x85h)ym9menahz5)lbt 7wo:tja d a4 p of a building with an initial speed of 26 m/s. It so:)njx wm, )4 a7hta lh85tad9ybm5 eztrikes the ground after 1.6 s. How high is the building?

  A ball is thrown straight up with a speed of 30 m/s. 4:psw0kdo /nx (only fill in numerical value spown:4/k0 xdin 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 air with a speed jj5jlk/ju2q ,- mjs0lof 40.2 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 velocity at t = 1.rf od 3e0ftg)y6m v64b0 s?

  In Fig. below, what isikahygbr7-s 18l;6xxo b) pmq/,czn + the velocity at t = 2.5 s?

  In Fig. below, what is the velocity at t = 4.l i-l*;z4fp2g phur u;0 s?

  In Fig. below, what is the velocity at t = s0a zd*vgxt6h)e7ww7)s b wj , w ee3m+ltmq185.5 s?

  In Fig. below, what is the average velocity from 0 to 4.0h3,, sbyiq ra r1d936 ;khunpz s?

  In Fig. below, what is the average velocity from 0 to 6lt:)n5169jzbaps j mz,3 olpe.0 s?

  In Fig. below, what is the p1ay4knlpz)km.b 4 - uacceleration at 1.0 s?

  In Fig. below, what is the u .jaceuw1v ;nw5m+ *zacceleration at 3.0 s?

  In Fig. below, what is the avk+p0lyz g9 y,nf8a-nxerage acceleration from 0 to 5.0 s?

  In Fig. below, what i8 nn9eil59 ze8,x7q m5 mcynfqs the average acceleration from 0 to 8.0 s?

  In Fig. below, what is the dis(1 7w air 2nkkqs6kja6placement from 0 to 8.0 s?

Does a car speedometer measure speed, velocity? {speed|velocity}+ljl -7mnl3juh/a1n: 2 xivko

  An object can have a varying speed if its velocithi/o7 x.3agafyk xb(o xl7hot4;t1 y-y is constant.

  The velocity of an object can be negative when its accelerarht1:x (l yln0tion is positive.

  If one object has a greater speed than a second obgfp9/dnv3-dq ject, the first must have a greate-gn dd3 9vq/fpr acceleration.

  Two cars emerge side by side from a tunnel. Car A is traveling with a speuafvn:ztf8l 38c+hkz.jp, p*z2, kb s ed 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 increasifl*l j.eql;-bng in speed as its acceleration decreases.

  A baseball player hits a foul ball straight up into the air. It leaves tc4qqo /06rhpp dtwg5: 8n)sjfhe bat with a sp)j4qno rcs 8hw5tp0p :d6 qg/feed 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 acceleratiih mwlvw(cnl9:s95 zdo + y*:xon, how does it chango9x *dm59iwhcn:+lzws :l (vy e if air friction is ignored?

  As a freely falling object speeds up, what is happening to its5g4pshw+r(ilw( 0 dxc acceleration, how does it change if air frict hw54wrg(xp( cs+dli0 ion CAN NOT be ignored?

  An object that is thrown vekwb tt3 :v- 5wr :4qzbh.vhot 3yzq0k.rtically upward will return to its original position with the same speed as it had initially if air resistance is negligible. If air res qz.3v 5v 4w-ok:0tb.bz htrhq:w yk3tistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzero acceleration ae2nmj12tv9u st the same time.

  An object can have n-j v9fnec : jzw+dje:,ertg;:onzero velocity and zero acceleration at the same time.

  An elevator moving from the second floor to the fifth fyei kk4ot 0 io;um.*dx(* ,yo(jxfc0gloor making no stops along the wa,(m;c* uox kx 4oeyf dj.y(* ki00iogty has zero acceleration all the time.

  A rolling ball moves5futzj dm0 8 ost 8a,3ry9bt ahr3+0ea from $x_1=2.1 \mathrm{~cm}$ to $x_2=-7.4 \mathrm{~cm}$ during the time from $t_1=0.9 \mathrm{~s}$ 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 $t_1=-2.5 \mathrm{~s}$ is at $x_1=3.0 \mathrm{~cm}$ and at $t_2=4.0 \mathrm{~s}$ is at $x_2=7.5 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps around a quarteh8z72ay2zy d:e xl*zyr-mile ($1 \; mile = 1609 \; m$) track in a total time of 8.0 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, moving 93 m away in 9p w2oh7t u9y8tlx6v)s.9 s. It tvu96ht 82w 7 so)txpylhen turns abruptly and gallops halfway back in 4.7 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 fropmut e1 t54yxudblje;x3a q69 0 1oda471e snwm $11 \; m/s$ to $23 \; m/s$ in 5.6 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 froodi5n bv fups:mli4 h,26m(z 7m $17 \; m/s$ to rest in a distance of 63 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a sp -3o6 elcd8bo7mhc) shjd n6z.eed of $30 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $3.0 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of the blocks to essentially tox6 ;k0gk96b /q5r ccmpt wv;etp speed about cxm pk9w;tvcb kr6/ t0e5;qg6$11.0 \; m/s$ in the first 11.1 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 from asuza/,a5+r k5yim:ua speed of $17 \; m/s$ to rest in 4.05 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 1xqt2)- cku ci 1sh9qton the highway. Assuming a deceleration )ux1ht91c-2iqstckq of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck n 76)os8vm x*z46vnd:vdeymj 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).    $m$