Suppose that an object travels from one point in space to another. Make a comphvn l2 6;htc+zarison between2vhc ;h6tn+lz the displacement and the distance traveled.

  When is the average velocity of an obje-4 k md6ac; ka7azw/n,wmk2fcct equal to the instantaneous velocity?

  A new car manufacturer advertises that their car can go "from zero to sixty innn7kzhz:8kizmf3ck;em2f-r45 z 0i.* xzpxc 8 s". This is a deskfzz ke:i-28 hmz;z*f. 45r kix0nc xc73mpzncription of

  An object moving in the +x axis experiences an acceler, x)nzsf60(jiko xt-lation of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling tqi a 9k4w)vkbfw6v /*so the East (+x direction) begins to slow down as it approaches a traffic light. Make a statement concerning its acceleration wiv*s/qb kwva)9k64f.

  Suppose that a car traveling to the West (-x direction)kf)z4x /dzswns/e+g 5 s+pbs 2 begins to slow down as it approaches a traffic light. Make a ssx/s +dws2 zke) 4s5g/pz n+fbtatement concerning its acceleration.

  Suppose that an object is moving with a constant velocity. 4 wpm, 4z/,/: c9gus2ltdy.uomxdbfc Make a statement concerning its accz2,,.9 c4/d lw cu4/yf:bomsug dpmxt eleration.

  If the velocity of an object is zero, does it mean that the acce qj)jm690(lbimvy.tz3 j5 opj/pl-wxleration is zero? Supplpz-3mjjoj) m 50vp/b( yjwxqi69. t lort your answer with an example.

  Can an object's velocity change*n0kmtv/v 4 piae ;d-u direction when its acceleration is constant? Support yourdi/* 0tvp;v a knu-4em answer with an example.

  Suppose that an objex:ho64,j/3rk81u ufqdzvste ct is moving with constant acceleration. Make a statement c4x 3 8te:j/d1v us,6ohkzqf ruoncerning its motion with respect to time.

  Can an object have increasing speed while its acceleration is decreasing? S(st2q9 gf)lj +*rvetjupport your answer with an examp *tj e()vr 9qstjg+l2fle.

  Suppose a can, after an initial kick, moves up along a2 *kt+grg8om-h ,i zlf smooth hill of ice. Make a statement concerninmrg +-l2gh8kzoi,*ft g its acceleration.

  Under what condition is average velocity equal to the average of the objectob ,z;i zl w3n0f ch:z1f1yi7e's initial and ff :;n,l iz1h ywzoz7 c1e0ib3final velocity?

  Objects A and B both start at rest. Thed)0u* 32vnsjz :tqx noy both accelerate at the same rate. Hown:j3x*vq uo02 tns) zdever, object A accelerates 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 rest. They 2bq9, zv8oq ttboth accelerate at the same rate. However, object A accelerates for twice the time as object B. What is the distance traveled by object 2o 8tt 9bzqvq,A compared to that of object B?

  When an object is releasedbn.zv s9hvvf: sx1; nq u8o91b from rest and falls in the absence of friction, which of the following is true concernix 1sn9vo1 :8.zfsvbbqu vn9h; ng its motion?

  When an object is released from rest and falls in the absence of friction, whiche m3waq69sij : of the followinqs6jmi a e39w:g is true concerning its motion?

  Suppose a ball is thrown straight up. Make uh v dullkv 01a778p,xy2cod: a statement about the velocity and the acceleration when th dp7cdl u8y7vlk2o x:,0uav1he ball reaches the highest point.

  Suppose a ball is thrown straight up. What is its acceleratih 25(wtr jtzc1 3luf-z 8;mmmron just before it reaches its highest poinrlmcrh5 zw3f8tzm 2 (m1t-u;jt?

  Suppose a ball is thrown straight up, reaches a maximum height, then falls tocts *.uuk1 r-sm7;psk its initial height. Make a statement about the direction of the ts-;1p *ck u.rkms7usvelocity and acceleration as the ball is going up.

  A ball is thrown straight up, reaches a maximum height, then falls to itsn9sb(;z 0 9on pzjaw/p initial height. Maj poszn/wz0 p99;nb(ake a statement about the direction of the velocity and acceleration as the ball is coming down.

  Suppose a ball is thrown downward in the absence of air resistan- 8 5 kd+ruaxfb)7mbuvce. Make a statement concernin7vdm )+afb-uk5 rxbu 8g its acceleration.

  Suppose a skydiver jumps fros3.zhzotce b5 n0+ (odm a high-flying plane. What is her acceleration when shcd( eo50nbthzsoz+.3 e she reaches terminal velocity?

  A ball is thrown vertically upward with a speed v. An identire4. jq) 7q) vuogokr9cal second ball is thrown upward with a speed 2v (twice as fast). What is the.j rv)7ke49rq) o ouqg 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. One second lashyz dk; h4a.1ter, ball B is dropped from the same buildhdskh za41 .;ying. As time progresses, the distance between them

  Ball A is dropped from the top of a building. One second later, ball B is dr*nitxm7yj-zs+ 8 udhi09y)nj opped from the same building. As time progrxhnij07d *-9ny ijz 8m+)usyt esses, the difference in their speeds

  Two objects are thrown from th zn,wb/c0:fhb e top of a tall building. One is thrown up, and the other is thrown down, both with the same initial speed. What arefzc w ,:bh/n0b their speeds when they hit the street?

  A brick is dropped fromq3 f/cdiw7m+n ,uj6ea the top of a building. A second brick is thrown straight down from the same building. They are released at the same time. Neglect aiwae f,m6/ +n7dqc3 iujr resistance. Compare the accelerations of the two bricks.

  An object is moving with copb lls,,no*x--rd0t znstant non-zero velocity in the +x axis. The position ve xt,r-p-*zod bl l,ns0rsus time graph of this object is

  An object is moving with constant non-zero acceleration in tv;nm2g *lwwc 6he +x axis. The position ve;m l2gc6n ww*vrsus time graph of this object is

  An object is moving with constant non-zero velocity in md6ainro q j+2y*)spfjlzb-c v9/ * +lthe +x axis. The velocity versus time graph of this obpiqlb+6o /nfjza*)vc*yjrm 2sl9+ d- ject is

  An object is moving with constant non-zero acceleration in the +x axis. The vel:8t g rqm7ob12mjsw y,8-j uizocity 7 mjjz1:ru,tsbo -m8qyw8 2g iversus time graph of this object is

  The slope of a position ver ieqpnxtbn)9+ z0bu-pe9g a)ias*9k 1sus time graph gives

  The slope of a velocity versus time graph giv smr .n()koykz5 8ap-ves

  The area under a cur+h/gkan xjc4(* 8cqaiyna)0h ve in an acceleration versus time graph gives

  The area under a curve in ogd6 u( f(jrn8mo9+s la velocity versus time graph gives

  If the position versus 8 zbf urpuau5kn; ,;v 9kf,l-btime graph of an object is a horizontal line, the object bu, kf zba;np9,5r- lvu8;kfuis

  If the position versus time graph of an object is a v 2 t2qqs*7npth1zra+yertical line, the object is nt1 y*a q2sz+hp2rqt7

  If the velocity versus time graph o3sbf6,jq +gk22)fjjabr t,rd f an object is a horizontal line, the object gqf3 , tjd 22rfa+,) 6rbjsjbkis

  If the velocity versus time graph of an object jw0p 2mgpi ;bq3u:fo9is a straight line making an angle of 30 degrees with the time axis, theb: p2goiwuq p;j3 9f0m object is

  An object moves 15.0 m 8azh m 6*zw:oafw* xc5north and then 11.0 m south. Find both the distance traveled and the magnitude of the displ6o* fz5hawczw:* 8axm acement vector.

  A boat can move at 30 km/h in still water. How long w r4 lkj 9;tiic7ye40kjill it take to move 12 km upstream in a river flowijy0kt7i;k4i9e 4r cjl ng 6.0 km/h?

  55 mi/h is how many m/s? (1 mi = 16hm amn g2q/8j6d(qp w609 m)

  What must be your average speed in order to travel 350 km in 5eaok45zr2fqtci ;( vu4tuz ,8 .15 h?

  A runner ran the mare)8wb/n cq3dvzm-(fx athon (approximately 42.0 km) in 2 hours and 57 min. What is the average speed of the runner e/3m() w-b cz8fd qvnxin m/s?

  A car travels 90 km/h. How long does it takba+thwkc1+* w up+u;b vgf;7te for it to travel 400 km?

  A ly (light year) is the distar2bdzv 5ae3rjtm.0)zmp nz27nce that light travels in one year. The speed of light)pd5er 7at z0j2vznmbr m.23 z 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 2e/bm/it -jkq/h along a straight road and you look to the side for 4.0 s, how fartib 2kmeq/- /j do you travel during this inattentive period?

  If you run a complete loop around anxclh-o39ofe;8av ld* outdoor track (400 m), in 100 s, your averae-odohlc 9*v 3la 8;fxge velocity is

  A polar bear starts at the North Pole. It travels 1.0 km southi9 yqqb -n. :3yuiqa)sxbuwv5ch9j0; , 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 bear's average; 9ycuiav0b xqq5hn.i:uy sw b39q- j) speed?

  A polar bear starts at the North Pole. It travels 14bhoqvm-v ,3 ol+7l ml.0 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 bear's average b, olh v3v qom-lml47+velocity?

  You are driving homeg*x7u1y ,6;yjxs 3od jgz+r lm on a weekend from school 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 sugym* +7 rl1dxz oyxg,3jj ;6hours and 15 minutes. How far is your hometown from school?

  A motorist travels 160 km at 80 nv*g-hceusfh+ zlb; t. e1.2ukm/h and 160 km at 100 km/h. What is the average speed of the motorist fors+h1tn 2lbc z-vfeh u.eu.g; * this trip?

  A motorist travels for 3.0tbj8lc-l 9x;b8g goc4 h at 80 km/h and 2.0 h at 100 km/h. What is her average spel 8 b9g8cxlo4cbgjt;-ed for the trip?

  An airplane travels at 300 mi/h south for 2.00 h and ti+mczm+zwbw imk1/ 22hen at 250 mi/h north for 750 miles. What is th/zmm 2ibczkm 2w+1 +iwe average speed for the trip?

  In a 400-m relay race the anchorman (the 5q6x qbfe1xlckk)9d -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 st9x k q edl-fq5b)6cx1karts 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 ve9/*iu1m dwf9gsl5 xafter 12 s. The car's average velocity during deceleration was 66 km/h. What was the car's deceleration while slu9mvgd 91wlf*e i sx5/owing down?

  An airplane increases its speed from 100 m/s to 160 m/s, at+,oifpx,djbk;5hp h 9 the average rate of 9xb p,p5jdik ;foh h,+$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h a 5zurnwdkp ,9(ccelerates 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 and accelerates i(r2 +)vkkuc:uwqs /h 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 apqp1w/4o8 bq hrq0 mt0 constant acceleratio qq pbtr/08hp4wq1m 0on 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 5.p4ch0o c* gk:.pml/y++y igi e7 m/s experiences a constant acceleration of y4ecipl im/0chy*.+ g kp+:o g$1.6 \; m/s^2$. What is the cart's displacement during the first 5.5 s of its motion?

  A bullet moving horizontally to the right (+2yzq/ sb.1sww) ml8obj )ba-hx direction) with a speed of 320 m/s strikes a sandbag and penetrates a distance of 24.71 cm. Whaw)1 qas /wz) h 2-msl8b.boyjbt is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is laun9c1dn hhq +xt0 mceu:t-6y/ixched from a catapult on an aircraft carrier. It reaches a speed of 42 m/s at the end of:m ty0- ndi cxtu91xce+ qh6h/ the catapult, and this requires 2.0 s. Assuming the acceleration is constant, what is the length of the catapult?

  A car starting from rest moves with vvuhh48k :uu: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 distanc*gn/,g r v/mxu:t t4dv1 bhlru(:qn(c e of 200 m. What is its average acceleqtgc/dthrgu(mx:4uv(,n /rn l*b: v1 ration?

  An object starts from rest and undergoes uniform accelera ff x cndm9523 g(+8enm)kugzetion. During the first second it travels 5.2 m. How far wilz 8m9(nefu g5m dkge3c2n)+x fl it travel during the third second?

  An object is moving in a: pp 1cjwlsz5uwt:uoy) cnc7z.y1,)i straight line with constant acceleration. Initially it is traveling at 16 m/s. Three seconds later it is traveling at 10 m/s. How far d,tz1w:.yu ) c )ni1wlp7 yp:zs5co cujoes it move during this time?

  A car starts from rest and accelerates uniformly avy,+f*bl ss soa62glo)pp5f /t $3.0 \; m/s^2$. 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 onv dncn zx-*,acs 8xt,4 a 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 ddd6t)/h6 zx qgreen, a car that has been waiting at the intersection starts ahead with a constant 6 htdq)zx6/ddacceleration 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 speed1urp 1 +i*vrflx-q0 :f0dbptz of 12 m/s on the surface of planet X where the acceleratio0qvlufr:d*-0 1p t+ 1b pfzrixn due to gravity is $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown upwara h *gq*tu:1wed with a speed of 12 m/s on the surface of planet X where the acceleration duaug* *1h:w teqe 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 h4 itwhq:l5fzm (v: ; ts4kbft;vo+a-upward with a speed of 15 m/s on the surface of planet X where the acceleration due to gravi -w bl;(tmqavt5:fks of; 4h4:tvi+zhty 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 planc201obp ,g .fhh7l;gdh(hqbr et X where the acceleration gb72h b1g.0 ( copr;q ,fhhldhdue 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 thojo-p muiy)9/an 0.10 s. If your friend holds a ruler between yoy-p9iujm oo)/ur fingers 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 vesmh1;,k2yw- uyiodt ;locity of 19.6 m/s. What is its velocity after 3.00 ;d2-k wo1myti;u,yh ss?

  A bullet shot straight up returns to its starting point in 13 s. What iltwa++ s4lr:c s the initial speed o+ 4wl+ c:arsltf the bullet?

  A ball is thrown straight up with a speevznkuc9koj ,*zh8. 9 47c5yicvf, wx ad of 36.0 m/s. How long does it take to return to its starting po9c8vvcizz, 45x f7ck*kau ,.whj9 ynoint?

  A ball is thrown downward from p3ynt*c ohhlb3 bl.)frcp4 45 the top of a building with an initial speed of 12 m/s. It strikes the grh 4f h)pc3. 5ntbolyp4lb *rc3ound after 6.6 s. How high is the building?

  A ball is thrown straight up with a speed o-9goe(tago;odmry 4(t e3ji2xq8 5j df 30 m/s. (only fill in numerical value4d ixeeyg ;58omdj 3( j roo-gqtt(a29 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 tdwn7u mz 1,8czvzjz 1lu4cn94he air with a speed of 34.5 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 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 ih2i w - x7wp+v7b8l1nzrfws* ns the velocity at t = 1.0 s?

  In Fig. below, what is the velocity at t = 2 eml+h412yh joee)t.y .5 s?

  In Fig. below, what is thecc3;onn-m2 foi l; p7h velocity at t = 4.0 s?

  In Fig. below, what is the velocwi /ob/: f8dtc lfy9j-ity at t = 5.5 s?

  In Fig. below, what is the average velociv a 8:94/bppp6bvagc hty from 0 to 4.0 s?

  In Fig. below, what is the average velocity from 0 to 62e z )dcp 2(jy ys:bc3iou-sm0.0 s?

  In Fig. below, what is the accelerationmjv,t7f6z7 ) ;n4 st bkqo)cio at 1.0 s?

  In Fig. below, what is the accelebju su i 8t6i4awb9y-;ration at 3.0 s?

  In Fig. below, what is thg,3 u (k.fgfx.eg,ticdi k08ie average acceleration from 0 to 5.0 s?

  In Fig. below, what is the average acceleration fromg+y qh z65+lquu4e h+m 0 to 8.0 s?

  In Fig. below, what is the displacement from 0 ty4w uylbyez7ww .k55 8e:/ wx86jrv qio 8.0 s?

Does a car speedometer measure speed, velocit;w,kbt j8g z,sy? {speed|velocity}

  An object can have a varying speed if its zt3ked.ua51 1 1jnyv cvelocity is constant.

  The velocity of an object can be negative when its acceleration is positivg7 .w rsgad7pzfx6t cl8w0-;xe.

  If one object has a greater speed than a sec3 yqlg vnj/86vond object, the first must have a greater accelerati 6v3j qvl/ny8gon.

  Two cars emerge side by side from a tunnel. Car A is travelingh8y erwaut t/0xb/ 5e3 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 accd95sim h2)kl)6nfvg jz2o6y i3w 7jdjeleration decreases.

  A baseball player hits a foul ball straight up iuvl-xvhy )pev 6 8do1:nto the air. It leaves the bat with a speed ofuv8xd-e 1:p )l6yvovh $120 \; km/h$. 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 hexkby yj5, g *y14gx,lappening to its acceleration, how does it changxy5y*1k,l4 ej gb,gyx e if air friction is ignored?

  As a freely falling object speeds up, whatqk mf z,t0p:*6gzl,ag is happening to its acceleration, how do qkz,:mplgzft*6 0a g,es it change if air friction CAN NOT be ignored?

  An object that is thrown vertically upward will return to its originalqjhfryj68 /.c h 9kaply f384m position with the same speed as y ff88mhcy/rl9 3hk6j. j4paq it had initially if air resistance is negligible. If air resistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzero acceleration at they2 ,cq8hea v,* nuk58hrr0pki same time.

  An object can have nonzero velocity and zero accel)lwb)z8w ;x2ov8v nv teration at the same time.

  An elevator moving from the seconds l91zf5- h) rtej-jwi floor to the fifth floor making no stops along the way has zero acceleration all the sj5e)l-fz9ithj1 r - wtime.

  A rolling ball moves fr54qz zu*d zb1w6tc1ywom $x_1=1.9 \mathrm{~cm}$ to $x_2=-7.8 \mathrm{~cm}$ during the time from $t_1=1.9 \mathrm{~s}$ to $t_2=5.1 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-2.2 \mathrm{~s}$ is at $x_1=2.9 \mathrm{~cm}$ and at $t_2=4.2 \mathrm{~s}$ is at $x_2=8.0 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight compjt6jpw 5(dcy .s* eu4wmbt+e. lete laps around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 12.1 min. Calculate (a) the average speed  (数值)  $m/s$ and (b) the average velocity    $m/s$

  A horse canters away from its trainer k5-g2-j c2ngpytf) vec6 d;ln in a straight line, moving 104 m away in 13.3 s. It then turns abruptly and gallops halfway ba;j62n ge-c ) 2tgvpkydc -f5lnck 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 from0r/r,ia7q1k;lizk n4s4e i qe $11 \; m/s$ to $22 \; m/s$ in 4.8 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 fromelm au)y)2l v9 $21 \; m/s$ to rest in a distance of 81 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a speeo91v1 rm 8oa4sv :rrcad of $29 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.6 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter ca e z3bp0utgpevq *94h)n burst out of the blocks to essentially top speed about 4 p*eb3guq h9zpe)v0t $10.7 \; m/s$ in the first 10.4 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 uniforml1kls p8f rrf4id9sb(-nsog5jux :,1ry from a speed of $16 \; m/s$ to rest in 4.97 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves skid marks 92 m l.n z81lm 7cz, mju:li.fs ste-uy8dv-ong on the highway. Assuming a :8l.tf8zdj m.1 l-sme- su iv7czu,nydeceleration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck (gd5p+jx2r8gpd nv w/ovw7 e 2going $25 \; m/s$ 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).    $m$