Suppose that an object travels from one point in space to anot;ooqgir 2j v.ey6r *73g d;wyxher. Make a comparison between the displacement and the distane3;xivyo2o.q6 wdgjr; 7r *ygce traveled.

  When is the average velocity of an objeoud0 qu2c* 1p5. wn+k/qs h m)hofyhj.ct equal to the instantaneous velocity?

  A new car manufacturer advertises that their car can go "from zeroer qlifq9b6 hpc9935 a,9d fvl to sixty in 8 s"3da blevfq9 ql5p9c,96hr i9f. This is a description of

  An object moving in the +x axis experiences an)e w crn4fj/tb-;uy:s9ty h, g acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car travelibxu 2d)fo*jk -ng to the East (+x direction) begins to slow down as it aokbd2xj*)u - fpproaches a traffic light. Make a statement concerning its acceleration.

  Suppose that a car traveling to the Wepb h2 fxkt*vfmc+y1cd5fd 0zu( r6 i6)st (-x direction) begins to slow down as it approaches a traffic light. Make a statement concerning its acceleratu)mfhkt2y6fzd6x v fbr(c 0 cd *5+p1iion.

  Suppose that an object is moving with a constant velocity. Make )3 evd r z0.8ywbl jce;kv. *j4yka2wua statement concerning)l.j be4rkvkc ye.yjuz2; vd3w*aw08 its acceleration.

  If the velocity of an object is zero, does it mean that the acceleration sxd,n( r dcs(8lt9 hu/is zero? Suppolxsdc98h/nd,sr (u t (rt your answer with an example.

  Can an object's velocity change direction when its acceleration is constanenk(v x d+r;,5 kpecn e7*;tfbt? Support your answer with an example7vf;exdckne+ 5b( kpne;r*,t .

  Suppose that an object is moving with constant acceleration. Make a statez/ euoqp8.op, ment concerning its motion with respect t8,u zpo op.qe/o time.

  Can an object have increasing sp v3si/sd e,.qieed while its acceleration is decreasing? Support your answer with an ex,3edi/.iqv ssample.

  Suppose a can, after an initial kick, moves up along a smooth hill ,rm;o s smbp) an;,j7yof ice. Make a aym nj7so bp;)r,;s,mstatement concerning its acceleration.

  Under what condition is averagel3br)kbn,kfg d)obg ,ow4 5i+ velocity equal to the average of the object's initial and f+ g ow i)r,n5dob)gbfl43kb,kinal velocity?

  Objects A and B both start at rest. They both accelerate at the same ras u.0w c;*)i)tcd)rbz vu0fwite. However, object A accelerates for twice the time as object B. What is the fv0zftw. di) *r)wcu0)subic; inal speed of object A compared to that of object B?

  Objects A and B both start from rest. They both accel6 -mh y-lgr:bid4 bt)*wpe q9eerate at the same rate. However, object A accelereb4 e yd-9p*rhl)it -:wbmqg6ates 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 rest and falls in .e: 6kj) :ner0sfq pkuthe absence of friction, which of the followir: ksk) e.60qunef: jpng is true concerning its motion?

  When an object is released from rest and falls in the absence of frictioon .p;7u y)pj1llsm 0aq; zmq6d zq7n0n, which of the following is tru71q p)0n7; mq. ld un6myz;ospazl jq0e concerning its motion?

  Suppose a ball is thrown straight up. Make a statement abouk 2gfa u1ojoq -k; dum(1qpl-*t the velocity and the a;2q*aogf k1k o-lu1-u(dqmjp cceleration when the ball reaches the highest point.

  Suppose a ball is thrown straight jhz(v+1i)+ s,pzrybkup. What is its acceleration just before it reaches its highest poi)sk jv+(b zy+rz, 1ihpnt?

  Suppose a ball is thrown straight up, reaches a maximum height*yupdxfvc 6:av* 8z)zvb-gh + , then falls to its initial height. Make a statement about the direction of the velocity and acceleration as the h:vc 6guy-+*p dvfzza bx *)v8ball is going up.

  A ball is thrown straight up 8fbl.93bcn xq, reaches a maximum height, then falls to its initial height. Make a statement about the direction of the velocity and acceleration as the ball is co8q. 3blb9x fcnming down.

  Suppose a ball is thrown downward in the absence of air resistance. Ma, 1i lcyng4: vrbczbd,6q(r:j ke a statement concerni r(vg:b :b4q6cyld,irncjz1 ,ng its acceleration.

  Suppose a skydiver ju 5 el-xoc0u5pamps from a high-flying plane. What is her acceleration when she she reaches terminal veloccl-apuxo5 05e ity?

  A ball is thrown vertically upward with a speed v.-wr :4 d ioi432m8e,nifdswb r 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 d oifi ebnrs4i4-:3w,2d8wr mto 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:t 1d,ckqwd:l . One second later, ball B is dropped from the,d q1w:kldct: same building. As time progresses, the distance between them

  Ball A is dropped from the top of a bzk )1lobct4y 1*.-pkka l4v eeuilding. One second later, ball B is dropped from the same buil.oyptke)*kllb -14 ezk 41vcading. As time progresses, the difference in their speeds

  Two objects are thrown from the top of a tall buildingytd p,y;u 7tc,. One is thrown up, and the other is thrown down, both with the same init;t yydt, c7pu,ial speed. What are their speeds when they hit the street?

  A brick is dropped from the top of a building. A second brick g u1h 6d/x7y*gvy:ptx is thrown straight down from the same building. They are released at theugh6*x x 17:yd/pvgyt same time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with constant noy2w5m n8krkax- h5 t3kn-zero velocity in the +x axis. The position versus time graph of this obk35h myatk8-25 nxwkrject is

  An object is moving with constant non-zero accelerati0mi 55i,fkk e-wh5s bcon in the +x axis. The position versus time grkmw5h-iie0, fs5cb 5 kaph of this object is

  An object is moving with constant non-zero velocity in the +x a z,m6bs 0sgs.fxis. The velocity versus time graph of this object isg,b 6zm0.s sfs

  An object is moving with constant non-zero accelwjomk9i 94*hm; *zz mveration in the +x axis. The velocity versus time graph of this objemz ozh *m94v 9;wmkij*ct is

  The slope of a positi0wswl ll;j j(z,2 rsqx) rypnsk.*6)qon versus time graph gives

  The slope of a velocity versus time grtpe k) 1)dk+a:s qki(top;h7zaph gives

  The area under a curve in an accel,vt8rt,s v2 dperation versus time graph gives

  The area under a curve in a velocity versus timjjg )i f9aj2,he graph gives

  If the position versus time graph of an object is a horizontal lzf o t3/ ,:c/)rkcjaodine, the object iszooj3 : /kctc,/fr ad)

  If the position versus time graph of an object is a vk1)b9s(ni+5z ;+ lzaf mokumxertical line, the object isb+k1 z;lm 5fa+() 9kzmisounx

  If the velocity versus time graph onq41y 2aykyaby2s /i nu+ 1f *c++zyxcf an object is a horizontal line, the object isak y yyus+fbxcn+1y 1 *acz2+/iy 24nq

  If the velocity versus time graph of an object is a straigh,8 5jhvargh6bt line making an angle of 30 degrees with the time axis, t6g vjh5 8r,bhahe object is

  An object moves 15.0 m north and then 11.0 m south. Find both the distance6 l8keb*vcw quh x zag4 ri*ua6o0e;,- traveled and thebq;ac80e uweik 4a o hxu *gl66rzv-,* magnitude of the displacement vector.

  A boat can move at 30 km/h in still water. How long will it take to move 12jfl/; 8oyqh6nx*z/wc zsi)f - km upstream in a river flowqz-wcni8f /l6 o*/)j yfszx;hing 6.0 km/h?

  55 mi/h is how many m/uumy8a, cpjeabpq y m:mq. sgy82,41( s? (1 mi = 1609 m)

  What must be your average speed in order to travel 350 k;e +n5fk ki(xmm in 5.15 h?

  A runner ran the maratho w4 nktee:bac+l0ba(t5ht; ;pn (approximately 42.0 km) in 2 hours and 57 min. What is the average speed of the r0elh; (5tp b kcn;+4ttbw aea:unner in m/s?

  A car travels 90 km/h. How long does it take for it to21dto(r xk9lvl;u +rz travel 400 km?

  A ly (light year) is the distance that light travels in one year.5 *nev2u1qoqr The speed of light *rv1 eqo25 qnuis $3.00 \times 10^8 \; m/s$. How many miles are there in a light year? (1 mi = 1609 m, 1 yr = 365 d.)

  If you are driving 72 km/h al25*t 9ow2k fmbzftgq 0ong a straight road and you look to the side for 4.0 s, how far do you travel during this in*9f2kzm bqt250owgt f attentive period?

  If you run a complete loop around an outdoor track (400 m), in 100 s, your avek68x3 bq vk z5zlx/yyw.6bgf(rage velo y/g6f b6.v zby(qxxkz35 kl8wcity is

  A polar bear starts at the North Pole. *tk29 qm-(i adtux)qi It travels 1.0 km south, then 1.0 km east, then 1.0 km north, then 1.0 km wesdqktmu9 i it(* q-xa2)t 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 lk6rt)qu,da (km east, then 1.0 km north, then 1.0 km west to return to it qk)ur6, td(las starting point. This trip takes 45 min. What was the bear's average velocity?

  You are driving home on a week rt m/d+mg-zs0nk.y*kend from school at 55 mi/h for 110 miles. It then starts to snow and you slow to 35* +/.mg-syndkzmrtk0 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. What is the vd0.ef nj7q-z average speed of the motorist for this trip?nz . qdev0-fj7

  A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h. zq7e c8i5f-xz What is her average 78fe- 5zzcqxi speed for the trip?

  An airplane travels at 300 mi/h south for 2.00 h ant+wmafz2t/yv2t:0 fjd then at 250 mi/h north for 750 mile ma/fz 2ttv+j 02wy:fts. What is the average speed for the trip?

  In a 400-m relay race the anchorman (the person who runs tn 8*-+kyb0cruv d/xe ghe 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 largeg/ ndre8bk+- c *u0yxvst 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 stop.l-v ne:0zj aq after 8 s. The car's average velocity :. laq jz0en-vduring deceleration was 39 km/h. What was the car's deceleration while slowing down?

  An airplane increases its speed from 100 m/s to 9kf 2g.ghk/ w o8z)t*i*4q j3lckpu vyt5cy/d160 m/s, at the average rate of t*2ukk d9jlgzyoih3y*kgc/ ). 4 fvtqc 58 /wp$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerated bcphcr. (hv/,z,;b ks 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 eha5b xb5*axwk- 7 6bfand 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. jn4x-r(y--e7x-thcubyx/e u It then speeds up with a constant acceleration(4x --rc-7ejth-u xynuxeb/ y 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 6.5 m9 v. u*djqcqq1z:up f- .lcg,b/s experiences a constant acceleration of g*j : v.1cqpz 9u-lu.dbqc,qf$4.4 \; m/s^2$. What is the cart's displacement during the first 5.6 s of its motion?

  A bullet moving horizontally to the right (+x d +-l hxvp 5+kmn3wrg1tirection) with a speed of 220 m/s strikes a sandbag and penetrates a distance of 41.04 cpv- wrl++gx3k1n5 t mhm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launch 7aet/u 6pjynh vy 4qgvf1n0:p4y6 c0ped from a catapult on an aircraft carrier. It reaches a speed of 42 m/s at the end of the cat6e4fn6:pycanv yq0pg v/u j701 4th pyapult, 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 constuwsw6p1ymhx-p6m (u ;ant 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 averagqg ;ja3 bap:bzxk0te k( r, x.b97;yjee acceleratioek3;ajx b:9bb ,qayjz0 .(xrp eg;7tkn?

  An object starts from rest and undergoes uniform acceleration. During the fi esqm(6.zgkfi1fyy1g/ si -2 zrst sef gz2ky if(gq sie6y /1.m-1szcond it travels 1.4 m. How far will it travel during the third second?

  An object is moving in a straight line with constant acceleration0 fgns*7smz hvcs(5c (. Initially it is traveling at 16 m/s. Three seconds later it is traveling at 10 m/sn 07gsv5* (( cchsfmzs. How far does it move during this time?

  A car starts from rest and accelerau8vmkv33fvgt .m;ce1 tes 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 rodi7z4d )0tl (jsj/ fqam/u 0pfad 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 green, a car that has been waiting at usshw/:)pcvl mq:;9.rew t).pbb1sz the intersection starts ahead with a const )slv;b9pzb::c psm1 ur / ww.qe.sth)ant 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 suroovt6 o3a5eu-0ex3v -bgbv 5 uface of planet X wherev3u 5v -ou-bgb3ev x t50e6aoo the 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 spepc4tn/h(. d. z8wv*: vr mbgbued of 12 m/s on the surface of planet X where the acce* v(z:gdhmrbunb8vp .w.t /4cleration due 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 surfak59wd4jz+uxa j 6d dv6u8dm4uce of planet X where the acceleration due to gravityduk4d 8mw+ d65u4x v9jzjd6au 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 ov1( 6iemm mbmota(x1( ii3iel,5jso(f planet X where the acceleration due to gravexatmb mse6mii,(ol 1 (om3 v(ij5(1iity is $3.5 \; m/s^2$. What is the speed of the object after 8.0 s?

  Human reaction time is usually greater than 0.1 r) ija)f9o(pj1zehp b;iv ,s/0 s. If your friend holds a ruler between your fingers and releases it without warning, how bhjjzei apf i/r,1)vo;p9s() far can you expect the ruler to fall before you catch it?

  A ball is thrown upward at a velocit hwy bbpu,5xq(r(v13k y of 19.6 m/s. What is its velocity after 3.h p3(yw b,b(kqvu51xr 00 s?

  A bullet shot straight up returns to its starting point in 18 s. What is they9 jm+ 9u;npw-r0d ljg ind09 w;9julrj pn-y+mgitial speed of the bullet?

  A ball is thrown straight up with a speed of 36.0 m/s. How loni jn)2;fwxvb *g does it take to retuw*n)x vbjf;i 2rn to its starting point?

  A ball is thrown downward from the top of a building wi by268zb u73q;h8z ot uzkc.y wi6i2b8 jsf*ceth an initial speed of 6 m/s. It strikes ye8tbhk*.6uw8 6z b2if7 b2qsyczicjz;uo 83the ground after 4.8 s. How high is the building?

  A ball is thrown straight up with a speed of 30 m/s. (only fill in nume8ir ouv- (3zv+h (nkjqrical value v(o r+-zj 38q(khn vuiin 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 ai7c68mjjxq 65r 44lh z;photc rr with a speed of 42.9 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 3 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 = x2k- rr7;nhcb 1.0 s?

  In Fig. below, what is the veloo5zyfd+t s,sh6t td v hr5:q*x qyc94:city at t = 2.5 s?

  In Fig. below, what is the velocity at eqdea-) k rwe6m*9e31mo x:vwt = 4.0 s?

  In Fig. below, what is thg;qp l7l f l3jm;/ty /ka/kqcmw8(gb-e velocity at t = 5.5 s?

  In Fig. below, what is the f jtr6fb*4lshh6(tg * average velocity from 0 to 4.0 s?

  In Fig. below, what idv 926o rp-ixvs the average velocity from 0 to 6.0 s?

  In Fig. below, what is the acceleration at yusyu744.pm+ku bn0b 1.0 s?

  In Fig. below, what is thxbi1pq8 3fi5m e acceleration at 3.0 s?

  In Fig. below, what is the average acceleration from 0 to 5.0 s1sv2;2y-udt ow9n s jy?

  In Fig. below, what is theuhw42 v 2sllb8f:d7;aj6 r spd average acceleration from 0 to 8.0 s?

  In Fig. below, what is the displacement from 0 to 8.7l3/mqooa(a9 jnp- 1 wl *jfom0 s?

Does a car speedometer measure speed, velocity? {speed|velocityv+hc07.b g;)saow rhiod9 qxsw8)le(}

  An object can have a varying speed if its velocity is c8b;nrjuxze/7 onstant.

  The velocity of an object can be negative when its acceleration is positqm2 hmtb j1.(mive.

  If one object has a greater speed than a second object, tr8*ux rl :k6:chs ui-ehe first must have a gre:ri6 h-uec:u srl*x8kater acceleration.

  Two cars emerge side by si go nh(y92lp lqv+e2;mde from a tunnel. Car 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 speed as its acceleration decreasesa+)klo1q p ok0.

  A baseball player hits a foul ball straight up into the air.msdyw8 7.(/nyl wel/ o 5y(36 oyw+i0myqgzpj It leaves the bat with a+y/ y(n.0 oyw7wypwm8jl3 mdo6l (s/y z5ieqg 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,pdvugf,r/5p,4 4-jo/ so qubs how r/5us4u ,/j-bp4,pvqodso g fdoes it change if air friction is ignored?

  As a freely falling object speeds up, what is happening to ijep9tsd; -* e m9vbri2ts acceleration, how does it change if air friction CAN NOT v m9e r j;2te*9dp-ibs be ignored?

  An object that is thrown verticallykoowkcb) im g(((k1(y upward will return to its original position with the same speed as it had initially if air resistani(1g(bm ( ko k(cokwy)ce is negligible. If air resistance is appreciable, how will this result be altered?

  An object can have zero velocish ,3szx z49emsk.qq;ty and nonzero acceleration at the same time.

  An object can have nonzero v;dbzqda7ib 2-5.nu 3r-jhp pnelocity and zero acceleration at the same time.

  An elevator moving from the second floor to the fifth floor making no stopsrn p :2:ewornq j3o7(o along the way has zero accele27rwj(epqon3ro:no : ration all the time.

  A rolling ball moves from 3/sur;inul,fyuf4a9au9-jrr )rw ,y$x_1=2.3 \mathrm{~cm}$ to $x_2=-7.4 \mathrm{~cm}$ during the time from $t_1=2.5 \mathrm{~s}$ to $t_2=5.4 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-3.8 \mathrm{~s}$ is at $x_1=2.2 \mathrm{~cm}$ and at $t_2=3.5 \mathrm{~s}$ is at $x_2=8.2 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps around a quah oaw,:+i(o f( y.asf b8iqq :;fvuw:zrter-mile ($1 \; mile = 1609 \; m$) track in a total time of 6.0 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 98 m away in 1c fzxwm1yoihq-6*hi 0 x19zg( 2.2 s. -6 czyqx*x9w1i(him 1 fozgh0 It then turns abruptly and gallops halfway back 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 fr8llktl :el65tgec;v(iuw( q 3om $11 \; m/s$ to $23 \; m/s$ in 5.1 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 from wzjk ;8y1bkp 0$21 \; m/s$ to rest in a distance of 85 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a speed of jpz;7)-.mjsa dld5db $28 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.7 \; m/s^2$ ?  (数值)  $m$

  A world-class sprint )-lzo k7auzyj; 5o)j7fwu5suer can burst out of the blocks to essentially top speed about 7)5kaw ul-ozuj7)y f ujszo5 ;$11.3 \; m/s$ 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 uniformly from a speed 6pm5t gzw; 6ojof $17 \; m/s$ to rest in 5.93 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 t cjogyguqf * /m-.y-4ihe highway. Assuming a decelef /gu-yygij 4c .*-moqration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck going x1 1*:2r nknmm hv7aym$25 \; m/s$ 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).    $m$