Suppose that an object travels from one points7jm;3x +kt tp in space to another. Make a comparison between+mk3j st7pt ;x the displacement and the distance traveled.

  When is the average velocity of an ol+6z y gmyte8;bject equal to the instantaneous velocity?

  A new car manufacturer advertises that their car ca 8wkl 5qsu hj2+;a-qzqn go "from zero to sixty in 8 s". This is a descriptionha- zqs2+qj lkw;5u 8q of

  An object moving in the +x axis experiences an accelxm9wu/bns0p e:7 m /zleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car trave3 )k.xhkw1g. kyzhd+ zling to the East (+x direction) begins to slow down as it approazkzdh)y xg1.k+h 3k.wches a traffic light. Make a statement concerning its acceleration.

  Suppose that a car traveling to the Wq 6 efvwh552h30i y+vncr2xycest (-x direction) begins to slow down as it approacwihf2 vcc xn+q6rhy 25vy03e5 hes a traffic light. Make a statement concerning its acceleration.

  Suppose that an object is moving with a constant velocity. Make a sb teqmba85s4. *dmn *htatement conc8 a4b* nhmdm*q5bs .eterning its acceleration.

  If the velocity of an object is +x)zmt)31z nev bq ev/zero, does it mean that the acceleration is zero? Support 1nz+/)exq zm3v)b etvyour answer with an example.

  Can an object's velocity change direction wh360 u0qebtq zpen its acceleration is constant? Support your answer wt3b 6u0epq 0qzith an example.

  Suppose that an object is moving with constant acceleration. Make a statement0 *ygi3 uq+jth concerning its motion wit3ygq 0+ iuht*jh respect to time.

  Can an object have incq i p rqx-/(9tl4f+ habtr8tq.reasing speed while its acceleration is decreasing? Support your answer withbft8ltr9xq q4q+t hi. r-a( p/ an example.

  Suppose a can, after an initial kicw :-yw7xxd(pqe4cq9 x k, moves up along a smooth hill of ice. Make a statement9 xxeqq :dyx7c(wp-4 w concerning its acceleration.

  Under what condition is average velocity equal to the average /a4e9r, b8;ydb5dk eez1rcsbof the object's initiare8 s4;d9rzdbecy5b/e k,1 ab l and final velocity?

  Objects A and B both start at rest. They both accelerate at the same rate.-k3dr * uk5u.n1kdbg h However, object A accelerates for twib1-hgr*d du5kn. u3k kce 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 xb4 21+e; bwxo4xlx ,b ql (f*evteau3from rest. They both accelerate at the same rate. However, object A accelerates for twice the time as object B. What is the distance traveled by obxt2;lewxb4 b ul*feev b1xx4 +o q3(,aject A compared to that of object B?

  When an object is released f - f vqzylqh0e;ti9:iz nz3- 5vky7k;orom rest and falls in the absence of friction, which of thektezv ; khyl z359;7f -i oniqzy0q-v: following is true concerning its motion?

  When an object is released from rest and falls in the absence of n(r- 4(xgt48 erxnxgkfriction, which of the following4nrxn48gktg (rxe(- x is true concerning its motion?

  Suppose a ball is thji,f0yyr nv/,am9hg7 rown straight up. Make a statement about the velocity and the acceleration when the ball reaches the n,y fgir,ma709hj /yvhighest point.

  Suppose a ball is thrown straight up. What is its acceleration just before it :wtp,1ffnq /.6ds7j m ; jmxhzreache:fn ;p xmd/jqzt mh,s7.w61f js its highest point?

  Suppose a ball is thrown straight up, reaches a maximum height, then falls to y g v)jw+thj(.its initial heighwv )h(tyjj+ g.t. Make a statement about the direction of the velocity and acceleration as the ball is going up.

  A ball is thrown straight up, reaches a maximum height, then falls y ye1sin yjf4;h vdwc.6 he9;(esh0x9to its initial height. Make (n9 e9;6f4j he0hwdey hs ivx1sycy ;.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 resistance. Make a staxi6tq51es.tr tement concerning i1r5i.tqx6 tes ts acceleration.

  Suppose a skydiver jumps from a high-flying plane. What is her acc-enull3n 6ppk 4i: vpis6sb:)eleration whev:p u)4s6 : np-6psl3klnbeiin she she reaches terminal velocity?

  A ball is thrown vertically upward with a speed v. An identical second 2ftkk5vz3:tz eym;b9 ball is thrown upward with a speed 2v (twice as fast). What is the ratio of thevt 9bz;k:z 32ke ytm5f 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 later, ball Bsa /;n:reja575jyi3riyny,evv ( cd 8 is dropped from the same build5d:ycyv;8n raev e(iy3 in ja7/sj,5r ing. As time progresses, the distance between them

  Ball A is dropped from the top o2 fgdyzmhc; j9-vu1c5 f a building. One second later, ball B is dropped from the same building. y-1c h 9mc ug;fjzvd52 As time progresses, the difference in their speeds

  Two objects are thrown from the top v,/i(5 3nj exoszv;nyof a tall building. One is thrown up, and the ;/oxzjsveiyn, ( nv35 other is 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 buildcv3h. ) x(i bhch.t4uiing. A second brick is thrown straight down from the same building. They are released at the same time. Neglect air resistance. Compare ttvi ib. c(. )4hhhxuc3he accelerations of the two bricks.

  An object is moving with constant nonm.7 95gn qfqs,gqyo*y -zero velocity in the +x axis. The position versusy,.ggyfmq5*nsq q o79 time graph of this object is

  An object is moving with constant non-zeroqa* v3zbo+gxyxzz/6:j-,u x z acceleration in the +x axis. The posig6bo u: 3xavyzxxq-+,jzzz/* tion versus time graph of this object is

  An object is moving w.bj*m cy : 9qz ryenenb *;9uchw-h57fith constant non-zero velocity in the +x axis. The velocity versus t9j5c.uzh e*n-ybhe9y7 :rbnwq *c;m fime graph of this object is

  An object is moving wizyv sa tyzqc,s.p)w;i13yw .6 th constant non-zero acceleration in the +x axis. The velocity versus time graph of this v.. )ayw,zt3 ;swyq isczy6 1pobject is

  The slope of a position versus time graph : nche kwndq-.)4v4e dgives

  The slope of a velocity versus time7o- zom2p,p c vuk7gjepa2x:.h/7vog graph gives

  The area under a curve in an a:h7 cm pw4k bpus2e(,uff:mt.cceleration versus time graph gives

  The area under a curve.m .iqba y2eeqewcxi0 g8,tu4.v pz)0 in a velocity versus time graph gives

  If the position versus time graph of an object is a horizo o ;fkk7s i-c/gh wjz0rxx 7pvn/.(b1cntal line, the object bs 1x chk(7w .-xf/;iorcpk7gz/0jnv is

  If the position versus time graph of an object is a 07zbk jlwffn j(;l72b vertical line, the object is7wjb02l(lnfzb7 ;f kj

  If the velocity versus time graph of an object is a horizontal line, thev 0zxwc3 )wx6y object is)wvxx w3y z06c

  If the velocity versus time graph of an object is a straight line making an an6s+. +hkkl ne d: b7+3sxormudgle ofs+ :7uml6enskdo r3 k+bxhd .+ 30 degrees with the time axis, the object is

  An object moves 15.0 m north e zrm,;sza8d;lts 3u-and then 11.0 m south. Find both the distance traveled an-sa 8;;t3zlzusdr,em d the magnitude of the displacement vector.

  A boat can move at 30 km/h in still water. How long will it take to )l90utcz,b bdmove 12 km upstream in a river flowing 6.0 km/h?t9zblcbd0 ,) u

  55 mi/h is how many hify4rp h7 r2/m/s? (1 mi = 1609 m)

  What must be your average speed in order 2lxf 3ha9+gl7 xr*t6iu1ugosto travel 350 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 km) in 2 hours and 5r.qh;(gz6 h 6 a/oqmhi7 min. What is thia. 6qh6zhg/om( ;rh qe average speed of the runner in m/s?

  A car travels 90 km/h. How long does it take for irj4o-soc m, l;t to travel 400 km?

  A ly (light year) is the distance thaq70 s v9tii+ydsn,c2dt light travels in one year. The speed of light viqc 0is9dy2,nd+ t7sis $3.00 \times 10^8 \; m/s$. How many miles are there in a light year? (1 mi = 1609 m, 1 yr = 365 d.)

  If you are driving 7: sewl:whybvp ; //*sz2 km/h along a straight road and you look to the side for 4.0 s, how far do you travel during this inat sls/e/ w pbzw*v:;h:ytentive period?

  If you run a complete loop ar0cps gte,:.yl* mq0h*kc3 kg-ipe 4i hound an outdoor track (400 m), in 100 s, your average velocity isqk y3hl4e p-tcm*hg0 e*,i0. kcpisg:

  A polar bear starts at the North Pole. It travels 1.0eh-a-o1) pkd- fovg,t km south, then 1.0 km east, then 1.0 km north, then 1.0 km west to return to its starting point.tdoo pk 1vgae--fh)-, 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 nyqn-2z ty;k7e f1 4f6oxy8j h.w*o mdkm east, then 1.0 km north, then 1.0 km west to return to its starting point. This triy nf4w.f2 yz-t q8 6ok7 jy;mhx1neo*dp takes 45 min. What was the bear's average velocity?

  You are driving home on a weekend fro x qp/2.y rh)ur4ldu9n8 wqmk;m 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 hours and 15 minutes. How far is your homemd8.9rqylq h ;w24uruk) /pnxtown from school?

  A motorist travels 160 km at 80 km/h and 160 km at 100 km/h. *0+gurt2jtb yWhat is the average speed of the motorist yg+02tur tj*bfor this trip?

  A motorist travels for 3.0 h at 80 a;*a mq :g.pm zo:s-azkm/h and 2.0 h at 100 km/h. What is her average s;*ammpa-go sa:. :zz qpeed for the trip?

  An airplane travels at 300 mi/h south for 2.00 smg xv-)y) tp4h and then at 250 mi/h north for 750 miles. W4stg-v) pym) xhat is the average speed for the trip?

  In a 400-m relay race the anchorman (the person who runs the lastbk 96dms ynx e n0.c.5eloo5q h17wi3t 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 teakct.o91qh7m s5i.d5nxe 60 3bl nyewom 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 after 9 s. The car's hprmw6mtfy6 rete.) 55c s(r0average velocity during deceleration was 33 km/h. What was the car's d )r e56( w.6 t5rtsmhmfrpcy0eeceleration while slowing down?

  An airplane increases its speed from 100 m/s to 160 m/s, at the average rate3dfx bd uxl,z+ -;;l ju;kx-iy of ju uxkb;il l,- ;yf+ d-3xd;xz$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerates at the rno. ku356teut ate 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 accc* ,dpy.e 6oo neaog; zs:2hh*elerates 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 3)dl hagxh7t3t s9i/b with a constant acceleration oghhla 37d3xb9i ts)/t f $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 3.1 m/s experiences a cons(. ebnd6hikn6tant acceleration o neni 6(.bdh6kf $1.2 \; m/s^2$. What is the cart's displacement during the first 9.9 s of its motion?

  A bullet moving horizontally to the 9g0njg (3 u9 vkzmx(o,bzf ;pcright (+x direction) with a speed of 424 m/s strikes a sandbag and penetrates a distance of z(mz3ujvkb 9nf,x;g 9 (pcog0 95.80 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on an aircraft carrie+k/p8zqu6kwf)e( qrm9a wz au7,2wqe r. It reaches a speed of 42 m/s at the end of the catapult, and this requires 2.0 s. Assuming the acceleration is const)9,e7w aa/kwr8f uk eqw qu6qzp 2z(+mant, what is the length of the catapult?

  A car starting from rest moves with constant accf 2pvb9x*b suzb;si -*eleration 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 i ,box8bo -** sqzwivq0ts average acceleration?z*0,b8bi- vqo xsowq*

  An object starts from rest:rr: 4.3dj z ndytz7nl and undergoes uniform acceleration. During the first second it travels 9.7 m. How far will it4rn y7trz z3 d.:lnj:d travel during the third second?

  An object is moving in a straight line with conu7iae ucfz i0k6.-yv p- 5in.zstant acceleration. Initially it is traveling at 16 m/s. Three seconds later it is traveling at 10 m/s. How far does it move durfe-.zv5n7i-aikcp y. 0zi6uu ing this time?

  A car starts from rest and accelerates unif) n(pe+piym4 p)tes 0normly 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 t 53y l8y1fiy7a0 dsweat 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 bfa :sb 4i);tcbeen waiting at the intersection starts ahead with a cofc)batbs 4i; :nstant 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 su ap;(2tkux :ga o09zqqrface of planet X where the acceleration due to gravityguax 0 qqz:9o(t;akp 2 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/s on the surfaced2u78 wvcv fonrl1t1; of planet X where the acceleration due to grav2fvcdw71 rlt vo1u 8;nity 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 ae u al:7kfe(;on the surface of planet X where the acceleration due to gravitye(a;k:af7 e ul 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 witq:,u h80 kty jipai(j5h a speed of 14 m/s on the surface of planet X where the accelerath:8p( uiq0j , ykti5jaion 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 greg7r n 62bgz:rhf: 5cshater than 0.10 s. If your friend holds a ruler between your fingers and releases it without warngr f: 56crhhgn2:z7sbing, how far can you expect the ruler to fall before you catch it?

  A ball is thrown upward a0,ud ;dldzus,o7iqw *ix. n.rt a velocity of 19.6 m/s. What is its velocity after 3.00 s* 7zrd..xqi, oi,dud;w0 lsnu?

  A bullet shot straight up returns to its starting point in 8 s. rkrq33cqh 6(y8 rdvajtkq1(bn 2 dh(4 What is the initial speed of th 68qyb3 hqt4k ca3khrv1r (jd(nq 2dr(e bullet?

  A ball is thrown straight up with a speed of 36.0 m/s. How lonyswndl./p+;j g does it take to return d/;w.nj l+ypsto its starting point?

  A ball is thrown downward from the top of a building with an ini*v5z dbp:vrb r z294* eopm sud4xz;x5tial speed of 12 m/s. It*9e:vsx5vz 4bxrb*d 2zr;45dpz omup strikes the ground after 5.4 s. How high is the building?

  A ball is thrown strpo6 s/zajcnna3(:s x4aight up with a speed of 30 m/s. (only fill in numerical value in the blanp n3:z6 j(ao/asc4n xsks)
(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 of 21.9ldms*eun*;.bd9t(mvm 04+u -jb kdtd 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 = m+pha/y r1 +ai1.0 s?

  In Fig. below, what is the velocity attn1eueem 4.jdxc r, er.u s)-: qhy/8r t = 2.5 s?

  In Fig. below, what is the velocity at t = 4 u6,* -*slj0jptvbdvk .0 s?

  In Fig. below, what is the velocity at t ,mtr-m2/ faxc = 5.5 s?

  In Fig. below, what is the average velocity from 0 to 4.0 sn5e,*d ijtk8d wh43)ca*z vlq;6u go o?

  In Fig. below, what is the average velocit+xw7bt3xg3h( nf7d zcy from 0 to 6.0 s?

  In Fig. below, what is the a0:c ybn 8)p-xwd6t hhacceleration at 1.0 s?

  In Fig. below, what is the acceleration p 9frq.:*njzyat 3.0 s?

  In Fig. below, what is the average acceleration *p/ fo mxqay5nfu:h 02from 0 to 5.0 s?

  In Fig. below, what is the average ac:sx;hv +0 gege 6jj l9:)tuinwceleration from 0 to 8.0 s?

  In Fig. below, what is the displacement from 0 rw.ongi*dw2g ,s g),bmhwz0 :to 8.0 s?

Does a car speedometer measure /qkvv57p xhu06ku8 gkspeed, velocity? {speed|velocity}

  An object can have a varying speed if it6p59bj;8/3duu mpvs b dvy v.os velocity is constant.

  The velocity of an objenw-:.lpycv lyk58ge3 w50iw s ct can be negative when its acceleration is positive.

  If one object has a gn(w2oy wyc *yck. 5l(jreater speed than a second object, the first must have a greater acceleration( yl*yo.5y kjwwc c(n2.

  Two cars emerge side by si10te:9trrl6uw yx0 q gfoh00gde 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 accelerah 4od; h,dy:ft cjjz*+tion decreases.

  A baseball player hits a foul ball straight7b; cpahhd2 s 7i9:sig up into the air. It leaves the bat with a s7 s7chd;ph9 gisbi 2a:peed 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 spe.w+boi0 8wmkeeds up, what is happening to its acceleration, how does it change if air friction is ignored?8ew .kwoi0m b+

  As a freely falling object speeds up, what is happening to its ack affogbw3fz 53qy mle-u ;gl0;x )9e)celeration, how dy l efq3;e0)b)ffxz3 5m9la guk;wg-ooes it change if air friction CAN NOT be ignored?

  An object that is thrown vertically upward wa,0ekhca3b+ ge oom97 b,sxk 4ill return to its original position with the same speed as it had initially if air resistance is negligible. If air resistance is apprecix ,h3omge9a 0k+4bc akobse ,7able, how will this result be altered?

  An object can have zero velocity and nonzero acceleration at the same time. cb+ ut6(mao4e

  An object can have nonzero velocity and zero acceleration at the same time.)7oxs*p 8 dc3bev,u hx9 u7syy

  An elevator moving from the second floor to the fnr 3 ogt6*vbof.z/ vqlx -zg4 z.c57yxifth floor making no stops along the way has zero acceleratio g -vqocz.g5 7o /4x*t.znrbvxf6yzl3 n all the time.

  A rolling ball moves fr(. po x.0sv+-qadtc puom $x_1=2.9 \mathrm{~cm}$ to $x_2=-6.7 \mathrm{~cm}$ during the time from $t_1=2.0 \mathrm{~s}$ 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 $t_1=-4.7 \mathrm{~s}$ is at $x_1=3.3 \mathrm{~cm}$ and at $t_2=4.4 \mathrm{~s}$ is at $x_2=7.6 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps around a quarter-milex6 ()raaij7 ;axrs)uijd;bg; ($1 \; mile = 1609 \; m$) track in a total time of 12.0 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, mo yxphhq vvbdeo7 i*x)t:ayqdh 3mt (:p24,1,eving 96 m away in 12.6 s. It then turns abruptly and gallops halfway back in 4.6 s. Calculate (a) its average speethx,v* ,omh3 hq(d1xp4bi2)ye:v pda :7ytqed  (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 fro8f fg34u8dfen. bd2 zxr iu6e/m $13 \; m/s$ to $23 \; m/s$ in 4.1 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 a9z0.m /xmq c ;f veus-;cm+aibg.b*w$18 \; m/s$ to rest in a distance of 84 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a spei-qmt80ot;l vs y,hd 7ed of $27 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.1 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of the blocksp. g1 9:)o :goq8b *1dgzht4qzsxcebu to essentially top speed aboub)89o4bs dg:gqhp *:1e cqz 1.ugzxo tt $10.5 \; m/s$ in the first 14.8 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 uniforml vxvx x32.(+dkwq/r w8,xxxi jy from a speed of $15 \; m/s$ to rest in 4.79 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 higqxm spi:q9 hvie0s7.as 05n.o.xnx )hhway. Assuming a decelerationo:nssxh i eqv0.x) sni7p.0q5xmah 9. of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck goinc0:wpjrz )pg z1kug5s1mx q4,g $25 \; m/s$ 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).    $m$