Suppose that an object travels from one point in space to another. Make a:jev ymq29lk cak7(-e comparison between the displacement and the distance 2a eq e7v-9kjc:( ylkmtraveled.

  When is the average velocity of an object equal to the fcro7/yz3wvtmt4 :o em)3ns 7 instantaneous velocity?

  A new car manufacturer advertises that their car can go "froj9 zrhb.k7rz+29f*ff+9 gx6 puvnee wm zero to sixty in 8 s". 7* refe 9nv f6z ujh +fp9+2wbgxz9rk.This is a description of

  An object moving in thw c k;q/zt1)v eprljg,j:9qo8e +x axis experiences an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x direction) begins to slow 2rg;0ygwe6g,xkkwy/: l j rm.down as it appwkg yj:;emgr.y2xk 6g0,w /r lroaches a traffic light. Make a statement concerning its acceleration.

  Suppose that a car traveling to the West (-x direction) begins to swki)3esybf, (k r53:bthyy,bm 9mw4llow down as it approaches a traffic light. Make a statement concernin4ei, kw h b)9335:ymlybfy(st,wkb rmg its acceleration.

  Suppose that an object is moving with a consta ds d0 k80ksqam*bn8z)nt velocity. Make a statement concerninq b08dzk)kss *8andm0g its acceleration.

  If the velocity of an object is zero, does it m;dn5 nxo6ev9f ean that the acceleration is zero? Supponv5f;onx96de rt your answer with an example.

  Can an object's velocity change direction when its acceleration is constan*lf6hp s0y 5t o+vmw;yt? Suppoyf*mvp yh6tol 5+0;swrt your answer with an example.

  Suppose that an object is moving with constant acceleration. M6l gc7e-bfd n5l8:ekzake a statement concern 8efb-z 7cld6e:gnk5ling its motion with respect to time.

  Can an object have increasing speed while its acceleration is decre-33 f; ovelk4q4aenjcasing? Support your answer with an eevn44jeqclf;-a33o kxample.

  Suppose a can, after an i2e 6ssasp bq g7,oyl,9e-ou5vnitial kick, moves up along a smooth hill of ice. Make a statement concerning its accelerati9ygelqs-s 5,soeo au6 2bv,7 pon.

  Under what condition is average velocity equal to the average of the o-20td xi0+xbss u,shprs3, nhbject's initial and 0u bxsxrs2-nht,i,d3h0 s +spfinal velocity?

  Objects A and B both start at rest. T+2c :1ojg hdo fxpc6/jhey both accelerate at the same rate. However, object A accelerates for twice the ti 21 fo jj6cchxo+d/:pgme 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.jxz /( r /a+mtbum-92kh.cpmt They both accelerate at the same rate. However, object A accelerates for twice the time as objex t- cp zhk.mujt /b92+ma(r/mct 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 the a ryb8l4rt8 0sgr4xfz+an /amb*7sd:ubsence of friction, which of the following is tru0nftm/x b a8:u4rg+ bsar8dy7srl 4*z e concerning its motion?

  When an object is released from rest and falls in the absence of fr y4lv80a:.dfqzlc 3x qiction, which of the following is trcf d :l3lqxyqz 8a0.4vue concerning its motion?

  Suppose a ball is thrown straigh. ox)n-g*tf kbt up. Make a statement about the velocity and the acceleration when the ball reaches the highe -bkx*og.)ft nst point.

  Suppose a ball is thrown stralm*no h50h xft-n7hk f4u +79ci xl+aaight up. What is its acceleration just before it reaches its ll+ u 7xc0m a4t7ni- hx9ohfk+n*hfa5highest point?

  Suppose a ball is thrown straighskd4x f)/0+ e 3opsud3oy fle(t up, reaches a maximum height, then falls to its initial height. Madfuo+l( )seo0s/xk4f e3 d 3pyke 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, vlenjd jm/)5v *bd /igx.vij+ 6r/6pfthen falls to its initial height. Make a statement about the direction of the velocity and acc /fmd6gix.p5 r+vi 6ln)edvvjj*/b/ jeleration as the ball is coming down.

  Suppose a ball is thrown downward in t. * z r79dp f,pr)ubicl.d:hifhe absence of air resistance. Make a statement concerning it dl,bpi 7hrirpf:c.zd9u*f . )s acceleration.

  Suppose a skydiver jumpskj 6dpa*gw 0d, from a high-flying plane. What is her acceleration when shewadp*j 6 gkd,0 she reaches terminal velocity?

  A ball is thrown vertically upward with a speed vqvelu q);xi b3kk(n 19. An identical second ball is thrown upward with a speed 2v (twice as fast). What is the rati ke 3) nbxv;ki9uq1(lqo 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 thb 62v .9c.4:mfruyegm uh n-dwe top of a building. One second later, ball B is dropped from the same building. As time pr-:n d.b.hmgm6 2f 9 c4wuryeuvogresses, the distance between them

  Ball A is dropped from the top of a building. One secondfk h3)lid,9fc6,hyo o later, ball B is droppe,y)6 hkhio9,fo 3l dcfd from the same building. As time progresses, the difference in their speeds

  Two objects are thrown from the top ofstr*q).1c/ w pe0prp-rrs 1jm a tall building. One is thrown up, and the other is thrown down, both)ctr-qprprs p1r*/e1m0 w j. s with the same initial speed. What are their speeds when they hit the street?

  A brick is dropped from the top xt/2vthzx-8j* ./b -hmnedlpof a building. A second brick is thrown straight down from the same building. They are released at the same time. Neglect air resistance. Compare the accelerations of the twoxblp v tjz /-n*x/thehd2.-8 m bricks.

  An object is moving with constagar )0y)beev7 nt non-zero velocity in the +x axis. The position versus time graph oya0vr))e7bge f this object is

  An object is moving with y0n l, vja8phhh t)ys-tqp7()constant non-zero acceleration in the +x axis. The position v yl )jtan p-h(h,pt0 8syh)qv7ersus time graph of this object is

  An object is moving with constant non-zero velocity in the +x axi1(bbd4wra ol5hyzcz : d9fj 2:s. The velocity versus time graph of this objectz b459br: ocaydj(z1h dwlf: 2 is

  An object is moving with constant non-zero accelu i,c8)ii5hp2)d yucveration in the +x axis. The velocity versus time graph of this dpc u8ii52)y, uvic)hobject is

  The slope of a position vk/0dh,zqf gctmkf3 s c+g1,zty/2x2 btm- w p+ersus time graph gives

  The slope of a velocity versus time graph givesm km3s4y(f55l h7 d4ui ;uygfg

  The area under a curve in an acceleration versus time grah) th3qba + 1ofc,5somph gives

  The area under a curve in a velocity0u+ c2pd df7,wza5t 0hjy7 yvj versus time graph gives

  If the position versus time graph ofb -vdo 81 pj+mtlh*njrh29l+q an object is a horizontal line, the object iso9lhlq8-v 1n+h 2jpb mdr*t+j

  If the position versus time graph of an oqh3/1jb wvu9q* axp*dbject is a vertical line, the object isq haj3*/ q1dxubw vp9*

  If the velocity versus time graph of an object is a horbge 1u8g,w 4lrizontal line, the object 1b8 w,u4rle ggis

  If the velocity versus time graph of an objup tq5h69y hp5q 2:jg-e6sb tiect is a straight line making an angle of 30 degrees with the time axis, the object 6 p:5thju b2ges5-yhp qq6i9tis

  An object moves 15.0 m north and then 11.0 m south. Find both t26x9xatx8y-+ ,ll yu pha2eszhe distance traveled and the magnitude of thexa 9,x te86 h2yl+lzyas-xu2p displacement vector.

  A boat can move at 30 km/h in still w zsq; 8m0vra9eu:2rxhater. How long will it take to move 12 km upstream in a river flow09aqsx:rh2; u mv ezr8ing 6.0 km/h?

  55 mi/h is how many m/s? (1 mi = 1609 -2ylp/iw .et my o2z9gm)

  What must be your avera 6mzxq2z,9jl kge speed in order to travel 350 km in 5.15 h?

  A runner ran the marathm2 w kzfhx7ag7+b8 e,5xquen.me.t 7t on (approximately 42.0 km) in 2 hours and 57 min. What is the average speed of the runner hxt7,zewqamg+87.fmkb .7u2 x5eetn in m/s?

  A car travels 90 km/h. How long does it take b6p b++cwl+2n ltt tg5for it to travel 400 km?

  A ly (light year) is the distance that light travels in one yea+s i-/74mg3xcn h*mbgdzp 3kdictw5. by,*q ar. The speed of light is w h*5am,pi33cqgi4m b/gb- c7d.xz*ntdsk+ y$3.00 \times 10^8 \; m/s$. How many miles are there in a light year? (1 mi = 1609 m, 1 yr = 365 d.)

  If you are driving 72 i30.x 1*umic id -ubkakm/h along a straight road and you look to the side for 4.0 s, aub i-d3 0mcx* k.i1iuhow far do you travel during this inattentive period?

  If you run a complete loop around an outdoor track (40om6mbwc* bq (3/ 0wd+lkrp tko0 d2yy10 m), in 100 s, your average veloci krm6 qy*2b3do/1cwb+ kyldp mwot00 (ty is

  A polar bear starts at the North Pole. It travels 1.0 km south, then 1.0ns(c )hjf:js4,i 9 f)vii kj*v km east, then 1.0 km north, then 1.0 km west to return si9vji(,fj *hk)4ifjs )vc:nto its starting point. This trip takes 45 min. What was the bear's average speed?

  A polar bear starts at the North P5b 15eo( 3c3wy plsrbjole. It travels 1.0 km south, then 1.0 km east, then 1.0 km north, then 1.0 km west to return to ieyjwcr1 ls ob335p(b 5ts starting point. This trip takes 45 min. What was the bear's average velocity?

  You are driving home on a weekend from seu5omw.kqgsv no ;gfw --;0 bou- g1e-chool 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 hometown from scho-eom -.kgw-e q nbs;0g wuvo;f1o-u5gol?

  A motorist travels 160 km at 80 kmkows3), 4 hawu/h and 160 km at 100 km/h. What is the average speed of the motorist fuwa3), hw 4sokor this trip?

  A motorist travels for 3.0 h at 80 km exo 7z udxm7*:zzg5/;wwgs;p/h and 2.0 h at 100 km/h. What is her average speed zg5zxezmg;7;sdw p7:xw /u o*for the trip?

  An airplane travels at 300 mi/h south for 2.00 h and then at 250 mi/h north for(t( qn+bj n(i0ajzn8z 750 miles. What is the average z8nbt0(jznj n+qa (i (speed for the trip?

  In a 400-m relay race the anchorman (the person who runs the last 10 . ycbfva k4ur8k5nk.;0 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 havk .fvru. an5k8;4kcy be 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 tyax3x gz7x c6u9: s3kro a stop after 9 s. The car's average velocity during deceleration wxk3rs6x7yxgu:z 3c9a as 39 km/h. What was the car's deceleration while slowing down?

  An airplane increases its speed from 100 m/s to 160 a7 .d(awba1l(ud8cjzxvldeh.m *wc *+lm8 3u m/s, at the average rate of e(jbuml lu (wcv.az17xm83+chld 8d*aw da.*$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerates at the rate,p3 3tx1 .hlhszcypy6mv/ +jh 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 r4/iplldhge8 ouo nfgt4 78 e;k5/ )pwat $4.0 \; m/s^2$ 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 conuu .w)4ko/in2 oqg+w(x;bxa wstant acceleration owx.u4x2/aw gwi +()knbouq;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 2.6 m/s experiences a cozn60a5 mx p/zdn 4p *trdfh6)fnstant acceleration of f)60hzp6d / 5fdx4zanpt mn*r$2.2 \; m/s^2$. What is the cart's displacement during the first 7.4 s of its motion?

  A bullet moving horizontally to the right (+x direction) +3heyvg bhxw(1r cr5. with a speed of 484 m/s strikes a sandbag and penetrates a distancxchvh. (g+ w5b3e1ryre of 29.11 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 carrier. It reac q,1je+j4*jy:x hua +alg ljqwxjt9s57*q 4qihes a speed of 42 m/s at the end of the catapult, and this requires 2.0 s. Assuming the acceleration is constant, what is the length of the ca* i1xxl+ay 4q45jwju*gqlth 9 :as ejqqj7+j, tapult?

  A car starting from rest moves with conzto* )(k07t q2 a5f qbxttddt6stant 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 diz1 4bie/uu:jj gnw :*ystance of 200 m. What is its average acwz4::u1 /eun*g ij jbyceleration?

  An object starts from rest ac l 1q-tl:xv-hnd undergoes uniform acceleration. During the first qch1:-t vl-l xsecond it travels 6.7 m. How far will it travel during the third second?

  An object is moving in a straight line with constanco6+sinl l -l+t acceleration. Initially it is traveling at 16 m/s. Three seconds later it is travesl+ cn+ll6i-o ling at 10 m/s. How far does it move during this time?

  A car starts from rest and accelet n;1hxzab; k e2n3yp;q(k2 mtrates 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 a3:v6(ydl px vat 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,k+ahbl v5xd4km1e.;ij t 7 8jh a car that has been waiting at the intersection starts ahead with 81lkk.jt+5xbhd; j7ivema4ha 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 spemxffn ad87-jrs3bk7vy . ,ik 9ed of 12 m/s on the surface of planet X where the acceleration due to gravity isjxf k9.i77r,y d k- 83mvabfns $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown upward r* ) zhy(dmxj,with a speed of 12 m/s on the surface of planet X where j*()h x dmzr,ythe acceleration 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 spb6oz +n )u)klreed of 15 m/s on the surface of planet X where the acceleration due to z )o6)rbl unk+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 ps z 0 so87px9, dv0csz)7rgxd14 m/s on the surface of planet X wherex79)zd8zs0s0g dx 7r,socvpp the acceleration 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 greater than 0.10 s k-c.bk0wqrq 4. If your friend holds a ruler between your fingers and releases it without warning, how far can you expect the ruler to fall bew bq4rqkk-c0.fore you catch it?

  A ball is thrown upward at9subw m)j/7t 3toya 1q a velocity of 19.6 m/s. What is its velocity after 3.u w my oa97sjtb)/3tq100 s?

  A bullet shot straigru4n:71, uqdwbam 6o- tn*ipcht up returns to its starting point in 19 s. What is the initial speed of the bullett7nambp*r d6nuc o-u ,iwq 1:4?

  A ball is thrown straight up with a speed of 3x 722potusv 7ix jqk;76.0 m/s. How long does it take to return to its j77txv puk;7x 2i2soq starting point?

  A ball is thrown downward from the top of a buileuwgrs3*8l s z ;xl88lding with an initial speed of 9 m/s. It strikes the ground after 5.2 s. 3x rsug 8lz;se 8l8wl* How high is the building?

  A ball is thrown straight up with a speed of 30 m/s. (only fiwbry cq9gp; 65ll in numerical value inqg9yb;p w6c r5 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 stv3td qiw(fpj u8k6/1traight up into the air with a speed of 33.9 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 2 seconds later.  (数值)  $m/s$
(e.) Determine the time at which the ball pass a point 14 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 14.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is the v0 ku12ng8 nfsqelocity at t = 1.0 s?

  In Fig. below, what is the velocity aana8kw2k e7d3m amw-)iyoc q.. +v3q rt t = 2.5 s?

  In Fig. below, what is the velopmglu)l:7h-.sfdf )(w ud/ v fkaw4i7city at t = 4.0 s?

  In Fig. below, what ij()i*vi-u q5w /njjde pf0l;ls the velocity at t = 5.5 s?

  In Fig. below, what is the average velocity from 0 to 4.0 s?a8l-vhil t/ z8uir. 5i

  In Fig. below, what is the average velocity from 0 to 6.);+.87mr+h ncw(:c v ze 1jzt xjqiggg0 s?

  In Fig. below, what is the accelera cu/8vm i0a: *fr:r/ qrdmd3rdtion at 1.0 s?

  In Fig. below, what is the acceleration at 3.0 8 kbw27wxbwa( : xv;4q*wgydnswt; :m s?

  In Fig. below, what i ,r (*yx-ney ev6p sk8amdx3w+s the average acceleration from 0 to 5.0 s?

  In Fig. below, what is the average acceleration o35em;4ss*u 4kb9qku 5 ix mrrfrom 0 to 8.0 s?

  In Fig. below, what is thef))qu e,eyp6w displacement from 0 to 8.0 s?

Does a car speedometer measure speed, velocity? {speed|veloci6ssp( 9g7i.d xz w1niq(wd ,naty}

  An object can have a varying speed if its veld;*tr/i w kfhs1ui5r/ocity is constant.

  The velocity of an object can be negative when its acceleraz/ xafnx099- vp-ef3kr yzz4ntion is positive.

  If one object has a greater speed than a sibq6x 0pdwn4 n 5.jl+ (wufo0gt5 ccm:econd object, the first must have a greater tw65054+mx(n ngjfd c0q uo b:pc l.iwacceleration.

  Two cars emerge side by side from a tunnel. Car A is traveling with a speed of k5lv3. hey1i3ncuf *u 6 lbx/6 k;krhf$60 \; km/h$ 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 decrease9pln)ltqpaq62g37 tp(*aa w i s.

  A baseball player hits a1x5mqc5c: qz.i wovc8yduuk1 dx87 6n foul ball straight up into the air. It leaves the bat with a speed of v15wdi8oc q7q zyc6xmkx.cd:1u n8 5u$120 \; km/h$. 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 +7ffh*:swzsnpu zh;j.8xh x esx)6 :ito its acceleration, how does fzfxw8h:;6ue : is).nzs7h pjx*hx+ s it change if air friction is ignored?

  As a freely falling object spevakqjxaqvx4f- *m(5 0c q )es/m2k7lseds up, what is happening to its acceleration, how does42v cksx*/qjslx)ka0(m fq7a 5q-vem it change if air friction CAN NOT be ignored?

  An object that is thrown vertically upward will return t-r frqh(js).7jse5 ph o its original position with the same speed as it had initially if aispj5hre-qs) jf.7r (hr resistance is negligible. If air resistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzero acceleration at the same+ilr5hzjwz5labvl,; q g +*u ;na/n1d time.

  An object can have nonze8 tqbvr )f:t*6 mph4h 4x7dyfxf:pywvl28.nu ro velocity and zero acceleration at the same time.

  An elevator moving from the second fll s-m n3su9 4qn uh/eopocqb;6(b(:gm /yzw8ooor to the fifth floor making no stops along the wa3qqsbzn86-w9bnu:oyhmc o/( m/ egulop ;4(sy has zero acceleration all the time.

  A rolling ball moves fro 7epz2 moahgpd);8go 9m $x_1=2.2 \mathrm{~cm}$ to $x_2=-7.1 \mathrm{~cm}$ during the time from $t_1=1.1 \mathrm{~s}$ to $t_2=5.5 \mathrm{~s}$. 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 $x_1=2.2 \mathrm{~cm}$ and at $t_2=4.1 \mathrm{~s}$ is at $x_2=7.7 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps around a quartet (s3v5+ zc x)tt*oshsr-mile ($1 \; mile = 1609 \; m$) track in a total time of 9.4 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 97 m away i4 ee.u:gjn x0o5/lpaw n 13.7 s. It then turns abruptly and gallops halfway bae:xo 5jwap ue0n4gl. /ck in 4.5 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 from7rk/*o pkszu2 $13 \; m/s$ to $22 \; m/s$ in 4.7 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-n 4gk;o vr +fmat+1u)dcem 1 s.h9pxb $19 \; m/s$ to rest in a distance of 69 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a spe2;md4l+.lm)( dbmxq3mof (exqct (o red of $32 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.9 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of the blocks to essentially top speef 0)-qm cp8rt;he5bqnd about m)tp-05 frq 8 cnqbhe;$10.6 \; m/s$ in the first 13.1 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 a speed oflfz yx0pnvrg 2w )oogw90s9 ox*u :28r $18 \; m/s$ to rest in 5.40 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 highway. Assumin mo3 b)n8ws 9fx8f:qqqg a deceleraq qn w:f qx8b8om93s)ftion of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a tr4.n fxkg5lb x7e4p :miuck 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).    $m$

  A runner hopes to complete the 10,000-m run in less tha1--1phbt u hpyn 30.0 min. After exactly 27.0 min, there are still 110-ht-pyu1 phb10 m to go. The runner must then accelerate at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$