Suppose that an object travels from one point in space to another. Make a ch;a+bsj,b n+g omparison between the dispj, as+n; h+bbglacement and the distance traveled.

  When is the average velocity of anuj1a5y3b qn9(z1( +m ljqjxbc object equal to the instantaneous velocity?

  A new car manufacturer advertises that their car can go "from zero tu h.priq. 1-m 6f7 iw:unrcwz)o sixty in 8 u 1..i:m7r z6wrnwhfuqpc) -i s". This is a description of

  An object moving in 9;eyg6l/ tl+evbq9 kf,8ak ghol0.jbthe +x axis experiences an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car travno o7j8le)) adyt 4n8deling to the East (+x direction) begins to slow down as it approaches aan8 dd8ony)l 7)t4o ej traffic light. Make a statement concerning its acceleration.

  Suppose that a car traveling to the Wdx-bl+jn9ls.q2yi : pest (-x direction) begins to slow down as it approaches a traffic light. Make a statement concerning id9+lq2 xp iy.jn-bls: ts acceleration.

  Suppose that an object is m xkkpl44; 0 )3fru*+yvmn-v;ijwkd ccoving with a constant velocity. Make a statement concerning itr; j c) ki3m;0fvc-k4 k+x*w4pdyulvns acceleration.

  If the velocity of an object is zero, does it mean that t,19 e+id1 lenmfx /pcwhe acceleration is zero? Support your answer with an ei,cp9wl /ee1dx n1fm+xample.

  Can an object's velocity change direction when its acceleration is ct j js ss8z d50jroxi* ,lb5l y4p;io94ni46qronstant? Support your ans0 5sds6yjn t, r4rsill;b4 54zi9j*i x8joopqwer with an example.

  Suppose that an object is moving with constant acceleration. Make a statemexw6ma .3x qy9/dr;hjant concerning its motion with 9 ;6w/m a3a. yqrjxxdhrespect to time.

  Can an object have increasing speed while its acceleration is decreasing? 6m0do uq8l,:bse-p*) 2xq o jnv,opym Support your answer with an j,om0s6u)o8 po-ym xd vp l,q:en2*qb example.

  Suppose a can, after an init/ a(*sk rqdm4xial kick, moves up along a smooth hill of ice. Make a statement concerning dsq ( rkx*m/a4its acceleration.

  Under what condition is average velocity e;3id qdan .k2hoh)k +jmo b30;t1fqppqual to the average of the object's initial and finaj3 hoqmh; pdo+213k)d 0 qiat;kfnp.b l velocity?

  Objects A and B both start at rest. They both accelerate td)7ogi*d m v4at the same rate. However, object A accelerates for twice the time as object B. What is the finod 74 dtvi)g*mal speed of object A compared to that of object B?

  Objects A and B both start from rest. They both acct j ; vfh u8moa.m9l*xn1swa2w 6xgo2rq03.vmelerate at the same rate. However, object A accelerates for twice the time as object B. What is the distance traveled by object A compareg w1hqnwu m9* ;oml xsa.f 6a8ovj03.v2 rmxt2d to that of object B?

  When an object is releaqsm90(8* h :yisybw sdsed from rest and falls in the absence of friction, which of the following is true concerning its motyq*sy9d msw h:bis0(8ion?

  When an object is reu 48p,eun)j l 5*ogkaxleased from rest and falls in the absence of friction, which of the following is true concerning its motion?lo 5uekg* )x,anu8p4j

  Suppose a ball is thrown straight up.9720wq ltz5vdte rvi, Make a statement about the velocity and the zli7e ,dqtrt 09v 52vwacceleration when the ball reaches the highest point.

  Suppose a ball is thrown straight up. What is its acceleration j ::;kvl ae( o 2;o)hhowqcao9pust before it reaches its highest point ceaaow:;2holh:)(v qo9o;k p?

  Suppose a ball is thrown straight up, reachy :d;61 e/u9dpqea qfzes a maximum height, then falls to its initial height. Make a statement about the direction of the velocity and acceleration as tp/fyzaeq6ed: 1q d;u9 he ball is going up.

  A ball is thrown straight up, reaches a maximum height, thw2u rs +x.g(12f-onme82lox8xr zt i8 gymi 6ten falls to its initial height. Make a statement about the direction of the velocity and acceleration as the ball is comi2fx r.tg 2e rt1y muixing8xlms 2o-8w( +oz68ng down.

  Suppose a ball is thrown dowbex cgdyh.q):j;ob)1 nward in the absence of air resistance. Make a statementjxb:q;y)hd c).ebg1o concerning its acceleration.

  Suppose a skydiver jump*-( *rwlhkzqwqj lgc 4eh21l: s from a high-flying plane. What is her acceleration when she she wq*klrqgw-l*(1jzhh4: c2le reaches terminal velocity?

  A ball is thrown vertically upward7ivm,7vh(l tv with a speed v. 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 to that m77,hvvivtl( 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 B is vm0mh;enej 06ps)4hw ve zsb2 z9 -ng4droppe0 ze 0nn-m62zvesw9s p4jvb)m4g e ;hhd from the same building. As time progresses, the distance between them

  Ball A is dropped from the top of a building. One second later, ball B is 8oj7dx*o2 hkl dropped from d*klo87hx oj2 the same building. As time progresses, the difference in their speeds

  Two objects are thrown from the top of a tall building. One is thrown up,m ,kdi cq b8497- /xxilnokad(so p(m+ and the other is thrown down, both with the same initial speed. What are their s xnimbdo/l-,7q ock 4aixpd m((k 9+8speeds when they hit the street?

  A brick is dropped from the top of a building. A second brick isg2w(ohy25llg w hzx+4+pv(d p thrown straight down from the same building. They are released at p pl(2dgw+ o xg(45 2yh+vzlwhthe same time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with constant non-zero velocity in the +x axis. T+3xzmav vm zy uf052n9w6ov *g(h,bvlhe position versus tiz l9m,3xv0 bog f5nu2wvyazvm+ ( 6hv*me graph of this object is

  An object is moving with constant non-zero acceleration in the +x axis. Thfm rz)+ s(bw;pe position versus t +;pmb )f(zrswime graph of this object is

  An object is moving with constant non-zero vm- dpt9*x cf;delocity in the +x axis. The velocity versus timcddtpf9 *-; xme graph of this object is

  An object is moving with constant non-zero acceleration i xbafxjf(2(d(y6yya 7k3tw +kn the +x axis. The velocity versus time graph of this object is2+x fj6 y7f(wba tyx(kdyka( 3

  The slope of a position versus time graph giv d+y.:xdxgno5ha lbz 9qz)tqp qu33a1.2bb , jes

  The slope of a velocity versus time gdukl1oo 1 :a,)3/ekir07wyjltygn2 f raph gives

  The area under a curve in an acceleration versus time g:lcqtudo(9,sf ps1xc(hq c/+raph gives

  The area under a curve in a velocixcm90u fr3k0 q)zu,e 5ofg gj4.gr ae6ty versus time graph gives

  If the position versus time gr;o zphm/ uhs.x; 2ivq1aph of an object is a horizontal line, the object ish2 iqh;z. ;px/ums ov1

  If the position versus time graph of an object is a vertical line, the objenu4 wkc 7+yc7fct isw7+ kc4cfun 7y

  If the velocity versus timeulv4q+kprk0o.ud*zid+)cm ;g*3h gu graph of an object is a horizontal line, the object io++l3) up kg.;h zm qgrcvuik0d4u* d*s

  If the velocity versus time graph of an object is a straight line making an anudyq 4g8myi3 9gle of 30 degrees with the timem3dqugi y4 y89 axis, the object is

  An object moves 15.0 m north and then 11.0 m south. xjt :n36p cks2 Find both the distance traveled and the magn6 k cj:ps2xn3titude of the displacement vector.

  A boat can move at 30 km 1jb5/awaa7 fe/h in still water. How long will it take to move 12 km upstream in a river flowing 6.0 km/aaj75 bwfa1 /eh?

  55 mi/h is how many m/s? (1 mi = 1609 q*6zm : 5wbekrm)

  What must be your average speediba46g e x9vo2/hcpb* in order to travel 350 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 km) in 2 hourst/mr c0z fcg ( ;e(mgmyq06u3a and 57 min. What is the average speed of g0u0 r6qz(ca3m;m( e yct fgm/the runner in m/s?

  A car travels 90 km/hpo (m0ds+4 *guq6lb/ n- hfbdn. How long does it take for it to travel 400 km?

  A ly (light year) is the distance that lightrv4p3bb 3ux.aptu( + i travels in one year. The speed of light ib3xbat4u ip u .r(3+pvs $3.00 \times 10^8 \; m/s$. 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 look to zvtb6yq m*d.mo ,9qt1the side for 4.0 s, how far dd6 btoq y 1*vm.t,m9zqo you travel during this inattentive period?

  If you run a complete loop around an outdoor track (400n lm(4n,,lfhwlt kvtg+i-06us ,kk 9b m), in 100 s, your average g,imf0bsw 4n(- l6+k,u 9l nhkklttv,velocity is

  A polar bear starts at the North Pole. It tr2ieqr baf r15(aev9lu4 9o5o ravels 1.0 km south, then 1.0 km east, then 1.0 km north, then 1.0 km west to o4(u2ilr av9 r r5qbfe9o5ae1 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.,,lg)u/ b 6h)sc wzy ;s6nu0abge8gdo0 km south, then 1.0 km east, then 1.0 km north, cg,szy)sdbh6 8o bw 0;ua)/gnule g6, then 1.0 km west to return to its starting point. This trip takes 45 min. What was the bear's average velocity?

  You are driving home on a weekend from school at 55 mi/h for 110 miles. It th 3evhmex+4(s ken starts to snow and you slow to 35 mi/h. You arrive home after driving 4 hours and 15 minutes. How far is yx(v em4 3s+kehour hometown from school?

  A motorist travels 160 km at 80 km/h and 160kvo0h4t rx0 f, km at 100 km/h. What is the average speed of the motorist for thhrft0x vk,o 04is trip?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h. Wha2*,kiae0-h qc ll0tght is her average2g*00ic, l hka-ethq l speed for the trip?

  An airplane travels at 300 mi/dd wj v9- 4,um*ecm +.a e7tdxulj/k aq,1pf:xh south for 2.00 h and then at 250 mi/h north for 750 miles. What isjcx-+j em,1.dl w4 auxd:d/me fu9pkq,a*vt7 the average speed for the trip?

  In a 400-m relay race the anchorman (th0c5ntqiratawq /4/ 1ze 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 wheqnitqa4 r50//wa1tzc n 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 av *oj vz/xkw:so7 gg0(nd comes to a stop after 12 s. The car's average velocity during deceleration was 76 km/h. What was the car's decegowj v7skvo/ :( *zx0gleration while slowing down?

  An airplane increases iskhan/plq24eq (i :m9ts speed from 100 m/s to 160 m/s, at the average rate of mlp/ iqa24e:ns (hk9q$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 kmd vo6(bbr+ti*/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 yau0.7n+uu1b (vk f8z+e sxshand 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 speedo26y4pk9iv t s4 kpz7g;f9jxds up with a constant acceleration of o yjpz;44xfid9 vk7g96t s2p k$2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 5rxd pxih+2 6 hv0kef srhlo:5)1m/fh-.7 m/s experiences a constant acceleration ofl)xm/ xf rd+:i0h5fo61h k2hvsp -ehr $1.3 \; m/s^2$. What is the cart's displacement during the first 5.6 s of its motion?

  A bullet moving horizontally to t46 jkptgbn:p0* p hph-he right (+x direction) with a speed of 347 m/s strikes a sandbag and penetrates a distance of 58.77 cm. What is the average acceleration, ip hp-p*bn60 phg :4jtkn $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on an aircraft carrier. It 2,dm,l;r+bgt5-vmhk5kjl kg 5ms; vcreaches a speed;m2,+m vlr5 c,bt- dlkjh5vmksg5;gk 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 catapult?

  A car starting from rest moves wixer*ct,ho4 lun;6a-9 s r f.vyw ky9(pps, a,fth 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 83vm o qxr vfas1;( /y-qnuhe(50 m/s in a distance of 200 m. What is its average acceleratio;y3q/v n (o5mh-fv a rqs1u(xen?

  An object starts from rest xh7j eqp) 9i.m(i2 p6pz)tfr f-kb7vband undergoes uniform acceleration. During the first second itv hix -9pr))qe(f7j tk6f p7zi.pm2bb travels 4.7 m. How far will it travel during the third second?

  An object is moving in a straight line with con lse:.qd9 z2ax0 no1enstant acceleration. Initially it is traveling at 16 m/s. Three seconds later it is traveling at 10 m/s. How far on9 x a2e.snd0:zq 1eldoes it move during this time?

  A car starts from rest and acceleeh dbjz:z;d23ho)kh q 12h+(g ge6 jsorates 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 decelerat5p ik+rfgc0 (ae 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 thatb m9ggrzwhbgk3g/yc76*,sp d4s1 2an has been waiting at the intersection starts r wszdcbayn 1 g2b3m*4hgsg,kgp/796ahead with 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 a speed of 12 m/s on tht eqr*c/ r mte1*ub2e,lknx,; ee)de9e surface of planet X where the accelere d,rxtee 2re9)/emnclq **;bt1ue k,ation due to gravity is $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown upway-a,t(uy slq wo c;d)0rd with a speed of 12 m/s on the surface of planet X wherosw c (a0)ytd- y;qul,e the 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 at 86 s,fzl 4o5q+cmup/qencb6 speed of 15 m/s on the surface of planet X where the acceleration due to gr p lz4 u8/5mt6bqnfos6eccq,+avity 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 upwards63w wev,et zu :,hzx um;;d(d with a speed of 14 m/s on the surface of planet X whe(;hz:m,d uxe6uw wz,d3te ; svre 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. If your friend hold. rgviv(bkw/ie;;bj7mpwu8 ka 5f73 u s a ruler between your fingers and releases it without warningk;weiib7a kbv.3f /rm7g wuj(u v5;p8, how far can you expect the ruler to fall before you catch it?

  A ball is thrown upward at a velocity of 19.6 m/s. What is its velocity rum-eg o8w,y*xy0mt* /p6heowtes 37 after 3.00te,o xprwo8gu e-m 7**/wy s3e 6mhty0 s?

  A bullet shot straight up returns to its startg7lta ::f*4z+nwhal z gxjn) *ing point in 6 s. What is the initial speed of the bullet?f*x4*na7wg ) z tg: ajh+:llzn

  A ball is thrown straight up withi,kw: filf+j:mw3b2h t z/v50bm grj 8 a speed of 36.0 m/s. How long does it take to return to its startwjb ,v3ri:fmbwl 025+hf/gi:t km j8 zing point?

  A ball is thrown downward frx6x 6zv a6zraon8*rp c(zs6v-h2z fc5om the top of a building with an initial speed of 23 m/s. It vh x6fr6acsv6z62z( 5 * n8czpazo-rxstrikes the ground after 1.2 s. How high is the building?

  A ball is thrown straight up with a speed of 30 m/s. (only fill ij 5(b3s unlei/n numerical value in the blankj/(nu3lesb 5 is)
(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 ps u**gtv q.wd)j0vcsl+ge6* with a speed of 36.6 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 11 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 11.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what isol( 1mx hk3xvf5j:u7g the velocity at t = 1.0 s?

  In Fig. below, what is the velocity at txtwuq .jy*r5+ = 2.5 s?

  In Fig. below, what is the velocity at t = 4.0 sm czcqw wf (h )x;4s2q/i;lc:h?

  In Fig. below, what is the vedq18txz 0p mcxi+j)d2locity at t = 5.5 s?

  In Fig. below, what is the average velocity from 0 to el v ++ z8/t4+8rt pjcw,udfyh4.0 s?

  In Fig. below, what is the average velocity from 0 to 6.n 2ibe ja3/l)+k/b rslbhey+ ;0 s?

  In Fig. below, what ytlw:+t.-/ ag4 knkgcis the acceleration at 1.0 s?

  In Fig. below, what z kpknx:u:99m is the acceleration at 3.0 s?

  In Fig. below, what is the average acceleration from 0 to hhimr,af wru:(2iex* 0z 43 bj5.0 s?

  In Fig. below, what is the average acceleration from 0 to 8.0 tqe*m.o); a:i (gff+ 5yrxuz9ti+as j+ iqr .cs?

  In Fig. below, what is thg0 dc)xl5 b4.h bizfx:5mo+mve displacement from 0 to 8.0 s?

Does a car speedometer measure speed) sev9f()a; sw4vkiqo, velocity? {speed|velocity}

  An object can have a varying speed if its v4owiu)zf y1 t5elocity is constant.

  The velocity of an object can be negative wh fmo( f;1lx r(a+)jeb7wm 5gumen its acceleration is positive.

  If one object has a greater speed than a second object, the first must hfp8hnc z6sg*n7wl h:-ave a greater acceleratiop6 h-ghz7snn *wc:l 8fn.

  Two cars emerge side by side from a tunnoy+i5y;j )zmjel. 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 increasio)(,ty gddukjm* :dy8 ng in speed as its acceleration decreases.

  A baseball player hits a foul ball straight up into the :s:tegxa:,s l air. It leaves the bat with a stgs:ex ls:,: apeed 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 accelera)wyq 8prymgq o/z6,q4 tion, how does it change if air frictio,w)qqy6 og 8yrqm/p4zn is ignored?

  As a freely falling ob :/ax1-lrbhuddw.d8 n ject speeds up, what is happening to its acceleration, how hn: bwdl.ad-ru1x 8d/does it change if air friction CAN NOT be ignored?

  An object that is thre- mv,ob)fs ;eown vertically upward will return to its original position with the same speed as it had initially if air resistance is negligible. If air resistance is appreciable, how will this reom)s-,; veb fesult be altered?

  An object can have zero vel b:olm71b8.twhsf5. o ,b+uekyo-l.bw ja9 t bocity and nonzero acceleration at the same time.

  An object can have nonzero velocity and zero acceleration at the same timtborg .,fiw0 5e.

  An elevator moving from the second floor to the fifth floor making no stopu git73ugpq* a3.fm:cs along the way has zero acceleration al*a3 u: ft.c igu37gqmpl the time.

  A rolling ball moves froxhv e26pmr)* v7 soz7wm $x_1=1.7 \mathrm{~cm}$ to $x_2=-5.8 \mathrm{~cm}$ during the time from $t_1=1.7 \mathrm{~s}$ to $t_2=5.9 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-3.5 \mathrm{~s}$ is at $x_1=2.9 \mathrm{~cm}$ and at $t_2=3.0 \mathrm{~s}$ 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 quac3e fna o0vtre .4-v*nrter-mile ($1 \; mile = 1609 \; m$) track in a total time of 6.7 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 lin-yy fo v2 rcn6:heue;9frxj +)q tfz3-e, moving 107 m away in 11.5 s. It then tu9 xn:o ht;yyzeqer+3)-f ucf62v-j frrns 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 fr3r7. f2brt xux.,oje5eq wlu/ om $10 \; m/s$ to $24 \; m/s$ in 5.3 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 frot9 9d okbo0;c.hdqr 4im $18 \; m/s$ to rest in a distance of 67 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a speed of vd wdn:tri,dhhsu.(:;k;p p 5$26 \; m/s$ 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 ohx-tlbn6 38ltf the blocks to essentially top speed abountbl8 tl-6xh3 t $11.4 \; m/s$ in the first 11.7 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 n)d-nm0v c3knof $16 \; m/s$ to rest in 4.38 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 rxu 60i oko+:k((pgnwhighway. Assuming a dei:knwoop 6x(+g( rku0celeration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a tr7of a/w a5zyq+w)zjd1 uck 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 t(emp5p7r g i hp,l9lr c5ng8u(han 30.0 min. After exactly 27.0 min, there are still 1100 m to go. The runner must thp9 ru(r58, e7n 5mlcpipl( gghen accelerate at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$