Suppose that an object travels from one point in0hd-sp f:x rp hdf8(x. space to another. Make a comparison between the displacement and thepf-8h 0 dsrhfx(p:.dx distance traveled.

  When is the average velocity of an object equal to the instantaneot keql m(8+4gzus velocity?

  A new car manufacturer av1x+ejhc*.)s *vno gddvertises that their car can go "from zero to sixty in 8 s". Thoche)+*vsv nd1 * gjx.is is a description of

  An object moving in the +x axis experiences an accelerationhfzj;-dq-qjt mds /v8 v6oc (3 of $2.0 \; m/s^2$. This means the object is

  Suppose that a car travel3ym f*+1d8/qnvk*l cxkrm9jb ing to the East (+x direction) begins to slow down as it approaches a traffic light. Make a statement cok8 dmyc1+bl*k*m jv 3f9xqnr/ncerning its acceleration.

  Suppose that a car traveling to the Wedjms /-ybow py(e 8y ,9o.j:anrymb)6st (-x direction) begins to slow down as it approaches)b n-.(yoa ,6sjy9:r 8ybm/wyoedjp m a traffic light. Make a statement concerning its acceleration.

  Suppose that an object is moving wid/h4awi; gb1eth a constant velocity. Make a statement concerning its acb1dge h a;w/4iceleration.

  If the velocity of an object is zero, does w7 i qv9 k00sv,xpa )52vzovonit mean that the acceleration is zero? Support your answervo 0n)7sk 2z5wxp9iav, v ovq0 with an example.

  Can an object's velocity change direction when its ha:6rlqz 9 g1xnn /fq ff3x3w1acceleration is constant? Support /l 1ffh:q 3za93wgx 1nnx6fqr your answer with an example.

  Suppose that an object is moving with constant acceleration. p/f)4e zsgx)g Make a statement concerning its motion with respect to t 4)xg zg)e/fpsime.

  Can an object have increasing 1e,z r mm2n8*zu9oppn der6z) speed while its acceleration is decreasing? Support your answer with an example.1oz ,*)ppuzmn ee 2zd9r6nrm8

  Suppose a can, after an initial kick, moves up along a smooth -*e( w6gghgqx hill of ice. Make a statement w*-(gg eqxh6gconcerning its acceleration.

  Under what condition is average velocity equal to the avera y0l7:4; oinsrdphwepy k;w4) ge of the object's initial and final velooyk44w 7ypels pdwn:;; 0r) ihcity?

  Objects A and B both start at rest. They both accel 9al1 lx2jkfd9 - osjdoo/cwy)* w-qo8erate at the same rate. However, object A accelerates for twice the time as object B. What is the final speed of object A compared to 89woj c-*d9q1 j fwll yak/o)2xdo -osthat of object B?

  Objects A and B both start from rest. They both accelerate atq(d,cty5 st1s3qdz: 69df kso the same rate. However, object A accelerates for twice the time as object B. What is the distance traveled b9ssk6:(d d3q zod 1f5qt ytsc,y object A compared to that of object B?

  When an object is released from rest and fall:3dy nu(phs- rs in the absence of friction, which of the follord3h:u s-yn(pwing is true concerning its motion?

  When an object is released frota0u r+r92yz9f j 3pinma*c5um rest and falls in the absence of friction, which of the following is true rf0zyr9n pmu52c ij3*+ 9 atuaconcerning its motion?

  Suppose a ball is thrown straight up. Make a statemen8w9nt5wao;/ kx (x gtd7ltwo3t about the velocity and th/awog3w (x ;do9n8tkw t7lx5 te acceleration when the ball reaches the highest point.

  Suppose a ball is thrown straight up. What is its acceleration just fokxw,vy3mllwoe 8t;: r,d7f2xy71 ybefore it reaches its f1,2lx;vx yfo,:lm8e7 t dwyy3rwko7highest point?

  Suppose a ball is thrown straight up, reachesn1:,ba()lfl3do pxg b a maximum height, then falls to its initial height. Make a state(afon, lbg:lx13 p)dbment about the direction of the velocity and acceleration as the ball is going up.

  A ball is thrown straight up, re y3q+mkhbc6y5 aches a maximum height, then falls to its initial height. Make a statement about the direction of the velocity and acceleration as the ball is coming d5b m+c3y6 ykhqown.

  Suppose a ball is thrown downward in the ajm,- yl +w1mfibsence of air resistance. Make a statement concerning its accelerat my,ilwmf- j+1ion.

  Suppose a skydiver jumps from a high-flying plaq80 xf,ldd +2dnxd.elne. What is her acceleration when she she reaches terminal veloxq ldn0xl8f .2dd,de+city?

  A ball is thrown vertically u rpa m8x-(r1h6uumepm k0 ;gg(pward with a speed v. An identical second ball is thrown upward with a speed 2v (twice as fast). (mmug- re6 up1 x0; p(r8kmghaWhat is the 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 bunz d):colk + r.4-t*nz: zwfvailding. One second later, ball B is dropped from the same building. As time progresses, the distance be) a:*nk-rozw+l dct 4nf .vz:ztween them

  Ball A is dropped from the top b qoy0w++.72.uey3 uypnvpuc of a building. One second later, ball B is dropped from the q . +b2pvp7.+u0nyyc 3 ouweuysame building. As time progresses, the difference in their speeds

  Two objects are thrown from the top of a tall building. One is *wibeve/h:,u thrown up, and the other is thrown down, both with the same initial speie/u,w:vb h*e ed. What are their speeds when they hit the street?

  A brick is dropped from the top of a building. A second brick is thrjm6) e/wtr /bz6o2aufown straight down from the same building. They are released at the same time. Neglect air resistance. Compare the acceleratio a66/wozufmjr/et) b2 ns of the two bricks.

  An object is moving with constant non-zero velocity in the +x axis. 4wy8fcsrazd1j( s -t2The position versus time graph of this tf2ycjas-4drs( 1 zw 8object is

  An object is moving with constant non-zero acceleration in the +x axis. The:;j1 yznu1 bzm posit1y:1muz;nz b jion versus time graph of this object is

  An object is moving with constantn f;es5d(bpk )/o7gjf non-zero velocity in the +x axis. The velocity vn5s/ gk(pbeff7 djo );ersus time graph of this object is

  An object is moving with constant non-zero acceleration cg(v1jfh9a (9.0xnxisg* d2 kfwqz4q in the +x axis. The velocity versus time graph ofkf xf9xg n*0q.1a4(v g2zj9w s(hq dci this object is

  The slope of a position versus time graphakp:nd z uzm22-:(hfe gives

  The slope of a velocity ver4z9g6/i bk)wpsn*d gasus time graph gives

  The area under a curve in an acceler4;mp(b esamk4- v +09x dxzuziation versus time graph gives

  The area under a curve in a velocity versus time grruyp.1 + 17cmemjkx 1n*;xzitaph gives

  If the position versus time graph of an object is a horizontal 6ddb)q4wq5x4x nqhhuw t 4q)2line, the object is5tqx hxn4ud46bq wq 42)qd hw)

  If the position versus time graph of an object is a vertical l wl17j3japl i)ine, the object isw37 ill1jpa)j

  If the velocity versus time graphxln 6 :jh .4n ;qukqt397bpmt)a*rcq-,jcopj of an object is a horizontal line, the object in-3 h muj 4k;clt 6,cj)tapj9nr pq. oq*qxb:7s

  If the velocity versus time graph of an oby(r:w**+rll fa4k hs zject is a straight line making an angle of 30 degrees with the time axis, th r*wh:4+*ya zr( llsfke object is

  An object moves 15.0 m north and then 11.0 m south. Find both the di( gs8d;m8y5 xwe5td xho85ihkstance traveled and the magnitude of the displacement vect85x8mdwty5ikg 5e;8o (hhdxs or.

  A boat can move at 30 km/h in still wateryx;uraq,l-gz9w 1o aq5q58by. How long will it take to move 12 km upstreb15 az;5,q9q-8yug awx yq rloam in a river flowing 6.0 km/h?

  55 mi/h is how many m/s? (1 mi :gp ;r i9 0kzcwtfb9,k whca vp.v+sg9e- z*3q= 1609 m)

  What must be your average speed in ordexg,* bobo)t8-prftwq -fl7 ;sr to travel 350 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 km) in 2 hours and 57 o.8y yspx e.u/min. What is the average speed of 8/ys.py .xo euthe runner in m/s?

  A car travels 90 km/h. How long does it take fobw623t9p -gi o+movv :wi 2m(w2wjgiu r it to travel 400 km?

  A ly (light year) is th1zm1h 6h , vc6jjo 8mtfkgf83be distance that light travels in one year. The speed of ltfh fj8g6zo8,vj 13mbh km16cight 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/h along a straight road and you look to the s+g hvda.w.o ,fide for 4.0 s, how far do you travel during t dva,wo.f+.gh his inattentive period?

  If you run a complete loop around an outdoor9x axk37 t8ta b:jmng 5vo+p*f track (400 m), in 100 s, your average velocity i apb g3ttxk:j8+oa7 9 5mvfn*xs

  A polar bear starts at the North Pole. It travels 1.0 u4van rgc *tb21ia3u0i. 1qozkm south, then 1.0 km east, then 1.0 ka4g.oac2i *u1z0ur3 1 bqtnvi m north, then 1.0 km west 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, 7rb yqu, 4ha7 pitz/uq*+s. rrthen 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 z7qqui .pas yr*rthr /7,4ub+the bear's average velocity?

  You are driving home on a weekend from school at 55 mi/h for 110 nx a(ukludiyige l.* a:2qv/,+.l 9sd miles. It then starts to snow and yod e g/nilayx .*sl:dv+(uq.92k, u ailu slow to 35 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. Whan/j5 ggixut 0+t is the average speed of the motorist g5+0xg/uj tn ifor this trip?

  A motorist travels for 3.0 h at 80 t p2gq)f klc9k6+u,)fr qmyt; zi+-eukm/h and 2.0 h at 100 km/h. What is her average speed for th+t k 9,i+lt-rfek;u f2 pq u6qy))gmzce trip?

  An airplane travels at 300 mi/h south for 2.00 hy9v854 1z-6hd*i fzz dswd qkl and then at 250 mi/h north for 750 mileh8wq95dy i k* fdzl-4zv6dz1ss. What is the average speed for the trip?

  In a 400-m relay race the anchorman (th8 )gev a4c)kqh-a1 pgde 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 r1g)4ehkvpa8ag )dc -q unner 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 stgbucs.* 8zg l0op after 14 s. The car's average velocity during deceleration was 65 km/h.g8glbs 0.u cz* What was the car's deceleration while slowing down?

  An airplane increases its speed from 100 m/s to 160 m/ss*x-dmb r8z7xj)1pgy.9 rj u e, at the average rate of 8s.zx)1xbp-rd m u97g jr*ejy $15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accel 1k lmpz h:sbxb 1h.bch19xn78erates 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 accelerate 2 x7 w3bi7wdn*qr9ezh3g6em ws 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 m97 m7o0cuwvuc2ok 7wwith a constant acceleration of 7 c9c70uu2kowmo7wv m $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 3.4 m/s experiences a constant accelera+;gy3y,cm-wz pb blk:tion of b wply3k+m;g- ,y:zbc$4.7 \; m/s^2$. What is the cart's displacement during the first 8.1 s of its motion?

  A bullet moving horizontally to the right (+x direction) prk1 4w: znmw,8o uu5f7gs2d/vf5fal with a speed of 369 m/s strikes a sandbag and penetrat82fufs l nk5p /gw1r,7wf4:uo amdvz5es a distance of 96.58 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on an (+uml-,et wk q* s,q(unz4drvaircraft carrier. It reaches a speed of 42 m/s at the end of the catapult, and this requires 2.0 s. Assuming the accelr(u +4dws- ,n*,m(ze qtku vlqeration is constant, what is the length of the catapult?

  A car starting from rest moveabs6x7qk;wiro /s/9m s with 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 z; bvw6t .u ra+-y8px.vm)l9 vkzhc6im/s in a distance of 200 m. What is its average ac8b )uvvpkrzl +hiw6zcta-y6 x.;m.v 9celeration?

  An object starts from rest andt1tyh)x,8,hw a m ehs0 undergoes uniform acceleration. During the first second it travels 2.1 m. How farmyhew,8xh ht,1 a )0ts will it travel during the third second?

  An object is moving in a straight line with constant acceleration. Initiallgzuxft+e5f6h0)n0r-)r+w5 fsby xsg y it is traveling at 16 m/s. Three seconds later u seg-wtf+bg0+yxn)x )z05hfr s5 r6fit is traveling at 10 m/s. How far does it move during this time?

  A car starts from rest and accelerates uniformly atn307 oubd+ n ; tk67cll 1g0kl6vdfzlb $3.0 \; m/s^2$. 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 at abogqmznj(npd 2j6;6 s6 uut $5.0 \; m/s^2$ 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 hashaz u.2*yl3+gs+jfp n f3jk9y been waiting at the intersection starts a u jk3+y+lafpy9.2 3j*gzsfh nhead 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 the s.n+/+ r4 2of ubq;ss.ryczv+p vzb dzx;7q0xuurface of planet X where the acceleratib v.dr4.p 0 sxqnx+/;uszzbf coqrz; yu2 ++v7on 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 speed d3qzr 1lnhf uj72wfrlji .5/2 of 12 m/s on the surface of planet X where the acceleratirl w3hj/z r22il7dq.1n5fjfu on 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 ww5:afxcuqw6i,, oli 6.1i lz rith a speed of 15 m/s on the surface of planet X where the alfiou x,w1c6z,al. 56wiri :qcceleration due to 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 ay-xf609s9je w ba9inq speed of 14 m/s on the surface of planet X where the acceleration due to gr-999xfnbs a0q yiw6e javity 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 holdssm5 +q(zzbr;qnf( 0sg a ruler between your fingers and releases it without warning, how far can you expect the ruler zq;(fbg0( ns+rz5s m qto fall before you catch it?

  A ball is thrown upward at a velocity of 19.6 m/s. Wph/ma 5g9m*5 djiya/ohat is its velocity after 3.00j9da*5ohg ip/5 my am/ s?

  A bullet shot straight up returns to its starting point in 12 s. What is tqt+ -66u*cqn+ kig vbw)zp;dbhe initial s6c*k+ wbq +bvui gp -6td;zn)qpeed of the bullet?

  A ball is thrown straight up with a speed of 36.0 m/s. How long ,1t ajew9i7u1/sbv 7sqmia9y does it take to ret77a 1vi,9 9 busme/yaq1tiswj urn to its starting point?

  A ball is thrown downward from the k) cg0bol m/ ;y*cts; .mdyo8etop of a building with an initial speed of 15 m/s. I)ctb8 k coy m.l*m;s/yg;0doet strikes the ground after 2.9 s. How high is the building?

  A ball is thrown straight up with a speed of 30 m/s. (only fill in nutwf qy04d3w1(wbefm :merical value in tfq1et 4wf d(ybwm:0 3whe 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 air with a speed o;urjs kv6 42yzf 20.5 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 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 is the velor u f(vd)*q/-a 1higdo4dt2f icity at t = 1.0 s?

  In Fig. below, what isn35f ( 0t cbb8crua5if9amg1z*7waqh the velocity at t = 2.5 s?

  In Fig. below, what is the velocity at t i4bg/,wpldg 8j7u0l1 avy8up = 4.0 s?

  In Fig. below, what is the velocity at t = 5g 4d,5r,x neil.5 s?

  In Fig. below, what is the average velocity from 0 to 4d/dxgoh 72)bs+2n i,py 6euj u 6ao8tr.0 s?

  In Fig. below, what x8pu 9:t4g7sqp.pw.13rp g mn52hvzsf e7c znis the average velocity from 0 to 6.0 s?

  In Fig. below, what is the acceleraticmj4 r jii3tcjd/ 6baly5 n,4.c bhj+2on at 1.0 s?

  In Fig. below, what is the acceleratio (hvxjxwa-mx6x8utnbx-x 9 (qbq7 :7 ln at 3.0 s?

  In Fig. below, what is the azgk9/;yc :1y4 2xtgbg;hg ab,fv*gb q/o7b yiverage acceleration from 0 to 5.0 s?

  In Fig. below, what is the average acceleration from 0 to 8.0 s/4 in;jy c/scwnh+5 utuv-e2i?

  In Fig. below, what is /q(ey jk. r)ebfy 0 ax7sp0cx8the displacement from 0 to 8.0 s?

Does a car speedometer measure speed, veloci79y z3k)pqnoch8n4e v(t a )ose u,1skty? {speed|velocity}

  An object can have a )o n)j pt( ahyo/-t)glvarying speed if its velocity is constant.

  The velocity of an obnba ccto0y2/vhugy+ vnq+fc y/i+*16ject can be negative when its acceleration is positive.

  If one object has a grea5xp 0)m-ztycp ter speed than a second object, the first must have a grpm5xt0-) p yczeater acceleration.

  Two cars emerge side by side from a auvwnhuz+3 r2e5zkxv/-cid *4+tde1 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 acc 6k;;3p nmc,ky/pesfutfv4s 8eleration decreases.

  A baseball player hits a foul ball straight up into the air. It leaves the q+vapk -1q(e66a 2 vdqnafk2gbat witpk2k(6qqa6na+dvae 2 v -gq1fh a 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 objec +pwdk;g(bx-t t speeds up, what is happening to its acceleration, how does id pbk ;g+-(wxtt change if air friction is ignored?

  As a freely falling object speedpisrs - :e+-q bmupj(yvv l450dwx1 f(s up, what is happening to its acceleration, how does it change if air friction CANpbm-wd0 (4pfujsvl(y1r5xe: s q-vi+ NOT be ignored?

  An object that is thrown vertically upward t lg u60:or6nrwill return to its original position with the same speed as it had initially if air resistance is negligible. If air resistance is appreciable, how willn6l rt6g0r ou: this result be altered?

  An object can have zero velocityucw4g-b.o *va and nonzero acceleration at the same time.

  An object can have nonzero)m 8pqjdq8jv9 velocity and zero acceleration at the same time.

  An elevator moving from the second floor to the fiu 0kd5g0lz d - 5xqimcg6;p;j7)cqtdrfth floor making no stops along the way has zero a x6 0;-j c05dcdmzgi5) tquqd;prkl7gcceleration all the time.

  A rolling ball moves from x4nkr8 854jlm cv6pk bjm0-7b2 yoab1od9xuz$x_1=3.1 \mathrm{~cm}$ to $x_2=-7.5 \mathrm{~cm}$ during the time from $t_1=1.6 \mathrm{~s}$ 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 $t_1=-3.3 \mathrm{~s}$ is at $x_1=2.5 \mathrm{~cm}$ and at $t_2=3.3 \mathrm{~s}$ is at $x_2=8.3 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps aro zt3mnirkxhrav q(b9 )nxex 3u(*7v 73und a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 7.0 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 ax58 dws2hq(rving 103 m away in 10.3 s. qwxrsh2a 58d(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 from:w.i czg.ikdc;x u929xhyl.o $13 \; m/s$ to $22 \; m/s$ in 5.6 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 fromzaw3e6, 2i c1g.erfy rwlko:l0as 9t90frlx- $16 \; m/s$ to rest in a distance of 76 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach aju4na3oz;j/ b) vdc; ub8w:uu speed of $26 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.2 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of the blocks to essgqfg r5in6( 0r8y-njwentially top speed abou0yw6 8n(rg rn5f qi-jgt $11.2 \; m/s$ in the first 13.8 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 uniformly from a speedq l;.pcive:j7 of $17 \; m/s$ to rest in 4.41 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 hi xkodk;+c x0a6ghway. Assuming c do0kx+6a ;xka deceleration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a tr1oi kv6)wg u(vuck 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 than 30.0 min. After bob+qog +g+;76qa p rcexactly 27.0 min, there are still 1100 m to go. The runner muso++7c;qb 6gpb+ oarqgt then accelerate at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$