Suppose that an object travels from one point in space to another.l/k 7+hmwq jb, Make a comparison between the displacement and the bhjqwm7 l/k+, distance traveled.

  When is the average velocity of an object equal to the instx hu(691ci :ise, kh2,jndiojantaneous velocity?

  A new car manufacturer advertisn q/fm b-hvh3l698 hqdi,t*apes that their car can go "from zero to sixty in 8 s". This is a hqldhmvatq6 nbp*83h -,i/f9description of

  An object moving in the +x 4sbbtx) 9hdo 1axis 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 down as iz7 ssgr::9yll./rm t3 mylz(vt approaches a traffic light. Make a statement concerning itsz:zrm9ysm/.yv r:l(glt 3l 7s acceleration.

  Suppose that a car traveling to the West (-x directiq j/ri ve;c,17rg 0ttyon) begins to slow down as it approaches a traffic lig;grjteyc 1, /tv0r7qiht. Make a statement concerning its acceleration.

  Suppose that an object is moving with a constant velocity. Make a statement co4lr h 7z/-rkdencerning its lhz-d47r/ rkeacceleration.

  If the velocity of anmkkjt1a c e54dj adjg1z 2;r44 object is zero, does it mean that the acceleration is zero? Support your anse45ddkma41 aj jz2rjg 1c;tk4wer with an example.

  Can an object's velocity change direction whe -8fzp xz*ffow- z5z7p0q0upxn its acceleration is constant? Support your answer with an exampl qw8xf5p-u7zpx0pz f0fzo -z *e.

  Suppose that an object is moving with constant acceleration. Make a stat4o9/ i8/lq ka: bmcbisement concerning its m qbil:k8/m 4 /b9ociasotion with respect to time.

  Can an object have increasing speed while its acceleration is(yh;9qm tg 6wt decreasing? Support your answer wiq;9tyhm(gt6 wth an example.

  Suppose a can, after an initial kick, movem-r6 zip-r82 2 :jdedae0 x)mzru9g kps up along a smooth hill of ice. Make a statement concerning its acceleraprkr 9j0drzpg)ee8m :6 xa-22- di uzmtion.

  Under what condition is average velocity equal to the average of;k9zg,xa1 +)teqzx, 6xzqhzx the object's initialzxx ;gz,,zk+ q9aexqt)1 zx6h and final velocity?

  Objects A and B both start at rest. They both accelerate at the same rate. 0t *n11 t;bxu gn.ibrqHowever, object A accelerates for twice the time as object B. What is th1t;.nbq gix0*1rt bu ne final speed of object A compared to that of object B?

  Objects A and B both start fr+xqnnz5 bqx, egi+-/ rom rest. They both accelerate at the same rate. However, object A accelerates for twice the time as object B. What is the distance traveled bn,x5i -bqrexg zq+n/ +y object A compared to that of object B?

  When an object is released from rest and falls in the absence ofqo7:r(l6k 4;mg fqf ljikr+ ,j friction, which of the follok;4ol mqr: j,r q7g fk(+jilf6wing is true concerning its motion?

  When an object is released from rest and fall5 eu4tm6 qiqxp7 a4rb(s in the absence of friction, which of the following is tre qaru(tq4i p 467m5bxue concerning its motion?

  Suppose a ball is thrown straight up. Make a statement about the velocity andmc-npiivsrsq36(l t1x 7u3ml w s4l-: thl-lc: (s3r6s7w p3q n-su ix1mtvli4me acceleration when the ball reaches the highest point.

  Suppose a ball is thrown stracixii3j;j8 )right up. What is its acceleration just before it reaches its highest porjji; )i i83xcint?

  Suppose a ball is thrown straight up, reaches a maximumr1a 4asl c; fnd,17vku height, then falls to its initial height. Make a statemen411rcdl7fk nsvu ; a,at about the direction of the velocity and acceleration as the ball is going up.

  A ball is thrown str z(adi+r pu g,jfk*sw ,*jla36aight up, reaches a maximum height, then falls to its initial height. Make a statement about the direction of the velocity and accf*+l ,ij(a,u jwkrdg6pa3*z seleration as the ball is coming down.

  Suppose a ball is thrown downward in the ax/o h:k zjf+0fbsence of air resistance. Make a stateh/:of0kz+ jxf ment concerning its acceleration.

  Suppose a skydiver jumps from a high-flying plane. What is her acceleratiody5 ngajp/:);/twlc nn when she she reaches pnagd:5 t/;)/j lc nwyterminal velocity?

  A ball is thrown vertically upward w y+vgw x 2hcqli4)33k-(o:dca p k mdc3qy;id-ith 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 of the first ball? (How many times higher does the second ball goc- wc d (k 4qlq2adhigkyy-io+dxcm: p);333v than the first ball?)

  Ball A is dropped from the top of a building. One second later, ball ha m4.2o, .rwp6n iqusB is dropped from the same building. As time progresses, the distance b p4umqi 2sn,owha..6retween them

  Ball A is dropped fro8fc+h,ybczs2 bc6one * v..plm the top of a building. One second later, ball B is dropped from the same buildingc* py. +cscz6,2onevf lb. 8bh. As time progresses, the difference in their speeds

  Two objects are thrown from the top of a tall building. One is thrown up, anf y 3;qe c:bj*4nor:zz 1mczz,d the ;obcrfnz3:q1mz zjz4 :e c* y,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 building. A second brick is thrown stmo8upqu;lg01h bg6hg m h9e*,raight down from the same building. They are released at the same time. Neglect aiohg 10 lephu6h,m;gm8qu* 9bgr resistance. Compare the accelerations of the two bricks.

  An object is moving with constant non-zero velocity in the +x axis.-4h j(safiu,uwy 0dg nz.pg2cr ;0s;g 1ggb/x The position versus time graph of this 1i sxh4;y/g ( -wp,. ;n c0ga0sgrf gdu2bjguzobject is

  An object is moving with constant non-zero acceleration in 0 ygc8 *kcc7 +wcdjc4: (mhe bth0q1hqthe +x axis. The position versus time ckch yqb cg(4h780+tm* cwd 1:ceqj0h graph of this object is

  An object is moving with constaxhq2sy1 3w 7vazk8 xg2r.jjh:nt non-zero velocity in the +x axis. The velocity versus time 82.j1wkj xa xv3hsh:yqgz2r7graph of this object is

  An object is moving with constant non-zero acceleration 1tst64h/ kgye in the +x axis. The velocity versus time graph of this object i4 16yh/egtksts

  The slope of a position ksk2fmme d +pya:w)p ) 36rj2m -zia4kversus time graph gives

  The slope of a velocity versus time gr 7g9gbd k 02livtvl3sad.1yn:aph gives

  The area under a curve in an acceleration versus time graph d/b0rukl ny,+gives

  The area under a curve in;jtbjt*g)2g+v xbj 0 x a velocity versus time graph gives

  If the position versus time graph of an object is a horizontal wlw0txw*tusp*;- m g-x ;9zua line, the object is t* twl0*; pux--u;gwzxs9 maw

  If the position versus time graph of an object is a vertical line,7 kt5o28o cnso4bfu(f the object isco4nsbft(85o k27ou f

  If the velocity versus time graph of an object is a horizontal line, the obj (yq5a4* -ry* yiqb)u lzzvvckq+:oa(ect bvl*4uair*c qq5 z-ya()+q zk:(v oyyis

  If the velocity versus time graph of an object is a 5*13ksgldl if straight line making an angle of 30 degrees with the time axis, isgd* 3k5lf l1the object is

  An object moves 15.0 m north and then 11.0 m south. Fsurzl7)mb/g5t.a ztq.1y ybt /c7)fyvm8 sr 6 ind both the distance travel 6qv7mgfu/a.z.y57 tsy /tslytr b1 cb)8m)zred and the magnitude of the displacement vector.

  A boat can move at 30 km/h in still water. How long will it take tob e/ce hsd v.oz; aeglvk8.57. move 12 km upstream in a river flowin;./ h a gsokvel be.c85dezv.7g 6.0 km/h?

  55 mi/h is how many m/s? (1 mi = 1609x0, yzbu k yy,fdv)df) ra5zjj(m;4u 5 m)

  What must be your average speed in order to travel 350 kqg l 1r8ehx.qw/h:v u tm .fwm0j06(rrm in 5.15 h?

  A runner ran the marathon (approximately 42.0 k 8qbjmw9hd8)b s6fr6vm) in 2 hours and 57 min. What is df msrbb98v)8w6jqh6 the average speed of the runner in m/s?

  A car travels 90 km/h. How long does it gm;2fs3 )itewtake for it to travel 400 km?

  A ly (light year) is the distance that light travels in one year. The b beu/te;c55g speed of 5ee/g;bu5c tblight 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 roa(: ya gfu *85yvrqzkp9d and you look to the side for 4.0 s, z*g:q ykpy(a9f58 rvuhow far do you travel during this inattentive period?

  If you run a complete lr3zt68xc9 d x1bibn7 loop around an outdoor track (400 m), in 100 s, your average 963btbxizrcd 7x1ln 8 velocity is

  A polar bear starts at the North Polnx (h.a ihg8zjq+d tu.nqj:01e. It travels 1.0 km south, then 1.0 km east, then 1.0 km north, then 1.0 km west to return to its (.8:jq z.ghi 1tjdqn+nuahx0 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, thenc-6h jihzwz(jrk) 5c2et -b i8 1.0 km east, then 1.0 km north, then 1.c8t2k)whz5-6( e izh-ij jcbr0 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/h3;7wzx,2e e j,u juylj 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 sch,3;u2j jweyljz xe u7,ool?

  A motorist travels 160 km at 80 km/h and 160 km atkc/zolc + *a6r ovh dcb0t44 mnj*4q-h 100 km/h. What is the average speed of the m l4b-40+cthro6ka*n zcdmcj/ q v oh4*otorist for this trip?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 kmb n/o uaw.(.: lpwjlh./h. What is her aver awwj .: u.hob.nl/p(lage speed for the trip?

  An airplane travels at 300 mi/h south for 2.nd jy8aqeh0+6 00 h and then at 250 mi/h north for 750 miles. What is the average speed fo+6j qeay n8dh0r the trip?

  In a 400-m relay race the anchorman (the person who runs the last 100 mx)zl rrc73uh or9(04qvtc1yx3qo/c g ) 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 when the team A runner starts the final leg of the racco(tux9l 3y q ro3c4/cxg)r z170qvhre, in order that the team A runner not lose the race?

  A car decelerates uniformly and comes to wit (ni660mbnmnd yjt *gxy.;b; q.m)a stop after 13 s. The car's average velocity during deceleration was 67 km/h. What was the car's deceleration while slowm g.jbq;ib tnx(yni d0m* twym6.;6n)ing down?

  An airplane increases its tht*/ 8pi 7apwgm9ba, speed from 100 m/s to 160 m/s, at the average rate of w9ph/gp7i b*t,8mt aa$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerates at the rabn ex*xgm, k k(8k ph.p:rq;8ote 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 acceleratemai0cp,+nytp:6.v sq s 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. t:, h5xqhtm6v It then speeds up with a constant acceleration oht t5: mvhqx,6f $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velot quvtvsxfhx l )7g5wd/6on *( 9ckmn-i :6n2scity of 5.4 m/s experiences a constant acceleration olxmtxn6)7 covi*w h6gvfsukns dt592 /:(qn- f $3.9 \; m/s^2$. What is the cart's displacement during the first 8.8 s of its motion?

  A bullet moving horizontally to the right (+3k.gq9/j z :pu*atf gtx direction) with a speed of 385 m/s strikes a sandbag and penetrates a di./*agp:t3jz kg9uqft stance of 31.94 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 carrii lb*aarz6m m hp u)348;:agaker. It reaches a speed of 42 m/s at the end of the catapult, and this requires 2.0 s. Assumin)*bz a:hmkal ag6m ;483ipraug the acceleration is constant, what is the length of the catapult?

  A car starting from rest moves wv e*qd:aw uj.l)kl3 4tou;*nxith 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 m/s in a distance of 200 m. What is its averbx130nw f6)nz6 xli- xkbh-j.j ju5qjage acwzjbx5h- )-xqjb6k6j 0fun lj.i1 3xnceleration?

  An object starts from rest and undergoes uniform acceleration. During the i,zs bbc*2lf0g(dcbgpuz8nb; (a0;ufirst second it travels 9.2 m. How far will it travel during the u0as((fbb8 0nd,iczu;zbgg 2lpb *c; third second?

  An object is moving in a straight lit 5/7si28tc3bg 6 9av4w4e hiipy kbbrne with constant acceleration. Initially it is traveling at 16 m/s. Three seconds later it is travelcb ib238pt 4argshwivi/9 yte64k7 b5 ing at 10 m/s. How far does it move during this time?

  A car starts from rest and acc*u :4t dukyw+delerates 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 diu 4z8ya+g9o xecelerate 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 yz ,y ob5/g i 4fg(ixx/l;gao/car that has been waiting at the intersection starts ahead with a constant acceleratioiflo g ggayix/; x(o45 /by/,zn 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 amk1nd/ 8nwtf+0su.l oxm k /l+zgc5/z speed of 12 m/s on the surface of planet X where the accelzsuk8 wc /o+fdz1gx 5/ +tn/km.0 llnmeration 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 of 12 m/s on the sd8w0jl qrv/y 4g2e5oh; lzsv9 peohv+t:n 0x)urface of planet X whejv /ov 2tl5hlr)xg8v9 z ny0:0 how;eds4peq+ re 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 a speed of 15 m/s on the surface of p8fpl:bd qt ,3o(xke2e jaoh o.*-,jwqlanet X where the acceleration aelow(p,o*o8xjq. k2 fd jt3he ,qb-: 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 a sp: xg35 k4b;wve cl8mqweed of 14 m/s on the surface of planet X wher3 :wemw4qlcb vk ;g5x8e 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(s(nd9qtm6y li2x r/( s+ye me.10 s. If your friend holds a ruler between your fingers and releases it without warning, how far can you expect tlynr ((2s9ysmq /(e tm+ exdi6he ruler to fall before you catch it?

  A ball is thrown upward at a velocity of 19.6 m/sce0o5 )5eyjdi . What is its velocity after 3.00 s?)dcj05ei oe5 y

  A bullet shot straig9sf 14lckh6 e46kkli eb0i;nk ht up returns to its starting point in 14 s. What is the initial speed of t6ck s9bki4n1ikfe 46k0lh ;e lhe bullet?

  A ball is thrown straight kbm0/8 av+t5jdke.lrk:w: e b up with a speed of 36.0 m/s. How long does it take to return to 0tk/: 5 a+j ewklke: .bb8mdvrits starting point?

  A ball is thrown downward from the top of a building with an initial speedk(y w4+ wuz0ze of 27 m/s. It strikes the ge 0w+yzwuz(4k round after 2.4 s. How high is the building?

  A ball is thrown straight up with a speed of 30 m/s. (only filn .ab k,hr/2.z0do md:it 2whil in numerical value /o2 .,nk idbri.mwt da:h0zh 2in the blanks)
(a.) How long does it take the ball to reach the maximum height?    $s$
(b.) What is the maximum height reached by the ball?    $m$
(c.) What is its speed after 4.2 s?    $m/s$

  A foul ball is hit straight up q1;,ng mk+ ttpinto the air with a speed of 24.4 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 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 velocity 73gymr1qnr .,,tiis p at t = 1.0 s?

  In Fig. below, what is the velocity at t = 2.5 s,pfd 8 h,7 f gasyob1b9ppp*8w?

  In Fig. below, what is the velocity at t = 4.0 igt nq20rht2.s?

  In Fig. below, what is the velociz;o,xfayy nb ol; 5(1fty at t = 5.5 s?

  In Fig. below, what is the average velocity fr.7ea,p2nce9gc ,*ux n pqyt1 6ie5lmvom 0 to 4.0 s?

  In Fig. below, what is the averagpi+ r3d k2f4j4 u ngk93ezwr(ee velocity from 0 to 6.0 s?

  In Fig. below, what is the acceleration(o5/z,lxvkb2u6jl9h le:-q xq1 u tym at 1.0 s?

  In Fig. below, what is the acceleration1s2.w1p i mxw2uwatbv)ioa -7 at 3.0 s?

  In Fig. below, what is the average acceleratioihl mq3x 3a87on from 0 to 5.0 s?

  In Fig. below, what is the average acceleration from 0 to k2 amoi2h,eiwcvaj7xp 8z:9. 8.0 s?

  In Fig. below, what is the dioxno,g)g+ m( w(- pguisplacement from 0 to 8.0 s?

Does a car speedometer measure speedp7o f jef08v9.4r nqil, velocity? {speed|velocity}

  An object can have a varying speed if its velocity is constao(4b ;aoz9 kh7nd;qlj nt.

  The velocity of an object can be negative when its acceleration gah9t:4unr72mw :k qvcm.yu4is positive.

  If one object has a greater speed than a second object, the firs+* hb2v)6 horol+op o 63mzoslt must have a greater accelslooo3* +m b)ohlrv2o 6z6+p heration.

  Two cars emerge side bd h8cfp.9v gf+y side 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 a mlptjgk30;c 16mg9j t /;xb)qd-tmkecceleration decreases.

  A baseball player hits a fo9a969lb.c e v z b7kr*rsrzm9 h9tybl9ul ball straight up into the air. It leaves the bat with a speed o999chbt9k. r*b69a 9re7 zv rmbyllz sf $120 \; km/h$. 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, dbmb6;xs91f:nqrf 0u4i;u pc what is happening to its acceleration, how does it change if air frictio;uxbnmup:f90 f isrbqdc46; 1 n is ignored?

  As a freely falling obdhb7nlmk:h:: ject speeds up, what is happening to its acceleration, how does it change if air friction:: mnlhh b7dk: CAN NOT be ignored?

  An object that is thrown vertically upward will return to its orig:lzf wc;m5a vq 77 xgb/7i,gpminal position with the same speed as it had initially if air resistance is negligible. If air gi5,pm/a7f;mb qc7 lx: z7gwvresistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzero acceleration at the same tiiqbhjm,.wu,p9 ad37 dp +e9 pame.

  An object can have nonzero velocity and zero acceleration ac8a oulojdw:7n( 0) sqt the same time.

  An elevator moving from the second floor to the fifth floor making no stv ;f 00lg+dbegops along tdfgl+b00 vge; he way has zero acceleration all the time.

  A rolling ball moves from,5zjdxnak ,zps ;.t6r $x_1=2.6 \mathrm{~cm}$ to $x_2=-7.8 \mathrm{~cm}$ during the time from $t_1=2.0 \mathrm{~s}$ to $t_2=6.0 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-2.0 \mathrm{~s}$ is at $x_1=3.4 \mathrm{~cm}$ and at $t_2=3.6 \mathrm{~s}$ 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 quarot o */t;:t0xfl +xpz1eb-izw ter-mile ($1 \; mile = 1609 \; m$) track in a total time of 11.5 min. Calculate (a) the average speed  (数值)  $m/s$ and (b) the average velocity    $m/s$

  A horse canters away from its t rl9clg(ja4 tc6t3 c/grainer in a straight line, moving 112 m away in 10.7 s. It then turns abruptly and gallops halfway bact3l 6/ jcc (9rlgt4gack in 4.7 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 fromgsd8i5 xv)pn- $10 \; m/s$ to $22 \; m/s$ in 5.2 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 from8ihuta ohlw.q -tp;)8 $19 \; m/s$ to rest in a distance of 68 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a spee o62-)jvh/ oogu6ckm dd of $33 \; m/s$ 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 blocknxe gh+9*4utj s to essentially top speed aboutxnet*hgju4 +9 $10.9 \; m/s$ in the first 11.2 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 unifn .biar::s mx(- sr-hnormly from a speed of $20 \; m/s$ to rest in 4.57 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves skid marks 92 m longa1oj1n q*l++9pq wk-un2 qkfjf q1:xy on the highway. Assuming a decel*wo -x nl1uqq+1fn21 jkpf9y: ajqqk+eration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a trtp9,nnerm1o7i 1 jc,pd -jld8uck 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 ,b ik)3dxuwl:um 5 x*jrun in less than 30.0 min. After exactly 27.0 min, there are still 11duk,x 3iw mbl xu*5:)j00 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?    $s$