Suppose that an object travels from one point in space to another. Make a co4rkv+ 7;x;lvk l.ebq kmparison betweenkb.e +qkr7l ;vlk4 v;x the displacement and the distance traveled.

  When is the average velocity of an object equal to the insta crlws5,b.sqav miex)f7v 5o3k2 5l 1dntaneous velocity?

  A new car manufacturer advertises that their car can go "from zero to smb- yh6 s2i4joixty in 8 s". This is a desc 6m jy-boshi42ription of

  An object moving in the +x axis experiences 5f cv6n8g(u+c9-g q v:nbabfu i04axpan acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+ux1qlx *ml(0s/.jz r 5a6qvqqx direction) begins to slow down as it approaches a traffic light. Make a statement concerning i*v6 qq.lmq x0jz1(sl5 rqxua/ ts acceleration.

  Suppose that a car traveling to the West (-x direct nw1 +mxjwt jw mt0kb;(bez+f4*0pz worg.x3: ion) begins to slow down as it approaches a traffic light. Make a statement concxj+wnt(r* z :zm0 kpe1bjbwg;wt4w.+f 30x om erning its acceleration.

  Suppose that an objectzrc(pvp )wj2 2 is moving with a constant velocity. Make a statement concerning its pvcp( z2j2rw) acceleration.

  If the velocity of an object is zero, does it mean that3 j6obdea9f-e ri/oj1 the acceleration is zero? Support b3ee -oj9 af6r1/jodi your answer with an example.

  Can an object's velocity change direction when c.kw b (xiw)/fits acceleration is constant? Suk/bc x(w.wi )fpport your answer with an example.

  Suppose that an object is moving with consvyi6mm:;j v;t i kmk) y1 l(u:vkx;av;tant acceleration. Make a statement concerning its motion with respec):ym;k:v 6uakimxli1; vvy tk;(v mj; t to time.

  Can an object have increasing speed while its acceleration is decreasing?qv m4uj2i5zvmq/ g/o3.e j3tw Support your answevv/4 /w 3j juieqm2.tmzgqo53r with an example.

  Suppose a can, after an initiwklo+j x xp1zo6c7kb*bg9x(5 al kick, moves up along a smooth hill of ice. Make a statement concerkjzw1p*6lk9x g x xb b+(5oo7cning its acceleration.

  Under what condition is a 1;m(kwfr2kp overage velocity equal to the average of the object's initial and final2wm1(pkofk r ; velocity?

  Objects A and B both start at rest. They h5of2hnid ((t (kq1hl both accelerate at the same rate. However, object A acc hkt1(lih2no (fqd(5h elerates for twice the time as object B. What is the final speed of object A compared to that of object B?

  Objects A and B both start from rest. They both accelerate at th2,+1hvf -, n0cfy m-vsiphauhe same rate. However, object A accelercphf ihh+0v-nuv,m1f, ya-2sates for twice the time as object 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 absel k5 hbus7rgk-a7plas 3; ;gpygj0.-rnce of friction, which of the following is true concerning it5sl.gy3u;a- k7g arp0j7k p -;b grslhs motion?

  When an object is released from resg ol.u n6rjrprk77/dbr28lm1 t and falls in the absence of friction, which of the following is true concerkrp r8r7mu .nrdlb6o7g j/1 2lning its motion?

  Suppose a ball is thrown straight up. Make a statement ab+ +aal/ :.y6ngvahguaout the velocity and the acceleration when the ball reaches the highest pointvy +gaua lg/a.:an6h+ .

  Suppose a ball is thrown straight up. What is its acceleratior kic .rkf5f62r1f;0xi ns)s fb9y i*pn just before it reaches its ryrf0f 1k n9fs6.)p brxiksf5 *c;ii2highest point?

  Suppose a ball is thrown straight up,*)z jken.5r ;n.nwsk n reaches a maximum height, then falls to its initial height. Make a starzw) *knennk. s;5n .jtement about the direction of the velocity and acceleration as the ball is going up.

  A ball is thrown straight up, reaches a maximum height, then falls to its xr1k unhx -6e,/wiq 2ow+mnf)initial height. Make a statement about the direction of thr) fx-w/+ nuwo1m h6qxeik,n2e velocity and acceleration as the ball is coming down.

  Suppose a ball is thrown downward in the abs9qj-quapjxg24r x :vp-b 0m 3oence of air resistance. Make a statement concerning itsqg:xvj j3-m0b pqou2p4r9-x a acceleration.

  Suppose a skydiver jumps from a high-flying plane. ,ydb6g,tts j. What is her acceleration when she she reaches,s tdjb.,6y gt terminal velocity?

  A ball is thrown vertically upward with a6ar(4 oxwmsve w,x7a5*y o -dl 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 wo6d l*w a4x ,s( rayoe7xmv5-ball to that of the first ball? (How many times higher does the second ball go than the first ball?)

  Ball A is dropped from the top of a building. Ontk b16he *ej86wb;afv e second later, ball B is dropped from the same building. As time progresses, the distance bet*8a6 vtewh1bk j;bef 6ween them

  Ball A is dropped from +8 3yx*qy wztzthe top of a building. One second later, ball B is dropped from the same building. As time progresses, the differe3zzy*wq t xy+8nce in their speeds

  Two objects are thrown from the top of a tall building. One vj9p. co .y4ztwn7dw ,is thrown up, and the other is thrwvc,p9.d4.y zt7n ow jown 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 strivdb .e5/ 9qffaight down from the same building. They are released at the same time. Neglect air resistance. Compare the accelef95/bdfe vq i.rations of the two bricks.

  An object is moving with constant non-zero velocity inc7 )em/hu.o dhhwz8e:zd h+8x the +x axis. The position versus time graph of thmeuhd8+ce / h w.dzx :oz)h78his object is

  An object is moving with constant non-zero acceleration in the +x axis. The9)yu)dq tli1of b: 6vz position versus time graph of this object 1l:yt i9q )doz6vu) bfis

  An object is moving with constant rbwq+ j*ssng8o+kw:2a,hp 4 vnon-zero velocity in the +x axis. The velocity vr ao+j4hw+ ,2 qnp*sv: kgwbs8ersus time graph of this object is

  An object is moving with constant non-zero acceleration a1r(t+fm/jwek*i u 2din the +x axis. The velocity versuste1fa/ jm(+ r2kiwd*u time graph of this object is

  The slope of a position v +)grlhv9nfofwq7 cu0yc.gtn64m*, xersus time graph gives

  The slope of a velocity:opcdfy)nw)2pts+ s 12 zw0 ay versus time graph gives

  The area under a curve in an+apcce:,z q;mw5ww3sjt p( t7 acceleration versus time graph gives

  The area under a curve in a velocity versus timek-7x6hxn5 xzmz75v+imw h6eu graph gives

  If the position versus time graph of an objecxr :q21sbu*mtur a7 2at is a horizontal line, the object i 7rtxu:22asr 1bqum *as

  If the position versuszil+4 l8(r :i cyyo*wc time graph of an object is a vertical line, the object isyc oli*i4 z(ycwr8+l:

  If the velocity versus timebbd1vm2wcga / f6j9scrhfn,b 6 m2c+9 graph of an object is a horizontal line, the object ,m2sbj cvn9bmfcgr9 c /16 bwha62+f dis

  If the velocity versus time graph of an object is a straight line making an p ,vhm0a,secnp5ylw9cv *5 3jangle of 30 degrees with the tiy9lsvn*vh w a5 ,jp30,emc5 cpme axis, the object is

  An object moves 15.0 m north and then 11.0 m south. Find both theb m m:*/dcb1rv 3d9iav/4hzk kh,h)tt distance traveled and the magnitude of the /k3mh9td,v vtkibb az*)hm 4h:1d/cr displacement vector.

  A boat can move at 30 km/h in still water. How long will it take to move 12 km60ys,lweg tgcq i)u8zigg ns*t,l, 0 7 upstream in a rgltwsg0z* 67 qcgs ,n,i,u)08yelgit iver flowing 6.0 km/h?

  55 mi/h is how many m/s? (:vk;i49nop 1mr 7vegi1 mi = 1609 m)

  What must be your average sp d t)uljo1h)*zz i8*t57wr ffseed in order to travel 350 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 k+ unfbho/ qdsf,*d;u e(9p 3hnm) in 2 hours and 57 min. What is the averagn(hn fo;bu*e+dhfd s,p/ u39qe speed of the runner in m/s?

  A car travels 90 km/h. How long does it take for it to tr7 pt+- uf(fndfavel 400 km?

  A ly (light year) is the distance that light travels in one year. The specvh8uu8 hvm/96d h dc)*u;jh ued of lihuh8dumu*;)6 hd cv89/ujhcvght 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 roadx 5akp k(/s(he;jc.k h and you look to the side for 4.0 s, how far do you travel during this inatten pkhh(e.kx sk;ac (5j/tive period?

  If you run a complete loop around an ojau9s :y0b 7pjpt7tw- qet1w0utdoor track (400 m), in 100 s, your averagt:wtt9p-bp 0qjs7u yj1e70 wae velocity is

  A polar bear starts at the North Pole. 0tfdh sab esg -6ip0:*,k - yuzre0xo*It travels 1.0 km south, then 1.0 km east, then 1.0 km north, then 1.0 kmsbkhz0pa,s:tr0d * ifx gu e*0 -y6o-e 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 d8mt zd5j.e+cv2vw5 f-0hb88 p xxwfa travels 1.0 km south, then 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 the bevh +8jp0bv5twxdf2a.5e - dcf8xwm8zar's average velocity?

  You are driving home on 6 )njshcs -.apxx(8 aha weekend from school at 55 mi/h for 110 miles. It then starts to snow and you slow to 35 mi/h. You )8h xsj 6h-s.napaxc(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 3cpw(p2 rzzsfezm21 0km/h. What is the average speec(em20 3zr1pfpswz2z d of the motorist for this trip?

  A motorist travels for 3. y4ywm5 aa+a hn1ql 743dr1tsu0 h at 80 km/h and 2.0 h at 100 km/h. What is her average spe37 +au4d l5tn4rw1 m1aysayqh ed for the trip?

  An airplane travels at 300 mi/h south for 2.00 h and then at 250 mi/h north fo nw): (tr1n* t/obxteor 750 milb /)tnr :twoe1x(on*tes. What is the average speed for the trip?

  In a 400-m relay race the anchorman (the person who runs the last /..4df cdfy oqu+b tjh:z so k92h7p1b100 m) for team A can run 100 m in 9.8 s. His rival, theups b.:d1 o9yzf hqkc. /hd2fto7bj+4 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 race, in order that the team A runner not lose the race?

  A car decelerates uniformly and comesn)fq m7bh dl7 xm63h7d to a stop after 14 s. The car's average velocity during dhm l6db7d 3f) qx7nh7meceleration was 43 km/h. What was the car's deceleration while slowing down?

  An airplane increases its speed from 100 m/s to 160 m/s, at the averg+sse 4;zsty71 adegy34j) fjage rate of eg ;ty+e7g)yz3adfsj sjs4 14$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h acyr7jm8b u;8eb xtp.6 gcelerates 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 accini8g se.yh *9elerates 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. I 0dsxa:e nsj7e):y6) bpxxcg2t then speeds up with a constant acceleration of s xb6ype)x: nge:caxd7)0 j 2s$2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 7.0 m/s exi;l+bnu*2a q:j gz .qpperiences a constant acceleration oiqpla nqb ;u: 2+gjz.*f $2.8 \; m/s^2$. What is the cart's displacement during the first 5.9 s of its motion?

  A bullet moving horizontally to the right (+x direction) grz+q+/ ) gqdowith a speed of 491 m/s strikes a sandbag and penetrates a distance of 81.74 cm. What is tz qo)gq+rd/ +ghe average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult o*o-iz fx0qzu6gayi 1/- 7y;m)xlg bfsn an aircraft carrier. It reaches a speed of 41gos60xa) q; 7-f zbzfmxy-iu /li*yg2 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 with constan2 ej81 qrd7tbzhgh:a6t 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 aver2y- qgjy) )g4ma:5w hp kj 8ua1rt8ezrage acgte yqaj: 418-g2jrk) mrpuwz5 8)ayhceleration?

  An object starts from rest and undergoes uniform acceleration. 5t25tify w+crtzeyn 7q, qg;6 During the first second it travelsq+ yw7t yq6 fn5e;iz2r5tg t,c 4.1 m. How far will it travel during the third second?

  An object is moving in a straigh0c+l )fvxhpev 41so )dt line with constant acceleration. Initially it is traveling at 16 m/s. Three seconds later it is tra h4sc0vdef+pxvo)l) 1veling at 10 m/s. How far does it move during this time?

  A car starts from rest and accelerates ;7+dbr .pd ql)oc)gf tuniformly 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 roady3 hl*zk,y ,lgi *wk5g can decelerate 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 8ne/a fkjw l,2turns green, a car that has been waiting at the intersection starts ahead with w2 jf8,/eklna 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 gew:etl)pz + 5ihy1)m of 12 m/s on the surface of planet X where the accelerey:)zh5pl +tw1g mei)ation due to gravity is $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown ) ,w*n iazmws w0saw+8upward with a speed of 12 m/s on the surface of planet X where the acs)wa z8m s*iwww0n+ a,celeration 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 planet X32o /xv qdnweimgt+8: where the ac: imtgo nvd+38/2xeqw celeration 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 speed of 14 m/s wpj4sig2.e9 c9 eq 7dyon the surface of planet X where the acceleration due to gg9c 49ye2p .qjdsiew7 ravity 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 holds a ru k64cgyif r1m2zdh )obb9)yc(ler between your fingers and releases it without warning, how far canb cib gk9c yydo2)z)41f(6mhr you expect the ruler to fall before you catch it?

  A ball is thrown upward at a velocity of 19.6 m/s. What iszj7dqen(b q;+lb3 j e r4 mzl3y*uf-9s its velocity after 3.00 ;z+zj4ry3nql(euf-j3e9qblmb d* s 7 s?

  A bullet shot straight up returns to its starting point in 5 s. What isfmpcr,n7 0y /c the initial speed of the bullet?mr70 yp cfn,c/

  A ball is thrown straight up with a speed of 36.0 m/s. How long does itb ;2i*q4 9tw- y(rvvik7wpire take to ve4wytiqbi (*;w7p-2 i vrr9 kreturn to its starting point?

  A ball is thrown downward from the top of a(wxfc1u(cddc s o17.m building with an initial speed of 18 m/s. It( 7w1(do.cf cduxsmc1 strikes the ground after 1.5 s. How high is the building?

  A ball is thrown straight up with a speed of 30 m/s. (onlydzxl 0tua+ oshh nt *i::d;93w fill in numerical value in the bs; x39+i0nu: dht al*hwdzt o:lanks)
(a.) How long does it take the ball to reach the maximum height?    $s$
(b.) What is the maximum height reached by the ball?    $m$
(c.) What is its speed after 4.2 s?    $m/s$

  A foul ball is hit straight up into the air with a speed of 42.8 mj99+-zn4vg 6fx.x 3 p8gk1 lrvdg wwhf/s. (use $g=10 \; m/s^2$, only fill in numerical value in the blank)
(a.) Calculate the time required for the ball to rise to its maximum height.  (数值)  $s$
(b.) Calculate the time for the ball to fall back to the height at which it was hit.  (数值)  $s$
(c.) Calculate the maximum height reached by the ball.  (数值)  $m$
(d.) Calculate the ball's speed 3 seconds later.  (数值)  $m/s$
(e.) Determine the time at which the ball pass a point 10 m above the point of contact between the bat and ball for the first time.  (数值)  $s$
(f.) Determine the time at which the ball pass a point 10.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is 8m 3 ib0tp gzh4 nzu4o+plt8+ el0yin1the velocity at t = 1.0 s?

  In Fig. below, what is the velocity at t -h vr;1snyqm7 = 2.5 s?

  In Fig. below, what is c ;;-,brwvp95ojnd/cf-e- gdat :u txthe velocity at t = 4.0 s?

  In Fig. below, what is the velb ,d/ 0aqx*zdeocity at t = 5.5 s?

  In Fig. below, what is the average velocityqahcasuiw8o. ;*ya q/1 +a -f kjocl2, from 0 to 4.0 s?

  In Fig. below, what is the average velr2,v 7gfgb ;ciocity from 0 to 6.0 s?

  In Fig. below, what is the acceleration ate0 lwk1s 2an2e 1.0 s?

  In Fig. below, what is the acytj m03st15py celeration at 3.0 s?

  In Fig. below, what is the average acceleration from 0 to 5 8c7kix2:jrg l.0 s?

  In Fig. below, what is the avergi ).seflb.o .r rbazl *+*6xld9zfz5age acceleration from 0 to 8.0 s?

  In Fig. below, what is the displacement fromcsk,kl(; jv,alq *cq 8 0 to 8.0 s?

Does a car speedometer measure speed v - 9djfsolscdj4ygc4fa); ,qorlw9 ;0;*gmg, velocity? {speed|velocity}

  An object can have a varying speed if its velocity isba 3ar(*yr;r7)4g)wiqs9zqn(bj owm constant.

  The velocity of an object can be negative when its accelerat 4ys5p,r1 9zxkyv:uqqion is positive.

  If one object has a greater speed than 8pey itg x74*aa second object, the first must have a greater acceleration.7 tpx8 eia*4yg

  Two cars emerge side by side from a lcw ,xncesz2/gqzr0; 1 x/q( qtunnel. 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 s5g)o+7myk vcits acceleration decreases.

  A baseball player hits a foul ball straight up into the air. It leaves the bat21z ltl*.+umxdw a 2qtevmu41 wiu1l*wxadm+qm2vzl 2.t4 uet 1th 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 object speeds up, what is happening 1:zhwe 2oh ij:5 ht7qrto its acceleration, how d:2whq7h r ot j:ie15hzoes it change if air friction is ignored?

  As a freely falling object speeh(/z4rpp (0 fd4vi heeds up, what is happening to its acceleration, how does it chanvhedp z44f0 pe(r(/ihge if air friction CAN NOT be ignored?

  An object that is thrown vertically do3gbz j4t.m 5bpfvu5,n+ -g*w)keay./ze ujupward 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 result be altev a5jz/ kegmb nywujo,z*edft5. 4g+-3).ubp red?

  An object can have zero v i5vdvoqt 4hg +dq2:-:kfe*kgelocity and nonzero acceleration at the same time.

  An object can have nonzero velocity and zero acceleration at the same time.3 xd +dotn:q2d

  An elevator moving from the second floor to the fifth floor mab:,pr8b9 fs rsking no stops along the way has zero accelera9bsrs 8: frbp,tion all the time.

  A rolling ball moves fro(+wafsk)*ogz ub n/klvww5hfjd /5(8 m $x_1=2.3 \mathrm{~cm}$ to $x_2=-5.8 \mathrm{~cm}$ during the time from $t_1=2.4 \mathrm{~s}$ to $t_2=5.4 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-3.0 \mathrm{~s}$ is at $x_1=2.6 \mathrm{~cm}$ and at $t_2=3.9 \mathrm{~s}$ is at $x_2=8.4 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps arounds9h5x wl6x;to ms .m5e a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 6.2 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 87 m away inc7, ey0jvq-a..5 ij7jkqgesp 10.1 s. It then turns abruptly and gallops halfwav.sq-7g ea0j iek,q .cyjj p75y 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 mjoo .+5,y25d 2gc2lbcu y tvf$10 \; m/s$ to $22 \; m/s$ 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 froe3simp9oa(:qj 10u w qm $21 \; m/s$ 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 speed of )wi56rckzu ,evhl /4c: yeg/a$29 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.5 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of the blocks to essentially top speed abo(u 8t ie/z h(lsd)vex:usd hlxe(t )(u/vi:z8 et $11.3 \; m/s$ 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 uniformly from a speelygf3lx4cx,kj d+7, fd of $20 \; m/s$ to rest in 4.31 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. A,+qviyvtpzv8 mi85. jssuming a deceleration ov itpmj88v5vi y+z., qf $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck go(uzmk)3as)+ b: a vzgjing $25 \; m/s$ 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 3b 8+qamz dx .2ba+xd9v+wy7 jgvl 4z)y0.0 min. After exactly 27.0 min, there are still m+vg. 9 4ab7v)qza bjwz+x2yd+l 8ydx1100 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?    $s$