Suppose that an objecfw oxk som/d4n4g rx28oo:g3a(+f r+mt travels from one point in space to another. Make a comparison between the displacement and the dist/mo4garr8 xsx:wk3+f o o n+(do m42fgance traveled.

  When is the average velocity of an object equal t.xa7b p+e jzofseu..qijg*( 1o the instantaneous velocity?

  A new car manufacturer adver2 cee tgd8biic8 y :z8f0p,z0xtises that their car can go "from zero to sixty in 8 s". This is a descriptiob8:gezt8,epi0zyf 2i d 8x c0cn of

  An object moving in the +x axis experiences an accs 9ncqxi-4 jt(eleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x direction) begins to slow qbn/y3d6 f/s*mi uo s/down as it approaches a traffic light. Make a statement con d3sy*bi/mqon//6fus cerning its acceleration.

  Suppose that a car traveling to the West (-x direction) begins to slow da7 asc5m/7ws ,i3q.kyoanz )pown as it approaches a traffic light. Make a statement concerning its am /ipn3aaa77qsk wc,zyo).5 scceleration.

  Suppose that an object is moving with a constant velocity. Make a sta un66hzei3 k4btement conce e66u4zbnhk3irning its acceleration.

  If the velocity of an object is zero, does it mean that the acceleration i-c9h+x4-qj;pdjvij: vm v 9j qs zero? Support yoq9p9m dvq j v;-xvjcji:h+-j4ur answer with an example.

  Can an object's velocity change directiontm:)yo73s;qn :. qoh,jykx iz when its acceleration is constant? Support your answer with an exh)y:,inqt mo.q7 xyk;j: szo3ample.

  Suppose that an object is moving with constant acceleration. Make a statement54sr4 rmm( yp*i1ufab conce1fms(y pa* rmb54iru4 rning its motion with respect to time.

  Can an object have increasing speed while its as7;uy 2g 5h9.x zqradocceleration is decreasing? Support your ao2gsy 7rd;5hqxu.a9z nswer with an example.

  Suppose a can, after an initial kick, moves up along a smooth hill of ice. expj/ l nem3 wje06v;/Make a stn pwje /0/lvee3j 6;xmatement concerning its acceleration.

  Under what condition is average velocity equal to the avw:uog9dbm q *7erage of the object's initial and fi7um9: owd *gbqnal velocity?

  Objects A and B both start at rest. The n0dqoli: o75q/we* rjy both accelerate at the same rate. However, w :dion5l q7q/j*ro e0object A accelerates 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 accyd,q4+zwvpji2w; alfgi ge 0 k,s73 r.elerate at the same rate. However, object A accelerates for twice the time as object B. What yf.lw+2 4jvgzia 7ie, ,;s0wd3kpqrg is the distance traveled by object A compared to that of object B?

  When an object is released from rest and fa+un jovb.v l b,3hlp07lls in the absence of friction, which of the ph 7ovbb l3,nvl.u+0jfollowing is true concerning its motion?

  When an object is released from rest and falls in the abe*5hy 7c b)ylf1n .p procw9j66tuz2g sence of friction, which of the following is truyfcb6u9p16zhn . oewy*527gtrj ) plce concerning its motion?

  Suppose a ball is thrown straight up. Make a statement about th2w8d*p zrgd1iu ,qz1ha:a*pde velocity and the acceleraiw*qda: gd8u1 dzr1pz,*p ha2tion when the ball reaches the highest point.

  Suppose a ball is thrown straigh p)mzy t0 vvk2+2g2vmrt up. What is its acceleration just before it reaches its highest por20 gvv2zky2mm)+ p tvint?

  Suppose a ball is thrown straight up, reaches a 4bumz// b92j 8rc,gwip u y,lrmaximum height, then falls to its initial height. Make a statement about the direction of the velocity and acceleration as the ball is goin,4c wz/yb8g,9blurj /rpu2img up.

  A ball is thrown straight up, reaches airb7gl2. (/oe9e5al oshzoa/ maximum height, then falls to its initial height. Make a statement about the direction of the velocity and accelerat(/ z s7.e a59oblgeo2ihrlao/ion as the ball is coming down.

  Suppose a ball is thrown downc ,rr:1c)gi1lr)*xup k mww;pward in the absence of air resistance. Make a statement corg u i* 1)mcc,ppr l1);ww:rxkncerning its acceleration.

  Suppose a skydiver jumps from a high-flying plane. What is her acceleration whtyz01cz hhmbkt6nu- z : k,*9ven she she reaches9h1n* 6ub, -hzv:tmyzk0 tkcz terminal velocity?

  A ball is thrown vertically upwardn dht ul,1tp;w*r.abjl13/gb with a speed v. An identical second ball is thrown upward with a sp ,ahwdr3jn*t;lltg1 /u.1bb peed 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 go than the first ball?)

  Ball A is dropped from the top of a building. One*qfq tj*hfb* 9 clpd:* second later, ball B is droppjt * :p* dbc9*fqfhl*qed from the same building. As time progresses, the distance between them

  Ball A is dropped from the top of a building. One n2wt6c;jbqrt :p ou85 second later, ball B is dropped from the same building. As time progrub;5 2 pqonwrt8 cj6t:esses, the difference in their speeds

  Two objects are thrown from the top of a tall building.za9 1.h0d2rfvw6w :7zv.qwj nmi xin65iw1 xw One is thrown up, and the other is thrown doa6v90 m1wx.qr j hniv1i7dwfxw5 w :znz.i62wwn, both with the same initial speed. What are their speeds when they hit the street?

  A brick is dropped fro +*j-szqm5uu o5w)khem the top of a building. A second brick is thrown straight down from the same building. Thek5 *z+s- h wuq)5mjoeuy are released at the same time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with constant non-zero veloc5:my5a 2w ezpxity in the +x axis. The position versu:xm25p yw5 aezs time graph of this object is

  An object is moving wg1q8qgn:e3 *z zu8pfpith constant non-zero acceleration in the +x axis. The position vegf 1n ppz8* u8q3z:gqersus time graph of this object is

  An object is moving with constant non-zep5pnu 7y- 4hnnro velocity in the +x axis. The velocity versus nh7-4 ppuy n5ntime graph of this object is

  An object is moving with constant non-zero acceleration in then/;zc:7 pzt7:j to cvi-2q fnlkic)0i +x axis. The velocity versus time graph of this object l/n;02co f7q z): i- :7czjpciikntvtis

  The slope of a position vrlzvx0+o2n7 bxy4l 1 mersus time graph gives

  The slope of a velocity versus time grapr+ga x7l,1vqg(: yeowh gives

  The area under a curve in ajw*x 1;e9t)1ul+t bgu*not gp n acceleration versus time graph gives

  The area under a curve in a velocity versus time graph y,x(u 0pas 3vsgives

  If the position versus time graph of an object is a horq x6ph/-sel1gal 4/plizontal line, the object is/ 4x1alhlpl6qg-e/ ps

  If the position versus timz)( fq(lgaq rm9 i4db9i5 hck.e graph of an object is a vertical line, the object is zr(qidgl(bci 5hq4a9m.fk )9

  If the velocity versus time graph of an object is a horizontal line, the ozu0z0oxup k6z9s* aw9 4tnx /(ys7 aambject i70skmza n69apazty xz/uxo 4us0w( * 9s

  If the velocity versuga.4w *k/g ious time graph of an object is a straight line making an angle of 30 degrees with the time axis, the object.uo*gwai k/ g4 is

  An object moves 15.0 m north and then 11.0 m south. Find bot ju-:;dwp 74befb,as pki-(h ph the distance traveled and the magnitud:(7i4,pfkadpb ;u- hpbwes-je of the displacement vector.

  A boat can move at 30 km/h in still w:, v/c/eq3-h.x5jc wjze /kp il- gjtkater. How long will it take to move 12 km upstream in a river wq-,j e/l/3pgx/t. vj:-5ecij czh kkflowing 6.0 km/h?

  55 mi/h is how many m/s? (1 mi = 1609 m)6.)ml p tp:pcn

  What must be your averasv mg:d3yr7 t69ay2hcto1j/ubb8b)ege speed in order to travel 350 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 km) in 2 ho)2tz f. il; (pgi.. xvgvz5zenw o:+fjurs and 57 min. What is the av:)v foep+ .itz.. xi ;l2nw5vggz(zjferage speed of the runner in m/s?

  A car travels 90 km/h. H ad*m3xj)hi9)2 jnpmwow long does it take for it to travel 400 km?

  A ly (light year) is the distance that light travels in onab,tqbp6 e -45yb29asrd .j-c,yr suje year. The speed of light is,ryc9pjsqb.-56t2d uerbj,4 yaba s- $3.00 \times 10^8 \; m/s$. How many miles are there in a light year? (1 mi = 1609 m, 1 yr = 365 d.)

  If you are driving 72 km/l5u:y0*s/x v1tmuk; j4 t;ca 6 nkuebxh along a straight road and you look to the side for 4.0 s, how far do you travel durs 6u4ycajt1ekvmul/:0;k*5utxx ; bn ing this inattentive period?

  If you run a complete loop around an outdoor track (400 m), in 100 s, your aver xnq7xic +h6j-age velocitc hixx-qn76+j y is

  A polar bear starts at the Nortyrr2yrn :mtw-*e p p8dg4..vv0qp ( gnh Pole. It travels 1.0 km south, then 1.0 km east, then 1.0 km north, then 1.0 km west to return. gyppr4 d*rt gr nwm-env0 v.8:py(2q 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 9q(onv*mi db7t-fxl. 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 mi-m f d.v*(xoltnb7q 9in. What was the bear's average velocity?

  You are driving home on 7spu z-+nv ..g am1i)rsajo; tax) wc)a weekend from school at 55 mi/h for 110 miles. It then starts to snow and you slow to 35 mi/h. You arrive home asgsxo n p)1zta7.rmv) ua c).j;ai+w-fter driving 4 hours and 15 minutes. How far is your hometown from school?

  A motorist travels 160 km ajprg za +.v*0zr8 4syywh(z9ut 80 km/h and 160 km at 100 km/h. What is the average speed of the motorist for thishajz4 zu0z* g(y prw v89.s+ry trip?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h. What is he d 361sb*qhuldet jb/.r average ud je6*btlsdq/1hb.3speed for the trip?

  An airplane travels at 300 f lxak6cr2o*y) eu( d-. +xh/7qsig2qcn,esumi/h south for 2.00 h and then at 250 mi/h north for 750 miles. What is the average speed for the tris 2(kqiqe7 g/6fu. xc2d+ns corh,)luxey- a*p?

  In a 400-m relay race the 8yi6* lupll*mo2 kya/ anchorman (the 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 when the team A runner starts the final leg of the race, in order that the team A runner not lose the race?6 pyykl uila 8mol/2**

  A car decelerates uniformly and comes to a s zbqk:a/u-x l-;n pve7top after 12 s. The car's average velociblx -qp -v:un7kaz/;e ty during deceleration was 77 km/h. What was the car's deceleration while slowing down?

  An airplane increases its speed from 100 m/s to 1s 1tb8h wp:x1h60 m/s, at the average rate of :h8 xhb t11wps$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h acdu fjqr sq4e 6,2ewfpu4 0v*1jcelerates 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 acceleraq c wn/h*y/m kkan)3 es7d dfv2*g:rt)tes 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 10lsx)l 86 nwlilb7 1k7i s. It then speeds up with a constant acceleration ol61)snbl w 87xii7kllf $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial veloc ;o9mhsmw-3uuw:ig hq 4vc pe.y),a7rity of 5.5 m/s experiences a constant acceleration o: a;3)hp9uc-yuwmiqws., m e4go7rvhf $1.2 \; m/s^2$. What is the cart's displacement during the first 8.0 s of its motion?

  A bullet moving horizontally to the right (+x 6 sf-ets:f9 rvdirection) with a speed of 568 m/s strikes a sandbag and penetrates a distance of 71.61 cm. What is the average acceleration, in 6e:rf -sfv ts9$m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult oxg3ik;s9)t ,jwr /xnrn an aircraft carrier. It reaches a speed of 42 m/s at sr;xw knr9x j/)gi t3,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 constant accelerataqtaen(t175 t ion 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 1j gfwcq: v*p2a distance of 200 m. What is its average accej2vp*c1wg q f:leration?

  An object starts from rest and undergoeuhx vln7 ff8/o 6s8.tjs uniform acceleration. During the first second itj.8nv/ 6hfl 78 xostuf travels 6.5 m. How far will it travel during the third second?

  An object is moving in a straight line with constant acceleration. Ini.:sc i(w7qgaoeb: s hdgl)g 0:tially it is ce:wlaggdh:.g7)0bsi o q (:straveling at 16 m/s. Three seconds later it is traveling at 10 m/s. How far does it move during this time?

  A car starts from rest and accelerates u6, ux oq.re te9+ppk9nniformly at $3.0 \; m/s^2$. A second car starts from rest 6.0 s later at the same point and accelerates uniformly at $5.0 \; m/s^2$. How long does it take the second car to overtake the first car?

  A car with good tires on a dry road can decelerate at aboum h:u3 j: 6)nte 8-zdfxemfh;wt $5.0 \; m/s^2$ 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 has been waiting at the ih*zn.g zk i/wi 81yx2hntersection starts ah 1ni w.z82zhh*/ykx giead 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 :6xxuizomqb: sb t c,(3h(r9asurface of planet X where the acceleration due to grr3 :6 sobqtib:z9,hcua( (x mxavity 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 surface of planet X whgiy0 ducz+: c0bt6;q ierebt+iicqu0ydz g :;c60 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 planet X whezt94dznpxk, 2 xr5hsh4e//fire the accelera9tnd xzhhz4x pkf/ r /2e54is,tion 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 sz91dq3k,xnbe sjji8k )oqb 2(peed of 14 m/s on the surface of planet X where the acceleration d,koe 9sb8d21qj)bz qj3( nx kiue to gravity is $3.5 \; m/s^2$. What is the speed of the object after 8.0 s?

  Human reaction time is)/sww8rphu z(yuk* / t usually greater than 0.10 s. If your friend holds a ruler between your fingers and releases it withou 8k(usw/wzu tp/)r *yht warning, 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 kl*3zt-vzd8n1+nbkv s /fr 4 ais its velocity after 3.00 4*dlabfvr /k -ksn 1z83t +nzvs?

  A bullet shot straight up returkv9x+ m+i0gsj 0sxoo2ns to its starting point in 17 s. What is the initial speed of the bugix0k 0+ 29xosmsovj+llet?

  A ball is thrown straight up with a speed of 36.0 m/s. How long does it takesdu)ud : i0;cy to return to its starting pod 0d)s: uuy;icint?

  A ball is thrown downward from the top of a building with an initial spee9gyaw t-sy(.z0te n((163chcoz squ md of 5 m/s. It strikes the ground after 4.9 s. How high isuzt1om a0gq n.((e9sy wzccyts6( 3 h- the building?

  A ball is thrown straight up with a speed of 30 m/s. (only z:1m.n8etiag9j-5uknujv)l fill in numerical value zg9a1vtj5 i-:j) nu.kml eun8in 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 into the air with a spe12:g;:y buo la66, kwexegy hwed of 46.1 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 1 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 velocityweq +c1 k2ry:iz2eu d) at t = 1.0 s?

  In Fig. below, what is the velocity k vbfm gk9;17ftb- yt(at t = 2.5 s?

  In Fig. below, what is the velocl ;i:n).fo nqtity at t = 4.0 s?

  In Fig. below, what is the velocity gw+i;(9tohei 4 hmf5t at t = 5.5 s?

  In Fig. below, what is the average velocity from yu/2l1,d t 6 z. ii+-ydrrxhfm0 to 4.0 s?

  In Fig. below, what is the average velpy yo.)lay14/r ud p8socity from 0 to 6.0 s?

  In Fig. below, what is the accd-d;1w; n gtvbeleration at 1.0 s?

  In Fig. below, what is the ah6xnhdbzmgc+.zgm.mx4jg+;;6jj 6 u cceleration at 3.0 s?

  In Fig. below, what isx 0+o-g.gaawf *b)opsk2)zmc the average acceleration from 0 to 5.0 s?

  In Fig. below, what is the (sil3*r80g/zn uqxg4rz t p7javerage acceleration from 0 to 8.0 s?

  In Fig. below, what is the displacement from 0 to 8.0,(q ,h0,l/a bmzkh*dr/zhem j s?

Does a car speedometer measure speed, velocity5 d4msh5to9 fp? {speed|velocity}

  An object can have aqx h,0nun2w:o varying speed if its velocity is constant.

  The velocity of an obje7-sf+7kb nzelct can be negative when its acceleration is positive.

  If one object has a greater speed than a second object, 7cbp z)-+.cu vzv.zi xoxjlqjb197a*the first must have a greater accelerqz)zi7cjux1 o xpb.9v c-ljav+ z. 7b*ation.

  Two cars emerge side by side from a tunnel. Car A is traveling with a speee6xsaam.qt+yb*; )z b)/rhhj d 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 acceleration h(up9f 0e+ )-m sy-btshrr7wv v*lr,ldecreases.

  A baseball player hits a foul ball straight up into the air. Itts,uz s rt2r:5uyyw./ 7n9v gy leaves the bat with.95/vy: 7yrsturuz t snyg,2w 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.vfh)rb a 3g0m is happening to its acceleration, howv)rha mfb .03g does it change if air friction is ignored?

  As a freely falling object speeds up, what is happening to its accelerath pgnif5 5)rc01pzij8 f,z9mtion, how does it change ifi nm0tz fh15p)5jpz9r8 fg ,ci air friction CAN NOT be ignored?

  An object that is thrown vertically upward will return to pu,tjgtohz *x(976rhpixbymx712)z its original position with the same speed as it had initially if air resixphx(t2jy*hu9 m 6,rtzz7 7ipb gox)1stance is negligible. If air resistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzero acceleration at the sas w :m).yy wkus2pus12me time.

  An object can have nonzero velocity and zero acceleration at th tknh s0;mj;7itec.-x e same time.

  An elevator moving from the second floor to the fift-, ugp 38p8:gg - -od gyfli(nrisi5ddh floor making no stops along the way has 5urnfg pg ,8- 3g-oigi:ildd8s ( -dpyzero acceleration all the time.

  A rolling ball moves (lgxdl*q t f,t5es39e from $x_1=3.1 \mathrm{~cm}$ to $x_2=-7.3 \mathrm{~cm}$ during the time from $t_1=2.7 \mathrm{~s}$ to $t_2=5.1 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-3.2 \mathrm{~s}$ is at $x_1=2.9 \mathrm{~cm}$ and at $t_2=3.4 \mathrm{~s}$ is at $x_2=8.0 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps around a8l3v* fb(kc+o;s(aoi *qjhmg quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 8.7 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 n dt*w+w:e1kf pp1- vkojm7f*a straight line, moving 92 m away in 11.0 s. It then turns 1wtj fnk* +7-fwm1d*oe:pp kvabruptly and gallops halfway back 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 from q c-uqmq w/7h9$11 \; m/s$ to $22 \; m/s$ in 4.9 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 fromrx 9kp6 gh7b mggv;.pw:e3 (ou $17 \; m/s$ to rest in a distance of 64 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach qxp+q6.aqr4 j )7hlega speed of $27 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.4 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of the blocks to essento x+w9 efbrnb*i1 ;c2wially top speed aboutwcnb wi2erfx + ob19;* $10.1 \; m/s$ in the first 10.0 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 fr*x h8+:,7enruw;cj cbg ptyrx(7a 0zfom a speed of $21 \; m/s$ to rest in 5.25 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 tc0+lbwh+2zamz/lz+5 p uwzit 2jz 09highway. Assuming a decm2 uwpat0w /zi5bhz + c+j9zz2+tl0zleleration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck goio:6oh q r0m zstj4uj9b 2(j1 5ikqmhc4ng $25 \; m/s$ 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 1wsu-fb*p3hwk yq :.(n0,000-m run in less than 30.0 min. After exactly 27.0 min, there arenp.wfk3yhq: w-*b s u( still 1100 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?    $s$