Suppose that an object travels from one point in spau.2hrobt9, szce to another. Make a comparison between the displacement and the distance t2sb 9 .urh,oztraveled.

  When is the average velocity of an object equal -nptm/s ojjl-2+p1s*//mwxq +kxxvw to the instantaneous velocity?

  A new car manufacturer advertises that their car can go "zc6n4(wwo7 rd/ w2lu*z ciy(g from zero to sixty in 8 s". Thiszz/c w24(o7 unlry(dw igc*6w is a description of

  An object moving in thjdzz2(dey( irhsnz,: + o (l,ae +x axis 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 ptajn2vp 7l )x *k*h ,v*njwq8it approaches a traffic light. Make a statement concerning its accelelj2v )t n, wn* *aqk*hv7px8jpration.

  Suppose that a car traveling to the West outtnw32* znhs o9:pkl2t)*b(-x direction) begins to slow down as it approaches a traffic light. Make a statement concerning its a*kz 2h 9b*)otnn2 pow3:lsttucceleration.

  Suppose that an object is moving with a constant velocity. M 9 he)bi ;:ad7 iq+yrjg9ev*ptake a statement concerning its accel; h ygv9e te+rbq*id:)ija 97peration.

  If the velocity of an object is zero, does it mean that the accel(df1zaftl0jd)+ b.v s dfk99 0 dr2ugheration is zero?v a09d +0uk h(l9bgf)fjd21drd zsf.t Support your answer with an example.

  Can an object's velocity change direction when its acceleration is consta 6mbpd qp1m;fdhtluv9: x.54 8c6 wchfnt? Support your answer w98c6q 4p;lw5fp:tfbh xcdm 6. d umvh1ith an example.

  Suppose that an object is moving with constant accel;3q/ch cckbauad w(9 9 ix0f(eeration. Make a statement concerning its motion with respect to ti afc(9xk;wdce0/ hi u9c3 (baqme.

  Can an object have increasing speed while its acceleration is decrea6laxi (b4ccqq 7sr9b2sing? Support your qlis (a2 x69c7bqb4cranswer with an example.

  Suppose a can, after an initial kick,imd.f45d 9 nbk moves up along a smooth hill of ice. Make a statement 4i5dmfk.9 db nconcerning its acceleration.

  Under what condition is average veabw/y q md2m;+pi +:tl(w x1eilocity equal to the average of the object's initii:1 p2+iww meybm x(/tq;d+alal and final velocity?

  Objects A and B both staio136 zxorg6thha f 193a,drhrt at rest. They both accelerate at the same rate. However, object A accelerates for twice the time as object B. What is the final s6zrd3h9ho a1ifg6a3t x h ,1orpeed of object A compared to that of object B?

  Objects A and B both start from rest. They both accelerate at the szf ;0amrobq +j e.da/:ame rate. However, object A accelerates for twr/ a+0bfao zq;. mde:jice 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 fallwkbxaq 5r9q-3s in the absence of friction, which of the following is true -3q9a xkr5wqb concerning its motion?

  When an object is released from rest and falls in the absence of friction, wv,k.c3 gznjpsqrs-;*hich of the following is tvq-,* ss;z gnc.pr k3jrue concerning its motion?

  Suppose a ball is thrown straight up. Make a statement about the y4y5q fmb7gww) 8n2rdvelocity and the acceleration when the ball reacheymw 4)8y5gw 2b qf7rdns the highest point.

  Suppose a ball is thrown straight up. Whagg ekc01v no8;t is its acceleration just before it reaches its highe o gg8n;vke10cst point?

  Suppose a ball is thrown straight up, reaches a maximum height, then falls tosmazw q11+4wxj;lf *o its initial height. Make a statement about the f w1z+lo x1j*saw ;q4mdirection of the velocity and acceleration as the ball is going up.

  A ball is thrown straight up, reaches a maximum height, azw )e u3xup52then falls to its initial height. Make a statement about the dipa ew5) zxu32urection of the velocity and acceleration as the ball is coming down.

  Suppose a ball is thrown downward in the absence of air resistance. Ma*u h*8yrb uf,lvu8w4cke a statemevwr 4uf lhb8u,y* *u8cnt concerning its acceleration.

  Suppose a skydiver jumps from a high-flying plane. What is her kc pra,dyuj)8lwb 3 +31bo9bqacceleration when she she reaches terminallb3k q,p9ujb da+yw cbo31r8) velocity?

  A ball is thrown verticb nii8cc78b6h ysb41xally upward with a speed v. An identical second ball is thrown upward with a speed1y 4cb8his7xbcnb 6i8 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 second later, ball vz at acxe(dym7l l ;-6i7:5edB is dropped from the same bamd6zy:(xd7i a7e-el5l c;vtuilding. As time progresses, the distance between them

  Ball A is dropped from the top of a building. One second later, ball B is dl+*d d0id ,. qmkx*ouvropped from the same building. As time progresses, the difference in the 0id o*q +m,d*uvklx.dir speeds

  Two objects are thrown from the top of b 9:x3yxpmt6n a tall building. One is thrown up, and the other is thrown down, both with the same initial speed. What 6tyx9pxb 3:mn are their speeds when they hit the street?

  A brick is dropped from the top of a building. A second brick is thrown straight gvp5c6exrt;+kh m4-x down fro4pg-r; xk+xch6temv 5m the same building. They are released at the same time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with constant non-zero velocity in the +x axis. +;b28*hla) 0,jzrrz tm ggxgiThe position versus time graph of thi l02 zxm8)gbi,+at;rrzgg jh *s object is

  An object is moving with constant non-zero acceleration in the +x axis. The zn( yu/owe pg876f,igpositiz yp7n u gfi6(,g/8eowon versus time graph of this object is

  An object is moving with constant non-zero ylk2eatm (wre18b4n3 velocity in the +x axis. The velocity versus time graph of this ob we1yle3mr 2n(8 4tbkaject is

  An object is moving with constant non-zero accbwf2l+-arsi u (9fjtj:0s9*d m6 iy sheleration in the +x axis. The velocity versus time graph of th(0m92hs wjfjyua i+: dbl 9rs*tsi -f6is object is

  The slope of a position versgyz9kq3 wq .4mus time graph gives

  The slope of a velocity versus time grac+x)7j wjj:os ph gives

  The area under a curve in an acceleration versus time gra h8( s,ke0r5 bwve0uweph gives

  The area under a curve in azrt1j s 1emix4,b.rahcf9r +- velocity versus time graph gives

  If the position versus time graph of an object is a horizonth8iq)-z bdcib a2k 0i2al line, the object -b2iq)c 2zba0h idi8kis

  If the position versus time graph of an object is a vertical line, the oa t1m,rjs s-*xw ;*,lci+fcocbject is ;**x cicl,w+t1ja ss,mco-fr

  If the velocity versus time gra erz4ambs 5q (m 6sb;y:jr46c3.jwn lj4bvxc.ph of an object is a horizontal line, the object ms;yw.j rv44 (r c6bxs.ebj qbclm6j4n: 35za is

  If the velocity versus time graph of an object isv2zoh8o i.e*k r r*bdtq) 6v/8ibk )jy a straight line making an anglvk) hb2vro.to/ r )z*iq8db8*jki6e ye of 30 degrees with the time axis, the object is

  An object moves 15.0 m north and then 11.0 m sazug j .*;b et:zf3xv9u6g,ahouth. Find both the distance traveled andb.xv :,aztu hu3e6*aj 9zfg;g the magnitude of the displacement vector.

  A boat can move at 30 km/h in still water. 8jd2zf*bx, fg *mhbk4w)v7jn How long will it take to move 12 km upstn4*zkxbdb)h 8j* m gvjw2 ff,7ream in a river flowing 6.0 km/h?

  55 mi/h is how many m/s? (1 mi = 1609 m)ij4yuqq0lnq k9c82s2

  What must be your average speed in order+ o rjv6q3dazn0bn9/vj;pcj;h i(/oz to travel 350 km in 5.15 h?

  A runner ran the marathon (approximately 42ta j/e8se u95pm*9 jl4- pugaw.0 km) in 2 hours and 57 min. What is thea *jle u4p9ut/wjsp 95-a mg8e average speed of the runner in m/s?

  A car travels 90 km/h. How long does it t 9patj p; xa:(mw21sheake for it to travel 400 km?

  A ly (light year) is the distancekuc.jg4:xtv0 qwrmz 9bl..- h that light travels in one year. The speed of light iswx-c0.ugk:4r .zv9qbh. lj tm $3.00 \times 10^8 \; m/s$. How many miles are there in a light year? (1 mi = 1609 m, 1 yr = 365 d.)

  If you are driving 72 km/h al0+rd8:j kpsx66 ga cktt cfg..ong a straight road and you look to the side for 4.0 s, how far do yt g68x0c6ka tp.r j+sdgck .f:ou travel during this inattentive period?

  If you run a complete loop around an outdoor track (40* mz7q qx9twmhas3h :,0 m), in 100 s, your average ve,:zwh am s9hq*7 tx3qmlocity is

  A polar bear starts at the North Pole. It travels 1.0 km south, then 1.034 i*cx1p b 2e,vmzoju+hij-)+ whipa km east, then 1.0 km north2m -bjevc, ppwi aj+huiz4*1 3o+)i xh, 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, then 1.0 khx g5.fzj s451ue)ho rm 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 bear's szj)fhu g o h5x451r.eaverage velocity?

  You are driving home on a weekend from school at 55 4 8wxupoo:j3 pou/9vv mi/h for 110 miles. It then starts to snow and y ovj9 vop3up4xu/o:w8ou 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 160p6zfyprybzm;6l:( :b)j9i umbl+ho ( km at 100 km/h. What is the average szz( +lu6lbjmr;:o(m:hybyifpp)96 b peed of the motorist for this trip?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h. What is her 1fv e)9: 0dcu fvgoz/eaverage speed/f)ee g: 9vd0uzc1ovf for the trip?

  An airplane travels atv9y;ni -yw1x;:s:4c aq/n hnggers z6 300 mi/h south for 2.00 h and then at 250 mi/h north for 750 miles. What is the average speed for th/cne- sz6r:1;gwq ng:hx ivnays49 y; e trip?

  In a 400-m relay race the anchorman (t)7v( mc4 wah0/lycwnzhe 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 finalcah(7l ) c/wmw4vnzy0 leg of the race, in order that the team A runner not lose the race?

  A car decelerates uniformly and comes to a s;f8;cq :lh8a vvhmmy3he4 j0ztop after 9 s. The car's average velocity durin8 m0fm3:;hla zcq hvjhe8v;y4g deceleration was 45 km/h. What was the car's deceleration while slowing down?

  An airplane increases its speed f 0t(h vox4:i+xlw* nyyrom 100 m/s to 160 m/s, at the average rate of lxy4n+w(yi0:ov* txh $15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerates at the 75tyn t 41- fwitixt,qrate 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 acce:6p+qea vpo hy2p6 .5c.m trfylerates 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.uo hxhejbmt04(64i *q It then speeds up with a constant acceleration ofm4b60 uj ih(oq*4tex h $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocizzzjj+ o)*-ikty of 4.6 m/s experiences a constant acceleration ojk-ozji+z )*z f $2.1 \; m/s^2$. What is the cart's displacement during the first 4.1 s of its motion?

  A bullet moving horizontally to the right (+x direction) with a speed of 22n: ;feo 2v or5og.t24ib1 y0zjz,kwhj4 m/s strikes a sandbag and penetrates a distance of 41.95 cm. What is the aveo;trvo4 f ,0zby2jij.n ke1:gh2z 5worage acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on kmhy4)3k/ho8 g yudigs0z9rjdx ( 5:pan aircraft carrier. It reaches a speed of 42 m/s at the end of the catapult, and this requires 2.jg9( szdhd )8g4ikrx5py u m3:ko /0hy0 s. Assuming the acceleration is constant, what is the length of the catapult?

  A car starting from resa( xzku+p9 bk 8j ocnz0*k.a9bt moves 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 h w+g-kby,t t y).vabvn3/ht 3to 80 m/s in a distance of 200 m. What is its average accelerationhg 3,-a yb.3)+tht /wbt kyvvn?

  An object starts from 0l7u dpx+;db e3g 4c . )95riswdbhvyarest and undergoes uniform acceleration. During the first second it travels 8.4 m. How far will it travel dur)bbhid+7dp; s0v45lcwg9 dr 3xea y .uing the third second?

  An object is moving in a straight line with constant acb wk( pq+6wcvt0,)iapceleration. Initially it is traveling at 16()kqwvit+apb c,w 6p 0 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 uniformly a(+fmq 4i x,sg0td s:got $3.0 \; m/s^2$. 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 tirev 7yvambji304g+ m l*us on a dry road 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 turns green, a car that har vtl3*61btr wo gen5a9vde.:s been waiting at the intersection starts aheagt 6blo5e vw.vr:1*etd9n3r ad 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 surface 00,ty24dpzaeq)xpy,+w(n j ;sv ie xzof planet X where the accelerq ;d2nxxasp p(v+e0y j )0zt,weiy4,zation 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 surfacl+-xcmk) 22c9+ziihp4- s1jotbnihk e of planet X where the acceleration du9p1kltj -o+hncc) zshiiki 4x -2m+2 be 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 .zusez 8q.xxzgz,b *2with a speed of 15 m/s on the surface of planet X where the acceleration due to grav xz82ebus z zg*q,x.z.ity 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 speq6a9e o5e30mq iat7 skd ).ayked of 14 m/s on the surface of planet X where the acceleration k0i q qay7s 9eam.6k)t oaed35due to gravity is $3.5 \; m/s^2$. What is the speed of the object after 8.0 s?

  Human reaction time is usually greigjmnwg od 809+lk 7vkzdi t oc0z9 6+r00dq7uater than 0.10 s. If your friend holds a ruler between your fingers and releases it w6dd 0+zziwuqo o0 7gm09 k+0jr8i n9gtldvkc 7ithout 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 is its velocity after 3t4ec2q fr+1: 30 ikrauawv7c b.04a3ce2a:u+fc ri7qbtk w01 r v0 s?

  A bullet shot straight up returns to its starting point in 8 s. What is*4wxs5yhijo7 i s)1b+ +ipw yq the initial speedxyi5+y+pshi s7w jq*o 1wi)b4 of the bullet?

  A ball is thrown straight up with a speed of 36.0 m/s. How longl8m gaa*wlmrpi 40,5e does it take to return pral*a,iw 0 m8 e5l4mgto its starting point?

  A ball is thrown downward frj k,wa/of 01bbom the top of a building with an initial speed of 15 m/sb0/1 aw b,okjf. It strikes the ground after 3.1 s. How high is the building?

  A ball is thrown straight up with b*o +wsd 4e:fla speed of 30 m/s. (only fill in numerical value in the blow4esb +f:*l danks)
(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 mzekme;g4o ; -with a speed of 48.2 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 12 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 12.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what uzze8,5 km l.mbvl 89kis the velocity at t = 1.0 s?

  In Fig. below, what is the velocity at t = 2.5 s? yhg0f*w .36eyfcqo5 m

  In Fig. below, what is the velocity at t = 4.0 sg oov5( vb *of3jfrq3p )+n3sp?

  In Fig. below, what is tl0cps fq;xqrh ;8q9 m0t;xk 4vhe velocity at t = 5.5 s?

  In Fig. below, what is the average 6d.2h pgtp*b*.jv)ew rr6kup * db(d ntar,5fvelocity from 0 to 4.0 s?

  In Fig. below, what is n6-u8vcd;v6x/: ffa je x7j cythe average velocity from 0 to 6.0 s?

  In Fig. below, what is the acceleration at 1.2*1zgytzeo w4qchp, p* dpw)(05 kftr0 s?

  In Fig. below, what is the accelerati (-kzs6lvr m muh(*ca2.d( dumon at 3.0 s?

  In Fig. below, what is the average acceleration from 0 to 5.0w4b 5i qvrzmg4tm+52u s?

  In Fig. below, what is the average acceleratiow i7 h,u,5mon9cc oo.hn from 0 to 8.0 s?

  In Fig. below, what is the displjor c/xd dii;838w)gkacement from 0 to 8.0 s?

Does a car speedometer measure speed, veloc.,) 2obgtrlzv ym-u angu;8;sity? {speed|velocity}

  An object can have a varying spee 3vnf -62ttmjad if its velocity is constant.

  The velocity of an object can be negative when its acceleration isq+sm un 6okq.2 78bonp positive.

  If one object has a greater s,;ftp n vr.of+j9ne;cpeed than a second object, the first must have a grea+;f pj o9;fc.t,nevrnter acceleration.

  Two cars emerge side by side f1:vs qg( +xv+v.ol qsirom 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 spef;yh r(u t(o 4;lht6aeed as its acceleration decreases.

  A baseball player hits a foul ball straiy,nhqe+) a 0boght up into the air. It leaves the bat with a spey)+0oa ,eqhnbed 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 objerh7p*) .j mlrzct speeds up, what is happening to its acceleration, how does*rl7m zp.h)j r it change if air friction is ignored?

  As a freely falling object speeds up, what is happening to ity8)srb2wwfs6 w 3 dif)qnrf+5pl-+g ns acceleration, how does it change if air )npsr8 5gbld)wir3+-2q nywsw f6+ f ffriction CAN NOT be ignored?

  An object that is thrown vertically upw0p; z*5c /.wdeuecqd0pm ib6c ard will return to its original position with the same speed as it had initialubp0/q. ; 0ip c 5dzcc*eed6mwly if air resistance is negligible. If air resistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzeroolrqm*7 8))h +aix lkw iayywnk9 28w6 acceleration at the same time.

  An object can have nonzero veloci96p+n) g)t+qtkc zljqty and zero acceleration at the same time.

  An elevator moving from the second floor to the fifth floor ma,e i+0gp,x jlbking no stops along thj+b ,l ipxg,0ee way has zero acceleration all the time.

  A rolling ball moves fof- 5e(a,x(iq0/m vfqytgl nxele 7,/rom $x_1=1.9 \mathrm{~cm}$ to $x_2=-6.6 \mathrm{~cm}$ during the time from $t_1=0.9 \mathrm{~s}$ to $t_2=5.6 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-3.7 \mathrm{~s}$ is at $x_1=2.8 \mathrm{~cm}$ and at $t_2=3.5 \mathrm{~s}$ is at $x_2=7.5 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete pyu48ruk dt7+qhse85laps around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 6.4 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 stra he6o,( l77 stt)b/ ehkifbz.bight line, moving 108 m away in 8.2 s. It then turns abruptly and gallops halfway bacbs ,b(elekzhhot6 / bt) f7.7ik 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 frop;.mtzc5 :f., 3kd vzzww jaj+m $11 \; m/s$ to $25 \; m/s$ in 5.9 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 fromzk:64x9 bp t 3u8ofmcbf:2pnj $21 \; m/s$ to rest in a distance of 67 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a speed 8ewbh+ agn(.uncv b*vz qo-5+)b xkk, of $26 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.6 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of the blocks to essentially top spe z1j7rlra qs7;ed aboutrlsjz 1q77 ;ar $10.7 \; m/s$ in the first 10.8 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 uniforqkv 7*9j *mu)dlhh pz4hj3;s bal7hz4 mly from a speed of $21 \; m/s$ to rest in 5.39 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves skuf c )spm f;),w9vg/yo5(**syyzv wdpid marks 92 m long on the highway. Assuming a deceleration s5my f)o*zf) p,wyd( upy9sc vg wv/*;of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck goi- iv6w xv+ h..bw v8qfav5 aj15m)llxjng $25 \; m/s$ 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).    $m$