Suppose that an object travels from one point in space to anothr8xi2c:kv5s wer. Make a comparison between the dispi:k82 xv5cs rwlacement and the distance traveled.

  When is the average velocity of an object equal kn on3; zo(qrb- 5dcy/to the instantaneous velocity?

  A new car manufacturer advertises that theirbg /8atkwd;pid jc0,* car can go "from zero to sixty in 8 s". This is aj0;bad i,g d pcktw/8* description of

  An object moving in the + bk gan.+5m:tw0p8pk px axis experiences an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car travelg n2bk; e.zs n ebohb/:j;9(;pkp4bj fing to the East (+x direction) begins to slow down as it approaches afb/o9 .e p(2j b;psn 4geb b;kzj:n;hk traffic light. Make a statement concerning its acceleration.

  Suppose that a car trav/ *g zv6vpbob9eling to the West (-x direction) begins to slow down as it approaches a traffic light. Make a statement concerni*v b v96bzpg/ong its acceleration.

  Suppose that an object is moving with a constant velocity. Make a statement co wqq0tr28n6; qx )fphgncerr)t f0q wx6g8hpq2 q;nning its acceleration.

  If the velocity of an object is zero, does it meawz hy3dim .i+8n that the acceleration is zero? Support your answer with an ediwh+izm.y8 3xample.

  Can an object's velocity change direction when its acceleddd,j )e9jm// oil o5bration is constant? Support yoj,9 m/de)dljio5 b/od ur answer with an example.

  Suppose that an object is moving with constant acceleration. Make a st 2x kan+5 m)zmp; r;gbfaah(7vx )i5zclrpt5/atement concerning its motn2/hg5x()pm;zt x+;p5 bmc7) zaikla r5vfa rion with respect to time.

  Can an object have increasing speed while its accelec)4g g- dr)u/iej( g4purff4pration is decreasing? Support your answer with an e4g/)rjdr-e ) fi pug4f gu(4cpxample.

  Suppose a can, after an initial kick, moves up alos9 czl7.ke2..t yzhrl ng a smooth hill of ice. Make a statement c7z9yet. z rchl 2.s.kloncerning its acceleration.

  Under what condition is aver+*o d8ls8us-w kqb n,gage velocity equal to the average of the object's initial and final velocitydsb-* go,lwn 8+su8qk ?

  Objects A and B both start at rest. They both accelerate at :clp4q biepktk 77vjy-(x+.58l q nitthe same rate. However, object A accelerates for twice the time as object lqbi xvq c:n .l(p7jkktit47 8e py5-+B. What is the final speed of object A compared to that of object B?

  Objects A and B both start from rest. Thn szx; ;zt6)pmb q zc(9v5nwc9ey both accelerate at the same rate. However, object A accelerates for twice the time as object B. What is the db cz5)wp 9zm;(q9vznc6 nxts ;istance traveled by object A compared to that of object B?

  When an object is released from rest and falls in the absenszugd9ns-y0 0 ce of friction, which of the following is true concerning its motion sznsy 0-09ugd?

  When an object is released from rest and falls in the absence of friction, whicy.z pj rycn;m5s/lu1zbk -hk p/2,d 9eh of the following i/2hrk ,d y/snbjz51e klu-9y cz;mp p.s true concerning its motion?

  Suppose a ball is thrown straight up. Make a statemcske8 ;q:urv: 58zgyhg9 adx4 ent about the velocity and the acceleration when the vk r ud8gxg9a:es4z;8h:y q5cball reaches the highest point.

  Suppose a ball is thrown strai 6*tmpgw+r4r* x ,ufuaght up. What is its acceleration just before it reachr*m+ arpu4*,fw x6ut ges its highest point?

  Suppose a ball is thrown straight up, reaches a maximum height, then falls t:+*vj0xq gbm, unlm s1*yxqu 1o its initial height. Make a statement about the direction of the velocity and acceleration as the ball is goinblsju +1mxy,m:0xng*v 1q*qug up.

  A ball is thrown straight up, reaches a maximum height, then falls4rxl3glq s (:s /;2g1f3tkkg( fqzxri to its initial height. Make a statement about the direction of the velocity and acce fg;fsz(/rl k3241x(ti 3glk q:q srgxleration as the ball is coming down.

  Suppose a ball is thrown downward in t-9xm ujo7r*flbiz() the absence of air resistance. Make a statement concerning its accelerux(9frm-i t )zob*7lj ation.

  Suppose a skydiver jumps from a high-flying plane.tis c srj em;q/4gvi.+:;lov( What is her acceleration when she she reaches terminal velov c le;4s/ti:g;o+(vsmjr .iqcity?

  A ball is thrown vertically upward with a speed vxe2v:) puj /nf. 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 go than the f /j)xnpu:2v feirst ball?)

  Ball A is dropped from the top oero,ke z,i o 9glp.a1:f a building. One second later, ball B is dropped from the same buildinge okzegi1lp ,o,a r9:.. As time progresses, the distance between them

  Ball A is dropped from the top of a building. One 5sj+)nd x+iize36gu y second later, ball B is dropped from the same nidgi+6jy xz3u)5 es +building. As time progresses, the difference in their speeds

  Two objects are thrown from the top of a tall building. One u7rfrtzj58h1ce y66yis thrown up, and the other is thrown down, both with the same initial spe7f6rch18uzj5y tye6 r ed. What are their speeds when they hit the street?

  A brick is dropped from the top of a building.a*hre (mvff 5: A second brick is thrown straight down from the same building. They are released at the same time. Neglect air resistance. Compare vfa5h:(rf *e mthe accelerations of the two bricks.

  An object is moving with constant non-zero velocity in the +x axis. The positiol9h7t q+ s5xo kl*8e,b(h ng4pqm nll5n versus time graph o le4 5poqls57gql 8(bxltnmkhh+*n9 ,f this object is

  An object is moving with mt,70nja0u (egj-wald x1w7/w rv5qxconstant non-zero acceleration in the +x axis. The position versus time graph of this object 5mw7l,a(w- qu0 ew0 j71vxard/jxtgnis

  An object is moving with constant non-zero velocity in the ldiecgb3n n 88x-q2 j5+x axis. The velocityxb-n c5njile823gd8q versus time graph of this object is

  An object is moving with constant non-zero acceleration in the 0gal p;b)hbh- +x axis. The velocity versus time graph of -)ahp ;bghl0bthis object is

  The slope of a position versus time graph giv fv09qtp-di 4g exa+z9es

  The slope of a velocitsb1oe4x7 2zf kh 6s;ify versus time graph gives

  The area under a curve in an acceleratiot7 d60ebz -nh ae22eton versus time graph gives

  The area under a curve in a velocity verz:xh ejg. /nss,h:s /5vcg:emzt 6yl 4sus time graph gives

  If the position versus time graph of an object f)zeryxio:t)7b :z g -is a horizontal line, the object isry )gzf 7to):-z :iebx

  If the position versus time graph of an object is a vertical line, th)xuhfga mj89: e object ishm8guf9):axj

  If the velocity versus time graph of an object ist2d: 4xs l/qo*adz7dj a horizontal line, the object i ls: za7od dt4/jx2*dqs

  If the velocity versus time graph of an object is a straight liz -23 xhrixdf5ne making an angle of 30 degrees with the time xhxir3zd5f-2 axis, the object is

  An object moves 15.0 m north and then 11.0 m south. Find both the eb v8/zfip8+)-swlovdistance traveled and the magnitude of the dispel)p+svbo vw88 f z-i/lacement vector.

  A boat can move at 30 km/h in still water. How long will it take to move 12 b;qvnvdj-.hdz.lq1cu )* d 1dkm upstream in a river flo1-q1v d n. .qucz;jdlhdbd)v*wing 6.0 km/h?

  55 mi/h is how many m/s? (1 mi = 1609 /d 05 o/vwvq*v6r.;q93amonps byv c fm)

  What must be your average speed in order to tra qzb6-x+h sq);jjamlqu.o v9-vel 350 km in 5.15 h?

  A runner ran the marathon (ah,p*kdvm0 8xhur:nq; 6fpnodz ; te:;s 2t a;cpproximately 42.0 km) in 2 hours and 57 min. What is the average speed oc,ox tpkdhvrtuqd:6e:pz2;*;8f 0;m ;hnsn af the runner in m/s?

  A car travels 90 km/hk6t) +l xeu247dc lvhuq 6w2ky. How long does it take for it to travel 400 km?

  A ly (light year) is the distance that light travels in one y:,u*:doiu3 vi tq2d xoear. The speed of light iix:odvd3u,:oqut 2 *i 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/h all//05 jc1(ki9yve hf ya ahn*xong a straight road and you look to the side for 4.0 s, how far do you travel during th 0k f*1hv( x /ayeciyahn9/j5lis inattentive period?

  If you run a complete loop around an outdoor track i33re26 mixt (; bsjqq(400 m), in 100 s, your average ( 3bise2x3q ;rjq6tmivelocity is

  A polar bear starts at the North Pole. It travels 1.0 km southv )1jps)zx 3lj, then 1.0 km east, then 1.0 km north, then 1.0 km west to return to its starting point. This trip takes 45z x1j v3s))plj min. What was the bear's average speed?

  A polar bear starts at the North Pole zt syog:uvoj8 :c;z5z0 1l4uz. 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 svgzoz4 5zs ty0zj;u c:8:1 uoltarting point. This trip takes 45 min. What was the bear's average velocity?

  You are driving home on a weekk/ (y h rz-(.9kvo q*qsttuxw,end from school at 55 mi/h 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 schoos.*wtkoq9kv,/txuz y h- rq ((l?

  A motorist travels 160 km at 80 b b/yq)vm/c1jkm/h and 160 km at 100 km/h. What is the average speed of the motorist for cj bqm1b//y)vthis trip?

  A motorist travels for 3.0 h at 80 t()yps 56 wt ji: uju3ql2 dltz19,wcxkm/h and 2.0 h at 100 km/h. What is her averagjt5lluxzq16c 2i)9 d(p:w s3t ,wuy tje speed for the trip?

  An airplane travels at 300 mi/h south for 2.00 h and then at diy):6kjr*5k/vfzs3d2e qp z 250 mi/h north for 750 miles. What is the average speed for the trip)j2v* 3ekfpdd5k6 zyisq:z/r?

  In a 400-m relay race the anchorman (the person who runs the last k) zk;s9xp-q:b6 u xir100 m) for team A can run 100 m in 9.8 s. His rival, the anchorman for team B, can coverqb up:xri)9x-k ;z s6k 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 uniformlyc*o3yvfdb 4scepg9waec81 ; ( and comes to a stop after 13 s. The car's average vel341 (9v pscwg*yadobce c8fe;ocity during deceleration was 64 km/h. What was the car's deceleration while slowing down?

  An airplane increases its speed from 100 m/s to 160 . ,cjk;it:qehcl6ka* m/s, at the average rate of ;, 6.k acj*ehiktql:c$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerates at th67awka-n fd.; qtrr tn4gq0oq b+y t3 y)ea9h-e 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 accelera.xwd9 k oqh2lth4 *jo-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 fuw1on t-g39 h 6hek6 mn29k 6dgu-rnkgor 10 s. It then speeds up with a constant accelerationoe-d6u9 6 tg-mn63ngg k2h9rn1kh uwk of $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initiajqg1 3qv cvrmm3290n4ff4fbqxdta4 3l velocity of 4.3 m/s experiences a constant acceleration of ncf304 fq2 m 9agdvbmxj3431t 4vfrqq$4.5 \; m/s^2$. What is the cart's displacement during the first 6.5 s of its motion?

  A bullet moving horizontally u:s xj9 n0bat+52 p scwm7weiakbv5:) to the right (+x direction) with a speed of 499 m/s strikes a sandbag and penetrates a distuk5:b0e5na+t) w:sp 92xbmvcs7i jaw ance of 37.52 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on an aircraahus2lh(g sz9;(x* vv ft carrier. It reaches a speed of 42 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 *(sg9huv2;xs vlh z(acatapult?

  A car starting from rest moves with constanv0jxcjjoc7plw. eoh2g* t82 rjz50 x4t 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 i/;m+ 6cxisi,p vkxhpb.r.u/uts average acceleratio.h /pkrx iu;/c x6,smpv i.+ubn?

  An object starts from res gy7eo0;s( eomkuceu8zxg +2 9t and undergoes uniform acceleration. During the first second it travels 3.7 m. How far will m;ocgekz(y euue+09gx 782soit travel during the third second?

  An object is moving in a straight line with constant a.x.m:opl sfdm *e4r5f8l mg cuw7w9f xm5av-(cceleration. Initially it is traveling at 16 m/s. Three ovl55f p9gxfm8efsw.ua*xwd .7mrmc-4 lm:( seconds later it is traveling at 10 m/s. How far does it move during this time?

  A car starts from rest and acc/x4f ik0ew+xvelerates 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 roae t2g qru uwe5f91xh53w/siq4d 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 traff/)ph oe qw*.-g .tozbcic light turns green, a car that has been waiting at the intersection starts aheago.*tp.cwzbe-oq) h /d 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 upk x 5qhy,rdl/9ward with a speed of 12 m/s on the surface of planet X wheqhr9k5d /ylx ,re the acceleration 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 surface of planet X wh8o6 t:y4qarku8 m8 jxuere the acceleration due to gravity is8uj86x4qm uk8tra o:y $1.5 \; m/s^2$. 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 th.1na :ajet/sjy/7a gse surface of planet X where the a.a/j1etnsa:y 7g/aj scceleration 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 on the surface of plaqb:bp8 s9dor- net X where the acceler qbp9d s-8or:bation 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 0.10 s. If yourqwq;l(6 fh3yt 5m m8o b7zihu+ friend holds a ruler between your fingers and ret5 zmhl73qb;of6 (+yhqm 8iwuleases it without warning, how far can you expect the ruler to fall before you catch it?

  A ball is thrown upward at a velocity ihvxjww 3*/q jv3/n j*of 19.6 m/s. What is its velocity after 3.00vin* j3*/qv /wxhwjj3 s?

  A bullet shot straight uj-0d+fva 1ju u7z i-5hi zn4mup returns to its starting point in 14 s. What is the initial speed oa+- u1in zumuzf5d4hi0- 7j jvf the bullet?

  A ball is thrown straight up with a speed of 36.0 m/s. How long does 4citx:zxs4lfm 4ja2 -it take to xtj4-xisz2ml4 a:fc 4 return to its starting point?

  A ball is thrown downward from the top of a building with an initial 2ymkc c: *ge:fspeed of 28 m/s. It strikes the ground after 1.5 s. How high is 2 cyg:*mefk c:the building?

  A ball is thrown straight up with a speed of bj cfq20m bh5 (jvn t4xj*/mo7i;ar1g30 m/s. (only fill in numerical valui*0agtnho4v m c /2 q;jbjjm5(x7f1rbe in 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 sjmf: *3t-hnl 8 6rqoyutraight up into the air with a speed of 23.0 m/s. (use $g=10 \; m/s^2$, only fill in numerical value in the blank)
(a.) Calculate the time required for the ball to rise to its maximum height.  (数值)  $s$
(b.) Calculate the time for the ball to fall back to the height at which it was hit.  (数值)  $s$
(c.) Calculate the maximum height reached by the ball.  (数值)  $m$
(d.) Calculate the ball's speed 2 seconds later.  (数值)  $m/s$
(e.) Determine the time at which the ball pass a point 11 m above the point of contact between the bat and ball for the first time.  (数值)  $s$
(f.) Determine the time at which the ball pass a point 11.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is the veloci gq; vkg/1d0tety at t = 1.0 s?

  In Fig. below, what is the vehwts c2l(jc.mpxx63 7uk 9sp j91 ef6wlocity at t = 2.5 s?

  In Fig. below, what is the veloc 7vrl6nrj7-5 hn4fojt )g dle8ity at t = 4.0 s?

  In Fig. below, what is the velocity at9.fy ttkfb( ;c;ey5q-u 2tyzd t = 5.5 s?

  In Fig. below, what is the average velocity from 0 t h 4 9e.zt3wndzm sjp+,x5f+nco 4.0 s?

  In Fig. below, what is the avcno)4kvftewb4 aj1sy/ ;z9g5erage velocity from 0 to 6.0 s?

  In Fig. below, what is the acceleration at 1.0 v-lhydw80 b5gs?

  In Fig. below, what is the acvhc m- 4qvvs67(2nxj cch v2h4celeration at 3.0 s?

  In Fig. below, what is the average accelj 1ketdp/,qnc btr6c8m 73,gteration from 0 to 5.0 s?

  In Fig. below, what is the q-2 g2kds-* mihn ebi5average acceleration from 0 to 8.0 s?

  In Fig. below, what is the displacement 2apt. o k ;kw-frl79gx u21vka:o;wxffrom 0 to 8.0 s?

Does a car speedometer measure spemvp+xwl 8pqsqv3 o)q0:.y 5eaed, velocity? {speed|velocity}

  An object can have a varying speed if its velocity is constantmf l n kc-g0 lc;n1an(:hvg1+m.

  The velocity of an object can be negative when its aj3c ex f,h/p1qcceleration is positive.

  If one object has a gnh oh12 t ne7 nnqp1t(c+e5ik;reater speed than a second object, the first must have a greater acconnq7eei+t 2hn115cktph n; (eleration.

  Two cars emerge side by side from a tunnel. Cb1u(qmw7 dcg67)g p hfar 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 acceleration decreas8poc /anv7d b8es.

  A baseball player hits a foul ball smenscnh zuf;+.1/ 6x)-vjv ny traight up into the air. It leaves the bat wnhnvj/c 6+u.xz );vs1f meyn -ith 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 xs0y daxd , :l,c;.gvris happening to its acceleration, how does i,; gxl0 sc.axv,dyd r:t change if air friction is ignored?

  As a freely falling oq.n4fe ,jx*bg39+i/ ov aeqdz : zyih-bject speeds up, what is happening to its acceleration, how does it chqj yz:ae idfx z -v*gbq,4n3.eo/ i+9hange if air friction CAN NOT be ignored?

  An object that is thrown vertically upwarqmlt z 927fe*i np:c*v/g-tm vd will return to its original position with the same speed as it had initfe qtpm/*vnvlm :i 2-g 9z*tc7ially if air resistance is negligible. If air resistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzero accelerkjhr of0e)6 v,-qur*g ation at the same time.

  An object can have nonzero velocity and zero acceleratiol sapx8n,/)a +b9wnrnxu6nb vbp 3(u*n at the same time.

  An elevator moving from the se4ou 1 /+nptzo-jf t9jicond floor to the fifth floor making no stops along the way has zero otfzi+ t o/ ujn9-j14pacceleration all the time.

  A rolling ball moves fj.w wzv;3n7 mirom $x_1=2.6 \mathrm{~cm}$ to $x_2=-5.3 \mathrm{~cm}$ during the time from $t_1=1.7 \mathrm{~s}$ to $t_2=6.1 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-4.4 \mathrm{~s}$ is at $x_1=2.3 \mathrm{~cm}$ and at $t_2=3.4 \mathrm{~s}$ is at $x_2=7.9 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight compk 51mu v6/zifelete laps around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 7.7 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 a straight line, moving 108 m)0i**mm;gva3v 7tcrtnv g 0mc away in 12.3 st0mnm0*;v7iv)m cc 3grtga* v. It then turns abruptly and gallops halfway back in 4.6 s. Calculate (a) its average speed  (数值)  $m/s$ and (b) its average velocity  (数值)  $m/s$ for the entire trip, using “away from the trainer” as the positive direction.

  A car accelerates fr) x 4z s+11tzptyvh7ayom $12 \; m/s$ to $23 \; m/s$ in 5.7 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 fromsgs:.a -9t st (iafy*dgw )6qg $17 \; m/s$ to rest in a distance of 56 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a m0-kuzgey *j* 5j13q8myci dvspeed of $26 \; m/s$ 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 towfr 1. 7enx:7zkhu;hpze,pv ; essentially top speed about vxrn:h u17ezkz;h wf ,p;.7ep$11.3 \; m/s$ in the first 10.2 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 uniformlw0zr5hrwqfw9 4.lb ukb5 19vwy from a speed of $15 \; m/s$ to rest in 4.20 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car rsrybk,+ x)opjdpxvt5) t )+ 4leaves skid marks 92 m long on the highway. Assuming a)y4)spvbr+t)t,jxx kp5+rod deceleration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck g 5 +o*ap*-kym yiak8v1wosyv:oing $25 \; m/s$ on the highway. The car’s driver looks for an opportunity to pass, guessing that his car can accelerate at $1.0 \; m/s^2$. He gauges that he has to cover the 20-m length of the truck, plus 10 m clear room at the rear of the truck and 10 m more at the front of it. In the oncoming lane, he sees a car approaching, probably also traveling at $25 \; m/s$. What is the closest distance of the approaching car that he can still sately make the attempt to pass the truck? (without hitting the approaching car).    $m$

  A runner hopes to complete the 10,000-m run in less than 30.0 min.nha-*h .e 6r mg1ca.isz s js3fk:s1j+)polm0 After exactly 27.0 min3* 1a1o. +sjsl:gh emj frpc is6.mn-0 zah)sk, there are 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?    $s$