Suppose that an object traex2ixd4eb2t6 v27 luwpx tw5 )vels from one point in space to another. Make a comparison between the displacement ttdlpv22 x2 56beu) w4xiexw7and the distance traveled.

  When is the average veloci/yjps2t2w- ub j3;mh 1:ch4xnx ov 5oity of an object equal to the instantaneous velocity?

  A new car manufacturer advertises thioib; n2ko iuoo8 ,+zm6fn :wl 1:rot6at their car can go "from zero to sixty in 8 s". This is a descru2wolb;i:k1nf+o ,zno:oo86 mr ti i6iption of

  An object moving in the +x axis experiencesbc20nz)ulst8pis:m , an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling 0ke0-xg / rrbs p 2trm;v(o:rtvfnr.0 to the East (+x direction) begins to slow down as it approaches a traffic light. x -(brrn.0tv;f t0e0mvop /krgsrr 2: Make a statement concerning its acceleration.

  Suppose that a car traveling to the West (-x direction) begins to slowppcsibm 17 d)- down as it app7cip-)sb d1pmroaches a traffic light. Make a statement concerning its acceleration.

  Suppose that an object is moving with a constant velocity. Make a statement conf.1qzwh;0fz85 fbp lccerning its a.5 ffhp0wqzlz8 ;1 bcfcceleration.

  If the velocity of an 2kwdu;fvt 7 2k)k all,object is zero, does it mean that the acceleration is zero? Support your answer with an v,k;uk )t2fd2 7lkwa lexample.

  Can an object's velocity change direction when its acceleratim-coqg23 nt56uvtbk/fu nb:n6 :3sii on is constant? Support yournuim6/5 b 2g:n: k boqc u3tt3i-fvs6n answer with an example.

  Suppose that an object imq t(ak sxd;,(7sj9qos moving with constant acceleration. Make a statement concerning its motio7(; qss kxjq a,o(tm9dn with respect to time.

  Can an object have increasing speed while its acceleration is decreasing? Sx e)es 2fk(eo y4wp1n1ahc/0hupport your an(heo1 1 0nfhce/)e2 xawsp 4ykswer with an example.

  Suppose a can, after an initial kick, move w kq(cajo*2f)s up along a smooth hill of ice. Make a statement concerning its a jwafk )2c*q(occeleration.

  Under what condition is average velocity equal to the average g)9ijk9 4 tirvzxaje1 79v;wq of the object's initial and finatw9r viji97xv k;azq ej 4)1g9l velocity?

  Objects A and B both start at rest. They both accelerate ata 7 *fu3vxf1nzjgff-sq ;j*,b the same rate. However, object Anfg* f*qzju,b-f;jvs 7a1xf 3 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 bothl 58y*2tj ,-tm x6t 2igho0dkwrw/iye accelerate at the same rate. However, object A accelerates for twice the time as o*t,elgxr5 ktwi/-ty86yho wjd2 0im2bject B. What is the distance traveled by object A compared to that of object B?

  When an object is relmthi; o4r8qzufnkr20 uj49i0 (yun ;beased from rest and falls in the absence of friction, which of the following is true concerning its motion9n2k u0iybrn04zi( t ;jm4rq8hf u;o u?

  When an object is released from rest and falls in the ckj4d03zu3g7 pc:k(vdsiy 4 q absence of friction, which of the following is true concerning its motion?c4kdg4p30v(dy ckq:juz i 7s3

  Suppose a ball is thrown straight up. Make a statement about the v0arg/en,ei/ d elocity and the acceleration when the ball reaches the highest,i0/rea ndg /e point.

  Suppose a ball is thrown straight up. What is its avbysbc(e9 j,)u ;nf n3cceleration just before it reaches its highest psncf u(;j)3 9nbeybv ,oint?

  Suppose a ball is thrown straigjb /3g0 jq;aicht up, reaches a maximum height, then falls to its initial height. Make a statement about the direction of the velocity and acceleration as the ba b0qj/ c;3ijgall is going up.

  A ball is thrown straight up, reaches a maximum height, thh *ohn1gg *cg4*fspu/en falls to its initial height. Maks ugf 4 *n*cgg*oh1hp/e a statement about the direction of the velocity and acceleration as the ball is coming down.

  Suppose a ball is thrown downwchmk;g-b+8 eg2k o)f; 6kguzz ard in the absence of air resistance. Make a statement concernibckuzkz g;gk+ ;f)-ego2mh86 ng its acceleration.

  Suppose a skydiver jumps from a high-flying ple01e i dutgiv 7 vbv/s6:)m0scane. What is her acceleration when she she reac1:u /evigb070dmtvssc) v6i ehes terminal velocity?

  A ball is thrown vertically upward with a speed v. An identical second ball +o,vc7zsx fc, 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 +c fvz,, oxc7sthe first ball?)

  Ball A is dropped from the top of a building. One secoeff q -jx6dyagt7xm .k48wb 57nd later, ball B is dropped from the same building. As time progress. x-bed657x 4a g8t7kjyfwf mqes, the distance between them

  Ball A is dropped from the top of a /xi jkj:x n/;zbuilding. One second later, ball B is dropped from the same building. As time progresses, the differenc;ij xjnz/xk: /e in their speeds

  Two objects are thrown from ;k* xgacg)l/jthe top of a tall building. One is thrown up, and the other is thrown down, both with a;jkgg*c/) l xthe same initial speed. What are their speeds when they hit the street?

  A brick is dropped from the top of a building. A qbdepee.8 u70wy0zrco. fc*) second brick is thrown straight down from the same building. They are released at the same time. Neglect air resistance. Compare the acc8cy urwe 0p cqbeze7d)o0.*f .elerations of the two bricks.

  An object is moving with constant non-zero velocity in the +x axis. The l-.nm-t ec4v4x lrh)aposition versrlmn4cl )ha.evt -x 4-us time graph of this object is

  An object is moving with constant non-zero acceleration in qclcgj. : vk3,7h8jtdthe +x axis. The position versus time graph.3cj,cg qld7v k:h 8jt of this object is

  An object is moving with constant non-zero velocity in the +x axis.vt, 3+s2cfo,f a.uyea The velocity versus tim,cavf. a 3,2tsfuy+eoe graph of this object is

  An object is moving with constant non-zero acceleration in the +x axi95w h, i0beaphte3+wbs. The velocity versus time graph o,e9b t ih+e3bhp wa5w0f this object is

  The slope of a position versus time graph giv60-nqik ziu* t2j7eje7q 3lz kes

  The slope of a velocitpg p 7qdrk7/ ca.t4zh3y versus time graph gives

  The area under a curve in an acceleh /dtc7wu 0*waration versus time graph gives

  The area under a curve in a velocity versus tim:4sg.rgmdv (6hfu ( tce graph gives

  If the position versus time graph of an q :pwg*(rua- rb 2ii;fobject is a horizontal line, the object q(f* iib2;g :-ruarw pis

  If the position versus tiul3e185wamv u me graph of an object is a vertical line, the object ism8auw1l 35uev

  If the velocity versus time graph of an object is a horizontal line, the objectk+3fsgfx1 + 1ssc(bpjh u8; nu i1bnf+c jx (;pgf+uush318k sss

  If the velocity versus time graph of an objtrqpdw j 4jln7 (6re ;pd1:qq:ect is a straight line making an angle of 30 degn:dj:r pw4;rle7 qjp( dq1qt6rees with the time axis, the object is

  An object moves 15.0 m north and then 11.0 m south. Find both the digx k,qzzl.o:z/a2jg4stance traveled and the magnitude of the displacement vza .gk2jzx4z q:/,lg oector.

  A boat can move at 30 km/h in still water. Howym 8nyw.3x q(q long will it take to move 12 km upstry w.qmxq n8y(3eam in a river flowing 6.0 km/h?

  55 mi/h is how many m/s? h u(dr(7qb b--drv/jr(1 mi = 1609 m)

  What must be your average speed i. j.bsamg: ma9 0c-qypn order to travel 350 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 km) in 2 hours 4 pk8bbv y3l0zand 57 min. What is the average speed of tkb ly30 vzb4p8he runner in m/s?

  A car travels 90 km/h. Hosd2, lp3yh dx1r(-jn zw long does it take for it to travel 400 km?

  A ly (light year) is the distance that light travelsg:om 0hf1jceq/3 (5a 1buejbthnv6mz7 --l kf in one year. The speed of lbz3ef jb0th 7n/e ul1ajqm-gc(k: 6f1v-o hm5ight 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 kh4u81;-pde lj sd b(qnfy*(kkm/h along a straight road and you look to the side for 4.0 s, how far do yo f 1k(pl (endq;d8yu -bkhj4*su travel during this inattentive period?

  If you run a complet gbr7j65 yfhe7 1 sj dy8g(:xn+vwcny,e loop around an outdoor track (400 m), in 100 s, your averag(shgxje5f 1r ncywb+n vyy8:7g76, j de velocity is

  A polar bear starts at the Npa.nz 4 ez*9cl5 rzdm/orth Pole. It travels 1.0 km south, then 1.0 km east, then 1.0 km north, then 1.0 km west to 4zz*mer59z ln a/c .pdreturn 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 13nep l4 ef92iyw2sd i(.0 km east, then 1.0 km north, then 1.0 km west to return t4p wiye29n(2sdlif3 eo its starting point. This trip takes 45 min. What was the bear's average velocity?

  You are driving home on a weekend x z/2 p pbj)tc ,ns,0l0xmdg,cfrom school at 55 mi/h for 110 miles. It then starts to snow and you slow to 35 mi/h. You arrive home after drivin xn002,cxjm, cb,zdglpps) t/ g 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 km/h. What is t m8wx/s s 7-w4u.iurx a;uib8w9sphw(he average speed of the motorist for thisp-us4(r w9wbuxa/i m s.i7h8 xw8;uws trip?

  A motorist travels for 3.0 h at p;i;(1nge0l q jg;h vn80 km/h and 2.0 h at 100 km/h. What is her average speed for the tri;qlnhv; 1;(i0np ej ggp?

  An airplane travels at 300 mi/h south for 2.00 h and then at 250 mi/h northr9 wcse2 wdvag .5(:sb for 750 miles. What is the average speed for t2 r:vda5w .e(9scw sbghe trip?

  In a 400-m relay race the anchorman (the person who runs the last 100 m) for b/./4 op rf1rm si3ol,-w zakhteam 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/b f-za .mr/,1lw4pi oho3rs k 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 comes to a stop after 13 s. The car's average tz9h;m8q +- oy lfo-/t:exzpqvelocity during deceleration was 72 km/h. What was the car's decelerfq +:8 z-oe9 lox/;-qy tzthmpation while slowing down?

  An airplane increases its speedk3xyx,8b(m lre91 x*vq2mubpn-nz( i from 100 m/s to 160 m/s, at the average rate of (x2 ,nrl9kbyzq3x enmb*8 -xuvim1(p $15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/hpsl8m (.qne6o accelerates 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 an)v*m/:gbo hczl,g mh cfm :k:-d accelerates 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. It then speeds up with a yio2og9y/jc+ constant acceleration of y2iog+o/jy 9c $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 3.01v j;:qb j o5+f;2m7cekzl ohr m/s experiences a constant acceleration of 2;mzej: ok5;1 7orv cqlfb+h j$3.4 \; m/s^2$. What is the cart's displacement during the first 9.1 s of its motion?

  A bullet moving horizontally to the right (+x21 mxj5goo;0)lbryb zx w6i .a direction) with a speed of 433 m/s strikes a sandbag and penetrates a distance of 75.01 cm. What is the avexo6z5y xbmrl1jo .ag )02b wi;rage acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on an aircr 98waxem4+ahze2p nhbmiyu. 80 sr7,naft 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 zme b,7ninyw .xh9h8a42 u0+arps8me length of the catapult?

  A car starting from rest moves with coy0/v l 9vhvg:xnstant 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. W*z.z:w 2h 8jq4c+c oacupz3fsu4y 7hbhat is its average acceb8z2.3uzaj4wp qh hc os4:uz+y f *c7cleration?

  An object starts from rej+zwr *f4euzo 3x /g8mst and undergoes uniform acceleration. During the first second it trf8j*gzr o +3 4uwm/zexavels 8.9 m. How far will it travel during the third second?

  An object is moving in a straigh9bpy q rd7s6js *4m*aqt line with constant acceleration. Initially it is traveling at 16 m/s. Three seconds later it is 4p rd s j9a6*qym*7sqbtraveling at 10 m/s. How far does it move during this time?

  A car starts from res4kpy-r6l;x/ uo9gnrv t and accelerates 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 ,r m-z8c-p/uch0aps nroad 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 t50 vo1tjriha7hnc ( ;yurns green, a car that has been waiting at the intersectionvh 1nj7y; cha 5t0ir(o starts ahead 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/s76wjmq 5zx d1e on the surface of planet X where the acceleration due to gravityxze5j dw m61q7 is $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown upward with a ;rs0 pdn 8x.(mjuh+okspeed of 12 m/s on the surface of planet X where the acceleration duej8x(kopn+ds r .hu0m; 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 rc . ,;:8 (jw kdwm rvcc9o6g(h5yerktm/s on the surface of planet X where the acceleration due to gradr( r(8j mh;gw 9k.ck y5tc6:r, cweovvity 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 planvgb46e6pw qp(iv;r/3kq)w/ wgtxm4 vet X where the acceleration due to gx4w3mqw 6 gv(vq6//) kgpiv4wrte;bp ravity is $3.5 \; m/s^2$. What is the speed of the object after 8.0 s?

  Human reaction time is usually greater0ncxei* : 0em0ohvo188ubsa f than 0.10 s. If your friend holds a ruler between your fingers and rele:su eabmxh0o08ocfvi 01 en*8 ases it without 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 itsa8 qubob+sy: 9lnb8s2 velocity after 3.008bqbs:o2ulb8y9 as + n s?

  A bullet shot straight up returns to its starting poio.)m- j7k:p; yb gqlnmnt in 12 s. What is the initial speed of the bulle )gbmn .lpy:j7 km;-qot?

  A ball is thrown straight up with a spk +xx 8frkxsm1jvdev4p pc.r3ug+ y64yl k(:9eed of 36.0 m/s. How long does it take to return tv(m krc guv3ykjdrxk8 s9.y f :+6xxl4e1+4ppo its starting point?

  A ball is thrown downward from the top of a buix9o: 94un uj1 +ks4 sr5bi(0 cogyugvmlding with an initial speed of 19 m/s. It strikes the ground after 7.7 s. How high is the 0ns1 g+o445sgj( 9uo xucibum rk:yv9 building?

  A ball is thrown straight up with a speed of 30 m/s. (only fill in numerical vfz.p szb8ir::onxa1 .a,re2g alue in the bsn81 ,a.a f. zbr:2ogzpir:exlanks)
(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 airb (ik0f;hj5tbv0g4nc with a speed of 24.3 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 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 is the velos oteodk44a6 7city at t = 1.0 s?

  In Fig. below, what is the velocity at t =svosfz *x22f/+wb2pjv :j6 rl 2.5 s?

  In Fig. below, what is the velocity at t = 4.0 spv)n/ mlni ;qe,;0 bpr?

  In Fig. below, what is the ve+vns0 yfn;va.locity at t = 5.5 s?

  In Fig. below, what is the average v nptp)4;p5eva3c kkc:cpc p1 1elocity from 0 to 4.0 s?

  In Fig. below, what is the average velocity fg;).0ps j5im: c,o j6gxcj woerom 0 to 6.0 s?

  In Fig. below, what is the acceleration at 1.0yvzj h,)r / qnib/u9(s s?

  In Fig. below, what is the accelera8b* )ncey5 yx-6nzsquo vp1.qtion at 3.0 s?

  In Fig. below, what is the average acceleration from 0 to 5.0 s?xziojwpi* mt-y(j30: ha4a, s

  In Fig. below, what is ,u01zpb5:au h ls:dwdthe average acceleration from 0 to 8.0 s?

  In Fig. below, what is the displacement from 0 to 8.0 ze: 5+c umg;sts?

Does a car speedometezapucm y+3b9nl6g ; -qr measure speed, velocity? {speed|velocity}

  An object can have a varying speed if its velocity is constant., /w129ou w qjj0fdtyh

  The velocity of an object f/ s4d7h/ntby n(1bx w1 um9oacan be negative when its acceleration is positive.

  If one object has a greater speed than a second object, the bxu88vw-sgsl4vk)v0ja6w: k first must have a greater accelera v ku 4b6jx8aw8slvv: -sgk)w0tion.

  Two cars emerge side by side from a tunnel. Car A is traveling with a speed w0(sny kap3oti11d(hof $60 \; km/h$ 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 spvwdu8b00; xcf 5m iwk:eed as its acceleration decreases.

  A baseball player hits a foul ball straight up into the air. It leaves thea0 .4xmo gti0(vv) tca bat with a speed o0 0 ct.mvo(vg )4tiaaxf $120 \; km/h$. 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 to its accelerationz q u a5 a5nlau:0qt+vd3 m,qn1( (3pojno)xla, how doeaojd(o alq zmuq v3,u5(5+n3 n a1qnalptx)0: s it change if air friction is ignored?

  As a freely falling object speeds up, what is happening to its accelerati bqr2f;u4ka a*c7wd6xon, how does it changeqx 7fc6d2 uw*;baa kr4 if air friction CAN NOT be ignored?

  An object that is thrown vertically upward wilm6fu2 4gkl.anun c9zq2p 1qj0l return to its original position with nq aj9q41u.kg 6znl 0cfp2mu2 the same speed as it had initially if air resistance is negligible. If air resistance is appreciable, how will this result be altered?

  An object can have zge;vo8 q26ui4 wxiel:ero velocity and nonzero acceleration at the same time.

  An object can have nonzero velocity and zero acceleratstm cy: 0xm 6-(afoh/z8,xqmm ion at the same time.

  An elevator moving from the second floor to the fifth floor making no stops al;s*w 6.cz0t5t zuoeuron u0est;*ou6rw5tcz.z g the way has zero acceleration all the time.

  A rolling ball moves from /lzupw a *q*-(d kr/j3zypie*$x_1=3.3 \mathrm{~cm}$ to $x_2=-5.6 \mathrm{~cm}$ during the time from $t_1=2.9 \mathrm{~s}$ to $t_2=5.2 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-2.8 \mathrm{~s}$ is at $x_1=3.1 \mathrm{~cm}$ and at $t_2=3.7 \mathrm{~s}$ is at $x_2=8.3 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps around a quarter-m3yv o 48y,.vzkhpn6ymile ($1 \; mile = 1609 \; m$) track in a total time of 8.8 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 5 dte.v;92 iksf7rdk z112 m away in 10.7 s. It then turns abrukk es527 dt.zdvirf;9ptly and gallops halfway back in 4.8 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 frogft.eyrs;k 3y exb); 6m $12 \; m/s$ to $23 \; m/s$ in 4.2 s. What was its acceleration?  (数值)  $m/s^2$ How far did it travel in this time?  (数值)  $m$ Assume constant acceleration.

  A car slows down fro 37/ ;vsqssfztegl4 7tm $20 \; m/s$ to rest in a distance of 64 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a spee4ofpdil 5x 01bd of $31 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.9 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of the blocks to essbgp yh*t f9e,h8g-w/u entially top speed abou,h9p*y- b/ 8wggufthet $10.2 \; m/s$ 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 fr u :fdx90sm4ppom a speed of $21 \; m/s$ to rest in 4.65 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 thexjb*xt tzif1p(e hmo-,kr1*m 5 . *mxy highway. Assuming a deceleration *y,h*o t .mx(1x1z-etibfmm5kjrpx * of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck g.r(bgymd64p(uxe mp u5 o g(3voing $25 \; m/s$ 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. After exao,du 2+pdugv+ ctly 27.0 min, there are still 1100 m to go.++ udup2gdo v, The runner must then accelerate at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$