Suppose that an object travels from one po8nlsj k ;hdfssk4c o m73tr13:int in space to another. Make a comparison between the displacement and the distance m:d7on sfjl ;ksc rts8h1433ktraveled.

  When is the average velocity of an object equal to the instantaneous velocfwc g6i7,(17wd r idi i,m0zyuity?

  A new car manufacturm nzn(owg8;:ca; vh)wnee* -ker advertises that their car can go "from zero to sixty in 8 s". This is a d * ;o:emvennn;(ka 8wgz w-h)cescription of

  An object moving in the +x axis experiences an 52jlqxjdnct,k*hgo g4ck9(cpfc3 o0f y)6t:acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the Easkoxwky/fi+;v37cx7l t (+x direction) begins to slow down as it approaches a trxf+7 yk7v/ wlox3kc; iaffic light. Make a statement concerning its acceleration.

  Suppose that a car traveling to the West (-x direction) begins tog,1weoek rsh 5c0e/q- slow down as it approaches a traffic light.ereoe5,h1k/- wcq 0gs Make a statement concerning its acceleration.

  Suppose that an object is moving with a constant velocityrt+h(fct g*z5+el0kym 0n9)sbxa yg :. Make a statement con)9satcrzk0ggxnhy+l 5ty+fb m (0 e :*cerning its acceleration.

  If the velocity of an object is zero, does it mean that the acceleration is zend8gb;3cml ny,n z06 jro? Support bnnl3j, n yg;cmdz608 your answer with an example.

  Can an object's velocity change direction whesb )zl)zi+ (uyn its acceleration is constant? Support your answer u ) lb(z)yzsi+with an example.

  Suppose that an object is moving with conxa9qny:q 81y,lz nolm- f5cs.stant acceleration. Make a statement concerning its motion with res: nnqy1a8q 5.yfl,zsxo mlc9-pect to time.

  Can an object have increasingylf/7d j -zt5r)*roke speed while its acceleration is decreasing? Support your answer wik o d)fl5jtez/r7*r-y th an example.

  Suppose a can, after an initial kick, 8uuo09b2ms m vo h-vo/97h qrkmoves up along a smooth hill of ice. Make a statement concerning its acceleration/9ro 7ub0hvqmosv k9m-u8oh2 .

  Under what condition is average velocity equal to the average of the object'ptp46 43bsoyys initialboty644pys3 p and final velocity?

  Objects A and B both start at rest. Thecu7hwqg9mkku in3.td : ncu;c;6j6 4dy both accelerate at the same rate. However, object A accelerates for twice the timu4;6 g.uh6dqu: dinw 9c3km ;cntkj7 ce 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 aa w0*,n. wuasg,m iz21ybl*k accelerate at the same rate. However, object A accelerates for twice the time as object B. What is the distance traveled by object A compared to kw2by* msal *zau1.ga,iw0 n ,that of object B?

  When an object is released from rest and falls in the absence of frictio 44bo4xea)thbr4: q ekn, whiche k o4tqahb4e 4:r)xb4 of the following is true concerning its motion?

  When an object is released from rest and falls in td)l w olbe vb755n; hs1tf(s1ihe absence of friction, which of thnstsow lfe1bvd( il;b7 1 )5h5e following is true concerning its motion?

  Suppose a ball is thrown straight up. Make a statement about th ib,r8he+ +ftte velocity and the acceleration when the ball reaches the highest point. 8tbr,t+eh+if

  Suppose a ball is thrown straight up. What is its 12rvh nc0gln.ja cyd). .fxe+acceleration just before it reaches its highestn.ax1cn. e h2.c0 dgy+)rfvlj point?

  Suppose a ball is thrown straight up, reaches a maximum height, then fa vp:g8lbomw ybl4*3x7lls to its initial height. Make a statement about the direction of the velocity and acceleration as the ball ob8m v7b4p:3 wlxy *lgis going up.

  A ball is thrown straight up, reaches a maximum heightz f(d4x 1::8(ybgbkx9jawqr b, then falls to its initial height. Make a statement about the direction of the velocity a ybqw (xfx9 z8bg::adb4( rj1knd acceleration as the ball is coming down.

  Suppose a ball is thrown downward in the absence+rss2 iafzeyr59i u ,el,/:ac of air resistance. Make a statement concerning its accell,5y9urfie,2 rzai:ec+s sa/ eration.

  Suppose a skydiver jumps from a high-flying plane. What is her acceleration wex ewt re f1x2x/f7r,1hen she she reaches terminal velof ex 1 /,wt7exfxrr21ecity?

  A ball is thrown verti ik5x.0utppufw;wo8r+b*zc9 cally upward with a speed v. An identical second ball is thrown upward with a speed 2v (twice as fast). What is thexcu5f o9b ; i.kzpw+0w*r8ut p 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 q6bi-sdd48 crpx:,wm2b .r cwsecond later, ball B is dropped from the sqbw,8cbriw x6 :r 4.p2sdm-cdame building. As time progresses, the distance between them

  Ball A is dropped from the top of a building. One second later, bab 668u,yn7gpp tf, (i/gkqvefll B is dropped from the same building. As time progresses, the differey7(n fgb6,,8 qp6pukgietf/vnce in their speeds

  Two objects are thrown from the topx6e11nc b(1sz rm35h:)sh en3v jzkyx of a tall building. One is thrown up, and the other is thrown down, both with the same initial speed. What are their speeds when they hit the strbhe:6xn1 sehky3sv 1m15z r3xczn( )jeet?

  A brick is dropped from am(-bkmsxu t-2d2* dythe top of a building. A second brick is thrown straight down from the same building. They are released at the same time. Neglect x--m2*ab(d2ktm u sdy air resistance. Compare the accelerations of the two bricks.

  An object is moving with *oa j3ao td uesy-+ny.+9,glyconstant non-zero velocity in the +x axis. The position versus time graph 3 j.,9+toug n *oy a+-lyaedsyof this object is

  An object is moving with constant non-zero acceleration in the +x axislsxu7+mb4 21z *n fcskkh f3m4. The position vef szs 2lmk3b44 1*mx7+cfuknh rsus time graph of this object is

  An object is moving with constant non-zero velocitq8 1s;mtrm/f h4abx/s*0 x xmcy in the +x axis. The velocity versus time gra0/f;/htcxm8qm s41r m xsb* xaph of this object is

  An object is moving with constant non-zero accelerationi/jj o746mbcb; vklq*nz +tf4 in the +x axis. The velocity veo4 *tbk f;n j4jvibmc z6+l/q7rsus time graph of this object is

  The slope of a position ver)h qg i,2m 6kmb*cdmzoi qd938sus time graph gives

  The slope of a velocity versus time gr vi14r /vz(f oeiig:h7aph gives

  The area under a curl2tzf.fz1 y6;x x;kz wve in an acceleration versus time graph gives

  The area under a curve in a velocity versus time graph * )2 +pfkr:x0jafz:qhat 8wlv gives

  If the position versus time vi3qfg,t( nuv.ejy rkv9(e 9, graph of an object is a horizontal line, the object irkv(iuy(ej.9v9,gtv, enf3q s

  If the position versus time graph of an object isrh 9;qltncw 9)gx2l) u a vertical line, the object isl) r9x2tcl hg9nu )qw;

  If the velocity versus tim1x 7 zdc)arj6wab)ho 5e graph of an object is a horizontal line, the object iwj abhx)z67 a)5cor 1ds

  If the velocity versus time graph of an object is a straight line makin4c b*s;b :xeqfg an angle of 30 degrees with the time axis, the objectq4 sx:ec bb*;f is

  An object moves 15.0 m north and then 11.0 m south. Find b 9kufm*4q:ao0u 5 poeqoth the distance traveled and the magnitude of the displ9of u m5p:40*q aequkoacement vector.

  A boat can move at 30 km/h in still water. How long will it take to move vgo-i. 2sm1b z12 km upstream in a river flowing 6.0 km/h. -b1ovg2z ims?

  55 mi/h is how many m/s? (1 mi =zygxgz g +cl70ih1-1j 1609 m)

  What must be your average speed in order to travel 350 km 7n6 ,ph -shbhtin 5.15 h?

  A runner ran the marathon (approximately 42.0 km) itl*t*m+:df pa/t3 lgw n 2 hours and 57 min. What is thedfa/mt3 + pgltl*t :*w average speed of the runner in m/s?

  A car travels 90 km/h. How long does it take for it to trpjh;wuw( :89pj/fo n1c cxzr/ avel 400 km?

  A ly (light year) is the distance that light travels in one ye-vijae/tk7bu 9*wjqvgr ( (t+ar. The speed of lt 9*vbw ajju7gi/r(vte(+- qkight is $3.00 \times 10^8 \; m/s$. How many miles are there in a light year? (1 mi = 1609 m, 1 yr = 365 d.)

  If you are driving 72 km/h along a straight road and you look to the side folw dx/1u* m0fjr 4.0 jxl1f/w0 mu*d s, how far do you travel during this inattentive period?

  If you run a complete loop around an outdoor track )9 jaybb i3aa(w*e1mx(400 m), in 100 s, your average velocity xy1ewb( ama39i bj)*a is

  A polar bear starts at the by:3y4i tc 6fdNorth Pole. It travels 1.0 km south, then 1.0 km east, then 1.0 km north, then 1.0 km west t :4iy cyb3t6fdo return to its starting point. This trip takes 45 min. What was the bear's average speed?

  A polar bear starts at the North P2b ga 0irtw7c6rsir,9o2wfj2f3 g0a yole. 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 starting point. ria ig9og60s2rf3,2 wbf0ja2ry7 wct This trip takes 45 min. What was the bear's average velocity?

  You are driving home on a weekend from school at 55 mi/h for 110 miles. It t jjcrz: fiy6*b/ ;pdg*9rjbf7hen starts to snow ajd *j;y7p bb/frigr9cjz*f:6 nd you 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 160 km at 100 km/h. z*w(. x:-ciqjoio gq3 What is the average sp.-3: zwcxoqgi* (oji qeed of the motorist for this trip?

  A motorist travels for 3.0 6:bhj ner,(q1 onl(lrh at 80 km/h and 2.0 h at 100 km/h. What is her average speed 6q,1r(:je bh (lnonlrfor the trip?

  An airplane travels at 300 mi/h south for 2.00 h and then a mav-6yphe4 hr 7d;.j;+tlcr, ot0fgzt 250 mi/h north for 750 mil t, hzt m+oj6r rpv-hlfgc.e47a;yd; 0es. What is the average speed for the trip?

  In a 400-m relay race the anchorma k-bza ,qz l31()bspfeq80z(jo(j pep4 0bajzn (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 a )(e1s(zfq4alojbb0ez,pj8 pb3(- pjz qz0klead 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 afterywh uw4g rcej5 pm//f4r-+hb *:p6xnn7tb as8 10 s. The car's average velocityb8*e:4r7h 5pwpjunxn4amc /hy w -s/6 t+fg br during deceleration was 65 km/h. What was the car's deceleration while slowing down?

  An airplane increases its speed fr;q/*ua/.py9rn y hc jzom 100 m/s to 160 m/s, at the average rate of z *9ny uqh/p;acyj/.r$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accel5vn5j++ pu0xs ukj4 foerates 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 respa;xm/slo7, rp*e 9ke t and 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 .u -w*t+qo kfrosej5c un4n..with a constant acceleration of fu qkt o4rn+jo*5u e.sc-.wn. $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 1.2 m/s experby vc1 2o,k7itiences a constant acceleration ofv2kto71yc bi, $4.9 \; m/s^2$. What is the cart's displacement during the first 8.2 s of its motion?

  A bullet moving horizontally owyn z;98owce k(h 95o44(+f dewuvjn to the right (+x direction) with a speed of 240 m/s strikes a sandbag and penetrates a distano49vd+8yn(ceo9 ukfh;zwn ojew(4w 5ce of 14.58 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on an aircrafn8mr as+ )rp5oahx 5a:t carrier. It reaches a speed of 42 m/s at the end of the catapult, and this requires 2.0 sr5mpr85)onaxh +a s:a . Assuming the acceleration is constant, what is the length of the catapult?

  A car starting from rest moves with conb/+rq wpuo. m;stant acceleration of $2.0 \; m/s^2$ for 10 s, then travels with constant speed for another 10 s, and then finally slows to a stop with constant acceleration of
-$2.0 \; m/s^2$. How far does it travel?

  A car goes from 40 m/s to 80 m/s in a distance of 200 m. What is its averagmx bob of* w7ski1 vt,9x(ix4446xuire accelerati im,xf4461ix4x97*kuvs r xbbo( owi ton?

  An object starts from rest and undergoes unif d f95qc 5nq6bpzl0fj+qgh)x ,orm acceleration. During the first second it t6fcq5+9,hzd n0jg5pf)l qxqb ravels 7.0 m. How far will it travel during the third second?

  An object is moving in a straight line p*u)4c ) e6;pfrv xff -qltbv.8 ep8cowith constant acceleration. Initially it is traveling at 16 m/s. Three seconds later it is travq 8;)8- pbrcvpxfeo6ft u*v)el pf4c.eling at 10 m/s. How far does it move during this time?

  A car starts from rest and accelerates /3jeucu cbh- 6uniformly 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 abo (.rljqvqea0h (l8/pput $5.0 \; m/s^2$ 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 almhj3 ht 9: o*:l8oiowaiting at the intersection starts ahead with a constant accelerl8lhomajo9* o3 it::hation 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 of planbsn8sqb 3zhs9-3p 4ku*b l w7pet X where the acceleration due to graw s4 3pbk3 b97hlzpnbus-s*q8vity 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 when1tqcsif p+9p s/ 1qb-rnt1pcf1q -9ps qb+s/ie 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 thx8 57c nqhpq(oe surface of planet X where the acce xcoqq(5 h7np8leration 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 planet X q 7hjn 8r+euavqtm6.d/7jr- uwhere the acceleration +/urmu -7q6je rvatj 8.ndq7hdue 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 thanamx-95p2swmv5vh)yw tpy sn2: h,e2u1o7eu y 0.10 s. If your friend holds a ruler between your fingers and releases it without warning, how far can you expect the ruler to fall before you catch it?my29o7 vpwtnwhxus: ve 2mu1pa2)s 55yh-ey,

  A ball is thrown upward at a velocity of 19.6 m/s. Whatd (x,e4aptz/ r is its velocity after 3.e4/,ax rtdp (z00 s?

  A bullet shot straight up returns to its starting point i pe,e voqj.(x/gjpq3; n 15 s. What is the initial speed of th/p(jgje,p; qo eqx v.3e bullet?

  A ball is thrown straight up with a spe:zyqnbba b- oxo7a7m hr;z (gjk8,7c*ed of 36.0 m/s. How long does it take to z anx bjk* q7;-c zymo(:7 7grb8hb,oareturn to its starting point?

  A ball is thrown downward from thedblm 4u xvxp6p0 73*rt top of a building with an initial speed of 21 m/s. It sxl t*mvd4ur3px0 76bptrikes the ground after 2.9 s. How high is the building?

  A ball is thrown straight up withk (7ig)iv;la v a speed of 30 m/s. (only fill in numerical value in the bl;k a7v)li(gvi anks)
(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 straightdoqjrjf sk)g1n+faa ..3 ;zf +wg/rs( up into the air with a speed of 29.4 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 velocity at t = 1.0 q(kdz,l:6 wu+5o , 2dgu)u ptlpyf :,oa1e gqls?

  In Fig. below, what is the velo4xfy. 6dhf;n1zilx a, city at t = 2.5 s?

  In Fig. below, what is the velocitn nad38(rkj 4ay at t = 4.0 s?

  In Fig. below, what is the velocity at t =7lj,dmhrf4y , 5.5 s?

  In Fig. below, what is the average velolpd xchp q:7br) :tj+-city from 0 to 4.0 s?

  In Fig. below, what is the average velocituo/ivu w y fl37eqm((d(j g:,sy from 0 to 6.0 s?

  In Fig. below, what is the acceleration at 1/ o6ja)q1 rj7zzs.cjd.0 s?

  In Fig. below, what is the jt k9 a 07vwe;fzwj3bfq36*qg acceleration at 3.0 s?

  In Fig. below, what is the average acceleration fn22/pmq e(r d,vx)puarom 0 to 5.0 s?

  In Fig. below, what is the average acceleration m*5 7-ys wyog* dhx+fhfrom 0 to 8.0 s?

  In Fig. below, what is the displacement from 0 to 8+w 5po bi-uh zp2itcw9nfb55*.0 s?

Does a car speedometer measure speed, velocity? {speed|vedbrm- k+nrh 3)i*5wsd+2i bfilocity}

  An object can have a varying speed if its velos8j 8vj7j6t mzm9s-jacity is constant.

  The velocity of an object can be negative when itg. z9lkway/b1 s acceleration is positive.

  If one object has a greater speed than a second oc4dg-h d87lc1e/ z eofbject, the first must have a greater acceleratio 7h1- eoczgec 8ldf4/dn.

  Two cars emerge side by side from a tunnel. Cgywk h8et:mgwm dps,4i .5. c4ar 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 dhca 9xg+a (zl*og:(moecreases.

  A baseball player hits a foul ball straight up into the air. It leave0kuhzy3/plrm()hv 9 ys the bat with a speed o yz)rkly9puv0h /( 3mhf $120 \; km/h$. 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, w/m/x(cac dbpc b 0s 5p.z.clf5hat is happening to its acceleration, how does it change if ai sxf//mc5.bb .5p(cdzc 0c lpar friction is ignored?

  As a freely falling object spe5daf jgoa9 ) 1zd)uqu9eds up, what is happening to its acceleration, how does it change if air friction CAN NOT be ignuu 5dzaf))1aod 9qj9gored?

  An object that is thrown vertically upward will return5ii4d g6 n4twi*hree; to its original position with the same speed as it had initially if air resistance is negligible. If air resistance is appreciable, how riweh4ni54*ig;t ed6will this result be altered?

  An object can have zero velocity and nonzero accele5d6 rjd/oz n+sy85zudg jhko6s v1s); ration at the same time.

  An object can have nonzero velocity and zero accelhd*e d u9dt*p03lz:lw* k dn-w*ooe*xeration at the same time.

  An elevator moving from the second floor to the fifth floor 3olzs,lb sx5 ,making no stops along the way has zero acceleration all t3,slob sl5zx ,he time.

  A rolling ball moves frt5dqs-4y* kgv*qnxx;xy 37g d om $x_1=1.9 \mathrm{~cm}$ to $x_2=-5.4 \mathrm{~cm}$ during the time from $t_1=3.0 \mathrm{~s}$ 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 $t_1=-4.5 \mathrm{~s}$ is at $x_1=2.3 \mathrm{~cm}$ and at $t_2=3.1 \mathrm{~s}$ is at $x_2=7.4 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complc*s pe2k :wx;wv81c 1qtnxrk:d .q xh5ete laps around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 7.5 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 107 m away in e1gvzb jf m8 /8lni v+uxry)8q y8*/ox11.6 s. It then turns abruptly and gallops halfway back eg8/ 8+j8b uy*ny/qx)81fvvi xz lo mrin 4.6 s. Calculate (a) its average speed  (数值)  $m/s$ and (b) its average velocity  (数值)  $m/s$ for the entire trip, using “away from the trainer” as the positive direction.

  A car accelerates from 5e6s:5)p*n*skduaf (mrkd ji $12 \; m/s$ to $25 \; m/s$ in 4.4 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 from 1yk-d c5s:li-.zojco$22 \; m/s$ to rest in a distance of 81 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must rez yw:yv.+ah isr96.rw ach a speed of $31 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.7 \; m/s^2$ ?  (数值)  $m$

  A world-class sprintehwwqp i576tm-d egf.9c y wa/4r can burst out of the blocks to essentially top speed about 4 9wt6w7aied5wfp/c q m-. gyh$10.7 \; m/s$ in the first 12.4 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 au5q2dh7pwo)hav7x 2from a speed of $20 \; m/s$ to rest in 4.80 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 nnn,t+.ot,nt;m ddq 9on the highway. Assuming dqmn.o+t;, n9 tn dn,ta deceleration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck goi72 2c)mhdot1 rqn sf;yng $25 \; m/s$ 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 r9ynyboj s o jl+r*-7c(un in less than 30.0 min. After exactly 27.0 min, there are still 1100 m to go. The runner must thc9y7jjys -o* o(bnl+ ren accelerate at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$