Suppose that an object travels from one point in space to another. Make aq6n ./ykmk9zd.y wxs. comparison between the displacement and tkn.sky dzwy.xm9/.6 q he distance traveled.

  When is the average velocity of an objec96vp*iy r ghx2t equal to the instantaneous velocity?

  A new car manufacturer advertises that their car d*g.x x3mkh37k-qijr.djf0 xcan go "from zero to sixty in 8 s". This is a descriptq0*mdjrx. x ki-g3kd3 7xh fj.ion of

  An object moving in the +x axis experi,z,h bl.qu2 u:9kc jwlences an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car tdbr-d 71.jdg,61 n xt5azsv/gns.xyaraveling to the East (+x direction) begins to slow down as idy.a as1dzsn n,rv- 61t .xbjg7x d5/gt approaches a traffic light. Make a statement concerning its acceleration.

  Suppose that a car traveling to the West (-x direco sqg9-atx 41wtion) begins to slow down as it approa4g -9stxwqa1o ches a traffic light. Make a statement concerning its acceleration.

  Suppose that an object is moving with a constant velocity. Make a ,zrhbei9s2z 0y )u9xv :5 nnqzstatement concerning its accelznrs:) xin9ze, 5zh9y0qb2v ueration.

  If the velocity of an object g+b rcfc:t-70bqfz :-d,zpoe is zero, does it mean that the acceleration is zero? Support your answer zc ::ob-0 -rg, z+tbcqf7df epwith an example.

  Can an object's velocity change direction when its acceleration is const7s8h .ymtj( ww8z+e frant? Support your .78hy mz tw+8wfs(erj answer with an example.

  Suppose that an object is moving with5fixp/ ; mfl.b constant acceleration. Make a statement concerning its motion withl;fbp5imf/x. respect to time.

  Can an object have increasing speed while its o)urh6,0z b obn,a wev*pe9o/acceleration is decreasing? Support yr/ ) zpbhn aeu,o6v,0w9boeo*our answer with an example.

  Suppose a can, after an initial kick, moves tf 2yl )aa;gcam0ao7/up along a smooth hill of ice. Make cal oa7 y)a2t g/af;m0a statement concerning its acceleration.

  Under what condition is average velocity equal to the average of the objenr59mpw:z3m7ot 9 x p-xtbp5 ict's initial and final velocity55mbprz7 mt-wpxi3o9p:9n xt ?

  Objects A and B both start at rest. They both accelerate at ta:4gm 6nqo/g frq ;fz:he same rate. However,6 ;z/4:gfgn :oarqfmq object 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 fbk:vfl:)m2f1lf04 lie4 ort both accelerate at the same rate. However, object A accelerates for twlmf4oib ::1e)frv l0 4ktlf f2ice 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 falls in the absence of friction, whe-/l o.u g62jemk- eusich of the following is true co/ke e.umsg-j le2u6- oncerning its motion?

  When an object is released from rest and falls in the absence : n9;asefg4 da1r8gcqof friction, which of the afn49acq:8gsg d 1r; efollowing is true concerning its motion?

  Suppose a ball is thrown straight up. z.6o odz ybj:f 0:yzc9 Make a statement about the velocity and the accelera.db9 z 6f0:j o:zyzcoytion when the ball reaches the highest point.

  Suppose a ball is thoo krb8ptd n/ 78i z7q6 l:omamx2br.6rown straight up. What is its acceleration just before it reac6ooiknmz8 t /p bb72 87mr.ro xd:6qalhes its highest point?

  Suppose a ball is thrown straight up, reaches a maxim5i l-l1zlsrx4um height, then falls to its initial height. Make a statement about the direction of the velocity and acceleration as the ball isx4srz i -5ll1l going up.

  A ball is thrown straight up, reaches a maximum height, then falls to itsbx) 3+ -*3ljsaif c,2ggpzvrj initial height. Make a ,zl fgb - *j) 33svrpx+jag2icstatement about the direction of the velocity and acceleration as the ball is coming down.

  Suppose a ball is thrown downward in the absence of air resistance. Ma/h 42h 82)slb* ,svmhiuvzvmh2 (tbtvke a statement concerning its accelerah 2m/ 4s2u ,mbs*vztvh)2hbv lht(vi8tion.

  Suppose a skydiver jumps from a high-flying plane. What is her acceleration 4b, ghxl. w-x;i pn9cpwhen she she reaches terminal velchx.bpl; i , 9wn-gpx4ocity?

  A ball is thrown vertically upward with a speed v. An id vgn2l,/ nl/aqg1.0pa en/f hvls vr8:entical 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 secahlfn q1v.n nv/ggvrae l2: 0l/ s8p,/ond ball go than the first ball?)

  Ball A is dropped frot)a(j telwzu*j/x23o m the top of a building. One second later, ball B is dropped from the same building. As time progresses, the dist wj(aot/ e)z2ltu x3j*ance between them

  Ball A is dropped from the top of a building. Onux) ilm6d9j*4 g , ow*upbtb*oe second later, ball B is dropped from the same building. As time progresses, the difference ibu6xg*49p*i *olut w,d) bomjn their speeds

  Two objects are thrown from the top of a tall building. One is0yyn5el; 4rv z thrown up, and the other is thrown down, both with the same initial speed. What are th ;ry zvl50ey4neir speeds when they hit the street?

  A brick is dropped from the top of a building. A yn9+j0 vroz,u4wkta4ma4 q7dsecond brick is thrown straight down from the same building. They are released at the same time. Neglect air resistance. Compare the accelerations of wadaj 79yv,m 4t u+n4o40zrq kthe two bricks.

  An object is moving with constant non-zero velocity in the +x axis. Th4 nhfs:ywi 0nl5jy:r uj5i 27le position versus time graphl7n5s:f 5rn wh4 i20iyj:yjlu of this object is

  An object is moving with constant nbty 1 oqz,6q*p3, hhvzon-zero acceleration in the +x axis. The position versus time graph of this obj1, vbqot z6zy3,hh *pqect is

  An object is moving with constant non-zeros p,xb1koag6cypk 7h/qao/o7) xz+0l velocity in the +x axis. The velocity v kz0ys/l+a)1/ ocpg k aqo7ox7h6bx,persus time graph of this object is

  An object is moving with const9 7n isf* o(ktdx1v7jeant non-zero acceleration in the +x axis. The velocity versus time graphfxio kj9s d1ev (n77*t of this object is

  The slope of a position versqg fyig+(wdg 9,d /hm7us time graph gives

  The slope of a velocity versus time graph gijk7goy1, xw, zves

  The area under a curve in an acceleration versus ti5e z u cov,vb68*feiu/me graph gives

  The area under a curve in a velocity versu)x -fwyh4k 1dfs time graph gives

  If the position versus timed:dn7fn24-nik j)duun.bp 1 f graph of an object is a horizontal line, the object isj-d 4nb72p k)fu.din:d 1unn f

  If the position versus time graph of an objep5 myz ds6q1y. 0xkt;ect is a vertical line, the object isym6t5pz0 dk; 1ex.yqs

  If the velocity versus time graph of an object is a horizontal line, the ooe t/d 6cu8s0ix zo)jk:0 qvl4bject il)uksc4 /td qe oo08z vixj:06s

  If the velocity versus time graph of an object is a straovpa,fsd w51.ight line making an angle ofsd.,5 a wofv1p 30 degrees with the time axis, the object is

  An object moves 15.0 m north and tgh:soru13t p/t2q0p8*vbib. x o9 aq phen 11.0 m south. Find both the distance traveled and the magnituv a:b0oxg3qp ipbtrs *h28q./9 to1pude of the displacement vector.

  A boat can move at 30 km/h in still water. How long will it take to move 1ber0 ca9:x:up 2 km upstream in a rivuxe : :ar9p0cber flowing 6.0 km/h?

  55 mi/h is how many m/)x f 7l-z1a),vlow mlzs? (1 mi = 1609 m)

  What must be your average speed in order to travel 350 km in 5.15 h? g8 rq48t./4nkx yfhjk5vczl gz35e+e4qyb2h

  A runner ran the marathon (approximately 42.0 km) inedds0 mt*p9xx f r1c,+is-+ndpr:ln ; 2 hours and 57 min. What is the average speed of the runps rnsdi,-f10r lx+pecx;n:* dt md9 +ner in m/s?

  A car travels 90 km/h. j1w 3 84f4;yok u/yjizkeak;b How long does it take for it to travel 400 km?

  A ly (light year) is the distance that light trave-uka 1c/wtpo;,a,kdj ls in one year. The speed of lad/-,aco j1wtk ,k pu;ight 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 roadf ypcz.qh p wjz29+e/5 and you look to the side for 4.0 s, how y.pfzp+/5w9 q cz e2hjfar do you travel during this inattentive period?

  If you run a complete loop around an outdoor trt4c;y 1hx7z nu w39 .*ge,e dlr;gyqsiack (400 m), in 100 s, your average velocitz9h*3yild wex;scu7q1gt.ny ;g,4er y is

  A polar bear starts at the North Pole. It travels 1.0 xa7hm u0u.d/*rko( eikm south, then 1.0 km east, then 1.0 km north, then 1.0 km west to returkxha0i./drum* ou(7e n 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 t49fl .zfkg t8jravels 1.0 km south, then 1.0 km east, then 1.0 km north, th z9lfg. 8jkt4fen 1.0 km west to return to its starting point. 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 milessb-2y 01ssr/cht /5z+fhmyfp. It then starts to snow and you slow to 35 mi/h. You arrive home after drivbhf0s5hs+yc/fmt sy/zp -r 21ing 4 hours and 15 minutes. How far is your hometown from school?

  A motorist travels 160 km at 8051*popos 3b8 93lyhv4d sm yw+1lq cqf km/h and 160 km at 100 km/h. What is the average speed of fo q *1138dlq+p polyhmc4wvs5 9 sby3the motorist for this trip?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 5j5 t szz(fnk.y)end+h b )r1ykm/h. What is her average speed for yyb5)jrd n+z)e1 z sht 5f.k(nthe trip?

  An airplane travels at 300 mi/h south for 2.00 h and tk-x7)g.ek;an mex 4z zhen at 250 mi/h north for 750 miles. What is the averag-)e kanz ;k4.zgx7emx e speed for the trip?

  In a 400-m relay raceoaf d,(-n .aq+vx /iul the 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 teadiau -qo.avxf, n+ l/(m 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?

  A car decelerates uniformly and comes to a stop after 13 m)taln8 p.kl. s. The car's average velocity during deceleration was 52 km/h. What was the car's deceleration whm8pllnta ). .kile slowing down?

  An airplane increases its spee 2;4+thfgfz d 9p(aijad from 100 m/s to 160 m/s, at the average rate of zgh ;d9 2+ta j4fpa(fi$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerates at the ;yz+u3k ag bm g (mpjvx*g28u+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 j6l+olvhf06m vn 86 wraccelerates 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. of 1c6, hvhsmpt 9 0rdf/n0a)o It then speeds up with a constant acceleration of0pn)vt01odf9 s /r,mo6f ahhc $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 6.1 m/s experiences a constant acceleration987gx-elllglp 3xcz 0r6b6 uj of 3lr8bpl-c6eu6gjz7 gl lx0 x9$2.3 \; m/s^2$. What is the cart's displacement during the first 4.6 s of its motion?

  A bullet moving horizontally to vf,28xsb,tfjd mrw6) the right (+x direction) with a speed of 228 m/s strikes a sandbag and penetrates a distance of 98.28 cm. What is therfxj,2wbf 8d, ) m6tvs average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane ixhim +.4ars6q s launched from a catapult on an aircraft carrier. It reaches a speed of 4i+mq.6 sh4arx 2 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 catapult?

  A car starting from rest moves with constant acceleration of 1j v6ru 93e+9dmmlj2 j leo(so$2.0 \; m/s^2$ 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 dista;,3ey ;4 z7y5xkj jo oyf0ad ld3djlt*nce of 200 m. What is its average acceleratio0z;yje*5ydt4o 7df jyj3d x;all,k3o n?

  An object starts from rest and undergoes uniform acceleration. mdes-lf)6 iw 8yjq47 vDuring the first second it travels 1.9 m. How far will it travel duvils y m-67fd)we8q4j ring the third second?

  An object is moving in a straight line with constant acceleration. ij4bm9.5 1 +nlwcjrzbInitially it is traveling at 16 m/s. Three seconds later it is traveling at 10 m/s. How far does it move durbic1 wn5b9 j4rm+l.z jing this time?

  A car starts from rest and ,b(8z7x rwzh vmh0 -djaccelerates 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 o( qo8e+4wew nef3e,-id/bz )yvy8rmc n 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 has been waiting at ;8oydhw1f83 rb (gismthe intersection starts ahead gi1 ;s3d8frb8o(wyh m 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 wit/xqm a*pe(i.rr 8( pcnh a speed of 12 m/s on the surface of planet X where the acceleration/rn8xp mqe.r i(* (pca 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 spidu s jx*umh* (()v4yurface of planet X where the acceleration due to gravity is j y*(4*umupi( )xsvdh$1.5 \; m/s^2$. How long does it take for the object to reach the maximum height?

  An object is thrown uplsdos3* ,vsrpb c zj-nw;rx / 90)gh0oward with a speed of 15 m/s on the surface of planet X where the acceleration du*9 rr/pono-,hzd00wls vsjx 3cg;s)be 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 ob xym jb*-2xc):2f dznf 14 m/s on the surface of planet X where the ayj fb2x-bx: )dmzn2c*cceleration 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 yourerk+34m,srib- iy7e n.th +ts,xmg /m friend holds a ruler between your fingers and releases it wit+ i hr.s g+mnmx,e sk/m tr3-4i7bt,eyhout 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 1 jrpi2v nc*v3 jl.:yv ec.w.)xp4plk3.pi1*vw).4plpc3r ljnvkv2 je. yx.:c00 s?

  A bullet shot straight up returns to its startxzkw2,8uqf/ fing point in 11 s. What is the initial speed o fw8 quf/2kzx,f the bullet?

  A ball is thrown straight up with a spm*c 0v8pq+2: lsmr aukeed of 36.0 m/s. How long does it take to return to its starts cm:mr +p82vaqk *lu0ing point?

  A ball is thrown downward from the top of a building with an initis mdy6 z. jq*tgaz6;0lal speed of 19 m/s. It strikes the grla6. j;dzzqyg0 6smt* ound after 4.8 s. How high is the building?

  A ball is thrown straight up with a speed of 30 m/s. (only fill in numerical vain p+fhk.0o1hu),ven 0.hht qlue in the bk ep nv.hhh 1ih0,.nfuo0)tq+lanks)
(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 s)+3cwz 7;nzihb+,ki d e j 0cqjjq-(nftraight up into the air with a speed of 41.9 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 10 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 10.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is the velocity at t = 1.0 s?2p w) 9g2;ghsp zuna-m

  In Fig. below, what is the velocity at t = 2.5 s?) t ,nvd gwr:4l:bueg1j-xl)w

  In Fig. below, what is the velocity at t = 4.0h:cs*pevo:rt0,** z bfzpj l - s?

  In Fig. below, what is the velocity p(.5t mar+c0o88p0ga, xc z;ibklcebuce t,4 at t = 5.5 s?

  In Fig. below, what istwso)3zb3 j(m the average velocity from 0 to 4.0 s?

  In Fig. below, what is thei5lzv r3)fs4f-cl 6ts average velocity from 0 to 6.0 s?

  In Fig. below, what is the acceleration ato,b 1cmrzq 365n8k.sc: thf zy 1.0 s?

  In Fig. below, what is the acceleration at e e*3ks x+y6ba3.0 s?

  In Fig. below, what is the average acceleration from 0 to 5.0z7 k x2,flj cgo/jiy7. s?

  In Fig. below, what is the average acceleration from 04*,ox 3ksjy ao,e9 yxj to 8.0 s?

  In Fig. below, what is the displacement frsh*gxbfso 60g4 d +tq8om 0 to 8.0 s?

Does a car speedometer measure speed, velocity? {speed|velocity}hx0gvpi- b5q8

  An object can have a varying s0l9 e8 8u ,mpowjzjh5speed if its velocity is constant.

  The velocity of an object can be negative when its acceleration isqc5-wuuh atk; j l526p positive.

  If one object has a g-ghs c3 s6j21. ht :39vm0pvmmrebhuyreater speed than a second object, the first must have a greater accelerati 31t - m6 rb.h3 hv2mps:vchum9jgse0yon.

  Two cars emerge side by side from a tunne:npfiy/r:1+;np: obi wbmhh. l. 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 speed as its acceleration de4af eb1ylasikh3y,s 4j-l 4v.creases.

  A baseball player hits a foul ball straigmr gf(v06 y( 4aoe sqxsg/p1x6c6; oheht up into the air. It leaves the bat with a speed ov 4om cqsr6a1e0gg ;(yeh6xsfxpo (6/ f $120 \; km/h$. 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 acc)c:ndmij oo7 ,eleration, how does it change if air)mnjc dio:o 7, friction is ignored?

  As a freely falling object speeds up, what+8xf isnm.a05. z ps m+4.kr ld2wylkd is happening to its acceleration, how does it change if air friction CAN NOT be .ma02xm l+i 4.rkz wkdl+fd58yn sp.s ignored?

  An object that is thrown vertically upward).xndlaa-( ;i*m0qhsvu5mm j 0 uxyp7 will return to its original position with the same speed as it had initially if air resistance is negligible. If air rm ay50nl (m sx7apuq* m-;vudxj0.ih)esistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzero acceleration atc*d*k;ahk )wqkb,+o p the same time.

  An object can have nonzero velocity and zero nw1 dp)ip6-i;jds(oueh d3e9acceleration at the same time.

  An elevator moving from the second floor to the fifth floor ma55z* g)pd xjvgq 4gsc9)z m6rvking no stops along th59s*x vd grv4 gjzpcm)z65gq)e way has zero acceleration all the time.

  A rolling ball moves from 6hwh )j8 h, yh*dxfpa)$x_1=1.9 \mathrm{~cm}$ to $x_2=-8.0 \mathrm{~cm}$ during the time from $t_1=0.9 \mathrm{~s}$ to $t_2=5.5 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-4.0 \mathrm{~s}$ is at $x_1=2.6 \mathrm{~cm}$ and at $t_2=3.9 \mathrm{~s}$ is at $x_2=7.3 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complet*rxp jyv-fmrxn /. /p5e laps around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 6.5 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 st 3ec9*p hwzur6 33ziejraight line, moving 99 m away in 9.4 s. It then turns abruptly and gallops halfway back in 4.6 s. Cau3c*zzi erw3pe 93h6jlculate (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 fr6p4blvm.ktg,a p k 2hd99 9ytyom $13 \; m/s$ to $24 \; m/s$ 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 frob:u g lbc:ww9/m $19 \; m/s$ to rest in a distance of 60 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a speeo/t5z :e ebt;md of $27 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.7 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of the blocks to essentially top speed augy+mdz *s;/j boutym jg;/sz +*du $10.1 \; m/s$ in the first 12.9 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 from a spm/ym.dj d*qqrr6 ls3 j7j18ameed of $20 \; m/s$ to rest in 4.87 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a dwphq1ia6 2y q+hpduw*6b8l0 car leaves skid marks 92 m long on the highway. Assuming a deceleration l yqbw6d1ahw hp+qp 8 6i*du20of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck goinjf80hh- .re(mdvz ui8g $25 \; m/s$ 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 e6g v6gw3wn+hsugq+xm5b* 7l30.0 min. After exactly 27.0 min, there are still 1100 m to go. The runner must5lxe+vhg 7buwgm63 g+ws*q6n then accelerate at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$