Suppose that an object travels frvabk( w m ht 7e3tto8n)y5i/cq6 m.y8aom one point in space to another. Make a comparison between the displacemmtko8cehw5aq8 t m .6)a3tvn7byy/ (ient and the distance traveled.

  When is the average velocit k uaib*byxh;l:( 0.ney of an object equal to the instantaneous velocity?

  A new car manufacturer advertises that their car can go "from zero to sixty h(ib848apml 1d( +g c yp8x zqoxc71jhrw))stin 8 s". This is a description ot yc)h7csh qp8l4p+ roz8(d xjmix1a)w (g81bf

  An object moving in the +x axis experiee :zj gl8c2xy2nces an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x direction) begins to 0ce2)hq iz8tbx- hscl jn19x5slow down as it approaches a traffixc 8- t)heq1 s 9b5ihx0lzjnc2c light. Make a statement concerning its acceleration.

  Suppose that a car traveling to the West (-x direction) beginsyx n+rl pe m,*ys1ji,v4w/y8 z to slow down as it ap4 sezy w*jr+ly n8p,yx1iv,/m proaches a traffic light. Make a statement concerning its acceleration.

  Suppose that an object is moving with a constant veloci:p lz)awcl) qgq8,qn( ty. Make a statement concerning its accelerat l qac)8,zqp)ln:(qg wion.

  If the velocity of an object is zero, dc(fly2dtnx 8orj4. g7-k/if does it mean that the acceleration is zero? Support youf j7ir(lg k.n4f82o-xc/dydt r answer with an example.

  Can an object's velocity change direction when its acceleratz3 qf n3.fl,qjion is constant? Support your answer wi fnzjl3f,q3 .qth an example.

  Suppose that an object is moving with constant acyw-)w, ;4:v vdtgq.bjxw4hexceleration. Make a statement concerning its motion .)w:vtgjyhwe wdb,; 44vxx- qwith respect to time.

  Can an object have increasing speed while its acceleration is decreasing? Suan xx0 0ww(s2mbv7m3apport your a0xsxavanmb w73 w02(m nswer with an example.

  Suppose a can, after an initial kick, moves up along x .,8nzfioq ).*byx g6rop.o ua smooth hill of ice. Make a statement cyib6on oxo.uzq fr8.g, x*).poncerning its acceleration.

  Under what condition is average velocity equal to the average of the ofkl m/1(j k7f ;mxk1fibject's initial and final velocitki ;1fjxk kmf(7/l mf1y?

  Objects A and B both start at rest. They both ax-:2h hejprlb52y 4jrccelerate at the same rate. However, object A acl4j:j-e2x2yhr rpb5 hcelerates 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 both accelerate a9ax- r.vtaku7q:i hh*9ayc i, t the same rate. However, object A accelerates for twice the time as object B. What is the distance traveled by object A compared to that ohia.-autrq :k7* acy, 9vi9hxf object B?

  When an object is released from rest and falls in the absence oi*)pp-x4w w bkf friction, whichpw xpik4*-) bw of the following is true concerning its motion?

  When an object is relezj bnf3zr) dtlfyn.qa43.48)xu 0lzaased from rest and falls in the absence of friction, which of the following is true concerning its moz8 3ry abxnff ua04 ) zz3lqjt).4.ldntion?

  Suppose a ball is thrown )4,l+.zin.8ryjpcmv r- 5n i nl bn.amstraight up. Make a statement about the velocity and the acceleration when the ball c.lp a)inbl5nn.ynmmivr r .4+,-jz8 reaches the highest point.

  Suppose a ball is thrown straight up. What is its d1l5ncr -k kgzxq kk58ujp7-3acceleration just before it reaches its highest poin7cl g8pxzrn-kjk5dkq 51 3 u-kt?

  Suppose a ball is thrown straight zlbs)p ,yp0sgsel.6. up, reaches a maximum height, then falls to its initial height. Make a statement about the direction of the velocity .0 se pz,gyl) l.ssp6band acceleration as the ball is going up.

  A ball is thrown straight up, reaches a maximum hpcv+kg+4*n(jtswh 3 y) br )lbeight, then falls to its initial height. Make a statement about the direction on g ( h3bpltwy 4b)+kscrjv*+)f the velocity and acceleration as the ball is coming down.

  Suppose a ball is thrown downward in the absence of air redm6f5d wdo;- *)q s8va wvxcw *ljnu*+sistance. Make a statement concerning its acceleratwdvlw6d-u v;a*o)w 85 *q msx djncf+*ion.

  Suppose a skydiver jumps from a high-flying plane. What is hezfyhq -8 q 1pcj0a(g;5z.t btgr acceleration when she she reaches tqqzaz;jtf0(g5 gch 1yb -.tp8erminal velocity?

  A ball is thrown vertically upward with a speed v. An idenn8vfwtoln744*( ddh u tical second ball is tdn4nvful( d*wh4o7 8thrown 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 first ball?)

  Ball A is dropped from the top of a building. One second later, ball B is dropp,pyxfq.)*hpgfn w-qe8h c.s 2f() rfled from the same building. As time progresses, the distance beth p -g,yx fr lsfnp).qfqf)2*8cwh(e.ween them

  Ball A is dropped from the top of a building. One second later, ball B is dr0em4rvli :b/7) aqvjy6 y qvi.opped iqbjm67:vy0lqv. y ) 4/ai rvefrom the same building. As time progresses, the difference in their speeds

  Two objects are thrown from the top of mdns;f 3*gm*l 6rkp)za tall building. One is thrown up, and the other is thrown down, ml3k **mdz prg)6nf; sboth with the same initial speed. What are their speeds when they hit the street?

  A brick is dropped from tw,g 27 x .ryb1ytq,rsihe top of a building. A second brick is thrown straight down from the same building. They are released at the sayrq7yt g.1,x2,s iwbrme time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with co9wr;ulxo50lu ua 9xs8nstant non-zero velocity in the +x axis. The position versus time graph of this object lrauuxuols 9x0 8;5w9 is

  An object is moving with constant non-zero acceleration ie9h5gqegyl3tpid 4 f902lvpy ;3y7xkn the +x axis. The position versyfv 3yg03 i 7 x2q g;pteph5e99d4lyklus time graph of this object is

  An object is moving with constant non-zero velocity in the +80 hucn :zxla6x axis. The velocity versus time graph of this obxuzh al6:0c n8ject is

  An object is moving with constant non-zero acceler);0 rvep3qk4d o kkrp67epg:aation in the +x axis. The velocity versus time graph of th43dppqop e0r6vkrg)7ak ;:e kis object is

  The slope of a position versus time grap ::fmcgb s* 5fuo8slp.h gives

  The slope of a velocity versus t 9,uj82))sk /gn7pcr kh/spkfuoohq6 ime graph gives

  The area under a curve in an acceleration versufkj bgjrv6b 9h)m17(xs time graph gives

  The area under a curve in a velocity versus timeu(45wu epwgvd.g+g0 ;q b9of w graph gives

  If the position versus time graph of an object is a horizontal lined-cs e5u8k2 cbzg7k 4l, the object gc5s dk7bz4k 2l e-8cuis

  If the position versus time graph:xa owr5 9re7kxhze7vj8x /7us9uk+h of an object is a vertical line, the object is:uh7h79jvze 8s aew /9kuk7rxx5rx + o

  If the velocity versus time graph of an object is a horizontal )n7 trvdc,dpzik:n6 2t -fdt: line, the object i :7:ttidrnc-2)6dvdz tfn k,ps

  If the velocity versus time graph of an object is a straight line making an ang 87 1shj7cvkctle of 30 degrees with the time axis, the objh7vcst k1 j87cect is

  An object moves 15.0 m north and e -gx3j3huxx.w52im )rjd*sdthen 11.0 m south. Find both the distance traveled and the m3ru dx5g-3j dhxsiw*.mje 2) xagnitude of the displacement vector.

  A boat can move at 30 km/h in still water. How long will it ta8f-svlnmn f:pwe/t .s:7u qz -ke to move 12 km upstream in a river flows.z8q7l:v f- etp- m n/wsfn:uing 6.0 km/h?

  55 mi/h is how many m/s? (1 mi = p7ddwe0 ,rz.7+mdc w3esc) ch1609 m)

  What must be your average speed in order7d+zl+- *c rbt.wq2 xoda cm8b:y bx8x to travel 350 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 km) in 2 gg.ce y7fxsrv n 092c0hours and 57 min. What is the avngg.efsxc20c 0yr97 verage speed of the runner in m/s?

  A car travels 90 km/h. How long does it take for it to trfuy+e25el)bfdk 9 .yozcff)p0e 3*opavel 400 km?

  A ly (light year) is the distance that light travels in one year. The spefos6+)b ntutn)e a9jk-n: ph9ed of light)su-j)oh:tebfnk 9+n tnap9 6 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 fgc+;48.1 ) g+z ffq.hl-l jngool8sxk9zyx bfor 4.0 s, how far do you travel duri+. g) fnsxq;81+yzkhl j8 .xlg9f- oob4zf glcng this inattentive period?

  If you run a complete looxjqoz*pe83m-pl1 -h /u uqt33mmo1qyp around an outdoor track (400 m), in 100 s, your averagpxe*t31lmp/ hq m8-1u -3m3ujyzooqqe velocity is

  A polar bear starts at the North Pole. It tfhh3h2.d3 npw2o a (psravels 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. This trip takes 45 min. What was t2h3p (d.npafhwo3 hs2he bear's average speed?

  A polar bear starts at the North Pole. It travels 1.0 km south, then nzo;i0:xj of; 1.0 km east, then 1.0 km north, then 1.0 km west to return to its starting point. This trip takes 45 min. What was tn o;j: fizo;x0he bear's average velocity?

  You are driving home on a weekend from school at 55 mi/h for 110 miles. It then)q,hvx,w 8sxhl, .0g tvp :jir starts to snow and you slow to 35 mi/h. You arrive home after driving 4 hours and 15 minutes. Hows :,vvgrql i8, xwh)t,hxj0.p far is your hometown from school?

  A motorist travels 16ka l1 9/kh;m blh:d xv.1snb(i0 km at 80 km/h and 160 km at 100 km/h. What is the average speed of the motorist fsi v;bh1 k9/ a.l bh1:ldkmx(nor this trip?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h. What is he0:th/xyjolhrqgz k5w7 3 i)q s7,0ipxr average sq0, h3tq5rkxiw)0:gz/7 lyh7ip jox speed for the trip?

  An airplane travels at 300 mi/h south9eh)h9k3qp * aqd*z cq for 2.00 h and then at 250 mi/h north for 750 miles. What is the average speed for theak9* 3)* e9qqqhdphz c trip?

  In a 400-m relay race the anchorman (the person who runs the last 100 m) for tjn qvf7( q1n yl i.i:wq1a86jleam A can run 100 m in 9.8 s. His rival, the anchorman for team B, can cover 100 m in 10.1 s. What is the largest lead the team B runner can have when the team A runner starts the final leg of the race, in order that the team A runner nfj1a.qlq( ylq781j6i :nv wniot lose the race?

  A car decelerates uniformly and comes + fco;xv4)5 nxixudtf+6 r gs g:zwjor9, oj+4to a stop after 11 s. The car's average velocity during deceleration was 53 km/h. Whagx+r z dc; ogr ot+4x9: j visnjw,54)6ff+uoxt was the car's deceleration while slowing down?

  An airplane increases its speed from 100 m/s to 160 m/s, at the average ratbej-ipo7 *.l ye of .*7pj el oi-by$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h acceec3 apdag7 y2)t1i;cxlerates 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 and accelerates atk:d ml-o qh2:z $4.0 \; m/s^2$ 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 l3om1,pnizgr 9/8x nxbzb2 oj0- lp,zup with a constant acceleration o nbnz,98ozr x3l z2x-b/1o ,gplmj0i pf $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 4.5 m/s experiences a 5g35ed8rxm3nwj7h ig constant acceleration ofwg 7d3 5m8hgexnr5j3i $1.1 \; m/s^2$. What is the cart's displacement during the first 5.1 s of its motion?

  A bullet moving horizontally to the right (+x direction) with a speed:tmal1xgq4:8s/ t izw of 368 m/s strikes a sandbag and penetrates a distance of 48.54wta : zxqm s:814g/itl cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launc1 ln61cb g hxn,:duu0zhqlh g.cwx,8:hed from a catapult on an aircraft 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 catapultx6hwnnquh:c :dl,zx c1ggl0b8h . u1 ,?

  A car starting from rest moves with constant acceler-ybmzw* .j e 7vznv/.jation 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. Whatb d+pu3a9-k.wih cjd ) is its average acceh3+ wabd)p -i .ujd9ckleration?

  An object starts from rest and undergoes 5( dqcwq.;5it0j s uyquniform acceleration. During the first second it travels 4.0 m. How far wilw ju.qcdiq s5(5tyq; 0l it travel during the third second?

  An object is moving in a straight line with*+yvz 5v(:ouhbczjnm9z a* e2 constant acceleration. Initially it is traveling at 16 m/s. Three seconds later it is traveling at 10 m/s. How farm5avu+*2hj v y onecz(z9b:z* does it move during this time?

  A car starts from rest63)lgc:bs ozyi s )d oedk,dc//i6z3k 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 road can decele(3foiw1ws zt *rate 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 hg( uox v9bn2,pas been waiting at the intersection starts ahead with a constant ac vg px(,ub2on9celeration 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 upf(q,nys-a c8 jqhr8c3ward with a speed of 12 m/s on the surface of planet X where the acceleration due to gravif3cns,h 88 cy-jaq rq(ty 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 plauz,j +umys;txwl:to 9 .* c()rzkc 5fsnet X where th) x l+9s:z( uc.mt5kyc roj* tu,fzw;se 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 / xpj6tr1x- qlm/s on the surface of planet X where q/rpt 16x-xj lthe acceleration 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 hkn...o;2br)v ezoe h3ua0mk mof- q5m/s on the surface of planet X where the acceleration df3 )he.5ebrm.khuma0vn oo;2- zqok . ue 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 your friend hkofpc +a0 cuen21 -.cuolds a ruler between your fingers and releases it without warning, how far canc01up e2cu.no fc-a+k you expect the ruler to fall before you catch it?

  A ball is thrown upward at a velocity of ;bc o.e(z n.0 aczbx5m19.6 m/s. What is its velocity after 3.00 b5 ;n z.cxbacozme0 (.s?

  A bullet shot straight up returns/q(dffweqi52 to its starting point in 14 s. What is the initial speed of the bw2q(qf5/ idef ullet?

  A ball is thrown straight up with a spej;bvbh2wo9eo:+qn p3ed of 36.0 m/s. How long does it take to return qnp:+oo 92bv;ejh3bwto its starting point?

  A ball is thrown downward lghtxm5;bzt39 q-c,f from the top of a building with an initial speed of 27 m/s. It strikzt 9x,5g ;btqhcmf- 3les the ground after 7.0 s. How high is the building?

  A ball is thrown straight ifiyxwu vlbx 86g7-+6 up with a speed of 30 m/s. (only fill in numerical value in 6 8yf+v xxwi biu7g-6lthe 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 straight up inu8+x/5 ;bfrxpijol;tto the air with a speed of 43.5 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 9 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 9.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is the velocity at t = 1mf.* o+q5whke .0 s?

  In Fig. below, what is the ve* y87 /pyh8jlutp5sqh locity at t = 2.5 s?

  In Fig. below, what is the velk1jvgp*;d) db x24 vno tn6e.yocity at t = 4.0 s?

  In Fig. below, what is thenv(rrsj1i, 5y velocity at t = 5.5 s?

  In Fig. below, what is t5j4d)a7kc idshe average velocity from 0 to 4.0 s?

  In Fig. below, what is the average velocityd5x;qm bwfe o) )ys8 lmhri736 from 0 to 6.0 s?

  In Fig. below, what is the a 4.n /pf 3m:up/mqkkmmr w5e7zcceleration at 1.0 s?

  In Fig. below, what is the acceleratiog.-d;(dg vmy 6,hvb qkn at 3.0 s?

  In Fig. below, what is the average acceleration from 0 to 5.0 sf3w8;z*ag)j -bi/yyddmgj7 x ?

  In Fig. below, what is the average acceleration from 0 tov5fhm ;o m0)om 8.0 s?

  In Fig. below, what is the a: ldc6g)05k *n: :dwhdb mvbycx v(i0displacement from 0 to 8.0 s?

Does a car speedometer measure spe55b,k x;oumtjxrvh (kw+l*1d ed, velocity? {speed|velocity}

  An object can have a va0dbnv4ioo ja6r 5q0(grying speed if its velocity is constant.

  The velocity of an object can be negative99sl-wa,e ef7yvmvb; when its acceleration is positive.

  If one object has a greater speed than a second ojf9).gcv9,g u; s ewsgbject, the first must have a greater accelerac,g js.9vu ;egg)s9 fwtion.

  Two cars emerge side by side from a tunnel. Car A is trade9ysj6d.c 7cz9 btl )veling 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 accelevkswx; 69yr/sih y yj6 k:2a*zration decreases.

  A baseball player hits a foul ballqu2l: 3mo 1m7y0w tapj straight up into the air. It leaves the bat with 2m7up:yotq 0a3 jml1 wa 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 is happening to 6x) 52gmmjskar 6yzc. 70rj m;oj-no dits acceleration, how does it change if air friction is ignor ordr nm.z);s-j 2m6 6jxa0mcj5kgy7 oed?

  As a freely falling object speeds up, what is happening to its acceleration,uh3 c6/ ,lr2 gsxr5kahhdw): 7uqyt ,p how does it change if air frictiohklcrx u uw):ay h6, qg spd7,t3h5r2/n CAN NOT be ignored?

  An object that is thrown vertically upward will retog8k10x4 3ifc dp ktm.urn to its original position with the same speed as it had initially if air resistance is negligible. If air resi0.xgdo34ct f 18ip mkkstance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzero acceleration qa6qc*in8 3r66 mmos jat the same time.

  An object can have nonzero velocity 1gazbpag ;*3h and zero acceleration at the same time.

  An elevator moving from the sb(q)gltj4giq ,)kt l /econd floor to the fifth floor making no stops along the way has zero accele)(ikjbqg 4q /tgll) t,ration all the time.

  A rolling ball moves fr/uxua m0g +zp)il5i .vom $x_1=2.5 \mathrm{~cm}$ to $x_2=-7.2 \mathrm{~cm}$ during the time from $t_1=1.2 \mathrm{~s}$ to $t_2=5.6 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-3.8 \mathrm{~s}$ is at $x_1=3.1 \mathrm{~cm}$ and at $t_2=3.6 \mathrm{~s}$ is at $x_2=7.8 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight co:x 7z0isap3gc mplete laps around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 8.1 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 115 m away id/rg+q / qw,gnn 11.4 s. It then turns abruptly and gallops halfway back in 4.6 s. Calculate ( gq r,gq/dw+n/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 fromi6f,5uan4+zi kf zv 6g $12 \; m/s$ to $23 \; m/s$ in 4.9 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 from9qy*gq ro:bd;) (bsxupe)el 1 $15 \; m/s$ to rest in a distance of 59 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a speny ix*qee7x (f37hx )ted of $32 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.1 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of the blocks to essentially t8pom5a: vi(mv3ob /kaop speed about km/:o(ibv 8mvp 5ao a3$11.1 \; m/s$ in the first 11.8 m of the race. What is the average acceleration of this sprinter?  (数值)  $m/s^2$ and how long does it take her to reach that speed?  (数值)  $s$

  A car slows down uniformly from a speed og. h/js- a.u6+yt vqpsh;/lz.p (dzo pf $20 \; m/s$ to rest in 4.75 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 the highw18af*,e rqfnx0 q e0 g7mn.y4kit5 mxnay. Assuming a d.,fge0n* t0 7qn k1rm8xf4qyn5ameixeceleration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck going ) e26,,zyu) ,9l aend0msxlqpm 4xlnx$25 \; m/s$ 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).    $m$