Suppose that an object travels from one point in space to zw8l6fkz)e 6nanother. Make a comparison between the displacement andz8kfe)6wlzn6 the distance traveled.

  When is the average velocity of an oh-*0yqq7i:spoi. *e o(bzw xwbject equal to the instantaneous velocity?

  A new car manufacturer adv4bae 0e+z4e aaertises that their car can go "from zero to sixty in 8 s". This is a des044zaeb +ae aecription of

  An object moving in the +x axis experiences an x6gr.hr 53kda acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the Eax1, g:8bnx d40wfngrrst (+x direction) begins to slow down as it approaches a traffic light. Make a statement concerning its accx,d x1 fgngrn04b 8wr:eleration.

  Suppose that a car traveling to the West (-x direction) begins to slow d hq)u1u6)y8b k )m/;rbt genffown as it approaches a traffic light. Make a statement concerning itsu1;qfh nybkg mu/r6e)t b)f)8 acceleration.

  Suppose that an object is moving witgk6-wkf kfw6+cjisv:;h b7: qh a constant velocity. Make a statement concekf-w6v wqb6h+i7:jcfg;:s kk rning its acceleration.

  If the velocity of an object is zero, does it mean tha4upuj ldj+*ps6kw w 1vk tc7:9t the acceleration is zero? Support y6:9t+cjjlw4*vk1 uwp k7pus dour answer with an example.

  Can an object's velocity change direction crjp ,/;fou tq.9vg/ ,cp42qk,toc ztwhen its acceleration is constant? Support your ans g4 ujrt9t;qv,c, o/kf2 qcpc,o /zt.pwer with an example.

  Suppose that an object is moving with constany mnp.x6d3 +ajt acceleration. Make a statement concxnpj. am 36y+derning its motion with respect to time.

  Can an object have inckvjxy6 r,sj; 7sim-p( reasing speed while its acceleration is decreasing? Support your answ yj-7m ikrj( p,;svx6ser with an example.

  Suppose a can, after an initial kick, moves up alobjk ,h r)uqhsvt*; 4b4ng a smooth hill of ice. Make a stv ) rq; hbk*b4t,uhs4jatement concerning its acceleration.

  Under what condition is average velocity equal tkm cx1d ,if/5lk 4lgok0lbr20 o the average of the object's initial5irklkkcx2lm/ 1 4ol 0bf,0g d and final velocity?

  Objects A and B both start at rest. They both accelerate at the same rat2wxg,bd oq :s grp )g*u.rt63he. However, object A accelerates for twice the time as obpt.hr3u* s, ) :g6wqgor g2dxbject B. What is the final speed of object A compared to that of object B?

  Objects A and B both start from resp+ z,gs kuhj,2t. They both accelerate at the same rate. However, object A accelerates for twice the time as object B. What is the distance traveled by object A ujghp+,2k s ,zcompared to that of object B?

  When an object is released 3t*gq.bfc+v w from rest and falls in the absence of friction, which of the followin+g f bcwq3*v.tg is true concerning its motion?

  When an object is released from rest and falls in the absence of frictio*k( pw t df4wwq6l4anfor vv:c*4q(l3n, which of the following is true concerwv6:qf4 tlnl4okwr3 (f**d ( ca pqv4wning its motion?

  Suppose a ball is thrown straight up. Make a statement about the velocity a22v2 ) sn,9lm klrpissarq 874umb0h cnd thkslnh m 27)b ir4cssp08 u9,lrmaqv2 2e acceleration when the ball reaches the highest point.

  Suppose a ball is thrown straight up. What is its acceleration just befor*v +dsa)*kv y3xs1 3ciecu+ore it reaches its highest po ir* 3x +do)va3ckv1s eusy*+cint?

  Suppose a ball is thrown straight up, reaches a maximum height, then falls xwh2lo *6bwrg .7yg9ito its initial height. Make a statement about the direction of the velocity and acceleration as thew9i w 2h 7rg6gyo.*xlb ball is going up.

  A ball is thrown straight up, reaches a maxi x41hw;n tefm;mum height, then falls to its initial height.h;m 1xwt ef;4n Make a statement 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. Make 6zp k7zqqgi-(p8rfn +a statement concerning its az7 p-q( nqirpzg6+8 fkcceleration.

  Suppose a skydiver jumps from a high-flying plane. What is her acceleration whekd*njw;hds2,aq3 .r1z z6azsp3 x gncu p5;4 nn she she reaches terminal ves,n;d q3r. 53aazn xjsw dpzu4k1*nzpg6 h;2clocity?

  A ball is thrown vertically upward with a speed v. An idenki m, v54,q-g ek2brobtical 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 bal eb kmg-5ioqvk,4,2 rbl? (How many times higher does the second ball go than the first ball?)

  Ball A is dropped from the t80h20wj9hmuqco k-jw ;x rjr1op of a building. One second later, ball B is dropped from the same building. As time progresses, the distance between;8w2-0 ockjuhq 1jh0rjxmw r9 them

  Ball A is dropped from the top of a building. One second later, ball B yh f5/f:izae 0but:9v:e u1 mvis dropped from the same building. As time progtu0azef vv9/1y:b 5 iehfm: u:resses, the difference in their speeds

  Two objects are thrown from the top of a tall building. One is thh/blo(k ,z2)zp b6:t+ ht) octvdbym.rown up, and the other is thrown down, both with the samehyokb,z)z. l2( bt 6)o t/vtmdcbhp+: initial speed. What are their speeds when they hit the street?

  A brick is dropped from the top of a building. A second brick is te 87f7m9jldsnz( 9tnu hrown straight down from the same building. They are released at the same time. Neglect air resistance. Compare the accelerations of the two bricks 7lj (f9uenn9t 7zs8md.

  An object is moving with constanisrpx ) sa8 sfr)d4j44q5a3*jn,n o hct non-zero velocity in the +x axis. The position s,*j 43cspdir)jf45)4qrn8aaonxh s versus time graph of this object is

  An object is moving with constant non-zero accel7/6rtkia0qz.(;psqx lloy y(eration in the +x axis. The position versus time graph llza q0;oqy6/. (xyips(r kt7 of this object is

  An object is moving with constant nocmw(npyn2hz4t z9:v 8+o/ olbn-zero velocity in the +x axis. The velocity versus time graph of this objw v2(zp o4+nzt9:cn 8b/lho ymect is

  An object is moving with constant non-zero acceleration in the +x axis. *poyp h:8* gpo The velocity versus time graph op g*8: oppohy*f this object is

  The slope of a position versus time graph r*3nkxx 6/2g6zbnw wf gives

  The slope of a velocity versus tbqtnps2 p-9di3 m ,8rcime graph gives

  The area under a curve in an acceleratiq(atl7nr5x7 iji3 : i6zd1bgs on versus time graph gives

  The area under a curve in a velocity ve.uo27 *snys.x 2mtjqc,dmk )xd7o t8 xrsus time graph gives

  If the position versl-uza4 +i( pnsus time graph of an object is a horizontal line, the object -pnzlu+4 sai(is

  If the position versus time graph of an objed6ui+, x jrw1kct is a vertical line, the object is+x uj1kwrid6,

  If the velocity versus :. t:aqnk ft8on ra.-1o 6njdvqb55pytime graph of an object is a horizontal line, the object bo:ry8ptjq5 -5qnf.:. d a1kntavon 6 is

  If the velocity versus time graph of an object isfw ;+a q 0rbrv(9a2wqht(tq5t a straight line making an angle of 30 degrea;wv ftrqrw ha2b(5t0 +qt( 9qes with the time axis, the object is

  An object moves 15.0 m north anp i3;j iz/dfwvr+(7h jd then 11.0 m south. Find both the distance traveled and the magnitude of the di/ jiv3rphw ;(+ 7zfijdsplacement vector.

  A boat can move at 30 km/h in still water. How long will it take tq:(c3o sqnet 2t 0n(pto move 12 km upstream in a river flowing 6t0( qe3pq2(c n :nttso.0 km/h?

  55 mi/h is how many m/s? (1 waonq3tu ljc6 :w:-eiswre o-u f)-1l0hyx9 0mi = 1609 m)

  What must be your average speed in order to travel 350 km in zl8 w ;gba8yjkqw91 )b5.15 h?

  A runner ran the marathon (approxismpf9ru 7+onnuc :j u8:0) pg* w.vqhamately 42.0 km) in 2 hours and 57 min. What is thvo:0prfm:a qp*u.c +u)hgn7 s 98wjnu e average speed of the runner in m/s?

  A car travels 90 km/h. How long does it take for it to travel 4+2ot84k; :aditk:ahg4kp kji00 km?

  A ly (light year) is the dist iirw*6 ayw/+tance that light travels in one year. The speed of light yi6wa/ t+*w riis $3.00 \times 10^8 \; m/s$. 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 st s(o 5cq8i3wkgw/)v wgraight road and you look to the side for 4.0 s, how far do you travel during this inattentiv5w/ kows8w cvi)q3g(g e period?

  If you run a complete loop around an outdoor track (400 m), in 1fg b,w*y7qnb*00 s, your average velocbg wynqb 7f,**ity is

  A polar bear starts at the North Pole. Iterhe+lq:0 *tby o1 7uc travels 1.0 km south, then 1.0 km east, te7oq+*bcre y0tu:l 1hhen 1.0 km north, then 1.0 km west to return 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 1dxv8e8+cp n9qa)hc6 l .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 the bea) q+nc9hea6cpd8v xl8 r's average velocity?

  You are driving home on a weekend from school at 55 mi/h for 110 miles. It 6 gepd bpxmnym*k. ,k6+--uhuthen starts to snow and you slow to 35 mi/h. You arrivek6umpek-,ph+ 6* duxn-.m gb y 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. Whaszlv* t ny 1h:2it(ju-t is the average lutisj:y(v1 n*h tz-2speed of the motorist for this trip?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h at 10wtk2.vs1h- lb 0 km/h. What is her average speed fot wbk .l-1vs2hr the trip?

  An airplane travels at 3002b2tb2d/jktu tl0, yp mi/h south for 2.00 h and then at 250 mi/h north for 7500u d2t2kljybtpbt 2/, miles. What is the average speed for the trip?

  In a 400-m relay race the anchorman (the person who runs the lastviray1mtdf ) /d6 no(( 100 m) for tea y at )/divr(6on1d(mfm 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 not lose the race?

  A car decelerates uniformly and comes to a stop after 14 s. The car's average v7jmg he45ryy-4bm; myelocity during deceleration was 56 km/h. What was the car's decejyymy-h;5 m4g r emb47leration while slowing down?

  An airplane increases its speed from 100 m/s to 160 m/s, atofio8w+in eo 2+xtg:1im /r-i the average rate of -e8 onwom fi21 rg/it+o +xii:$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 kmvz6l u1sf;tjgw8 )0 6npy ev)v. (rigp/h 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 d6u i zskbstcm yubn20( e5x4v:(4b*xand 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 w qim gw89kg0yvx5z 50qith a constant acceleratioq9x m50gy5w80i zgkqvn of $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velqo6pu8 ,t,4sagg 6q6-sod tgzf- 1njf ocity of 5.2 m/s experiences a constant acceleration ofjpz- tsua- gqnq81os6f,t46g,f d go6 $4.0 \; m/s^2$. What is the cart's displacement during the first 6.0 s of its motion?

  A bullet moving horizontally to the rxvzeuv;4 w 2x;ight (+x direction) with a speed of 576 m/s strikes a sandbag and penetrates a distance of 29.53 cm. What is the average acceleration, invxz2u4 w vxe;; $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on an aircraft carrier. Itsz/pr r1tk;/: g9m-xb, kbfmq 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 catapupkmbmtq/;s b-:k9,x /rgz rf1lt?

  A car starting from rest moves with cons1op)dwsqiasd6 z5a +-tant 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 average 9va)ayxgu .5e )d2)azw hw8xh acceaw5heaa)yzxudw2.h xv8g 9 ))leration?

  An object starts from rest and undnj,z46i1r4gjh0euj5 fg) m1 cikjss4;yej )j ergoes uniform acceleration. During the first sec),j4 jszychk) u1 g 6nijjj j4egi0re4;s 15fmond it travels 9.2 m. How far will it travel during the third second?

  An object is moving in a strn:rt-yk4zu ixym(; )1fno e(z aight line with constant acceleration. Initially it is traveling at 16 m/s. Three seconds later it is traveling at 10 m/s. How far does it move during this t-n(4yezmk f1 rty:)u;xo ( inzime?

  A car starts from rest and acceler mz)zlj3 )kksv 8mz7pm c,d4/v7c(qlk ates 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 deceler :r* efy ttm8micp5)1aate 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 v9.q(bv) wf((qv(xot*w hbb75 dorfhlight turns green, a car that has been waiting at the intersection starts ahead with a (d(fo) 5r(7h*hqf ob( vbwvvqx9.wt bconstant 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 spei8i0 vjk:w:2 y p*py7mfdl/54n bhmnh ed of 12 m/s on the surface of planet X where the acceleration due to: kymlwbp2pji :vh/ 4d8yn*m7fih5 0n gravity is $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown upwardvlkl:2:z9ocejg5 - ba with a speed of 12 m/s on the surface of planet X where the accelerat9j:ogk25 c vl:b-ezlaion 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 spe okn5xj; 5.sh2 i2mbkhed of 15 m/s on the surface of planet X where the ak. khoj hm5bi252s xn;cceleration 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 alr/+p:chw0zmu 6zel;dl tlg :je) /2z speed of 14 m/s on the surface of planet X where the acceleration due to gravity isrch/llm);le0 +zj/6:t2d l: egupzwz $3.5 \; m/s^2$. What is the speed of the object after 8.0 s?

  Human reaction time is usually greater than 0jcpy/9t6ne :-r h* z*ytub.va.10 s. If your friend holds a ruler between ub*r.jyv6h9pcn * y t:-eazt/your fingers and releases it without warning, how far can you expect the ruler to fall before you catch it?

  A ball is thrown upward at jfq 7xezc 3ow ; 2sdlsu)d9)8adl-a:xa velocity of 19.6 m/s. What is its velocity after 3.00 s?a c;qzfl23d xd :)sw-dlu8)o9ea x7sj

  A bullet shot straight up retur 3h ae952o6ivl3web urns to its starting point in 4 s. What is the initial speed of the bull3oeew2vb ai9u rl563het?

  A ball is thrown straight up with a speed of 36.0 m/s. How long does itmcuurnhe:.fc84z /ko9+ +2 : oqdciog take to return to its starting pocgm:+8dnqz : 2cfr9ui/ho 4 u c.eo+okint?

  A ball is thrown downward from tloqlb58v w zjc,i)74vy t3u0lhe top of a building with an initial speed of 14 m/s. It strik b4l5tl 7wquz) v, oyc3lji8v0es the ground after 3.4 s. How high is the building?

  A ball is thrown straiil8azkja1j;29lk4 zqlzr:0i ght up with a speed of 30 m/s. (only fill in numerical value in the b4 k12qlja8:zai0 kz;9jll ir zlanks)
(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 y:1dvmhf 6.y h;pivi2air with a speed of 29.7 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 3 seconds later.  (数值)  $m/s$
(e.) Determine the time at which the ball pass a point 6 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 6.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is the velocity atf1o8ow2f1,io v ep -cz t = 1.0 s?

  In Fig. below, what is th+b4:u 4 alvgq(axpi8 ue velocity at t = 2.5 s?

  In Fig. below, what is the velocity at t 0z / 6b .h5zdka3k0lf) dyfsbs1p9i eu= 4.0 s?

  In Fig. below, what is the velocgj/*9y-u y hility at t = 5.5 s?

  In Fig. below, what is the average velocity from 0 to 4.0 s;s 3o2a3pj x3y x.kxvi?

  In Fig. below, what is the 1:6mpsbj /fd baverage velocity from 0 to 6.0 s?

  In Fig. below, what is the accele +r )fke7tlct zx0jw)4 77psekz .xqa+ration at 1.0 s?

  In Fig. below, what is the acceleration acdow xx e(2, 7n-j.vuue)snhw2g0lo1t 3.0 s?

  In Fig. below, what is the average v.*f( g+ftrruacceleration from 0 to 5.0 s?

  In Fig. below, what is th0 w6z9iufu vcg 6d+gd2czet,/ e average acceleration from 0 to 8.0 s?

  In Fig. below, what is :spps(:ms w hn/ 5gsoa/z8z2wthe displacement from 0 to 8.0 s?

Does a car speedometer measure speed, velocity? {speep/em 76 znax.zd|velocity}

  An object can have a vah ux7s:/wa r(wud( ,fnp )8f)zosb j1prying speed if its velocity is constant.

  The velocity of an object can be negative when its acceleratioj,g g-m**bxj kwxd/y3tk74x ln is positive.

  If one object has a greater speed than a second obog*:zy a*0 g) rcrq7fbject, the first must have a greater acceleray c)r qr:baf 07g*gz*otion.

  Two cars emerge side by sid 6vtifq.kni3 k9jr2lmt/; +wm e from a tunnel. 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 accelerationn)2c*sk+; hs 9pbnr te decreases.

  A baseball player hits a foul ball straight up into the air. It leaves the bat4k* w3j,g ncsl with3 ,wnj kl*sg4c 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 upzbv-aqip4g qducr 9,9 4 /8oerftysgs4 u8x,2, what is happening to its acceleration, how does it change if air friction is ignored?8,g 4qu9 xg4 edto4aq- iyvs/8fp9 r2b, cruzs

  As a freely falling object speeds up, what is happening to its accelerjl w+r3vaht1-* w.8g * pexzqration, how does it change if air friction CAN NOT ber *xh .e 3aqpvw1ltg*8rwzj+- ignored?

  An object that is thrown vertically upward will q2i6,7 z 93vir eqhscs cfm6g7return to its original position with the same speed as it had initially if air resistance is negligible. If air ree7 zcri6 cmgq3h6qs7siv f 92,sistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzero acceleration at the same time.(dct g;w7l/ icg*m-wrv2mi,b

  An object can have nonzero velocity and zero acceleration at the same timkhanr,+h;xk :e.

  An elevator moving from the second floor to the fifth floor making no stops al of2jo3 o6yfl5ong the way haj3ol2fo 5o fy6s zero acceleration all the time.

  A rolling ball moves from 5vsr mf ;0e/ti$x_1=3.0 \mathrm{~cm}$ to $x_2=-4.5 \mathrm{~cm}$ during the time from $t_1=1.5 \mathrm{~s}$ to $t_2=5.8 \mathrm{~s}$. 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 $x_1=2.7 \mathrm{~cm}$ and at $t_2=3.2 \mathrm{~s}$ is at $x_2=7.9 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps around a quarteo+. u yzp0l) /ixuua:vr-mile ($1 \; mile = 1609 \; m$) track in a total time of 7.0 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;h5zdhf( b7 a,mvc u9y 89 m away in 12.9 s. It the hfh(vzab mdu,;7y59cn 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 from8so,hyfx zm az-rl ;-aojr)2rn .-.s l $13 \; m/s$ to $23 \; m/s$ in 4.6 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 gh aa:-d;wtwf/5ab *g $19 \; m/s$ to rest in a distance of 74 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a speed ofhkoiy3mh )caw 44+g d( $31 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.3 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of the blocks to essentially top u xuzwi 0,vm825i xcs/speed aboutucw,i0v 2x us i5/xz8m $10.3 \; m/s$ in the first 12.3 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 w0,unm2p skl8of $18 \; m/s$ to rest in 4.72 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves skid marks 92 m log.ddq ( 19wkctng on the highway. Assuming a gkw .1(dtdc9q 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 h vyf;5ic0-haoing $25 \; m/s$ 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. Auiv x 68ro kdplg )uh )7ge8i2c4r7ap3fter exactly 27.0 min, there are still 1100 m to go. The runner must then accelerat cg)v)2rig6u7x4h ulp 8de ko38pra7ie at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$