Suppose that an object travels from one px5gzm*ex hchi y()c.( oint in space to another. Make a comparison between thg(c*z 5cemxxih(h.y) e displacement and the distance traveled.

  When is the average velocity of an object equal to the instantriv :k9 nfq 4/dwbvu6(aneous velocity?

  A new car manufacturer advevsh*foko1t5j)m- t, p rtises that their car can go "from zero to sixty in 8 s". This is tmjpv -,*kf 1oo)h5ts a description of

  An object moving in the +x axa n,tv;0 qmh x-y3dbh/is experiences 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 slhvbf m 4l6g,a3 1.cbbdy v6d4dow down as it approacd v3b6a g4ylb,bd4.1vdmfh 6ches a traffic light. Make a statement concerning its acceleration.

  Suppose that a car traveling to the West (-x directirh+q yx 63zynj .z40wg/(xec don) begins to slow down as it approaches a traffic light. Make a statement concerning its acce6 /qrjzzgw04 (+ x 3enxhy.ydcleration.

  Suppose that an object is moving with a constant velocity. Make a statev- rtw (piit4 k-so4z,ment concern,t4rok( w- i-ipt4z vsing its acceleration.

  If the velocity of an object is zero, does it o.m boaqq95 5imean that the acceleration is zero? Su omiq95qab 5o.pport your answer with an example.

  Can an object's velocity chan;g:5:f7we hk/6afbt cj meeh9ge direction when its acceleration is constant? Supp7f h; fa6/:emeew :k tg95hjbcort your answer with an example.

  Suppose that an object is moving with constant acceleration. Make a uz;znaks.6z 9vel 34 ved6 et5 statement concerning its motion with respece354nluzsez a etv.;d6k 96z vt to time.

  Can an object have incr cueyot2z x25 byoo752io4)ko easing speed while its acceleration is decreasing? Support your answerk24 2o7z 5o)tio5eybco ouxy 2 with an example.

  Suppose a can, after an4jflbins+mbianb:9z -+o0 x- initial kick, moves up along a smooth hill of ice. Make a statement com 0 olabx+4i9 si+n-fbjn:- bzncerning its acceleration.

  Under what condition is average velocity equal to the average of the object4czy6pp/,o5i l* dggc's initi6zo l*pg5pg/ ,diy4c cal and final velocity?

  Objects A and B both start at rest. They bot1n m;j+8 a)0 0z-jbdcjxu ezfph accelerate at the same rate. However, object A accelerates for twice the time as+0jj 1 czx-)epu nbafm0zd;j8 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 accelerq pdfsul +/2nezqa10nge8* gd u8m (0eate at the same rate. However, object A ae/zd8euql1 qfe *u(a 2+g0pd8 snmg0nccelerates for twice 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 f -ssdv6t:19cb4k )sq)ao def in the absence of friction, which os 4 d)e9:ck-t vads1boqf )f6sf the following is true concerning its motion?

  When an object is released from rest and falls in the absence of fri4;: o,u xfsnig)iz ev;sulti8)c;4 lpction, which of the following is true con x :)s cpiin,e;4l)84l;ugs;vfiout z cerning its motion?

  Suppose a ball is thrown straight up. Make a statement about the velocity and c.kssu7m:h ik wt u du4q0rk+f( t2g/-the acceleration when tdtu(uk47kq+. 2c f /is:h t0mksrwg- uhe ball reaches the highest point.

  Suppose a ball is thrown0 ,etlwa vv7af1 xr:1d 5uwm9j straight up. What is its acceleration just before it reaches itd9mf:7x ,at1vwelwu1 vj0a r5s highest point?

  Suppose a ball is thrown straight up, reaches a maximum height, then falls to itbv4dpu2o 19k yg .c xm6m87rfps initial height. Make a statement about the direction v1p4 gbcu9rk my.872 doxm6pfof the velocity and acceleration as the ball is going up.

  A ball is thrown straight up, reaches a maximumoklq- gtr) g:p: rg-3v height, then falls to its initial height. Make a statement abourgt3g-:v kglo-p :) qrt the direction of the velocity and acceleration as the ball is coming down.

  Suppose a ball is thrown downward i/v,pk29:buys cviu en n/ y *hmcf 6nzt,pp59*n the absence of air resistance. Make a state/*,6unm n*u5p9hc9: ty znv/ eifkbyc2sp p,v ment concerning its acceleration.

  Suppose a skydiver jumps from a high-flying pq cg22y ),j pwly)nw sj5*umg-ycp ;-wlane. What is her acceleration when she she reaches terminal vwg* c pq-wyc yw)ps u22nl)-5 ,;ygjjmelocity?

  A ball is thrown vertically upward with a speed v. An identicbsijf .a;o1h6 dytf(,3 lp0ckal second ball is thrown upward with a speedcy1t ( i36,;sjdfpahkf .obl0 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 laiphpl j0 bvm)ma0usj7m :5+c3ter, ball B is dropped from the same building. As time progre j 0p 7+3)p0:mmlaishubj5 mvcsses, the distance between them

  Ball A is dropped from the top of a building. One second later, bara vm9y(/nwn+8mg,mzs26rgb xh + w1u ll B is dropped from the same building. As time progresses, the differzr8+ wb6 g mn,x vr9gmnya1hsw( /u+2mence in their speeds

  Two objects are thrown from the top of a tall building. cz) ers jl8(pbl22ds1 One is thrown up, and the other is thrown down, both with the same initial speedle81b2sz)cs( j lrd2p . What are their speeds when they hit the street?

  A brick is dropped from the top of a building. A second ( h elo)6qx b)jtj1;anbrick is thrown straight down from the same building. Thxjb1l qhon;ej )(6 a)tey are released at the same time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with cjjwn2xo 6z:;gonstant non-zero velocity in the +x axis. The position :no;x6j2gjzw versus time graph of this object is

  An object is moving with cor4),ao8yz mclnstant non-zero acceleration in the +x axis. The position versus time graph of zy)c,m l4ora8 this object is

  An object is moving with constant non-zero velocity inhb9i.-lnuhu,v 1) jpse t9r7n the +x axis. The velocityib v-e 1utn7h j9,.sn9uh)prl versus time graph of this object is

  An object is moving with constcbbk )6uls ai)1b/ty: ant non-zero acceleration in the +x axis. The velocity versus time c)ily:1s /6) bbk aubtgraph of this object is

  The slope of a position vers+ + 3lawgxoq77 gh3evjus time graph gives

  The slope of a velocity versus time graphnsqprx0 -cb3 ; gives

  The area under a curve in an acceleration 5zrjk.e3:s us d9mc0x versus time graph gives

  The area under a curve in a velocity versus time graph give,d m8js8w*hd5n4q hpb s

  If the position versus time graph of an object:rg:obv 6q/bw is a horizontal line, the object iswr/:ogbv 6 bq:

  If the position versus time graph of an object is a vertical p vf7u 53df:ww9s5k;;i eegtyline, the object isp d;wfyw st7ufek5:3vig 9 e;5

  If the velocity versus9;gkxp ig3ky2+ef2v63 lld j(6 vbvtp time graph of an object is a horizontal line, the object 962gjkt felpy3d 62(i v3vglxpkv +b; is

  If the velocity versus time graph of an , wl/:csix e10p 7aahdq;j p/fb5d r3gxr)4hrobject is a straight line making an angle of 30 dhr b0dh5w;gl,ir c q7dx4/3:raajs)/pxe 1p fegrees with the time axis, the object is

  An object moves 15.0 m north and then 11.0 7km ck+w7a 5wno8(3b ui0jsdu m south. Find both the distance traveled and the 7k 8j75sdkin0+wmu(w cou ba3magnitude of the displacement vector.

  A boat can move at 30 km/h in still water. How long will it take to movwktpx2 5.2soee 12 km upstream in a r.e k5p2toxs 2wiver flowing 6.0 km/h?

  55 mi/h is how many m/s? (1 mi = 1i)eoa. pdhkgt8d 0a,j;x * ;dg609 m)

  What must be your average speed in order to travel 350 km in.gdz,iua d(p( 5.15 h?

  A runner ran the marathon (approximately 42.0 km) in ng gt k4+uiu(12 hours and 57 min. What is the average speed of the runner itu+gg ( kin1u4n m/s?

  A car travels 90 km/h. How long does it take for it to*a6z e3.g*e6qwu uige travel 400 km?

  A ly (light year) is the distance that light travels in one year. The speedi+s* of61):2k suu 5+nxh gsdbsufw3d of light is +u ssu*fx: wdn5)s +1ug oshdkbf26i3 $3.00 \times 10^8 \; m/s$. 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 tq ;wixco1i( /unfid., o the side for 4.0 s, how far do you travel duri ic1u.idnq (oif/x;w,ng this inattentive period?

  If you run a complete loop around an outdoor track (400 m), in 100 s, your averp3maz. yh:; yjage vel3 yzaj.y h;:pmocity is

  A polar bear starts at the North Pole. Iuzb:o.-qqj0uc98b, /noih cm t travels 1.0 km south, then 1.0 km east, then 1.0 km north, then 1.0i-o q 0.9nmuzuchjc/,qb:bo8 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 1.0 km south, then 1.0 k,f-b ymcgqr x73)9gs8ckn /p-o3i bifm east, then 1.0 km north, then 1.0 km west to return to its starting point. This 7 q-,-p n)3f/3m9gbkiyc8r ox cbs figtrip 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 y) ,fe-qmuu,n*,ezxcpg pljm/qd ,x /t *zf)*. It then starts to snow and you slow to 35 mi/h. You arrive home after driving 4 hours and 15 minutes. guzj mqtnlc,*d)p/zemeuyff-)x/, q*,*, xp 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 qdkop35 y*gj, the average speed of the motorist for this 53 dkgy *j,opqtrip?

  A motorist travels for 3.0 h at 8xc(ap3cd+lmi-ey25p m5v9 x9tz x 3kk0 km/h and 2.0 h at 100 km/h. What is her average speed fok9mlc5 xez pcy3a(9idvp -xk t5xm2+3r the trip?

  An airplane travels at 300 mi/h south for 2.0lf 0rt7p3ef. rb ;9aox0 h and then at 250 mi/h north for 7lr9f7o;x 3bp0rf. a et50 miles. What is the average speed for the trip?

  In a 400-m relay race the axektvk a7r 3;, sn)1b6jt9zgk nchorman (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 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,)kbt37v 1 gxskkzr;ena96 jt?

  A car decelerates uniformly and comes to a stop after 13 s. The caouqc nd9 f89 ) njpkp mjjgs/dg;8r1tx4 u:-p4r's average velocity during deceleratiodu) j4rmgpuc pn1kgs 8xqo-9j9;tnj4 :fpd 8 /n was 49 km/h. What was the car's deceleration while slowing down?

  An airplane increases its speed from 100 m/s to 160 m/s, at the av8g/qrfxo(r - rerage rate of 8-xr fr(gr /oq$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerates at thq -9q,ee wu0vae 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 reqqqi z26 rge-:/jzoc5q,c v6qst 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 with a constant acceler h.l2ot( gkh-, dgpvk1ation ov., t-hklo hd1p(gg k2f $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 4.2 m/s experiences a constant acceleratiopp7j:cv yo: k mblqn+kj2c55.lta4)wn ofk)b4c 7llk:pjajv +qc2p tyw5 m. :5no $2.4 \; m/s^2$. What is the cart's displacement during the first 7.3 s of its motion?

  A bullet moving horizontally to the right (+x direction)djzh3ldu5z; 17*xifc , //hza(l wjrv with a speed of 481 m/s strikes a hzald/dwz7fc3jz j/(h u, i;*l5v1xrsandbag and penetrates a distance of 49.24 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is lahjf1q.1 h1e 5 mobxd3aunched 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 accelerati.j f1ahhe 13bqm1x5do on is constant, what is the length of the catapult?

  A car starting from rest moves with constant acceleration of2pd idin.dm;e1 b)9c+,yc vl;xh,o 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 distance of 2 -az.dcoostn)4iyc1pu we4/ b23c s( j00 m. What is its average accelerationspaoi.to4(c2 / cc1 )w sbj4udnzey-3?

  An object starts from rest and undergoes uniformtu36wev )3dbf acceleration. During the first second it travels etf wudb63 )v37.0 m. How far will it travel during the third second?

  An object is moving in a straight line with constant acceleration. Initialgt17 rxs3i c.p;k+jb yly it ig xry7sj1tkpc. b3;+ is traveling at 16 m/s. Three seconds later it is traveling at 10 m/s. How far does it move during this time?

  A car starts from rest and ac kmlv6hrw.s9 -celerates 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 decehv ysmetw)tm4hr -zs0hi0v x;o(f9+3lerate 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 cc7+2 )icce )axeyd .fcar that has been waiting at the intersection starts ahefe2a .c)ci x)7+deyc cad 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/s on the surface of plan.eqmg(re-0 imet X where the ac-em r( eq.0mgiceleration 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 mzucrh acro-3i9v:9hmmo 5x+7 /s on the surface of planet X where the acceleration due to gru-ocr9:m3z9v mca 7+hi h5rxoavity 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 the surface rw7u,sgrdo -b ,:tt4 d6q2lvm of planet X where the acceleration due to gravityl64rq,d2b to,vr-wtsmu g :7d 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 spee4:x0b)rdn *n eeex 3ssd of 14 m/s on the surface of planet X where the acceleration due to gravity e3)0e xdne4xnsrbs*: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 yct(- ll1v t(vhour friend holds a ruler between your fingers and releases it without warning, how far can you expect the ruler to fl(-vt(lh t1cv all before you catch it?

  A ball is thrown upward at a velocity of 19.6q /x0pl56 hcym m/s. What is its velocity after 3.00 q/c0p5y 6mlhxs?

  A bullet shot straight up returns to its stnz ,svz 1+myl6l /tih)arting point in 17 s. What is the initial spitllhs /v1my,z 6zn) +eed of the bullet?

  A ball is thrown straight up with a speed of 36.0 m/slf: +l8g7 wc.c+ ppmcb. How long does it take to return to its starting poin:gclflb+ c.m78ppc +wt?

  A ball is thrown downward from tvc xpcsc* ud/60.l2v-8hu ib fhe top of a building with an initial speed of 25 m/s. Ifv.d8ch2x/ iu bp6vucl-*0cs t strikes the ground after 4.0 s. How high is the building?

  A ball is thrown straight up with a speed of 30 m/s. (only fill in numerp. fe 0,4pjjl o3dvy oo/dn7)nical value in the beon7 pj pv o3.n,jd/f0 y4do)llanks)
(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 air with a speem/v+r* lrhfss 0n*) cfd of 21.1 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 1 seconds later.  (数值)  $m/s$
(e.) Determine the time at which the ball pass a point 8 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 8.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is the velocity-v;oq d*ou l lip7:*lz at t = 1.0 s?

  In Fig. below, what 2ni/*k1mwly6x /orx; af gi /eis the velocity at t = 2.5 s?

  In Fig. below, what is the velocity at t = y wvckkn6zk zx269gw x:l:6d34.0 s?

  In Fig. below, what is a 5-mm; 8rlwu3h*bmqhthe velocity at t = 5.5 s?

  In Fig. below, what is the average velocity fruy4pz4jky,,epi y v11q j*/e.rf dc;uom 0 to 4.0 s?

  In Fig. below, what is4 1pol f.xc8vb the average velocity from 0 to 6.0 s?

  In Fig. below, what is the ac;5zvjz6 me c,neh/yx7 celeration at 1.0 s?

  In Fig. below, what is the acceleration at ontwg5oty5 z )52p1bk3.0 s?

  In Fig. below, what is the average accefbe/eex:bp 5 9leration from 0 to 5.0 s?

  In Fig. below, what is the average acceleration from 0 t15xl* p a(iun8xe7 dzdjh(5dgo 8.0 s?

  In Fig. below, what is the displacement from 0 to 8e v800ckjt9*fy2 ;an6dezfl1av)wek .0 s?

Does a car speedometer measure speed, ves:w136g 2zhhjl0ufc:xw3jv w locity? {speed|velocity}

  An object can have a varying speed if itnp 45-7lu4in8j fotc5 wkn ot,s velocity is constant.

  The velocity of an object can be negative when its ac5m(sw6w/yd/c(p dgx1tfn k 0qceleration is positive.

  If one object has a greater sgpkeln-ug9xk : 7t1 a3peed than a second object, the first must have a greatelg nkup3-9:tga 7 kex1r acceleration.

  Two cars emerge side by side from a tunnel. Car A is traveug.2dla; f9b(( mreteling 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 speex4f* ce/h4tves lci1 .d as its acceleration decreases.

  A baseball player hits a foul ball straight1dj+ 1 mrpzk ms3u3j8v up into the air. It leaves the bat with a spee1+ zp kr33dm81vjsjmud 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 its acceleration, how(iv nzv d72n(qb8xhldqb75yi gc.- b9 does it change if airqc 5y.7ndvbihz-vid72n 8x l((bgb9q friction is ignored?

  As a freely falling object speeds up, what is happening to t : ttuexo9dsi)4 2k8;d8ncdlits acceleration, how does it change if air fricnd xoes 4d8uk t)t89ct:;2d iltion CAN NOT be ignored?

  An object that is thrown vertically upward will return to its hbzx5/7w(y w:gyaya ak1isdy 9l:2: horiginal position with the say d7i z/ gxyb yywl25:(w:sa1hkah9 :ame 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 zero velocityukvat8/ dhcz )d;,uk;;k/ spt and nonzero acceleration at the same time.

  An object can have nonzero velocity and zero acceleration at th .x;pt98nece4/ 5djp )vyngtjt.in*fe same time.

  An elevator moving from the second floor to the fifth floor tw2maj5 yrb -+7nm tk,making no stops alongta5bmtj 2n -yk,+7wr m the way has zero acceleration all the time.

  A rolling ball movesm8crj/q cgc jblxw,4pe w- m)y jt1/3) from $x_1=2.9 \mathrm{~cm}$ to $x_2=-6.8 \mathrm{~cm}$ during the time from $t_1=1.1 \mathrm{~s}$ to $t_2=6.1 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-4.9 \mathrm{~s}$ is at $x_1=2.9 \mathrm{~cm}$ and at $t_2=3.7 \mathrm{~s}$ is at $x_2=8.4 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps ar/rqjdul:9 xut 6u wfo5 ;hi,v5ound a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 10.5 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,9z p knw:o.hq bsl1s:mlap3) 9 moving 109 m away in 13.7 s. It then turns abruptly and pw)s 3m ph:kzolbs 1:9na9 .qlgallops 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 fromv6 byn)jnlv 946m80cuago-u q $11 \; m/s$ to $23 \; m/s$ in 4.1 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 td j :mrde61yi68mq u4$22 \; m/s$ to rest in a distance of 61 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a speejhf8tilu: 3;yi0j+nfw o x8 1xd of $30 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.5 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of the blocks to essentida//eykpu)2 wally top speed about /y2w kp/au )de$10.9 \; m/s$ 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 from a shzsmf0.s7-p u peed of $18 \; m/s$ to rest in 5.63 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves ii px 1i voh-ec 0-we8+c7ii*tskid marks 92 m long on the highway. Assuming a deceleiw8t0chex1ic p*v-iioi -7 +eration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a trucnh0ix3gvm- s :k going $25 \; m/s$ 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 l+gt; *:axskpl0 q:u)f hvqn*the 10,000-m run in less than 30.0 min. After exactly 27.0 min, there are still 1100 m to go. The runner musgk+ 0qs*n q:havut;:ll)pf*x t then accelerate at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$