Suppose that an object travels from one point in space to another. Make a :/wnc qo5* qf0lqh,wgcomparison between the displacegoqn,cwqfl /0h5 qw:*ment and the distance traveled.

  When is the average velocity of an object equal to the instantaneous velociq9h kc57(m xbcty?

  A new car manufacturer advertises+*ls )(ncsnbz that their car can go "from zero to sixty in 8 s". This is a ds zl)*sn(b+ ncescription of

  An object moving in th66rzzqx8lkry 0v/.xne +x axis experiences an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x directio69 )8+gksuk/yvzkrtdlm s: k8n) begins to slow down as it approaches s6l:km+gst)kd y8kur8kz9/ v a traffic light. Make a statement concerning its acceleration.

  Suppose that a car traveling to the West (-x direixzu qz00+ 7nq hvbjp2sj( )5h -c3mpsction) begins to slow down as it appvc()5zqj7u s3xm 0p phb0s- z+hqnji2roaches a traffic light. Make a statement concerning its acceleration.

  Suppose that an object is moving with a constant velocity.zor*;5.t ;i pqjp9mbp Make a statement conpbpp z;j5ori tm*;.9qcerning its acceleration.

  If the velocity of an oc(2 vvycvh3g1c ,o5zvbject is zero, does it mean that the acceleration is zero? Support your answer with an exampl c,vzv(vc1ogh 32c 5vye.

  Can an object's velocity change direction when its acceleratio2 4v4l6b.8sv2 0hsfw a yvjwxnn is constant? Support your answer withayjsvx0fw2.bh2 4l s64vnw v 8 an example.

  Suppose that an object is moving with constant acceleration. Mayaj bix:lx 5z1(a om1vna6/8ake a statement concerning its motion with( n 5:lxv/i1 1za8ma baxaoy6j respect to time.

  Can an object have increasing speed while its acceleration is decreasing? j73tel6w ltjz as):x0Support your answew ejlla0s 7z):j3t 6txr with an example.

  Suppose a can, after an initial kick, moves up along a smooth hill oa0p4 qv1 tye6a8)rt 1vmx gy7ef ice. Make a statement cv8t4 7 qg6x1 ay0re)y1vpmteaoncerning its acceleration.

  Under what condition is average velocit*o5 l1 kd gnw3dbmv1;ny equal to the average of the object's initial and final 1 w35gmonkvd* dbl1;n velocity?

  Objects A and B both start at rest. Thqjs-:oi 8h-v udocwy 7ggsk7xy(6)5uflj27v ey both accelerate at the same rate. However, object A accelerates for twice the time as object B. What is the final s y- v7y jj2:gol(o87c5uss)h dx7wq k ivgu-6fpeed of object A compared to that of object B?

  Objects A and B both start from rest. They both accelerate at thx0ybqk (shmp 4w2wcvg 6 .8.qoe same rate. However, object A accelerates for twice the time as object B. What is the distance traveled by obje0( 6qw8 smyk2wxh.p.vcq4ob gct A compared to that of object B?

  When an object is released from rest and falls in thefmv.b h::; bsh7rse0b absence of friction, which of the following is true concerning itsh:;b bs:e7b. rv hmsf0 motion?

  When an object is released from rest and falls in thcq +.z 6aq mi/cxow:zch:mg3n;2 sqp5e absence of friction, which of the following is true concerning its motiha6 ccocqmz/ smi ;q2n3.5gzp :+wx:qon?

  Suppose a ball is thrown straight up. Make a statement a)vn/ 1 geyq; x5vo( yhq.oxm0cbout the velocity and the acceleration when the ball reaches the highest poinqy1o.5 v(ov eh/c0xmqy xg);nt.

  Suppose a ball is thrown straigtf5rz 0l- ;crn3o*h3m w+grl94 bqqoxht up. What is its acceleration just before it reaches itshll 34m*ot5w;3go nr 9z-c +rbfq0rqx highest point?

  Suppose a ball is thrown straight up, reaches a maximum height, then falls to ;gw*)oko4 sn scfv(a1,skh j sx,n5f6its initial height. Make a statement about the direction of the velocicos4s (,ws jnns6,v ko*fhf);k xg51aty and acceleration as the ball is going up.

  A ball is thrown straight up, reaches a maximum height, then falls to itdg .rxe:9aknumhfn34 t ipfs2z725p 7s initial hei. es2npkx:n5 af92z7 7pm4i guth3fd rght. 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. Mak4slerhzvb*iff4g v(p( * ;w9r e a statement concerning its accelewie ((vrz4f s4*;vhrf9lg*b pration.

  Suppose a skydiver jumps from a high-flying plane. /-cs)d gn9;x/1 z4kedwlwbzcWhat is her acceleration when she she reaches terminal veloci)z/ zsw9bnk4 1w ddl/-cegxc;ty?

  A ball is thrown vertically upward with a speed v. An identical second ball inhq. ym0g h.z 6-ppw:cs thrown upward with a speed 2v (twice as fast). What is the ratio oyz.- 60 qpgpwhmhc :n.f 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 sedl3 lw1p64gub cond later, ball B is dropped from the same buildiu1d6 lwbgl p43ng. As time progresses, the distance between them

  Ball A is dropped from the top of a building. One second later, ball B is droppv-n7hakfdlc *zi2fz+ 5r-x2red from the same building. As time progresses, the differe r 5cark 7z-dhilz2+v xf*-2fnnce in their speeds

  Two objects are thrown from the top of a tallshx1aa 5h bu9gh(qa 1,l ccw.v9pex+: building. One is thrown up, and the other is thrown downusw9h5gqa(19xhphx l+ acva , :c1 b.e, both with the same initial speed. What are their speeds when they hit the street?

  A brick is dropped from the top of a building. A second bricr(t qk9/t ky tg8*nj3pk is thrown straight down from the same build tt qk3k8/ntyprgj* (9ing. They are released at the same time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with constant non-zero veloc1 zfq+yn;qit(ity in the +x axis. The position versus time graph of this object iqqi; +fn(tyz1s

  An object is moving with constant non-zero acceleration in the +x axis. The pt6e zg6z0jx 3rosition versust3 rejxg 066zz time graph of this object is

  An object is moving with conshny *2l2qfj0 m/bmt0ptant non-zero velocity in the +x axis. The velocity versus time graph of thisn *mp 0 0b/qy2j2tlfmh object is

  An object is moving with constant non-zero acceleration in the +x az4n,*,z/6uj6m 4hed vgv uy ljxis. The velocity verju64zjdghz,v* lym6, ue4 nv/sus time graph of this object is

  The slope of a position versus time gr+zjdhk:6dnb wgwc;cxp ,zf ey)bd 21*(h,( qtaph gives

  The slope of a velocii rks2 wy).f:kg8iy.q ty versus time graph gives

  The area under a curve in an acceleration versus tb-efsqr vt ( lv(d,28oime graph gives

  The area under a curve in a velocity versus tx 0rr-hrk+tsd bdd, eo1,6)q vime graph gives

  If the position versus time graph of an object is a h9kq 6. xj,8pwj0no7b8bxmk xoorizontal line, the object b9 k88mko.x,bjpj w0x7xo6nq is

  If the position versus time graph of an object is a vertical line, the obja)mh unohn+,2g1 z x0qfh,zf1ect iszm1 gx1ah0foh n,n+uf qz 2)h,

  If the velocity versus time graph of an object is a h *h7l-be bbwq80k gge9orizontal line, the object 9lbg*0 gb 8 hebwq7e-kis

  If the velocity versus time graph of an object is /7w:4t y63cbqa gi usxa straight line making an angle of 30 degrees with the time s/tbq c4wi x 76a3uy:gaxis, the object is

  An object moves 15.0 m north and then 11.0 m south. Find both thefrim0- +ryuin*p 8nm8xx6 ; ee distance traveled and the magnitude of the displacement ve 0xer8ni+e; 8u6f*ynx rpi-mmctor.

  A boat can move at 30 km/h in still water. How long will it take to movelvqzv8zzb p9p;,m35tsi 8 1px1zh:k c 12 km upstream in a rivezvz ipp,;31pms8:zc1v9 kq8 t5 hzlbxr flowing 6.0 km/h?

  55 mi/h is how many m/+tg s(fj0; + dmel6igos? (1 mi = 1609 m)

  What must be your averap437 1equa iqage speed in order to travel 350 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 km) in 2 hours1he*tr-uu qg6 and 57 min. What is the average speed of the runner ingre61u-qh *ut m/s?

  A car travels 90 km/h. How long does it take for it to travel 4cs uchp-tn;3tc +g; r100 km?

  A ly (light year) is the dis ;mwgdl/6-6jiz x h6mmtance that light travels in one year. The speed of ligh-wimx6z ;hml/j d6 m6gt 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 l*cou6(t mxh,b y lq,*book to the side for 4.0 s, how far do you travel during this inattentive period? 6qm , b,cuotybh**lx(

  If you run a complete loop around an outdoor track (4006/i; yn12 hvatkw c2cpor.z/h m), in 100 s, your average velocici/ph1h. k;wvn 2 6ytz/ 2craoty is

  A polar bear starts at the North Pole. It travels 1.0 km south, thikj 9)c+1 :w1: zcmcvkp+snmi5 k6 jnmen 1.0 km east, then 1.0 km north:j1mnm1i mwzj)+ i :k kcckv 9nscp56+, 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 trar lv: sk e.h:d6w-krl;vels 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 lsrd: 6ke:-rh vw;lk.min. What was the bear's average velocity?

  You are driving home on a weekend from school at 55 mi/h for 110 milesiusy8 ;rf 2xvober3v( dq5 r16. It then starts to snow and you slow to 35 mi/h. You arrive home after driving 4 hours and 15 minutes. How far is i;o 2vfy6 esd158v(rbqrr3xu your hometown from school?

  A motorist travels 160 km at 80 km/h and 160 km at 100 km/u)jkc0pyx: * s.loch )i/9eerh. What is the average sp sxyp/c9 o heirel)k*cj. :u)0eed of the motorist for this trip?

  A motorist travels for 3.0 h )ag jst mdy0t 4*rml.v(1sil2 at 80 km/h and 2.0 h at 100 km/h. What is her average speed for thedsjl1 *0)t24 lmy .tvrm(agis trip?

  An airplane travels at halva9rp6+ ,fwymc j( :p;nj8300 mi/h south for 2.00 h and then at 250 mi/h north for 750 miles. What is the avera:8+c a,6awj hn(pp9flyv mjr; ge speed for the trip?

  In a 400-m relay race t+uab120ltzzr z p-nak v99pacx89 z2whe 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 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 runnerkzx90z1-pvaatnuzr28pbz9+c9 lw2 a 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 xa4,1 sqw5.pk;bpu mca stop after 10 s. The car's average velocity during deceleration was 41 km/h. What was the car's deceleration ,mp;xbu kw4cp1 sa.5q while slowing down?

  An airplane increases its speed from 100 m/s to 160 m/s, at the average rate obm qfk4gqpc)yk*4 3u v15-hfxf fvqc1 bm5q-4 xfkyg k43hp u)*$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h ar 8p58h/s82hswkca 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 and accelerates dds6o45ihhd5 h4 - n6 dmdcc;sat $4.0 \; m/s^2$ 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 ff e+lir7f9;rwith a constant acceleration of97l f;i r+frfe $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 2.0 m/s experien0bma0. 5582 h+fb wjvi jvignmces a constant acceleration ofw0mb 2jnbv5 i+ ig. f5a8mvhj0 $3.1 \; m/s^2$. What is the cart's displacement during the first 5.6 s of its motion?

  A bullet moving horizoy h fyvr)., y;bnz5n j*il3hq.ntally to the right (+x direction) with a speed of 230 m/s strikes a sandbag and penetrates a distance of 10.60 cm. What is v ;y yjh ,nzyr.3*)hn bf.5qlithe average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on 5)fk; y9qhy6i++ -l xg5 l1mutx xabnian aircraft carrier. It reaches a speed of 42 m/s at the end of the catapult, and this requires 2.0 s. Assuming the 5m-y gf9x;xhl +t n)16xqu+ aiki5bly acceleration is constant, what is the length of the catapult?

  A car starting from rest moves with constant acco;z uwa 4k3.vz9p oz2heleration 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 4b f1 sq4bc4.*p8;gdzhy ivi ta distance of 200 m. What is its average accelerativbiq 41d fbhc;*t i4zgp.s8y4 on?

  An object starts from rest and undergoes uniform acceleration. Duringmj ,lp+ gs3ygl;qnd5m/o:8af the first second it travels 6.3 m. How far will it travel duajf; mqo3 p ,/g:l8+sdl5nygmring the third second?

  An object is moving in a straight line with cs t m3zq mcmb u;)c29ah-hbw78onstant acceleration. Initially it is traveling at 16 m/s. Three seconds later it is traveling at 10 m/s. How far does it m;buwm89cmambz 32- s h7qch)tove during this time?

  A car starts from rest and accelerates uniformlyi9w:jd/u93jq1tg myu x l c26p 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 2z vm/3ejqk,ocan 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 libka5 )0d mli*kght turns green, a car that has been waiting at the intersection starts ahead wit0ldmkki a b*5)h 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 upw( 8tkukex.s ;oard with a speed of 12 m/s on the surface of planet X where ths8x.(kto ue k;e acceleration 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 surface of zpw1tfi4 q .yoqzf-x6e*xt + )planet X where the acceleration due to grav +.zte)zx tq6ffwy4 p1qxio *-ity 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 f18v2r v jt;vmg dbf*dh8:rms.; bki8 of planet X where the acceleration due to gravity;t :bk.18v rh2 b;fvimvmdd88sgrj*f is $2.5 \; m/s^2$. How long does it take for the object to return to where it is thrown?

  An object is thrown upward with a speed of 14 m/s on the sur rrshxg/z+jt(3u4pu t0qj3 z0i1iq+ gface of planet X where the u 04pjr/t3guxgjs1+(3 + zrqihztqi0acceleration due to gravity is $3.5 \; m/s^2$. What is the speed of the object after 8.0 s?

  Human reaction time i7 n)wb 9/kz8oh:clb-kkwqau8tj +n1w s usually greater than 0.10 s. If your friend holds a ruler between your fingers and releases it witho-uwqn at wlcwbhk1z +kj98 ko/7):n8but warning, how far can you expect the ruler to fall before you catch it?

  A ball is thrown upwardj7mtbjo4ho8w h w z/a33nsv5( at a velocity of 19.6 m/s. What is its velocity after 3.00 (3 3 w7ohbow5zh4mv /8jj snats?

  A bullet shot straight up returns to its starting pow1lja5wd 6r/so9rrzm f5-* y gint in 16 s. What is the initial speed of th51 /5 jd6myo*rzwlsawrr 9-fge bullet?

  A ball is thrown straight up witfq cl3onp:a+ iw(+j(mj9f0 io h a speed of 36.0 m/s. How long does it take to return to its startinfqj iwo(a++m9(fn ji0ocl p 3:g point?

  A ball is thrown downward from the top -0n(pp 8wmxih/ u+;v-icre qv of a building with an initial speed of 27 m/s. Ihpwc (-mu p+qrx-/v8;v ni0eit strikes the ground after 6.3 s. How high is the building?

  A ball is thrown straight up with a sp1recj4bm/smz) n r; tuvyu,63 eed of 30 m/s. (only fill in numerical value in the blank ncetrvj uym;6z)r 34s /,m1ubs)
(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 ) 1wwx *a,m j,ac)viccinto the air with a speed of 41.8 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 14 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 14.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is;i xx+ab7l 9ngo hlrasl8c3z;p yj) 8. the velocity at t = 1.0 s?

  In Fig. below, what is the velocity at t yich7mjs +fx,8 k7vn7= 2.5 s?

  In Fig. below, what is the velocity at t = (4zex8 , jlyb bb s98m7c4qm0gqj9;lopd+cq m4.0 s?

  In Fig. below, what is the velocity at t = 5.5 s?r,-r7, l0chwibu 2rr.lfi;xvs si(g:

  In Fig. below, what is the average velocity from 0 to 4.0f6vt7 wfzyh-4 s?

  In Fig. below, what is the average veloc,1cnl1c bh nh/ity from 0 to 6.0 s?

  In Fig. below, what is the acceqxon- u j,3qy m3-;qauleration at 1.0 s?

  In Fig. below, what is tqlehb52q x3a6z 54y qohe acceleration at 3.0 s?

  In Fig. below, what is the avq9ix- tfr8z se5*t o.merage acceleration from 0 to 5.0 s?

  In Fig. below, what is the average acceleration frone1dc+o6z zm 0m 0 to 8.0 s?

  In Fig. below, what is the displacement from 0 to 8.0 sq;y 9w 9j.yeig?

Does a car speedometer measure speed, velocity? {spe7wqrh8sbf3d ) k .38ri7dqy qued|velocity}

  An object can have a varying spee tc:i.*wk5ypkt2-wu/jzt c29adv3 ywd if its velocity is constant.

  The velocity of an object can be negative when its acceleration is positaf9i9 ; 6w1 cstx8y rmw,b1rmpive.

  If one object has a greater speed than m.:s2 fk44*cj fdjces a second object, the first must have a greater ac*k s4mfj:.c2 de4fs cjceleration.

  Two cars emerge side by side from a tunnel. Car A is traveling with k8d3je21p eun 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 decreases.m qn3 0p0qunfe7 pdcu;2jix5(

  A baseball player hits a foob/g85pd7 hx qq7s 4vz 8uqae)1p* puj.kou7 yul ball straight up into the air. It leaves the bat with a spejk/zu yg qeuxp*4sphd8oq )7 au v.qo5871b7ped 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 ha (juyhv8+ a2bdppening to its acceleration, how does it change if air friction isya2+v8u j hd(b ignored?

  As a freely falling object speeds up, what is happening to its acceleration,8 dx 3dkf85kvr how does it chanv8f 58rkd kxd3ge if air friction CAN NOT be ignored?

  An object that is thrown verticax: cvm1 dprt*hq8,d gm p.9*lvlly upward will return to its original position with the same speed as it had initially if air resistance is negligible. If air resistance is appreciable, ptlmmp*v:c ddv ghrx98,1q* .how will this result be altered?

  An object can have zero velocity and nonzero acceleration at the same time.n 7y;j 0qr: bektogij8u(xi; q;-wn3f

  An object can have nonzero velocity and zgwy0:uv;yw 8 j1zltc) ero acceleration at the same time.

  An elevator moving from the second floor to the fz8:,hq 4 srpynzhgh))ifth floor making no stops along the way has zero acceleration all g,: nqyz))4h8prs zhhthe time.

  A rolling ball moves fd5)mvyrrz5.wbw3f o2 rom $x_1=2.1 \mathrm{~cm}$ to $x_2=-6.2 \mathrm{~cm}$ during the time from $t_1=2.8 \mathrm{~s}$ to $t_2=5.2 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-3.2 \mathrm{~s}$ is at $x_1=3.2 \mathrm{~cm}$ and at $t_2=3.5 \mathrm{~s}$ is at $x_2=8.0 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps ar2f2pmwg0djy. swo 93vound a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 7.7 min. Calculate (a) the average speed  (数值)  $m/s$ and (b) the average velocity    $m/s$

  A horse canters away from its trainer fg ukwggl( xlt;42. /wrms-m;in a straight line, moving 87 m away in 12.1 s. It then turns abruptly and gallops halfway back in 4.5 s. Calculate (a) its aver4/- ( lmgms;.2f tkgrxwl;wg uage 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 fro0v rcnyipg kk8 9*yz7/m $13 \; m/s$ 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 fro:izn/, a yw/wkm $18 \; m/s$ to rest in a distance of 79 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must re9sx f0:gsp vzumh0jt j7119m qach a speed of $28 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.8 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of the . t)l wujpmz.;blocks to essentially top speed aboutjwlt zu m;.).p $10.6 \; m/s$ in the first 13.1 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 uniform b(,z;alc(rjzv+ di.d ly from a speed of $19 \; m/s$ to rest in 4.63 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 yrp 3lut6l (6uthe highway. Assuming a deceleration ofull63 yup( rt6 $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck goine7d76 e)tyi uql2pzb5g $25 \; m/s$ 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. Aft bn ) al2kf1+ki2fddt(er exactly 27.0 min, a) 2f(ktbdfd1i kn2l+there are still 1100 m to go. The runner must then accelerate at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$