Suppose that an object travels o9t9+f+, g6zvn2 j5 tndyfted from one point in space to another. Make a comparison between the displacement and t 6t vzgn+td2y n,5d9 ftj9o+fehe distance traveled.

  When is the average velocity of an ob dzo0rs-jo a:.:)vyz jject equal to the instantaneous velocity?

  A new car manufacturer advertises that tjgcc;t4y*m; - uvvr ww;(gbbd5uc 2 x:heir car can go "from zero to sixty in 8 s". This is a descrid;ywgb;gx*u-w uvm ccv:r;b( 25 tc4j ption of

  An object moving in the +x axis exprjzgj 0 9y(w3geriences an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car t cmcr4 pg:xih3s0hy8-x1g ema+gf,r h8 m80oh raveling to the East (+x direction) begins to slow down as it aphi3,8y-fggom x+ 8hmxa18msrpc c0h g: 0e r4hproaches a traffic light. Make a statement concerning its acceleration.

  Suppose that a car travelo4-/z s.osdp,5 qhjxr ;)e7+jwxxfwling to the West (-x direction) begins to slow down as it appjhx4plx5 ;x )wj. 7oo qzf+wses/d,-rroaches a traffic light. Make a statement concerning its acceleration.

  Suppose that an object is moving with a constant veloc/: n he(d lmf;5ozbi/br/iec )ity. Make a statement concerning its accele;bzb)erfd( /5/m/enc oli h: iration.

  If the velocity of an object is zero, does it mean that thejk tui9 k 64xocl ki5:ojt8tu dl4o.:. acceleration is zero? Support your answer5 kx 9:ok ci8oto44u.tju6iljt. d lk: with an example.

  Can an object's velocity change direction whfe :2:a4pw tqun9 nj8qen its acceleration is constant? Support your ann9 w2 fqjq::8u4ae tpnswer with an example.

  Suppose that an object is moving witnpish-dh 4i 7tk;ot.7 h constant acceleration. Make a statement concerning its motion with respect nhko i.7;t p-h4idst 7to time.

  Can an object have increasing speed while its acceleration is decreaptip u;r5rt,u.od01i zse0ra (5d6 c vsing? Support your answer wit tp1av,t .r 6si5cuperrd0ozdi u;0 5(h an example.

  Suppose a can, after an initial kick, moves up along a smooth hg,pd0ejpss89,nd ct )ill of ice. Make a statement concerning its acceleration.dppdssejt,, )n9 cg08

  Under what condition is average velocity equal to the average of the object's innh x/5v;t66am ujf(gsuqqx 2sj2 z78xitial and fi(hsu2qxamqj5jn zt x6sf7x /u62v8 g;nal velocity?

  Objects A and B both start at rd4lym+o/8 9 w yucui(vest. They both accelerate at the same rate. However, object A accelerates for twice the time as object B. What yi4vc9(ydm +u ol /uw8is the final speed of object A compared to that of object B?

  Objects A and B both start from rest. They both accelerate at the same o3g3ms2n)5tf3 pm jkprate. However, object A accelerates for twice the time as object B. What is the distance traveled by object A cotpgo3k3jm)ms n5pf 23mpared to that of object B?

  When an object is released from rest and falls in the absence of friction zq su,n/xa/7rgei,su3cmi(jl-cjm 65uv(n * , which of the following is true concerning its mot/auj,c,s5m3jms *uc7r ( v/ x-ln6( iqiuezng ion?

  When an object is released from rest and falj,xe)l8r2jq;xr6q p8 w:g ndl ls in the absence of friction, which of the following is true conce6edn llgq;2rx:x8 j)wr,q 8pjrning its motion?

  Suppose a ball is thrown straight up. Make a statement about the ve/psl he7 8 9iauwxqwq2q1t+z3locity and the acceleration when tx /ptaw1s 27qlez q u8+ih9qw3he ball reaches the highest point.

  Suppose a ball is thrown straight up. What is its acceleration ju01 3uembv+pt jst before it reaches its highest pointj 1embtv 0u+p3?

  Suppose a ball is thrown straight up, reaches a maximut i,v0gz)wxm2 l9)k rbm height, then falls to its initial height. Make a stat, rvz0)t9k2blg wix )mement about the direction of the velocity and acceleration as the ball is going up.

  A ball is thrown straight up, reaches a maximum height, then falls to its initwx9j(lr k8n8ia a)5 ehial height. Make a statement about the direction of the velocity and8aij heal )5 9nkx(rw8 acceleration as the ball is coming down.

  Suppose a ball is thrown downward in the abgzomx;x(g m*6c)y awfo8z y/2 sence of air resistance. Make a statem )x2gfxo;yy(zmoc/m a8*gz w6ent concerning its acceleration.

  Suppose a skydiver juv1k.reu//s xk mps from a high-flying plane. What is her acceleration when r /ku. s1vex/kshe she reaches terminal velocity?

  A ball is thrown vertically upward with a speed v. An identical second ball is* gfd04k5iy og5kq f/c thrown upward with a speed 2v (twice as fast). What is the ratio of the maximum height of the second ball to that of the first ball? (How many times higher does the second ball go than the first ba5 g0g4 /5dfo*yi kckfqll?)

  Ball A is dropped from the top of a building. One2f /ahm bdj.0l dz9:qd second later, ball B is dropped 9 m:jahd/2b0zf .dqldfrom the same building. As time progresses, the distance between them

  Ball A is dropped from the top of a b3 wj3ef,tppd 6)ap(mduilding. One second later, ball B is dropped from the same building. As time progresses, the differejm pp,6fpd) dweat3(3nce in their speeds

  Two objects are thrown from the top ofnw7b3i*u q .vr a tall building. One is thrown up, and the other is thrown down, both with thrqbi3* .n 7uvwe same initial speed. What are their speeds when they hit the street?

  A brick is dropped from the top of a buildijn5xb/ tf),kphepu j;mew bkh770,2 cng. A second brick is thrown straight down from the same building. They are released at tju xj, 0 ,bchhe7mepbkw fn2)5p7k; /the same time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with constant nd v2 wv.uow/wy 8gu9*gon-zero velocity in the +x axis. The position ver8wvy d2*u9wg.wvu / gosus time graph of this object is

  An object is moving with constant non-zero aaupmyv eii6gdu03)+ 6b*m8s acceleration in the +x axis. The position versus um)ba dy* 8si 6av3mig6e0up+time graph of this object is

  An object is moving with constant non-zero velocity in the +x axis. The velgtfa:yiqz4+,no e4g3ocity versus time fq, 3 gant4 :oye+4izggraph of this object is

  An object is moving with constant non-zero acceleration insq(e35 mk6l(flq.nnx the +x axis. The velocity versus time graph of this l.5 6((ms nexlq3qnkf object is

  The slope of a position versus timhvd) rq a cjz9u81dy )3f1e0fbe graph gives

  The slope of a velocity versus tmh+/c3nayi e:2 /6ssgal nwt*ime graph gives

  The area under a curbvn.dd. 0oxxzsote3 :2d i4:qve in an acceleration versus time graph gives

  The area under a curve in a velocity versus time graph givey ul ,n/)kvb;rs

  If the position versus time graph of an object is a horizonql: w :in89zy+*ybhvc9j z hk/tal line, the object ny/ 8z9+j wl:*hbqzvi ky9hc:is

  If the position versus time z: :a m21:cwadc gxm1xgraph of an object is a vertical line, the object iswamg :mxacd1x 2:1c z:

  If the velocity versus time graph of an object is a horizon0a 6btlgwb: lx.6cox.uitg8 --8 rumm tal line, the object is.0r m:ua 6-tx cul g.itwbxg8blo m86-

  If the velocity versus time graph of an object is a straight line makingjkaft1e-;m5 o mnjw vg3-. kp+ an angle of 30 degrees with the time axifjk.+k o 5mvpnt3;gm-w-a1 e js, the object is

  An object moves 15.0 m north and then 11.0 m south. Fwgro.t q5q* nl7bwv4,tm3(a7l s/i cyind both the distance traveled and the magnitude nt7srqcbvowal7wt4 g ,*l3 q/ymi5.( of the displacement vector.

  A boat can move at 30 km/h in stilzu rhz -g4u*8dcgp:5 rl water. How long will it take to move 12 km upstream in a river flowic*rz8u z 4: dp5ug-ghrng 6.0 km/h?

  55 mi/h is how many m/s?k42wh -ce8ja+ht( zmx (1 mi = 1609 m)

  What must be your average speejom*yp) u t);t9hojhe98wp;d d in order to travel 350 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 km) inwufw/g/ inl/9 2 hours and 57 min. What isuww fn//g/il9 the average speed of the runner in m/s?

  A car travels 90 km/h. How long does it take forndbqjwf ckn8s0(kzjs*zo4 b- 36rx )4 it to travel 400 km?

  A ly (light year) is the distance that licj(ly)bdo r9 2ght travels in one year. The speed of ligh2oj9 ldrbc y)(t 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 th ktjoim;: i)y0we(n d.e side for 4.0 s, how far do you travel during wn( yt .ii)e:0m;kodj this inattentive period?

  If you run a complete loop arogbj9319nw r 1-j regwsund an outdoor track (400 m), in 100 s, your average velocity irbg1nj9-e1 wrg9j 3sw s

  A polar bear starts at the North Pole. It travels 1.0 km soiosh 7/tt6yt:l;ynw 0uth, then 1.0 km east, then 1.0 km north, then 1.0 km west to return to its starting o0yi:7ytst nht/6;wl 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, thuvj5kks.0b-5ofom-c * 97wb.eziw yaen 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 tof9u. cz-5- y.j wb7w ska5kombe*i0v he bear's average velocity?

  You are driving home on a weekend from schooll+hl:qms.)umv/ b-8o+jb gne at 55 mi/h for 110 miles. It then starts to snow and you+m. jg+/u l8)oenvlsbq m-:hb slow to 35 mi/h. You arrive 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. What is tj5q7x*d :jb3fotcu 76d 1brv fhe average o5 *uf bf:3r6qv7d1jt7jbcxd speed of the motorist for this trip?

  A motorist travels for 3.0 h at 80 km/hwen*s-p26 1ubykle- -fn7om(c q)r2 4ykoe ez and 2.0 h at 100 km/h. What is her average speed for24uml- fe7n2eb6-yk1(o seoe nw- )*r yckp qz the trip?

  An airplane travels at 300 mi/h south for 2.00 h and the zf/ (crq 3*dvu;7 cyk0z(htzrn at 250 mi/h north for 750 milesrr/hyf7u * ;(ctd(vc zq 0k3zz. What is the average speed for the trip?

  In a 400-m relay race the anchorman (the person who runs the la as70zwd6g rdf-(f (kest 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 the7kr0ad(zgd wsf 6-e f( race, in order that the team A runner not lose the race?

  A car decelerates uniformly and comes to a stop after 10 s. The car's averageb92b q8guxxk9)xfa51 ia:o7d/yt vdg velocity during deceleration was 80 km/h. What was the car's deceleration whileqyo2aidd bxf1b7: )ug a/k 59tvg8x9x slowing down?

  An airplane increases its speed from 1 rdl(s 5/bv*nde*xu n(00 m/s to 160 m/s, at the average rate of dn/xv ub(*e(nls *rd 5$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h acceler8hu thh3a7)kb xf h5rr +9cw4o3oq(etates 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 accelerates56 snd:k da2npg-3ngg 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 spets3lf7bxv( :i 4xnl y.:iyp2k eds up with a constant acceleration ob y4t2:xxy: ik fin.vsll p(73f $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initifc kk5y9(j1nt scs1 : vf(3j+7quxow cal velocity of 3.5 m/s experiences a constant acceleration o: vuk( w cx3fq+k57fcs nj1t y9js(1ocf $1.1 \; m/s^2$. What is the cart's displacement during the first 4.9 s of its motion?

  A bullet moving horizontally to th +mg9yyeumspki 6d5 11ec3f( he right (+x direction) with a speed of 500 m/s strikes a sandbag and penetrates a distance of 91.10 cm. What is the average accelerationyi+g uch( 6dme9y3 f5ep1k1s m, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on an aircraft carrier. :1i1zi9 2 kitp5vj z+wi6kkg iIt 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 th:i iik+tz6jp9 i 5ki1zgk2vw1e catapult?

  A car starting from wv.3zha)k fbq br8j. .rest moves with constant 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 averglni 8d1vz ckb 84ni:ld2h0.nage ac18diblnvdh4 . 8c k0:nz ing2lceleration?

  An object starts from rest and undergoes uniformkwc9-k1r 1whbxab,i 5t vge01 acceleration. During the first second it travels 1.2 m. How far 5-t1ghb91rk,kwcea0 wxib1v will it travel during the third second?

  An object is moving in a straight j-xb 7 e- k4y3cccjl.gline 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 ti7 xbjy.4g3j-l- ekcc cme?

  A car starts from rest and accelerates uniform8x0e4wtt)r dkly 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 tiresltd;:p)mpa2 f on a dry road can decelerate at about $5.0 \; m/s^2$ when braking. Suppose a car is initially traveling at 55 mi/h.
(a.) How much time does it take the car to stop?    $s$ (only input numerical values)
(b.) What is the stopping distance?    $m$ ((only input numerical values)

  At the instant a traffic light turns green, a car that ha t u3+ax;p 3w/9 84afar o-fbm/lgenqps been waiting at the intersection starts ahead with a constantaem/+waln 9t ;4o/q3au b 8rg-ffp3x p 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 u,o*hs.te ne bq90vr) a speed of 12 m/s on the surface of planet X where the acceleration due to gravity isb ,h9oes*q nt0)u. ver $1.5 \; m/s^2$. 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 plane)cjub*gf1..hohvyf 6 xs1gyq 7c v s36t X where the accele s ogh)1 fyyjc66vscu.bv7g.3hqf x1* ration 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 m/s on the surface of planet X wg /d5zq vos-hvlt7p3 nv/:a+d 2zx k7ihere the accel d ln/z5 ta:2dg37h/-qxoikv7s+pzvv eration 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 m/s on theqnyw qxv1u+ hz2-e +um.z64 2otzkw:s surface of planet X where the acceleration due to gra. 6e zuov tw+ zhu2yzsw1qqk2x:+4m- nvity is $3.5 \; m/s^2$. What is the speed of the object after 8.0 s?

  Human reaction time is usually greater than 2yrhe h iyx40418lc1ubed8d d mw.:or 0.10 s. If your friend holds a ruler between your fingers and releases it without war8.e dymob xw4r1 1hr:l0dh4d 2cey8uining, how far can you expect the ruler to fall before you catch it?

  A ball is thrown upward at a velocity of 19.6 m/s. What is its velocity afus( ha,a qs ,zpsa;)n6ter 3.00 su ahsa;a,s(qn)6 z ,ps?

  A bullet shot straight tsvk, v;9oh(u :e 97prt5emi y;su0pd up returns to its starting point in 18 s. What is the initial speed so s;9,iu7vu rv(h; :0ty t9ppdee5kmof the bullet?

  A ball is thrown straight up with a speed of 36.0 m/s. Hmwam.mk7fazy; 2+u+k ow long does it take to return to its st;y7. ++kz maumfwkm2aarting point?

  A ball is thrown downward from the top of a buil x4 dq/- lb3jljjpjx/-ding with an initial speed of 27 m/s. It strikes the ground after 5.5 s. How high is the building?-dbx/- lpjl 4j/x3 jjq

  A ball is thrown straight up with a speed of 30 m/s. (onlyed nz*tvbcl k5d,( / i) 0qrg6lgl;u.q fill in numerical value in thqg/60k, cq;r t bdzgnv5l.ilde()*lu e 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 into the air with a speed of 24.4 m/ s- 34syjkxfj/l)/jbe s. (use $g=10 \; m/s^2$, only fill in numerical value in the blank)
(a.) Calculate the time required for the ball to rise to its maximum height.  (数值)  $s$
(b.) Calculate the time for the ball to fall back to the height at which it was hit.  (数值)  $s$
(c.) Calculate the maximum height reached by the ball.  (数值)  $m$
(d.) Calculate the ball's speed 2 seconds later.  (数值)  $m/s$
(e.) Determine the time at which the ball pass a point 10 m above the point of contact between the bat and ball for the first time.  (数值)  $s$
(f.) Determine the time at which the ball pass a point 10.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is the velocity at t =0zkqedl./feyd4j .r 6 1.0 s?

  In Fig. below, what is the velocity sri8ev. ml8h .yk-2jthh2bfs7 . 7tjoat t = 2.5 s?

  In Fig. below, what is the velocity at t = ss e 1cab7gk4ajy.kc*) dv ;4o4.0 s?

  In Fig. below, what is the v+roaz8xwnjtjv6,k5awm 8:f w61y r9 selocity at t = 5.5 s?

  In Fig. below, what is the averagew3- 27s*8bzml b dyuq)l4pn lc velocity from 0 to 4.0 s?

  In Fig. below, what is the averag/mmwi.n9gko5bxhg m)d+idw66 9sj .m e velocity from 0 to 6.0 s?

  In Fig. below, what is the accel80l tn19jvmhg pq .nsyn8fv ;5eration at 1.0 s?

  In Fig. below, what is the acceleration nxmzqn6qlk.x-s u 6p*2 e60xncfy:, lat 3.0 s?

  In Fig. below, what is the average acceleray1r2tzrq(*s3gxj ,qq u: gw3ntion from 0 to 5.0 s?

  In Fig. below, what is the average accc)n05u7r ladjeleration from 0 to 8.0 s?

  In Fig. below, what is the displacement from 0 to;j 0 /d7akzv)dys js 2znfc2*i 8.0 s?

Does a car speedometez ,i4z)s2hgg vr measure speed, velocity? {speed|velocity}

  An object can have a va7us ( z;+ld+u1uoll4m ttc 52f)isfkwrying speed if its velocity is constant.

  The velocity of an object can be negative when its acceleratiok 5yh8 y7 ix1fv0s0cssn is positive.

  If one object has a greater speed than a second object, the first must have ah:9;k k8e 4 q k;agwge,lq57vmtxfy /d greater accelk5ax kk,eq4v gwfq9 :8/leh;7d y;mg teration.

  Two cars emerge side by side from a tunnel. Car 9z --,gm awepl7oyyw+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 spenkq(x +om rm,1mjek(3oduc u.d o 35s*ed as its acceleration decreases.

  A baseball player hits a foul ball straight up into the air. It leaves hyr2*7mzd-tk lel+ .fthe bat with a setd-hlyk 72l*rfmz+. peed 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,y: bb y0coed2 fbl*o*8 how does it change if ayb2o*8l befb :d* c0oyir friction is ignored?

  As a freely falling object speeds up, what is happening to its accel 1xd .c+c/ 4i1kfsb kozj2o7gaeration, how does it change if air friction CAN NOT kxzo1 7c a+bkdc 1.jf2gsi4/o be ignored?

  An object that is thrown vertically upward will return to its original posymxciss2)n9* sg1.vk ition with the same speed as it had initially if air resistance is negli1s 2nsi *ks)mgxc. vy9gible. If air resistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzero acceleration at the sanuvdl)-i;e b ab9- i/ome time.

  An object can have nonzero vel)+r vh0 2pzlcy,+yax+ll2 :ndx kj1 vxocity and zero acceleration at the same time.

  An elevator moving frqcf3/ io/oy8v om the second floor to the fifth floor making no stops along the way has zero accelerqc8/ o/ fv3oiyation all the time.

  A rolling ball moves fromax b+v,6 zg8pe91lx av $x_1=1.9 \mathrm{~cm}$ to $x_2=-8.8 \mathrm{~cm}$ during the time from $t_1=2.5 \mathrm{~s}$ 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 $t_1=-2.8 \mathrm{~s}$ is at $x_1=3.1 \mathrm{~cm}$ and at $t_2=3.2 \mathrm{~s}$ is at $x_2=7.4 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete lapiannh/k98 ed)l i5 sn(s around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 7.3 min. Calculate (a) the average speed  (数值)  $m/s$ and (b) the average velocity    $m/s$

  A horse canters away from 80 bhw :q,mmvy8sa9e5dfe y o*its trainer in a straight line, moving 99 m away in 12.4 s. It then turns abruptly and gallops halfway8y8qe , 0b5y9d msmvw*feaoh: 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 from+j-:fak0f7 u)n yod fp*86wewqpnk-w $10 \; m/s$ to $24 \; m/s$ in 5.4 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;ykj,n6cgunz xg,+ )p $16 \; m/s$ to rest in a distance of 71 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reachm s1-uv eiw;)hce)hb0 a speed of $27 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.9 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of the blocks to essentially top ss3 3sp(gqbd xx3:yqv( peed aboutbp(3ds3xqxq v3(:y gs $11.0 \; m/s$ in the first 12.7 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 7t hhtcx)m0u +speed of $16 \; m/s$ to rest in 4.68 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 highp; ;amn+/wwtvp/vcapdw2tw ky 1:+u 0way. Assuming a decelerationt +v wc k+ap/;u2w 1v yw0tnp:;w/dapm of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truckiag+diw2 -iis/ +x aip69 7fe +rg*cve 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).    $m$