Suppose that an object travels from dmk (oalx8s3 vf,+anb9l99rb, (l cuzj)ye3 lone point in space to another. Make a comparison b3vam yleulrb+f9 (ax 3ldjs,k 9)8, olbn(zc9etween the displacement and the distance traveled.

  When is the average velocity of anm -6 ef)qsjjc; object equal to the instantaneous velocity?

  A new car manufacturer advertises that their car can go "fl.i akn;8eim4 rom zero to sixty in 8 s". This is a de8l ei.amn ;4kiscription of

  An object moving in the +x axis experiences aqpe(m :buzi8wo*4ym( n acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x direction) bcl) +f sh++* zz/84jrgqzu23uqlpcd segins to slow down as it approaches a traffic light. Make a statement concerning its acce43q* sl/gcuzc+lqzpu sh)d+ fj8+ z2rleration.

  Suppose that a car tr(7culf x ,r1piaveling to the West (-x direction) begins to slow down as it approaches a traffic light. Make a statement concerning its acceleratc,f 7plu( ir1xion.

  Suppose that an object is me9mx z ( r,,lwxrzcw61oving with a constant velocity. Make a statement concern6z (l zw,9wxcm1x,rer ing its acceleration.

  If the velocity of an object is zero, dohya;xm 5.ftig,uv;j5 es it mean that the acceleration is zero? Support taymg; .,5 jufvi5;hx your answer with an example.

  Can an object's velocity change dirl tf qr2p 14.,rfj:ahiection when its acceleration is constant? Suqa,2fr 4ipt1f:.lr hjpport your answer with an example.

  Suppose that an object is moving with cons2b7ornxm -vfz:inn 67sn.bkx h- 76petant acceleration. Make a statement concerning its vnf-nm7nniop x-s6 726 7eb. hzkbr:x motion with respect to time.

  Can an object have increasing speed while its acceleration is decreasing9:dvo,xovtn eqe(-x x5 *a:fb? Support your answer with an eox(tnxxeev:9f,v*d ao5q : b- xample.

  Suppose a can, after an jn3:y+ h7pxy 8g0 wi48osayps initial kick, moves up along a smooth hill of ice. Make a statement concerning xo7 :s8+y3yjh 4was0iy g pn8pits acceleration.

  Under what condition is average velocity equal to the averagqkfl ):7 pit2ge of the object's initial and kg2p 7):iqtlffinal velocity?

  Objects A and B both start at rest. They both accelerate at thw7gcrx4q/h(cwc a+6gs s:cw9e same rate. However, object A accelerates fh79swgcsw cr(6 g+ a:/qw cx4cor twice the time as object B. What is the final speed of object A compared to that of object B?

  Objects A and B both start fromjzsc: sy:9s3 c t6+ghg,-87wqa zsn cu rest. 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 comn qyu gw3z+c,:zg6:ss7c 9asjst -c8hpared to that of object B?

  When an object is released from rest and f70wiqv(xr:k cz 6g2 efalls in the absence of friction, which of the following is tru2fkrwei z07qg(: 6xv ce concerning its motion?

  When an object is released from rest and falls inw001;yc xit*qfp l rt *u5hl3o the absence of friction, which of the foq*l10h* p3y0l r xwtiotc ;u5fllowing is true concerning its motion?

  Suppose a ball is thrown straight up. Make a statement about the velocity and )m*lt 5k,tr/a+e g*o/dcepsn 3ptg ;vthe acceleration when the ball reaches tkdgc;p5/e*l r+m,taen vop *g)t /st3he highest point.

  Suppose a ball is thrown straight uphxs.jzi+3uw-hz zpv+ j2oi k): dy-s+. What is its acceleration just before it reaches its highest pointskv2: w z3ozxh - j+dh.+zjyi)i+sup-?

  Suppose a ball is thrown straight up, reaches a maximum height, then fl8oyb;f )ofqgj6g ;qxt9,1 a ealls to its initial height. Make a statement about the direction of the velocity an;flq)ty e,9f;a 1ogx6jb gqo8d acceleration as the ball is going up.

  A ball is thrown straigh2eavccu4j 9x,t up, reaches a maximum height, then falls to its initial hei2v 4ca,ue jcx9ght. 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. Mak+q1voi6r 4 myjn.* biue a statemei6 nm .1o*uqrvbi +y4jnt concerning its acceleration.

  Suppose a skydiver jumps from a high-flying plane. l. (ngzz)q*r 5rt ahm5 What is her acceleration when she she reacr(5 g. znlr) *zhaqt5mhes terminal velocity?

  A ball is thrown vert xpjs: vj8l *t446wmhxically upward with a speed v. An identical 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 firs s6h*jmvp:4wtj 48lx xt ball? (How many times higher does the second ball go than the first ball?)

  Ball A is dropped from the top of kzv qzl/,*q3g5ju xmzb)e ,,:7v/bzdrxr j9la building. One second later, ball B is dropped from the same build, q/z r jlrz,kub:x 9qelx7/zvj *d g5vmzb),3ing. As time progresses, the distance between them

  Ball A is dropped from the top of a building. One s;,74o- z6 w.upfa p i4deochdaecond later, ball B is dropped from the same building. As time progresses, the difference in theaph64fc w7dei; a,d4z puoo. -ir speeds

  Two objects are thrown from the top of a tall building. One is thrfg +; z8hekvq)own up, and the other is thrown down, both with the same initial speed. What are their s q;8fe hk)zvg+peeds when they hit the street?

  A brick is dropped from the top of a building. A second brick is thrown straid3u8crfsz 3 h4ght down from the same building. They are released at3 ucdsz83hfr 4 the same time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving wihwba fda sle/l;*s 6:9th constant non-zero velocity in the +x axis. The position versus time graph of this objec69;wbals*hedf: sal/t is

  An object is moving with constant non-zerwnxe t 71j8nsrze77l 9o acceleration in the +x axis. The position v77 7rnlw1 js8eze9tn xersus time graph of this object is

  An object is moving with constant non-zero velocity in the +x axis. The vem+l 0xc4a ;j glkpby-l5jg43rlocity versus time graph of t g - j 403mxjal+;4l5rgbpclkyhis object is

  An object is moving with constant non-zero acceleration in the +x 2p djm:iop szjm6 u+9 ;dlb;f7axis. The velocim+ l2s 9djzdoupb:j7f6;;mip ty versus time graph of this object is

  The slope of a position versus time zgf1)4fr5/4 s gpwwbcgraph gives

  The slope of a velocijac p :-wlxwq,x(u4 9hj rk6y3t)ufy4 ty versus time graph gives

  The area under a curve in 49spajko7* gj ys)nv, an acceleration versus time graph gives

  The area under a curve in a velocity versus time gvo+nv0 /9qv: arhk .ysraph gives

  If the position versus time graph of an s.vn y1y1cnp9object is a horizontal line, the object cy9yn.v11np s is

  If the position versus time graph of an object is a vertical line, the obje. e*-anl.n .uoixy6z uct ise 6yaluzn ux-..o .*in

  If the velocity versus time graph of an object i(n:+*6dk omf/zh ;sbbtf) 7yar-mdpgs a horizontal line, the object is;(mkbm gr+/f d*) 7t- oz:6fhsnbdayp

  If the velocity versus r6 wj ;6*uzrantime graph of an object is a straight line making an angle of 30 6raz*r6 w; unjdegrees with the time axis, the object is

  An object moves 15.0 m north and then 11.0 m so 0d( 6hlq;a3vrmm+itk uth. Find both the distance traveled and the mag0;mmtd6h3k (ivq +al rnitude of the displacement vector.

  A boat can move at 30 km/h inc*qf8ly(;b h mj2 sz1l gf(co. still water. How long will it take to move 12 km upstream in *my z;1cf.g ofl 2h8l((qscjb a river flowing 6.0 km/h?

  55 mi/h is how many m/s? (1 mou2f8evmr)4kn (am* d8 /yuxi i = 1609 m)

  What must be your average sm g cx548nuds6jvi cg :nc :rg084uz1speed in order to travel 350 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 km) in 2 hours and 57 mi-/v iaaqazy*5gen3i c8 3lo/ln. What is the n*gaa/y-cz8la/o35qil 3v ieaverage speed of the runner in m/s?

  A car travels 90 km/h. How long does it take for it to traveavr 90541(2x1 htfxbe tt7 e uhmoamr+l 400 km?

  A ly (light year) is the distance that light travels in one year. The s ;juhurzgu )os l,jg,0i(mo ,5peed of lightshgr lju,o5j, 0 igm ;oz(),uu 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 straighvys1/bd9 n4(f o6q3 pub1 x5; tcagrrut road and you look to the side for 4.0 s, how far do you nryu 1tc p5 fur6dxq sgba49 /vo(b;13travel during this inattentive period?

  If you run a complete loop around an outdoor track (400 m), o4hed6-cx1x ph1,bt m uvs3m) in 100 s, your average veloc463xxo1dm,cm)b h- p eh1 svutity is

  A polar bear starts at the North y--:sw( cgo6pcgc yo59u 4emqPole. It travels 1.0 km south, then 1.0 km east, then 1.0 km north, thgycs(:gyqu46 oc- 5o9p-m wceen 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 : td) 8hbrxr gyidd-i(.(p8vaPole. It travels 1.0 km south, then 1.0 km east, then 1.0 km north, then 1.0 km west to return to its starting point. This trip takes 45 min. What was the bear's averagdadb8 it:gd r-(hv yxi.(pr8)e velocity?

  You are driving home on 34f u,jv wmjt53(hq uda weekend from school at 55 mi/h for 110 miles. It then starts to snow and you slow to 35 mi/h. You arrive home after driving 4 hours and 15 minutes. 3q ( 3wmdu,tvu4jhjf5How far is your hometown from school?

  A motorist travels 160 km at abj3r/s9oll:43 ljgn 80 km/h and 160 km at 100 km/h. What is the average speed of the motori ja3/3nl lb4gr:9jlso st for this trip?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h. What 7ri0lbp;ctnqlwokr( o 2v;5; is her average speed fo2;lpvtiw75 k; bq(o;n0rlro cr the trip?

  An airplane travels at 310 fvn1pu(xk x4tsg rx 5cx29k00 mi/h south for 2.00 h and then at 250 mi/h north for 750 mile nsxc5xpxf2gu xk9r4kv1t(10 s. What is the average speed for the trip?

  In a 400-m relay race the anchorman (the person who runs the last 100 m) fo ps, f.)q9kh2eym1 iwvr team A can run 100 m in 9.8 s. Hisi.9ek, 2pq)myv1 fswh 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 ah;6gzn :yiq h1 stop after 9 s. The car's average velocity during deceleration was 36 km/h. Why:i ;qh61zhgnat was the car's deceleration while slowing down?

  An airplane increases its speed from 100 m/s to 160 m/s, at the average ratezqjossqr w,shyb +w1 7i/0 29a of wh0s/1bwsq,+qiz9ar 2 7 ys jo$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerates at tt9 h+di bqchk25yhj0(he 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 acceleds+4-cafo p(bs hd+k 5jaqg. +rates 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. 4t /t7h6-gfv vx nosvyt).r, i It then speeds up with a constant acceleration txtrv4hov,t6 / f g- yiv.sn7)of $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 7.8 m/s experiences a conssz i+ vjkr)b pc11 yp2 e/quoya:y1*l;tant acceleration of qyy:jyp21c;+1a b)zlu*pr v/kse1io $2.8 \; m/s^2$. What is the cart's displacement during the first 9.5 s of its motion?

  A bullet moving horizontally to the right (+x direction) with a speed of 532 mw-+2bi iiqoq;x8k4z b/s strikes a sandbag and penetrates aiwkb4q- ;b zqi+2ix8o distance of 26.37 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on an aircraft carrier. It reaxcu/ed w1* 1q1(6yrh67 afno ipn*tirches a s1d( or 61c*wa*6ey nt1/ii fp7xrn qhupeed 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 catapult?

  A car starting from rhuwf *05 mkh8west 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 au9jb.jid s5,m/s in a distance of 200 m. What is its average acceleration? i,uj .95adjsb

  An object starts from rest and undergoes uniform accel9y u com3 mjh/80xrzq8eration. During the first second it tra9rc m0x/mj8h8 ozyqu 3vels 4.5 m. How far will it travel during the third second?

  An object is moving in a straight line a5r4v0/-sn mfgv 5hz nwith constant acceleration. Initially it imsn4-f grha 0vvz5/5ns 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 resop d7k+7wi b:.f5x32c qphwult and accelerates uniformly at $3.0 \; m/s^2$. A second car starts from rest 6.0 s later at the same point and accelerates uniformly at $5.0 \; m/s^2$. How long does it take the second car to overtake the first car?

  A car with good tires on a dry roa +ecqkz x;k3:cd 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 has b.n8 7y1vz z3arkdobbyqx6 ) j/een waiting at the intersection starts ahead with a constant acceleratioyd3 z /1bj)zkxbqany78 o.r6vn 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 tupg ,-3xb;sa0ue +iixhe surface of planet X where the acceleration due to gravity i g,xiexu3;0sbiua -+ ps $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown upward(x z3fk/fnc: j with a speed of 12 m/s on the surface of planet X where the ac/ :k cff3(zjnxceleration 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 suz3ask9g4 fmcia5: hs lgir 68/rface of planet X where the acceleration due to grag3 4ilhgzc m/:6fr 9kaa85iss vity 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 ww td0/;p ny1o/2iddmdnhh* 2 ea7v5govx -j4a speed of 14 m/s on the surface of planet X where the acceleratoyhovvn5dwp gd ;dhiwn/- 0 d2 *2/a1m4et7x jion due to gravity is $3.5 \; m/s^2$. What is the speed of the object after 8.0 s?

  Human reaction time is usuallzr 6+rx z tznl**jjp)k 5l96ucy greater than 0.10 s. If your friend holds a ruler between your fingers and releases it without warning, how far can yoz+pju zczj* l rrl*96)xk65tn u 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 vdwss,) 0fjk(8uk ckq 6j(i7v jelocity after 3.0j f(i)v0d6s j8kq ksk(u7c,wj 0 s?

  A bullet shot straight up returns to its starting point in 8 s. What is tgij 2ak;6*sd6d9xcr+ 5bsp lehe initial speed of t* g;is6 b62djesx9kal5r+cdphe bullet?

  A ball is thrown straight up with a speed of 36.0 m/s. How long does it take trlfj 7.8niu00rx v z6ko returif 6nzu xrvkj.0l80r 7n to its starting point?

  A ball is thrown downward from the t/ot5w-fn.zgmspp:w; ) 0nnj v 3idn) xop of a building with an initial speed of 22 m/s. It strikes the ground after 4.8 s. How high is the bunmxw:nodj .zp/-)vw5spn ;0i) 3f nt gilding?

  A ball is thrown straight up*x7fq n( fhe2b3wiel 8 with a speed of 30 m/s. (only fill in numerical value inn(qi3w*bf7 e8 x2 lfeh the 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 th1o 9ozai88 jkre air with a speed of 38.4 m/s. (use $g=10 \; m/s^2$, only fill in numerical value in the blank)
(a.) Calculate the time required for the ball to rise to its maximum height.  (数值)  $s$
(b.) Calculate the time for the ball to fall back to the height at which it was hit.  (数值)  $s$
(c.) Calculate the maximum height reached by the ball.  (数值)  $m$
(d.) Calculate the ball's speed 2 seconds later.  (数值)  $m/s$
(e.) Determine the time at which the ball pass a point 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 the v-ks/uqw x8as 8elocity at t = 1.0 s?

  In Fig. below, what is the velocity at t = 2.5/xp3b.mer,b. 8t wyoo s?

  In Fig. below, what is the velocity at t =k9 07;p8cd+cmewvy f+dvlpv9 4.0 s?

  In Fig. below, what is the rm5g/ d - jwg 1zu;i1vxfrxy gt;5-1ufvelocity at t = 5.5 s?

  In Fig. below, what u3n6qhx 398 vdafg,hwis the average velocity from 0 to 4.0 s?

  In Fig. below, what is the average velocity from 5z(kiw pgf46i jee (-r0 to 6.0 s?

  In Fig. below, what is therqq 5d *+tweu g-)-a( gyx:isg acceleration at 1.0 s?

  In Fig. below, what is the accq,b7xtf+e 5rki/ 8xhk n p v0vjv+u3z5eleration at 3.0 s?

  In Fig. below, what is the average acceleratiod hr0tkmv0:xk4badm3 *5ael .vt 7(tf- *ujqr n from 0 to 5.0 s?

  In Fig. below, what is the average acceleration fbkk, wv*3veo/fsvvw npa.1z (r hi6 8e9y:ax0rom 0 to 8.0 s?

  In Fig. below, what is the displacement from 0x7h3y :f-t *v myi 4pvjlej;-y to 8.0 s?

Does a car speedometer meke81:epsb/id2p* sz8tt17ato c (jyoasure speed, velocity? {speed|velocity}

  An object can have a varying speed if its velocity is c )dpmi(p;br 3 t4eed8 d6agb6konstant.

  The velocity of an object can be negative when itk+ 2s(ijc7+ mzc -xs jd-5pjl0c/sisys acceleration is positive.

  If one object has a greater speed than a second object, the first must have a g+gfuiqnysy6 ua i. 0qk9:oz:3rei.qnoq f3za06: :9+ gskyuiyuater acceleration.

  Two cars emerge side by)rp );b4rabsl side 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 acceleration dev /, 5 8lklmz7hvzwvr9creases.

  A baseball player hits a foul ball straight up int t+lmsb.9d. -c/uoy)mox5s hr o the air. It leaves the bat with a speed oxc b9 td.ro/+5s.sm)uym ho -lf $120 \; km/h$. 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 kecm 6m/l2yoh;fry8c .(2r2 if gzxa9acceleration, how does it change if ah;.face6cg2 2y lr9k mofm/8 (zrxy2iir friction is ignored?

  As a freely falling object speeds up, what is happeningt5l05n usp y0ch.a/ip to its acceleration, how doesl0 s05nt .ciyp/u a5hp it change if air friction CAN NOT be ignored?

  An object that is thrown vertically up;+oirop n gn--h+px/pward will return to its original position with the same speed as it had initially if air resistance is negli -;i-x g+ /+popnnohprgible. If air resistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzerodfs 4;gq kq*)y 4maj8c acceleration at the same time.

  An object can have nonzero v9.2pideo) qxra wy j3 6o26ciuelocity and zero acceleration at the same time.

  An elevator moving from the second floor to the fiftmv02/ bhgl5vc3 f.,9ccpq9y9z ouewnh floor making no stops along the way has zero acceleration all the 9v q03fznu lc e,bh9gpymw2o.cc9v/5 time.

  A rolling ball movest+b5h (;-wj0qb wko8l zyi uk/ from $x_1=3.3 \mathrm{~cm}$ to $x_2=-6.5 \mathrm{~cm}$ during the time from $t_1=1.8 \mathrm{~s}$ 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 $t_1=-4.6 \mathrm{~s}$ is at $x_1=2.9 \mathrm{~cm}$ and at $t_2=4.0 \mathrm{~s}$ is at $x_2=7.6 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps aro-qv6 6jawflsb:w+ya +und a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 7.5 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, moving 87 m awd.m 9nul jilvk418i)etjee;k *bav;)ay in 10.4 s. It then turns abruptl8tn;)1uijelld; v .jkbe a 9 )m*evi4ky and gallops halfway back in 4.5 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 q8q-c7a 9cnrpg 1)-m a :uiutt$12 \; m/s$ to $23 \; m/s$ in 4.8 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 frocn q,kz /jd*-dm $16 \; m/s$ to rest in a distance of 60 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a speed ofo pj8m:l)dj yqut -)9p $29 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.1 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of the blocks to essentially tnt;g4 *kftu2sop speed abouttf 4n ugk*;ts2 $10.5 \; m/s$ in the first 10.7 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 speed ka++xfrf9,gs :edz 0 -hlou ;fof $20 \; m/s$ to rest in 5.19 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves skid marks 92 m long1k w.w rwkub /7+05 jkw.u)xj 80dz2tfyeqyea on the highway. Assuming a dbfu+ .5 z w y7w8x.jwkk0k01e2tdu)jery wa/qeceleration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a trucv+ejij0gz*xs,f;9w dalg4 d vt:)7 b jk 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 the 10,000-m run in less than 30.0 min. Aftejj5uh75ei em6r exactly 27.0 min, there are still h5 5e6ejjmi7 u1100 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?    $s$