Suppose that an object travels from one pgg .ddnvm332(ig cxv(oint in space to another. Make a compari g3i(gv(m.dv dg 23cnxson between the displacement and the distance traveled.

  When is the average velocity of an object equal to thesdis2rqb7; 0m0 e6 4ijql xwiaa,mk3 + instantaneous velocity?

  A new car manufacturer advertises that 06.d /b 2kro54lk5ni;q pahvxnatt;etheir car can go "from zero to sixty in 8 s". This qd;n2ibthrkela5o.p /46 ; n0 k axvt5is a description of

  An object moving in the +x aximh):d g24tkns s experiences an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x direction) kdzo(x n,qzgj9k 8v04begins to slow down as it approached,8 z9(qjgnkkz4vo0x s a traffic light. Make a statement concerning its acceleration.

  Suppose that a car traveling to the Westr9pk,k4l w(su qtt l:*7g 6no1pae -uc (-x direction) begins to slow down as it approaches a trt*(srlla kwk4pgo91 6up7ectu n,-q: affic light. Make a statement concerning its acceleration.

  Suppose that an object is moving with a cons)9w(b km8zyx sf+jn .,pp o7:bkxpp. ktant velocity. Make a statement conknp.(k bf :xkz8po bx7,m.y9sp wj)+pcerning its acceleration.

  If the velocity of an object is zero, doesz n+f:p+ xltj3ri s(2t it mean that the acceleration is zero? Support your answer wit3rit t: n2 +fl(zjsx+ph an example.

  Can an object's velocity change direction when its acceleratiosq4 * dnf ,8zlig*i8*xr .sv t9n8kqnhn is constant? Support your a8 8tl8d r *sn,k9h.fivz*nqsx*ngqi4nswer with an example.

  Suppose that an object is movlc djzyh (7s-+ing with constant acceleration. Make a statement concerning its motion with r- cy(zs+h7ld jespect to time.

  Can an object have increasing speed while its acceleration is decri* lm4r1 ti1.xjfp 1edeasing? Support your answeri114 1 t.dx*rlfmp ije with an example.

  Suppose a can, after an initial kick, moves up along a)vrecr4 hi4 1w)4o,ipq45j 3dujhrxe smooth hill of ice. Make a statement concerning its a ri3 c5vu)reqe41ojd,44irp wxj h4) hcceleration.

  Under what condition is average velocity equal to the average of -fo4rw,,rsmi a-y)ovc b;t x/7ai;nnthe object's initial ani7xvtfor/ ) ay,s;rnb ,c;-o-a mnw4i d final velocity?

  Objects A and B both start at rest. Thehg.x:o:30ryrrk4ppi y both accelerate at the same rate. Howeve .ix0rr 3pphg:4r:kyor, object A accelerates for 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 from rest. They both acceleranj8usoj+ z dx0pf..1 yte at the same rate. However, object A accelerates for twice tdu1 zs.yf. ojn08+pjxhe time as object B. What is the distance traveled by object A compared to that of object B?

  When an object is revys d +4pa)i;ileased from rest and falls in the absence of friction, which of the followin4+)d vpi; isayg is true concerning its motion?

  When an object is released from rest and falls inp f4 ,)g*t5 jwqujwbk, the absence of friction, which of the following is trb) ww ,f*gkpj5qj4ut,ue concerning its motion?

  Suppose a ball is thrown straight up. a0zz:mo*j(a xp 4tj-st/mx t: Make a statement about the velocity and the acceleration when the ball reaches the highest poi:t aj/pamtos-z*:x t4xj 0( zmnt.

  Suppose a ball is thrown straight up. What is its acceleration juw 8 4o05 fosiq-k3vowgst before it reaches is-wok3vfgw 58 oo4q 0its highest point?

  Suppose a ball is thrown straight up, reaches a maximum height, then falls togl ij.e, zh *0qz8qrg9 its initial height. Make a statement about the direction of the velocity and acceleratiqhz0jz9eirl 8qg.g*,on as the ball is going up.

  A ball is thrown straight up, reaches a maximum height *hphzemnbg))c ja6 v.(4 ;kcv, then falls to its initial height. Make a statement about the direction of the velgnecv.* hhk 4c)(pm6)ba j;zvocity and acceleration as the ball is coming down.

  Suppose a ball is thrown dot nsj 5h2nr7ekzl:5hvvr3, )jwnward in the absence of air resistance. Make a statement concerning,nk 3)nv5h er2lzrthjs :v7 5j its acceleration.

  Suppose a skydiver jumps frovc7gt5myqa- t3ors(8 de m6slpnu(. )m a high-flying plane. What is her acceleration when she she reaches terminal6puc tns8lvdqs .g(57re-y tm(a3 om) velocity?

  A ball is thrown vertically upward wip,)a-*w;zmgijnjq/,qo c a0 q th a speed v. An identical second ball is thrown u0g,/w -iqo* q anc)jqpm;j,azpward 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 ball?)

  Ball A is dropped from the t)l ozd- igvoxep1 e6bj,;.(2 yglem1zfd+ (xeop of a building. One second later, ball B is dropped from the same building. As time progresses, the distance between them.gb,ev)6lezo(g12 x 1ed d;lzx( op+yij -emf

  Ball A is dropped from the top of a building. One second lke 5l vun8p d;zjuc3.*khbttd 6a2b79ater, ball B is dropped from t3kv*n 79hta 6lt ezujp b;5 dbu2kd.8che same building. As time progresses, the difference in their speeds

  Two objects are thrown from the top of a tall buiiqaqm sk+biv5a;qr n83 c-2j5.j ywg ;lding. One is thrown up, and the oya;q- awm.; kcis r+j535jvqb2 iq 8ngther is thrown down, 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 brick is thrown sts ;r t, kdjir/409)sligz kzi/.wu 5sxraight down from the same building. They are released at the samzsk/)d.zgls 90kj5;i4iitu/,r r s xwe time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with constant non-zero velocity in the +x ax fc8q5o zxj44ar;gu 2:;ox vixis. The position versus time graph of this object 4fqo j;x;8 z5 4:ugxrcix2oav is

  An object is moving with constant non-zero acceleration4cg;nrx irg. cvj8q/3hu p3b2 in the +x axis. The position versc 2g4gpxiq3cu8rjv 3r./bh; nus time graph of this object is

  An object is moving with constant non-zero velo6kf+nq /ctcl5m)bw/ a city in the +x axis. The velocity versus ti b/nf q6lcc+)5mw/a ktme graph of this object is

  An object is moving with constant non-zo7hyj 849 qojhero acceleration in the +x axis. The velocity versus time graph ofoo98 jhhj 4q7y this object is

  The slope of a position versuugwm ci9(e4e b6rk-w4s time graph gives

  The slope of a velocity versus time grap b(p ao6,apcln7a1g( hrji4(zh gives

  The area under a curve in an acceleration versus time graph givesl-( yzblkz,j0p qqc6w95uqlm9waz/6

  The area under a curve in a velocity versus tiabj5g 37 :3vl9xkkm dcme graph gives

  If the position versus time graph of an object is a horizontal line, th6z j3np,vj0rce object rpv,03c 6jjnzis

  If the position versus timejmh,s7 24hsvq graph of an object is a vertical line, the object is7jhm ,hs2sv q4

  If the velocity versus time graph of an object is a horizontag(d;b o4kn7 vw cb-wi(t4q0hj l line, the object iw tvc(0jdb ikobg 7h n4(4qw-;s

  If the velocity versus time graph of an object is a straighc nuu+l7r0-t f zi. :lgrfp-;st line making an angle of 30 degrees with the time axis, pzcru7t u+.sf:0 fnli-r ;g-lthe object is

  An object moves 15.0 m north and then 11.0 5r , 1gar1p9e-t3ffvp0 e ugtem south. Find both the distance traveled and the magnitude of the displacement eft ,-p01 v1p5rg93tfae uegrvector.

  A boat can move at 30 km/h in still wate )1 ou3s c+mexiyau,(br. How long will it take to move 12 km upstream in a river flowing 6.0 km/h) sy(a ,ocbmu31+uxie ?

  55 mi/h is how many m/s? (1 mi = 1609 m,l- w07z yvq.l03kgbw;d gpernjw: h +)

  What must be your average speed in order to travel 3509ih or6pg4/b nz7s2 wd km in 5.15 h?

  A runner ran the marathon (approximately 42.0 km) in 2 hours and 57 mif0) 1wit 0)z (jcczqexn. What is the av1 zxiw fz)qjtc)c0(0e erage speed of the runner in m/s?

  A car travels 90 km/h. How lonkonop j10 r(x0g does it take for it to travel 400 km?

  A ly (light year) is the distanc:e.ql5h + +egt7dvg89wwodw5qn0asy e that light travels in one year. The speed of light is0 dg5ltq ao7 eqs8dweywh.9w +:+n5gv $3.00 \times 10^8 \; m/s$. 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;sv d84w9rmjj you look to the side for 4.0 s, how far do you travel during this 94mwrdj;vs j 8inattentive period?

  If you run a complete loop around an outdoor track (400 m), in 100 s, your ) -kkpic: ypf7yji*5n 3: x*s by,cwmnaverage)57 m3c*b ,f pkx wnyyi:i*y pnk-cjs: velocity is

  A polar bear starts at the North Pole. It travels 1.0 km south, then 1.0 km spagiu35+ *1ilski)veast, then 1.0 km north, then 1.0 km west to return to its starting point. 1s vl i5iksi*u+a3) gpThis 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 km7:6dgoa )bpp rupb k28 t.7(x0zbclkf east, then 1.0 km n dockx u pt g6k ba0lp7bz.p)fr7(8b2:orth, then 1.0 km west to return to its starting point. This trip takes 45 min. What was the bear's average velocity?

  You are driving home on a weekeny8be40 nkzx) d. r:egpd 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. H dg8b )4 exnkp0z.yr:eow far is your hometown from school?

  A motorist travels 160 km at 80 km/h and 160 km at 100 km/*svqa, adqtxy ac y/7u 99d5e+h. What is the average speed of the motorist9 /tvcaya *dyd5ux,q79sa + eq for this trip?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h. Whc rpb uruv7,pvq 4b,p1gkx1/+ at is her average x vv4bp+upc11q7,,/uk rb gr pspeed for the trip?

  An airplane travels at 300 mi/h south fo eh+8ld7jzbb.r 2.00 h and then at 250 mi/h north for 750 me . 7+bbz8hdljiles. What is the average speed for the trip?

  In a 400-m relay race the anchorman (the person w)lo :e8 *p.1afd .kl;oz uhyp7d8nejdho runs the last 100 m) for team A can run 100 m in 9.8 s.)8e*k: pd lzy8o;d1ulhn jpao7 edf.. His rival, the anchorman for team B, can cover 100 m in 10.1 s. What is the largest lead the team B runner can have when the team A runner starts the final leg of the race, in order that the team A runner not lose the race?

  A car decelerates uniformly and come5iy j w .3(1a3w1juz(imlfb hps to a stop after 10 s. The car's average velocity during deceleration was 57 km/f 1a1pujy.mi3h zbwil 3( w5j(h. What was the car's deceleration while slowing down?

  An airplane increases its speqa1n0kksp + z9 8rf2ixq7hj l9ed from 100 m/s to 160 m/s, at the average rate of s8kfj2+0pql qahi99 n71 rkxz $15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerates at the rate of njn y+w 0dbqnx(l20l5)b9 tyr$2.0 \; m/s^2$. How much time is required for the car to reach a speed of 90 km/h?

  A cart starts from rest and accelees.8-ho7a h 9hfj6j damzxx xa,w *35erates 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 rgmzu owt8ccfk a -k:gt3j2cqj;r.-q75//q g a constant acceleratio37-rtr8qct z/;qoujm .j: g cwf5/-g2q kc agkn of $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocityi-qukoney0y1kjgt/ wd 7;9l 8 of 2.0 m/s experiences a constant acceleration of gj-8 ;y w0 7oi/ye1nqdtk9klu$3.0 \; m/s^2$. What is the cart's displacement during the first 5.1 s of its motion?

  A bullet moving horizontally to the right (+x directiogjg9t1r x94:exjofdsuk1 j 2;n) with a speed of 427 m/s strikes a sandbag and penetrates a distance of 37.58 cm. What is t;9jfx 1urx2oj14geg9: tsj dk he average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on an aa3m 9oshj6mt1ircraft carrier. It 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 h 9jts 61ma3omof the catapult?

  A car starting from rest moves with constant acceleratif(7re(c gtpzg ,g;e) bon 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/sa :;debam;e 8p in a distance of 200 m. What is its average accel:m ae b8daep;;eration?

  An object starts from rest and unde /e/8d+x//ezg6i jsv;l hmv2 c dx+vlmrgoes uniform acceleration. During the first second it tr d/dvj/8xm hv6 eg/2s + v/zcl+eilm;xavels 5.0 m. How far will it travel during the third second?

  An object is moving in a straight line with constant acceleration k7csxffdhw74tqy5 dn i218v*. Initially it is traveling at 16 m/s. Three seconds later it is traveling at 10 m/s. Hod5kwd*f yxfcs 4h77tiv2q n18 w far does it move during this time?

  A car starts from rest and ac gs+ d9 1asz-z g2tl1+reyh:0i(p ,gdanc y(xacelerates 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 j/cf ti;rdd+air)b,sj(1m p 7b rn.2m 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 has been wt+h5tmo y)ca9 aiting at the into th+5)mtya9cersection starts ahead 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/sxwb.: ypco 81i on the surface of planet X where the acceleration due tocpyb:x w. 81io gravity is $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown upward with a speed ofhn89 frl0hkf. 12 m/s on the surface of planet X where the acceleratior hk fn9l8.hf0n 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 surf irp b nn) e+74ho3dz0mfn*u-dace of planet X where the ac03ne p b)nodd4num+i*hzf7 r- celeration 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 uln) t(ol7+/wn9 ukhjw pward with a speed of 14 m/s on the surface of planet X where the acceleration j7ut o+kw)lnln(w9h/due to gravity is $3.5 \; m/s^2$. What is the speed of the object after 8.0 s?

  Human reaction time is usually greater than 0.103z g yc61pusr- s. If your friend holds a ruler between your fingers and releases it without warning, how far can you expect the ruler to fall berz6p 1-uc3 sygfore you catch it?

  A ball is thrown upward at a velocity of 19.6 m/s. What is its velocity after+x1mm1o0feu) s bb6u , (rackh 3.00 ska0m f xusb1cb+ro,(6h)1ume ?

  A bullet shot straight up returns to its starting poin tpj9v 2je-)g +jrr,stt in 10 s. What is the initial speed of tr 9 pj2tr)v-tjj, esg+he bullet?

  A ball is thrown straight up with a speed of3h 948 t /mlz /fblke.udq+fvn 36.0 m/s. How long does it take to return to its starting poind u9lv.zlt8 qkbehf fn+ 4/m/3t?

  A ball is thrown downward from the top of a building with an initial speed of z;rx,k1tl; e5x-hge:y ew9 val+ zfk, 7 m/s. It x fekt1-e,a9e, y:whz5vkz;;l+ lxgr strikes the ground after 1.6 s. How high is the building?

  A ball is thrown straight up with a speed of 30 m/s. (only fill in nume4* ow:y.l 9s e3ur(vju)rhfu vrical value in theu9f(ors3 h re)u.v* u:yv4wlj 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 :fxw5)fdo, ob with a speed of 48.4 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 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 ve l wm;0hyckv q:5a cguen0:y1( d-;wyilocity at t = 1.0 s?

  In Fig. below, what is the velocity at t = 2 t0pr31wifc e.3on du(.5 s?

  In Fig. below, what is the vel +equs f2-4(5ahys cer )hbhb-ocity at t = 4.0 s?

  In Fig. below, what is the velocity a(iwshga/)ib-1 lji +at t = 5.5 s?

  In Fig. below, what is the average velocit.trw0oxj1 cqgr9d/ 0my from 0 to 4.0 s?

  In Fig. below, what is the argwd b9:we*4q verage velocity from 0 to 6.0 s?

  In Fig. below, what is the acceleragqz(0ybp7 c5 qd / :blq/dph2wtion at 1.0 s?

  In Fig. below, what is the acceleration atfi. / smp*p8zb 3.0 s?

  In Fig. below, what is z h *0 /zx11 cs5txurpwuut,p8the average acceleration from 0 to 5.0 s?

  In Fig. below, what is the average acc ;;uqc(5te4wxavrk w *eleration from 0 to 8.0 s?

  In Fig. below, what is the displacement from 0 to 8uo)uh66s 4bvf .0 s?

Does a car speedometer measure speed, velocity? {speed|c q.xi:b3n)89j9mj/l kbv. 6wi xtss dvelocity}

  An object can have a var,/;/(d+*r9zu c apk qbbvg1rsg4 zfhuying speed if its velocity is constant.

  The velocity of an object can be negative when its acceler7d; oghcd*wp,ation is positive.

  If one object has a greater speed than a second object, the 0u54wskz 0jscfirst must have a greater accew05jcsz4k0 suleration.

  Two cars emerge side by side from a tunnel. Car A is traveling with a speedmlo-*raj pu:. 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 acceg 8-/uv*u dj oeut*-,wobz/exleration decreases.

  A baseball player hits a foul ball straight jxz6f zv6f1 s3up into the air. It leaves the bat with a speed ofvsf61 zj 3x6zf $120 \; km/h$. 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 olccs* 4zo k/wx/6d + wx2dqs(tbject speeds up, what is happening to its acceleration, how does it change if air frictiols4x wo 2cdw(+/xqsd*kzt c /6n is ignored?

  As a freely falling object speeds up, what is happen2.v ow*no(jmw, l )iajing to its acceleration, how does it change if air friction CAN NOT be i(,lma v*o 2)w.n jwjoignored?

  An object that is thrown vertically upward will return to its original position q4lpr(s9.ob5;l;cp4lki7 tf kimf fa44sx 4twith the same speed as it had initially if air resistance is negligible. If air resistance is appreciabb 9ct l ppx4af;ll5f;. 4kms47 4irit(4qs kofle, how will this result be altered?

  An object can have zero velocity and nonzero acceleration at t j1xh0ng imau8l(e,s9 he same time.

  An object can have nonzer5pk5. 0 zwa.p2gxkd)d8 6c ffo dugf+ao velocity and zero acceleration at the same time.

  An elevator moving from the)q -s8vws5+ht;iya n35( ev0ropws bc second floor to the fifth floor making no stops along tvwqvts) ic8 5ey+n 3sa hwo0s ;5rb-(phe way has zero acceleration all the time.

  A rolling ball moves bg0v,1u ww)peuzpj * kp 7m/v)from $x_1=3.0 \mathrm{~cm}$ to $x_2=-7.6 \mathrm{~cm}$ during the time from $t_1=2.4 \mathrm{~s}$ to $t_2=6.0 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-4.2 \mathrm{~s}$ is at $x_1=3.2 \mathrm{~cm}$ and at $t_2=4.4 \mathrm{~s}$ is at $x_2=7.7 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight comcq/9.k xqe;pgj8a+ 1k3 intglplete laps around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 6.5 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,) hfsy6hlh/yff 4n 5n9 moving 100 m away in 11.2 s. It then turns abruptly and gallops halfway back in 4.6 s. Calcus)9hyny nlfhf 45hf6/late (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 8ylz- wq qmdpx3 b6up(*( w3js$12 \; m/s$ to $24 \; m/s$ in 4.6 s. What was its acceleration?  (数值)  $m/s^2$ How far did it travel in this time?  (数值)  $m$ Assume constant acceleration.

  A car slows down from -:4m)qr0t b.ghtto ys $16 \; m/s$ to rest in a distance of 70 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must rea ze2v cthzm.0khl5 *b zku01do+h5c8wch a speed of $27 \; m/s$ 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 blocks to essentially top r+e:zzyy)lbtco,q(; speed aboute z,y+rboc :l ztyq)(; $11.0 \; m/s$ in the first 12.8 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+geom78b 8)fmr,nc m jly from a speed of $15 \; m/s$ to rest in 4.72 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves skid marks 92 m long on)ou s * ,d+kzpnljn7x- the highway. Assuming a decelerationp +k)-n do*j7,slnzxu of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck g/p87 ja eg,azv8xt s9boing $25 \; m/s$ 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 t 3h1:wdo 7rylchan 30.0 min. After exactly 27.0 min, there are still 1100 m to go. The runner must then accelerayhc1d:wo3 r l7te at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$