Suppose that an object travels from one point in space to anollkm :z wlfw,l)mgv3gnrv zl ):)4en 50*s w/xther. Make a comparison between the displacement and the distance travelexwgms )lklzrvn4,:m) n*wevll f 3):/gwl0z5 d.

  When is the average velocity of an object equax 0ff3f/sdt-(jjfl17 js8l xhl to the instantaneous velocity?

  A new car manufacturer advertises that their car can go "fromcp 2jngifx 7x+ d;c0.m zero to sixty in 8 s". This is a descriccmjix fxpd0n2.;7g+ ption of

  An object moving in the +x axis ex.*m1 cre7 bwwtperiences an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car travelin69irra8 rurhg5 2d6rxg to the East (+x direction) begins to slow down as it approaches a traffic light. Make a statement concerning its accelerati hr2dagrxri66 9r8u5ron.

  Suppose that a car traveling to the West (-x direction) begins to slow down as (g x4ypnifqy 4:cun19 it approaches a traffic light. Make a statement concerning its accelerxcnq9uyin4 1:pg 4 yf(ation.

  Suppose that an object is moving with a constant velocity. Make a statnuwl 8lf8b frm 28xzaml(3x3-jv (yd 2ement concerning its accelerat(d8w3flx3 2v(lmzxna j r-mfl2b8u y8ion.

  If the velocity of an object is zero, does it mean yjc9g,rc) oyuvb (*f .that the acceleration is zero? Support your ag9job. )yrc,c f *vuy(nswer with an example.

  Can an object's velocity change direction when its acceleration is consd.gvl2q 4 w4nrtant? Support your answer wir lvnw24dg. 4qth an example.

  Suppose that an object is movin0nnx k8ft)8vf 8v+sxzg with constant acceleration. Make a statement concerning its motion with kvfvx +8ts)0x8fz8nn respect to time.

  Can an object have increasing speed while its acceleration is decrea mds-2 a/gij3msing? Support yo 3g jma-sid2m/ur answer with an example.

  Suppose a can, after an initial kick, moves up aloqz, fy 0 9zp+:exbb.nk:x/sksng a smooth hill of ice. Make a statement co/kb+z,sbsp9xqk:0y z n.:efx ncerning its acceleration.

  Under what condition is average velocity equal to the average of thbza ;jin.s57 je object's initial and7; n5b .sjjiza final velocity?

  Objects A and B both start at rest. They both accelerate at the same rate. H2m -7e4k;(cxeo7i:balf ot uwj7 eu:g owever, object A accelerates for twice the time as object B. What is the final speeow-:xb 7ojke:l a u7 igm2tue;ef(7c4 d of object A compared to that of object B?

  Objects A and B both start f*vs p;yru*e3arom rest. They both accelerate at the same rate. However, object A acceleratesr;es*y a*up v3 for twice the time as object B. What is the distance traveled by object A compared to that of object B?

  When an object is released fromls7crgu z nnmdi:8 v( p5d/sh(k 5(g2k rest and falls in the absence of friction, which ol28rgkiun(svsnh/m7(c kd ( d:z g 55pf the following is true concerning its motion?

  When an object is released f44+ jwwlypei tjq(3- ky80nnk2s :mojrom rest and falls in the absence of friction, which of the following is true conce: 8l 2nyik- j0j(jn3tswq4mpw4 ko+e yrning its motion?

  Suppose a ball is thrown straigh tm+n6tar )6kwt up. Make a statement about the velocity and the acceleration when the ball reaches th na t6m+6)rtwke highest point.

  Suppose a ball is thrown straight bbxlit4 yu2j14k 1*huup. What is its acceleration just before it reaches its highest poiu ybi2ub*t klh14xj1 4nt?

  Suppose a ball is thrown straigpaj:ot.p9hz0 /l 9a/7 why qghht up, reaches a maximum height, then falls to its initial height. Make a statement about the direction of the v9z.:pa h/ qjo9wygpl7a 0h /thelocity and acceleration as the ball is going up.

  A ball is thrown straight up, reaches a maximum height, then falls to 92*kr1uzdnt8 7yv6n2v p 67 njsaoqor its initial height. Make a statement about the direction of the velocity and acceleration as the ball is cu1r *8 jr67o9ytpnzknov2s6aq 2d7 nvoming down.

  Suppose a ball is thrown downward in the absence of epaxy5qdn4- :air resistance. Make a stateq-a y4en:pxd5 ment concerning its acceleration.

  Suppose a skydiver jumps from a high-flying planimz d.7)q*q ,pu3r-hmjnn1e ie. What is her acceleration wheniqpzn 1r .qh*n)7d 3jieumm,- she she reaches terminal velocity?

  A ball is thrown vertically upward w;,k/ r y;nrpsk0o8 rsjith a speed v. An identical second ball is thrown upward with a speed 2v (twice as fast). What is the ratio of the maximum hes;s k,nyrj8rrp/; 0koight 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. (sur 47n9vhv tic3ktj 5zy; 9b One second later, ball B is dropped from the same building. As time progresses, the distance between h;4jb is9n5vvc 7(3zku9y ttrthem

  Ball A is dropped from the top of a building. One secontt;*nmy42 p(.d yrw9wy dq3s ud later, ball B is dropped qtm2s4yrdu(9 pwdyt3 .; y *wnfrom the same building. As time progresses, the difference in their speeds

  Two objects are thrown from the top of a ta zmv hvuo(yb-i3g n66v74op ;all building. One is thrown up, and thu3by o 6vm(v6av7nizopgh4 -;e other 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 sec2o /c5.fgf fhbond brick is thrown straight down from the same building. They are released at the samebf5g hf of2c/. time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with constant non-zero velrlvp;o92 *u i+se p 7ocx4qw-mocity in the +x axis. The position versus time graph of this or-lo4qps +mu ci2x vow9p;*e7bject is

  An object is moving with constant non-zero accelerdde .a 2-ah;vay+7t uwation in the +x axis. The position versus time graph7d tew.ahd- vau;y2 +a of this object is

  An object is moving with constant n 1v/e /rf ctyy+k/4 ct5rsiuz;on-zero velocity in the +x axis. The velocity versus i ;uv/rtf e4/k+ s/yyt rzcc51time graph of this object is

  An object is moving with constant non 8tiw 5rbosq x:((g/qohtl02 m-zero acceleration in the +x axis. The velocity versus time graph of this objglto 8w/oqi(bqm( h05x2 t:rs ect is

  The slope of a position versus time graph givesv j(cd 1ldfejjm **5e7 6jy -bflvmb:7

  The slope of a velocity versus time graph g0*7g d1ssw hr 4 eqpw.u/q3lfcx7r -mqives

  The area under a curve in an acceleration vers j7v0cn;svrsm12y p+k: ka:hrus time graph gives

  The area under a curve in a velocity versus time graph giveyq i.zv0w,. yvs

  If the position versus tim,jb q0pi* raq2 (qj )uhlr.ulz3 b/jr6e graph of an object is a horizontal line, the object qjuqhju2ba r0 6rbrq,p/) *3l.(lzij is

  If the position versus ti wuntt5q4cufn; )( at9me graph of an object is a vertical line, the object isutqcn( tnt 549;f)uw a

  If the velocity versus time graph of an object is a horizontal lina50j79nw z 0 e/iwdbqje, the object isqd9j 7z 5jn/0wabeiw0

  If the velocity versus time graph of n*lqwky r567l an object is a straight line making an angle of 30 degrees with t5lk76q ny rl*whe time axis, the object is

  An object moves 15.0 m north and then 11.0 m south. Find both the d8*u 0bbnaaabc;uxo-f ; s 7,sfistance travele u cnb-o;8 *a,bx ua0fsa;bfs7d and the magnitude of the displacement vector.

  A boat can move at 30 km/h in still water. How lonqys ,8 xgq)z+8f howm j3+bfg*g will it take to move 12 km upstream in agq+ 3 sfo*) gmqzyjf+8,bhwx 8 river flowing 6.0 km/h?

  55 mi/h is how many m/s?mcl0qrk- m- wf: oi-;l (1 mi = 1609 m)

  What must be your average sp8e)f-+brgy+ g o*qjxteed in order to travel 350 km in 5.15 h?

  A runner ran the marathon (approximatec,.5ag2n a /zohd59z9 arokg xly 42.0 km) in 2 hours and 57 min. What is the average speed of the aozc9dr 55 2xn/aaz, h9og kg.runner in m/s?

  A car travels 90 km/h. How long does it take for it tomxv(;ly d uaux ps)v74n5/g-f9vwhv; travel 400 km?

  A ly (light year) is the distance that light travels in one year. The sp x:yv/v-x2stb jn38 ju ill4h8eed of lightnbu 3 2i8lhvj-8ysxjtlv :x/ 4 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 the side for 4.j tiq4k)0/dxdv/-g4s au5wk/1brirz 0 s, how far do you travel duigx/ v 0zd /krrk4 tw/5u)adi 1jq-4sbring this inattentive period?

  If you run a complete loop around an outdoor t,/s 5pvpfnqe0qk; * furack (400 m), in 100 s, your average velocpqn v f0,spk/;5e*fu qity is

  A polar bear starts at the North Pole. It travels 1.0 km south, then 1.0 km v8vlxr-i+mk7mf:3 bcut e a3mx5s*q, east, then 1.0 km north, ts:m m v xb q vlmafux+,3ei-krct*7385hen 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 travels 1.piauf*fl3lvnl:e248 dq6 y7x0 km south, then 1.0 km east, then 1.0 km north, then 1.0 km west to return to its starte 4d*yv f2nx8qpall7u:i l6 f3ing point. This trip takes 45 min. What was the bear's average velocity?

  You are driving home on a weekend from schs* p;6pg 5vphfwm4y,(h0e9ht6aurdbool 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 1g406 6 sewv*f9dhth ;5pymup rp bh,a(5 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 r l+5mz.: mgf4pps k; ldmqk01is the average speed of the motorist flflpq. :gmsr k54;k0z+1pmd m or this trip?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h. What is her50m esg/uv+pcjo bq0, average so,pesumgj /+q 5cvb00peed for the trip?

  An airplane travels at 3q fbb caqk 36x0z:q6.d00 mi/h south for 2.00 h and then at 250 mi/h north for 750 miles. What is the average speed for the tq 630qad f.6zx: kcqbbrip?

  In a 400-m relay race the anchoww g3p /-2 fn4np9bcfqrman (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 runnf ngcbp/ p432qnfw 9-wer 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 a stop after 9 s. The car's ckaz3*np6*naa4 *+r2nz wuj f average velocity duan2acr4z*fn nw6* 3 p u+*zakjring deceleration was 80 km/h. What was the car's deceleration while slowing down?

  An airplane increases its n 0 g u+k-gza+mnsv8rbso96ore,m:g -speed from 100 m/s to 160 m/s, at the average rate of nvrm :a-bro +86gngokzmg,s -e9u0+s$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerates at the ratey8 xj9x*ts 55 lwb)etp 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 accelerat xb,x4f7 7qy6zu+b0wnxfgv 2 kes at $4.0 \; m/s^2$ for 5.0 s, then maintain that velocity for 10 s, and then decelerates at the rate of $2.0 \; m/s^2$ for 4.0 s. What is the final speed of the car?

  A car travels at 15 m/s for 10 s. It then speeds up with a cg ek17cv..nlg9(1s )eidyi gar9at x8onstant acceleration e vi(xld gte)8ya9k as.1gn97gc.r i1of $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of in4ouuznjd:er f :+56+xwy r, 4.9 m/s experiences a constant acceleration or fr:: ux56z+y od,inen wu+4jf $4.6 \; m/s^2$. What is the cart's displacement during the first 6.0 s of its motion?

  A bullet moving horizontally ts d5*o+ o/q em6beot4do the right (+x direction) with a speed of 289 m/s strikes a sandbag and penetrates a disbdo/*oq+s5 to6 4e edmtance of 70.01 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.y*k hu 6xuhwxuejf9itrc8f; 08+/id 1 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 ux8* d/8fh k0 16u;hi9eycwf+xuijrt length of the catapult?

  A car starting from rest moves fpz3rrkc (:t; 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 i9eckb( y7sw/ a-8kiu hts average accelerat7w(8ucabe ys/k -i 9khion?

  An object starts from res2cv55uy+fwi5 thlg 7y t and undergoes uniform acceleration. During the first second it travwh52tcy5 7y 5iflug v+els 1.8 m. How far will it travel during the third second?

  An object is moving in avmgcpcvumgc4vl2k,de-:9 n2 /5 :uub straight line 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 tu:-g4 vl bkcc v5umn,m/pucd9ev2g:2 his time?

  A car starts from rest and accelerates unifo )fj6;xnh9 uknrmly at $3.0 \; m/s^2$. A second car starts from rest 6.0 s later at the same point and accelerates uniformly at $5.0 \; m/s^2$. How long does it take the second car to overtake the first car?

  A car with good tires on a dry road can decel+ y+;9qk u,c- a03 n1m-plutsdvosfmgerate 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 waiting at thvmnw8.v5 gmj/ e interse 5v ./8jnmmgvwction 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 spvd ac rgc8yojbi0h nm; -5,;u2eed of 12 m/s on the surface of planet X wherhcmn 8g ,boi uyd5; ;02-vajcre the acceleration due to gravity is $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown up (r6 xzlbly f38sr)mqtx0 8(sbward with a speed of 12 m/s on the surface of planet X where the accxyx3b(sr8 sz)rlqlt 0bm( 68feleration 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 sur ilshv niqao7:0zf ;05face of planet X whereilfqv i0s;z0h:5ano 7 the acceleration 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/sutdnj *r )8.wcl ta*8s on the surface of planet X where the acceleration due* c.)8lsdarn * 8wttuj to gravity is $3.5 \; m/s^2$. What is the speed of the object after 8.0 s?

  Human reaction time is usually 9( ; ndx:hhyjkgreater than 0.10 s. If your friend holds a ruler between your fingers and releases it without warning, how far can you expect the ruler to fall befoydj ;9:(kn hhxre you catch it?

  A ball is thrown upward at a velocity of 19.6 m/s. l )*lgzvzq 1p4What is its velocity after 3.00l*pgvz l14qz) s?

  A bullet shot straightktl(b ra/0-ls up returns to its starting point in 16 s. What is the initialb0sl/rt a-lk ( speed of the bullet?

  A ball is thrown straight up with a speed of 36.0 m/s. How long does it take t-lyb0p :d 4cc)u)kfcno r): l bu0)-yccfd4 kcpneturn to its starting point?

  A ball is thrown downward from the top of a building withajyai*pg4z/h9 2sqg *pd . br(xwt+w 4 an initial speed of 24 m/s. It strikebtrys *+/ wpxhd ( 92 g4wg.4p*jzaiqas the ground after 1.4 s. How high is the building?

  A ball is thrown straight up with a speed of 30 m/sdkyqh, i.x;c za+ .zuve*u, y1t.c3wv . (only fill in numerical value in the blanks)chwa;t.*+3.ey yq. uxvdzkc 1 z,,viu
(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 ot( fq* c kg zm:r5jbeb4fl6 11-iu0acsf 24.5 m/s. (use $g=10 \; m/s^2$, only fill in numerical value in the blank)
(a.) Calculate the time required for the ball to rise to its maximum height.  (数值)  $s$
(b.) Calculate the time for the ball to fall back to the height at which it was hit.  (数值)  $s$
(c.) Calculate the maximum height reached by the ball.  (数值)  $m$
(d.) Calculate the ball's speed 1 seconds later.  (数值)  $m/s$
(e.) Determine the time at which the ball pass a point 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 = 13ey (h 7j+8aslzc f(cve8jp 9w.0 s?

  In Fig. below, what is the velocity at t = 2.o24 gw 4+ox0eygekt1h 5 s?

  In Fig. below, what is the vuf-5z mfrm rb;e* j2/uelocity at t = 4.0 s?

  In Fig. below, what is the velom,d s )f+o1drdcity at t = 5.5 s?

  In Fig. below, what is the average v7gtsp5n:*j39l d6t uc j2+kxes p9km aelocity from 0 to 4.0 s?

  In Fig. below, what is the average velocity yyju m5(l qb9)from 0 to 6.0 s?

  In Fig. below, what is the acceljsy4zz00y o/gx3tx k7eration at 1.0 s?

  In Fig. below, what is the acceleratio h:;x y m;9sd2s*uttoxn at 3.0 s?

  In Fig. below, what is the average accelerarf *ho) 11hqgfx88b isgzgrmktklsu58/ q ,*4 tion from 0 to 5.0 s?

  In Fig. below, what is the average x4ialg 6:a5foxi ;i2e acceleration from 0 to 8.0 s?

  In Fig. below, what iy;k6a, jtrf9 bs the displacement from 0 to 8.0 s?

Does a car speedometer measure speed, veloo i c,c+o tl/ck(7y1srcity? {speed|velocity}

  An object can have a varyikyo l038 eef: ;xy)lypng speed if its velocity is constant.

  The velocity of an object can be negac; ih5e8b+wogtive when its acceleration is positive.

  If one object has a greater speed than a second object, the first :a;ga.+il*g gi8ty6z mumx*i 02k bhsmust have a greater gt.xy;ui0*amgkb 8g:zi*+lai2m hs6 acceleration.

  Two cars emerge side by side from a tunnel. Car A is trav2mn p e(03wi5q)stolfeling 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 sp o lgm0r:6:y0t;s gzdreed as its acceleration decreases.

  A baseball player hits a foulau2t 74uzclbyg-k ns; cy;:+a ball straight up into the air. It leaves the bat with a t lcauy+s7gnyb4 -kz;u c;2:a speed 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 spee jmow8u a5,snqa-(.ebds up, what is happening to its acceleration, how does it change if air friction is ignorea(j5 q, aewsm.u-8bond?

  As a freely falling object speeds up, what is happening to its acwvjeu8fbsh1m 0g/ *si7w*9ozceleration, how does it change if air friction CAN NOT m0s b/w7e* ijgvfuoh89*s 1zwbe ignored?

  An object that is th//0vfy5 ir4akl:5yazt6i ug y rown vertically upward will return to its original position with the same speed as it had initially if air resistance is lr 4y if 6:y 5v/izkagt0u5/yanegligible. If air resistance is appreciable, how will this result be altered?

  An object can have zero p,qkxrq; x0pj lsk00 -velocity and nonzero acceleration at the same time.

  An object can have nonzero velocity and zero acceleration at the sam/gv3:zc6 rdbf5nn2jgtu/s 7 wsam1 0xe time.

  An elevator moving from the second floor w 54y, 6hs4tbaeeuxbygmy3fd1 /l) t 1to the fifth floor making no stops alonyx4y s6be /ab41w)e3yu5f 1gdtlh t,m g the way has zero acceleration all the time.

  A rolling ball moves from/lemcgb.vk* 5o3 y+b. 8l v;ia j8hwbe $x_1=2.1 \mathrm{~cm}$ to $x_2=-7.4 \mathrm{~cm}$ during the time from $t_1=2.0 \mathrm{~s}$ to $t_2=5.9 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-2.5 \mathrm{~s}$ is at $x_1=2.3 \mathrm{~cm}$ and at $t_2=4.5 \mathrm{~s}$ is at $x_2=7.9 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps around a quarter-miw jhl eavzp8wem:; )2g c+td/9le ($1 \; mile = 1609 \; m$) track in a total time of 12.5 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, movv - ll092;ljnmiwntxg-be4i /ing 105 m away in 12.2 sn20-lx lm 4l9vgi betwnij/- ;. It then turns abruptly and gallops halfway back in 4.6 s. Calculate (a) its average speed  (数值)  $m/s$ and (b) its average velocity  (数值)  $m/s$ for the entire trip, using “away from the trainer” as the positive direction.

  A car accelerates froggum/ ;;b(,.e qh jqim 4qua*bkaav 6:m $11 \; m/s$ to $24 \; m/s$ in 5.8 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 from 6bkfx) n d:ud6$18 \; m/s$ to rest in a distance of 79 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a speed 1lvx. vyrg-x-5* jv yjw+7lse of $30 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.3 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of the kc dd8orrm22 1blocks to essentially top speed about2omr2d18d rkc $10.1 \; m/s$ in the first 12.3 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 aov3(1 qndj5gg n4mpvt qp s-)* speed of $20 \; m/s$ to rest in 5.69 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves skntcxo/,n8zdr 7i qay7 258 iqaid marks 92 m long on the highway. Assuming a deceleration of o da8rqtq5n nc7iy /82z,ia7x $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$