Suppose that an object travels from one point in space to another. Make a 0yx 9b*3waksccomparison between thk3wbxc0 9 *saye displacement and the distance traveled.

  When is the average velocity of an object equal to the instantaneowhf;k 20ox0:fiowl *l us velocity?

  A new car manufacturer advertises that their car can go "from zero to s);+wus ylgrw( 8c/ 8ihs*vz irixty in 8 s". Thzs8+ c)iry(wh8/u*swl virg; is is a description of

  An object moving in the +x*-(d jymbe pego2zrzv0w 3tj4iq jo;;rf*:r , axis experiences an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x direction) begins to slow down a(jx e0h4 g9y biej7lv(s it approaches a traffic light. Make a statement concerb hexg 9 (ij7j0e(4vylning its acceleration.

  Suppose that a car traveling to the West (-x direction) beg3 yc tq*rle;q: 6lzev4ins to slow down as it approaches a traffic light. Make a statement conclz:q;*6 vtlqcy4 e re3erning its acceleration.

  Suppose that an object is moving with a constant velocity. Make a s0azirj1 8qug cqbmgo:8s75 a7tatement concerning its acc cbz 718omrjia7gu: qg s85aq0eleration.

  If the velocity of an object is zero, does it mean tr5y4.22g4b qgd jkcfrhat the acceleration is zero? Support ykyb24r d5gcjq r.42fgour answer with an example.

  Can an object's velocity change direction when its acceleration is csumj065chs, zu7or0xonstant? Supp os0z,sm0xj6hc ur57u ort your answer with an example.

  Suppose that an object is moving with constant acceleration. Make a statement 6;suoo ohj+(l concerning its motion with respo+j;uhlos6o (ect to time.

  Can an object have increasing speed while u2xplpnwt4w)0 :i2b ba8e )xsits acceleration is decreasing? Support your answer with an ewl0)ts ixn)4up: p2 2bbe8xawxample.

  Suppose a can, after an initial kick, moves up along a smoot jiy v817el iid*cuk:;+lfr 6kh hill of ice. Make a statement concerning its accell 1cvkje;8ify ik*i:+rdl76 ueration.

  Under what condition is average velocity equal to the average tjm1zywlgtrw - g: .7:of the object's initial and final velocitg-jl7r ::w1 tzy.tmgwy?

  Objects A and B both start at rest. They both accy2qp3)/p.y4op -yb.fdu kp+gfsak8 helerate at the same rate. However, object A accelerates for twice the time fp8u 2og dakf 3.s/kyhp.yb)yq4p p- +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. Thuk+yf 3uaj c2a38j9msey both accelerate at the same rate. However, object A accelerates for twic92 juk3+sacy uf8j ma3e the time as object B. What is the distance traveled by object A compared to that of object B?

  When an object is released from rest and falls in the absence obj4k49 oo cn+-*/ t, dalrzbkyf friction, which of the following is true concerning its motion?,+zc/db t44jl ka*9ornyob- k

  When an object is released from rest and falls in okw/6bn.q:d gt ( m4wrthe absence of friction, which of the following is true conce6m :/rd(bt.k4gwqn owrning its motion?

  Suppose a ball is thrown straight up. Make a stateme ) uts2yfly gn/a+j,.qnt about the velocity and the accelerati/ js.tyf,qly) 2gu+naon when the ball reaches the highest point.

  Suppose a ball is thrown straight up. What is its:zuemmmf5+lg-,m 2rhfh 8( ms acceleration just before it reaches its highehz:f - mfrh2e+mmmu(58 lgms,st point?

  Suppose a ball is thrown stra x pfiakc)26pz u05l,light up, reaches a maximum height, then falls to its initial height. Make a statement aboutc0 p lx)k25,zip6f lua the direction of the velocity and acceleration as the ball is going up.

  A ball is thrown straight up, reaches a maxbj :*rl1drqc7 lvd kp0; jpt/ wg57(ngimum height, then falls to its initial height. Make a statement about the direction of the velocity and accele(c77p1j0;d/5 qgk rj wvrlgl:dbn*ptration as the ball is coming down.

  Suppose a ball is thrown downward in the absence of air re/se3lugy g crd ibg5)5f8,t(gsistance. Make a statemcygie8g 5tb/(fl 5dgs 3gu),r ent concerning its acceleration.

  Suppose a skydiver jumps from a high-flying plane. What is her acce0vbmvmh ,jfa ,db9.t q6k:ny0leration when she she reaches ter.6:myfh t0 k,mbqvb,jn v9da0minal velocity?

  A ball is thrown verticallylbv fxsqurvuv:-39 76 upward with a speed v. An identical second ball is thrown upward with a speed 2v (twice as fast). What is the ra3u6 9 7lusbf vvqx-vr:tio 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 top of a building. One r8oy mt1+ :mupsecond later, ball B is dropped from the same building.18:+oyu mm trp As time progresses, the distance between them

  Ball A is dropped from the top of a building. One second later, ba,jfzp0 + r jt9/fhrx5kyl- o*pll B is dropped from the same building. As time progresses, the difference in their speeds0ftpl op*kz j,fx-ryj/+9h r5

  Two objects are thrown from the top of a tall b4fcwm j64a; n1sp*tqy u:ay i,uilding. One is thrown up, and the other is thrown down, both with the same initial speed. What are their speeds when they hi44ja stpw 6c;u,qy* n :maif1yt the street?

  A brick is dropped from the top of a building.a5 1, gqb4 fzp26axhrb A second brick is thrown straight down from the same building. They are relr2bhx4 ,a1gq6f5zbp a eased at the same time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with constant non(g, yoz,fowd9v+1rd dbms4+b-zero velocity in the +x axis. The position versus time grap9 4+1dsovbom rdd(yg ,zwf, +bh of this object is

  An object is moving with constant non-zero accelerationd7e0y w jvql+ww*/-d ymqa6e7isx j1 : oyl-s3 in the +x axis. The position 0wy y+soq ad x13e s7d *ll-evwq:iwyj 7-jm6/versus time graph of this object is

  An object is moving with constantgvf );z,hdzo6 non-zero velocity in the +x axis. The velocity versus time graph of this object 6 vg,zdzo;hf)is

  An object is moving with constant non-zero acceleration in the +x u+ o6ktk9l -n5-r9lcspz4iihjx: b y+axis. The velocity versus tii iyo5r-k- 9bsz jp 46ktl++h9x: culnme graph of this object is

  The slope of a position ver2(8qkpnj) :0dy cqfqc b1w:/qwmvdh, sus time graph gives

  The slope of a velocity versus time graph givlde:,ods5d.y lkz-+*+)q5y q ivbx vpes

  The area under a curve in an acceffctsg3tjebv8 8 k t--ir(,8aleration versus time graph gives

  The area under a curve in a velocity versus time graph giv griu.ki290 kuv6e1d aes

  If the position versus time graphu8v wrdid58qny0 qh86 of an object is a horizontal line, the object i6qn q 8y rdd08hwi58vus

  If the position versus time graph of as bi--huk,d ppu6 tcfto,4m+(n object is a vertical line, the object is-kc+pi6 hsu 4fbu-,m o dtpt(,

  If the velocity versus time graph of an obj*1py)u 6zon qt l1 uwbqhj03(oect is a horizontal line, the object is)1o6bqy 3 n(u0lo1*w zqpuhtj

  If the velocity versus time graph ,6jqidyr -a4/qa8c+rch7s7 ixmn 4mi of an object is a straight line making an angle of 30 degrees with theaqc+,xr7c6 d -rmmh4a nqiji i7s8y4/ time axis, the object is

  An object moves 15.0 m north and then 11.0 m south. Find both the distance trwe iu ;2ugzu 0)hp3vg6aveled anpu ;v6u hiu0)3g2ewgzd the magnitude of the displacement vector.

  A boat can move at 30 km/h in still water8m5:gya exl-v syqs1z3c f8u 7. How long will it take to move 12 km upstream in a river f8sc fvlmsyu ey:835 -7q zag1xlowing 6.0 km/h?

  55 mi/h is how many m/s? (1 mi = 160.dl ia5;jyb f/9 m)

  What must be your average speed in order to trav b6z+ 3h2bdunh l wdz+ i.bf,bujf9)h,el 350 km in 5.15 h?

  A runner ran the marayxo0hx+w mq88aucin4 (zg1j4;0a x ak thon (approximately 42.0 km) in 2 hours and 57 min. What is the averageim0wgxq;kahn c y0xz 8aax(1u4j+84o speed of the runner in m/s?

  A car travels 90 km/h. How lo3t91q0g b/tdh +hdek w4pz9ring does it take for it to travel 400 km?

  A ly (light year) is the distadsx-9zi;q xdbp+ (cxwz*jg/ : nce that light travels in one year. The speed of ligz; (iq: d*9wjbzcgs+xd - xpx/ht 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 roadayq9x j g0b, 7+vvgml09n k-qd and you look to the side for 4.0 s, how far do you travel durink lgd y9q79xg b0v0m+-vn ja,qg this inattentive period?

  If you run a complete loop around an outhbf0,:hh,rlt3w: /0 khv wsyhg* y+m ldoor track (400 m), in 100 s, your average velocbl3w+:m,0yt hlg/fs:vh*y 0, wkhrhhity is

  A polar bear starts at (g71fr veqo0x;rc(a eta*w/kthe North Pole. 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 mew*q 0f;e g7tr kar aovx(c1(/in. What was the bear's average speed?

  A polar bear starts at the North Poleye1mdo vvprl l-m*o2p/ bz7:,. 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 average *lm:yz,/p7v2mvrl be odop1 - velocity?

  You are driving home on a weekend from school /n ,m/( al5ss,6qbzz-aqt ;u yly a6ipat 55 mi/h for 110 miles. It then starts to snow and you slow to 35 mi/h. You arrive home after driving 4 hoursuq, ln /lpi6/bz,6a z-;ta qsysmay(5 and 15 minutes. How far is your hometown from school?

  A motorist travels 160 v-ggr k4go/ y/km at 80 km/h and 160 km at 100 km/h. What is the average speed of the motorist for this gvyg- r/ko/g4 trip?

  A motorist travels forfwtld/ hu4u; 79gd fr6ikaj09 3.0 h at 80 km/h and 2.0 h at 100 km/h. What is her average j4df;wighur 7a/9ltku 0 9 fd6speed for the trip?

  An airplane travels at 300 mi/h south for 2.00 h and then at 250 mi/h north fxcfx0 rb2wk 79jjjck-wf;l8yc1 v 4q2 or 750 miles. What is the averacvw0 ;cjyfk2 brjc9 w fkq4-x8x721 ljge speed for the trip?

  In a 400-m relay race the anchorman (the person who runs the last 100 mt72w liuq:sj. )y v7nm) 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 t7vym:)2 uq i.ltnj7 swhe 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 a stop after 8 s. The car's ave.1 vh kqb+(f5 sfxkwfqz a.)o lu;re/)rage velocity during deceleration was 32 km/h. What was( rlfhb) 1)5f/k.e+ a;fo kq. qusvzwx the car's deceleration while slowing down?

  An airplane increases its speed from 100 m/sh+h 569h mz7qw:b q.ljq3 ytpc to 160 m/s, at the average rate of .:mhhcw5 +b 6jtqz hqyqp97 l3$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h acceq8tiyp(ui*s qe7reohe wz4 cb3*j(0)lerates 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 rest2* mxugc9 sxlh/qiakd*h w:26 and accelerates 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 spee pz) mx-p4d3nkds up with a constant acceleration3pdm xp4kn-z) 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 3.2 m/sj1a( .k s.yscq experiences a constant acceleration o(sc ayk .q1s.jf $2.9 \; m/s^2$. What is the cart's displacement during the first 4.4 s of its motion?

  A bullet moving horizontally to the right (+x .fbt 4 r1eq(uuecy53g direction) with a speed of 434 m/s strikes a sandbag and penetrates a distanbefg4 u3cet( q u1r.y5ce of 79.18 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from 3t-ob gizu 4to:o89zv6 ti ,yja catapult on an aircraft carrier. It reaches a speed of 42 m/s at the end of the catapult, and this requires 2.0 sziu:t68tjz ,3 iobt vo-4goy9. Assuming the acceleration is constant, what is the length of the catapult?

  A car starting from rest moves with cons;o. wgc1n97hm(dek 4fdg szk0nr b4 -rtant 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 2eo,e wlc3dl9 y v4-l f*8ci1eg23k v.qziira900 m. What is its average acceleef 9g3liy21, oiz k49ic8e*leaw . cqdrv-3vl ration?

  An object starts from rest and undergoes uniform acceleration. Duufiglx ln ,-+t0mfr +.ring the first second it travels 7.1 mmfxnu,-fl+ ri +0 ltg.. How far will it travel during the third second?

  An object is moving in a straight line with constant vz6s+nkezp 8+6i+s-yq buqqc1k1;r w acceleration. Initially it is traveling at 16 m/s. Thiky+z+qruwk1- n;vqezq8s +b6 psc 16 ree seconds later it is traveling at 10 m/s. How far does it move during this time?

  A car starts from rest and accelh/e((wh hi b*yxw4 o0oerates 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 road can dec4ae:eecc:r w n. 70ga c4ev5naelerate 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 traue xq;x-y205u96zklz3h k pqu ffic light turns green, a car that has been waiting at the intersection kexp x32h qzqu605 -u uzkly;9starts 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/s on the surface)i37buscnktm.6 dgl1/t :f; k:ykik c of planet X where the l3 ckkgmncd :i/sk6) b1k.:iyf7t ;utacceleration 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 planes*6q0u8d;wt vth; yo, 6ofv kqt X where the acceleratit kvqo,foyt6 6 ;d8*sqvu0wh; on 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 wich79:uyen p6 ith a speed of 15 m/s on the surface of planet X where the accelerahn y: u9ci6ep7tion 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 the se(sm cd49 la(aurface of planet X where the acceleration due to gra (l(a9 asd4mecvity is $3.5 \; m/s^2$. What is the speed of the object after 8.0 s?

  Human reaction time is usually greater than 0.10 s. If your frien0wx0;l ; (w,8wg2q6gxa e3qewyq kqvdd holds a ruler betwew8w qwyv00k,qdx3qe (2 6 a;ggeqwx; len your fingers and releases it without warning, how far can you expect the ruler to fall before you catch it?

  A ball is thrown upwarvag;g8j 34um+iwi ei :d at a velocity of 19.6 m/s. What is its velocity after 3.00 e:uaimv; +3 g ijw8ig4s?

  A bullet shot straight up returns to its start2)h6jsnao -: ckt1z*p)sb l tming point in 10 s. What is the initial speed of the bullet?j*s6)t1b2lchao:tn)k z -s mp

  A ball is thrown straight uptl) --+bc 9hcmfgp2ycp 7 9bez with a speed of 36.0 m/s. How long does it take to return to its starting poig -my9)hcp 2 bt9eclfpc7+bz-nt?

  A ball is thrown downward from the top of a building wit lhv --dtr9 y*,biljycf5hk2)h an initial speed of 15 m/s. It strikes the ground after 3.9 s. How kyti-)cj9 5y h,*rlf vhbl2d- high is the building?

  A ball is thrown straight up with a speed of 30 m/s. (only fila+nlrb.g ewb+2 2shh0l in numerical value in the blah b+nrae0hbgl.w 2+s2nks)
(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 pkh(;h b tg*b1p hd-)l 9cr/goair with a speed of 26.6 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 11 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 11.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is the b:zw8 c8m1uf si2ky j4velocity at t = 1.0 s?

  In Fig. below, what is the velocityl* t2 x1/iosfo at t = 2.5 s?

  In Fig. below, what is thed2;l5 cjw.z lb velocity at t = 4.0 s?

  In Fig. below, what is tu *u -kvf9cxr39vbcbi:f 1m a/he velocity at t = 5.5 s?

  In Fig. below, what is the average velocity from 0 to 4.0 s?vg pfs((57guz

  In Fig. below, what is bp0h67 ;n+eid lytgm*t :ppx9the average velocity from 0 to 6.0 s?

  In Fig. below, what is the acn0lmuh*q-r 7p celeration at 1.0 s?

  In Fig. below, what is the acceleration at 3.:xmqigujb vsf z125 )*0 s?

  In Fig. below, what is the average acceleration frazj:i8nwcy ;4;of w0t m4n 9twom 0 to 5.0 s?

  In Fig. below, what is the averagekxq7 (s) r twdfn,w/6p acceleration from 0 to 8.0 s?

  In Fig. below, what is the displacement from 0 to 858 x;1ezhfcev.0 s?

Does a car speedometer measurebw,w9q s :giw2w1k5 xb2el n*s speed, velocity? {speed|velocity}

  An object can have a varying speedc//1ctz pcd:gz i48) te74 go5rs gowj if its velocity is constant.

  The velocity of an object can be negative when its acce)+d ;kjqfj,-,hm lateleration is positive.

  If one object has a greate ay43jqcga 0t(:1kmscr speed than a second object, the first must have a greatecy0j:kactgqm41 s (a3 r acceleration.

  Two cars emerge side by side from a tunnel. Car A is traveling with (2acs3leh)5f ash(dy5wsvet 0 lq v+0a 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 accelnp4.:p 0/ cep02xxw qc9*evgwdsox,e eration decreases.

  A baseball player hits a foul ball straight up in2oi1 dwps9uz +;vpv6ux;duz1to the air. It leaves the bat with a u91i2u;xszw vpo6dv1 z up+d; 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 speeds up, what is hanbc6xqkvd-6i / fzt.,ppening to its acceleration, how does itfdt/c,vi 6z 6n.b k-qx change if air friction is ignored?

  As a freely falling object speeds up, what is happening to its acceleratis m(a3jyc8- za+ a6cn55dvq kgon, how doeg5nsd(3 85 -+c6zycq a ajvmkas it change if air friction CAN NOT be ignored?

  An object that is thrown vertically uke3)f-uzky- (pe+x jp pward will return to its original position e(uekk-3) xz -jyp pf+with the same speed as it had initially if air resistance is negligible. If air resistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzero ac p r*x8vf+hsp.celeration at the same time.

  An object can have nonzero velocity and zero acceleration at the same time. r.l d )8m vny4ew(lc2x2np4ox

  An elevator moving from the second .rt8fv-pfl n) floor to the fifth floor making no stops along the way has zero acc. vf8rtfpn)- leleration all the time.

  A rolling ball moves f)-bvc8 u y3mkdrom $x_1=3.4 \mathrm{~cm}$ to $x_2=-8.2 \mathrm{~cm}$ during the time from $t_1=2.5 \mathrm{~s}$ to $t_2=5.5 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-3.1 \mathrm{~s}$ is at $x_1=3.3 \mathrm{~cm}$ and at $t_2=4.5 \mathrm{~s}$ is at $x_2=7.4 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight f):hyp,f8m e rcxxcaa-x,o9gs0cn70 complete laps around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 6.8 min. Calculate (a) the average speed  (数值)  $m/s$ and (b) the average velocity    $m/s$

  A horse canters away from its kt; x ,f dio)y8uqg rsm2c9(t4p*ln,be8 db3h trainer in a straight line, moving 115 m away in 8.8 s. It then turns abruptly and gallops halxut ,;glnr8cb8*, d4p9f oyt(i3ms)2ekq bhd fway back in 4.7 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 frog/g/66+ i z5bcvz)hcqdte 1 ltm $10 \; m/s$ to $23 \; m/s$ in 4.7 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 frome0jagwu.iy4 2 $21 \; m/s$ to rest in a distance of 78 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a spei( e9( g/nwg8l9otwly ed of $29 \; m/s$ 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 burstqf: d+5x )pl,qfh2-f*so tmb/n2aqdy out of the blocks to essentially top speed aboup h* ,: yx 5qq fob+tdsa2dlnq/f2f)-mt $10.5 \; m/s$ in the first 12.5 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 sp9v,v 8a8w kyi1cdbtjp+ rc*v4eed of $20 \; m/s$ to rest in 4.07 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a carx+6nlggfy+9cx -u:rw o:qy5n leaves skid marks 92 m long on the highway. Assuming a decelxl c-ng:rnyfxu+:9g+65yw oqeration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truc;eoj;x t7j j-xabu bg h2(nu4-2gib2u k 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).    $m$