Suppose that an object travels from one point in spacjai,av4lw7.r5r 4 w jqe to another. Make a comparison betwe4 j.iv4 lw7rj a5raqw,en the displacement and the distance traveled.

  When is the average velocity of an object equal to the instantaneous vel82vifyuo7xknz 6 *w)m ocity?

  A new car manufacturer advertises that their car can go "from zero to sixty uil),buv5+v ww*4ov 6s1u stgin 8 s". Thisvs +b1,iv5v u6ul4g)o ww tu*s is a description of

  An object moving in the 2x+ ;fmd1nsej+x 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) bei dfeq0.38gjz b,p r3vo ,9tcpez-; nzgins to slow down as it approaches a traffic light. Make a statement concern ofve,qpdzg-9 n8c0, 3 bepzr;t.ji z3ing its acceleration.

  Suppose that a car traveling to the Wes.a5hcd :,- dc ofnn:tqt (-x direction) begins to slow down as it approaches h5t:-a. f,donc qnd:ca traffic light. Make a statement concerning its acceleration.

  Suppose that an object is mo)z(5vo8o stv lving with a constant velocity. Make a statement concerningoz5 8 )vl(sotv its acceleration.

  If the velocity of an oig/oie x.kdr2/ lb,z6bject is zero, does it mean that the acceleration is zero? Suppo/odbg2il/ix zk,6. r ert your answer with an example.

  Can an object's velocity change dz i /f xaazu,7d87sl41afqui(irection when its acceleration is constant? Suzudfasai/z(1,7 q 8af7x iu l4pport your answer with an example.

  Suppose that an object is mofpjsna ::zl- lktu0 uisz67h5 l+s)34ms q .jqving with constant acceleration. Make a statement concerning its motion z 4+q s:-)t7n lu la5muj. lzkhqjs06s s3i:pfwith respect to time.

  Can an object have increasing speed while its acceleration is decren: g1hkkgv ,pj ;xdc6.asing? Support your answer with an examplekvhg.6;kpc n:j gdx,1.

  Suppose a can, after an initial kick, moves up along a smcl*zwcqozt ,c(55c + nooth hill of ice. Make a statement concerning its accelera5zl ( wo5nc+czcq ,ct*tion.

  Under what condition is average vvda: hp0rtl gh s+c- :m*d5pu4elocity equal to the average of the object's initial and final velocityhl5 -p d:tp+0sr * vga4cmu:hd?

  Objects A and B both start at rest. )5vjvwnj 0 v+w0.7xve cxzx w+,jfn6d They both accelerate at the same rate. Howe5f,w6j0vxde+)vx0 cxw n7w+ j.v znjvver, 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 fshiwy9 *-+pf3 x 30m8 snlxwdfrom 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 compared to that of objx3f 8wdn x0hs-fsywm9lp+*i 3ect B?

  When an object is released from rest and falls in the absence of ,5y3( n.t n7-xdt dlx*qnvkf2lfov3g friction, which of the followdy,(f5x no.nd f ttq2 vxlkn33v-7g *ling is true concerning its motion?

  When an object is rel2zo * rc1jv c8 4vklb4ny)7zicx55piqlo8ml 7eased from rest and falls in the absence of friction, which of the fol)in 5v4k j5qcbmxyoz1v 78z li4clo*8c l7 pr2lowing is true concerning its motion?

  Suppose a ball is thrown straight up. Make a statement about the velocit/t j6zvz.v9;;lmux is)acc /ty and the acceleration when the ball reaches the hig; jv)/i;uc.x 9taz6 m/tvzsclhest point.

  Suppose a ball is thrown straight up. What is its accelera6 jz(bl492nj *izbilbtion just before it reaches its highest point 96jib*z 2( ljbznli4b?

  Suppose a ball is thrown straight up, reaches a magu wscy92k;fh- 0nfk 3ximum height, then falls to its initial height. Make a statement about the direc3w-u fg fck2 hnsy0k9;tion of the velocity and acceleration as the ball is going up.

  A ball is thrown straight up, reaches a maximum height, d5l5 fpndc8 1qthen falls to its initial height. Make a statement about the direction of the velocity and acceleration as the ball is coming dd lf 1pn8cq55down.

  Suppose a ball is thrown 7xm ybl :a*q0 mn7ca3odownward in the absence of air resistance. Make a statement concerning its acceleratiqlxa:myonba7c 0m* 73on.

  Suppose a skydiver jumps from a high-flying plane. What is her acceleration whe,j0 e/e 7utntk*r-u/fj)jbe un she sn*tuuj/t -eerbj 0e , )kfj7u/he reaches terminal velocity?

  A ball is thrown vertically upward with a speed v. An identical second baiy vw,y 3jau +a+lw2jgt .tn:/ll 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 first ball? (How many timewytju lw2g jt.y +a ,n/3ia+v:s higher does the second ball go than the first ball?)

  Ball A is dropped from the top of a buil 5n3 pthsqr .m,u2)wkpding. One second later, ball B is dropped from the same building. As time progresses, the distanceqp) .sn 23um kw5pht,r between them

  Ball A is dropped from the top of a building. One second gzkv*g 0+rbxj :)9 qhklater, ball B is dropped from the same building. As time progresses, the djkb9q r:*k z+v g0g)xhifference in their speeds

  Two objects are thrown from the top j w+sbq3ebi +o 5r0(rb ,db)jnof a tall building. One is thrown up, and the other is thrown dowr5qbbi bw (+0 e,+nb djj)rs3on, both with the same initial speed. What are their speeds when they hit the street?

  A brick is dropped from the top of a buildiny1:.lm knyi+gj6u2zaptxm.-f86dmi g. A second brick is thrown straight down from the same building. They are released at the same time. Neglect air resistance. Compare the accelerations of thej1+.-i8nmfzym k tli2y .:g6mx6d uap two bricks.

  An object is moving with constant non-zelki 7sv uuio om 15u:wkkt13+1ro velocity in the +x axis. The position versus time graph of this obj5so:mt +ik o3kk117v u1wiuluect is

  An object is moving with constant non-zero acceleration in the +x axis. b 0,by2nf jal,The position versus tiy,0b2nl, a fjbme graph of this object is

  An object is moving with constant non-zero velocity in the +xltv 3u ,oy/0rh axis. The velocity versus timetvyl0 o/3hur , graph of this object is

  An object is moving with constant non-zero acceleratf os-4ewu zigmuglcck93+/ 51ion in the +x axis. The velocity versus time graph of this object is3f5c4-usg/ uecg w9+miz 1olk

  The slope of a position versusi0 ggy76 qimr8r; z8dh time graph gives

  The slope of a velocity versus t*jxjkcp -v4 n5ime graph gives

  The area under a curve in an acceleration versus time grapa yn4:1 (huhvi8bvf7ph gives

  The area under a curve in a velocity versus time graph givw jo91cb)3szu a:87xmv f:zid es

  If the position versueb -a9 f*v +x6-hoagf8/wm ipus time graph of an object is a horizontal line, the object ih*8pgffe6vb+ o a -axwium-/9s

  If the position versus time graph of an object is a vertic - eeuwd ef;ilx1il71*al line, the object is1 f 7e-;lw*ulexii1de

  If the velocity versus tijmxa y.y,6h,t me graph of an object is a horizontal line, the object ishyt6.j,, yamx

  If the velocity versus time graphtyit:xa, 6/wm q.1nir of an object is a straight line making an angle of 30 degrees with the time axis, the objeciir1t/m x6:nqa ,w yt.t is

  An object moves 15.0 m north and then 11.0 m south. Fi ed y;+eg6w2gwnd both the distance travg 2 e;dw+6wegyeled and the magnitude of the displacement vector.

  A boat can move at 30 km/h igj. h7r0wah2l87h hwqn still water. How long will it take to move 12 km upstream in a rihgr8h 77h2a. jlq0whwver flowing 6.0 km/h?

  55 mi/h is how many m/s? (1 sfwyf,9un 4xo20jw6n mi = 1609 m)

  What must be your average speed in order to travel b8y hb8mn,vfq 9f2 ldxa4i bn(5p1j.l350 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 km) in 2 hours and 57 min.oohpxjbh ypto*uko -0)e,6q.. yr b ;4 What is the ave orbpk;o.h-qop.je)tyh4u * y6b,o0x rage speed of the runner in m/s?

  A car travels 90 km/h. How long does it take for it to trave+w(+flc2fhe: fcyml mn;2*p bxs/c-il 400 km?

  A ly (light year) is the distance that li* ef.luwx+q;q mzq.-ff( um- rght travels in one year. The speed of lil-e.(*z;umf-xfqrqmq + uw .f ght 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 t +cl)um q*tmopdz p39pkp(3t- o the side for 4.0 s, how far do t lp - m)pzdco+p*mk(93u tqp3you travel during this inattentive period?

  If you run a complete loop around an outdoor trs8:izr kfv1e78km5a k 0mqj9o ack (400 m), in 100 s, your average velocity if51 9:q 8 szjverk7ik8a m0koms

  A polar bear starts at the North Po/ t2npdalcja90:*sa jm4ore7le. 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. Thism t0a:l en4*/7da a2ojjsprc9 trip takes 45 min. What was the bear's average speed?

  A polar bear starts at the N gm-x hr+6b -cft o(e2xv(+fptorth Pole. It travels 1.0 km south, then 1.0 km east, then 1.0 km north, then 1.0 km wes6( hm xv2f-gbp c ttfe++x-r(ot to return to its starting point. This trip takes 45 min. What was the bear's average velocity?

  You are driving home on a weekend from scq02noc qz :azny:p ;z8w xmu;;hool at 55 mi/h for 110 miles. It then starts to snow and you slow to 35 mi/h. You arrive home after driving0pyn;:wqcxz:z 2;nzu aqm; o8 4 hours and 15 minutes. How far is your hometown from school?

  A motorist travels 160 km at 80 km r00j wuprw5ahe-z)b-/h and 160 km at 100 km/h. What is the average speed of the motorjrea b p50-wz0) r-hwuist for this trip?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h. What is hee 7 ubv70wledd)q4x p*r average speed for the trix l*7qd7v0uwdeb)e 4p p?

  An airplane travels at 300 mi/h sou9/9hch +wixu4* 2h p7xekvnbm th for 2.00 h and then at 250 mi/h north for 750 miles. What is the average speed for the4n92w9h7p i*xc+mev/hb kxh u trip?

  In a 400-m relay race the anchorman (the 9jegly 7q*(liq wk0*3* c fpytperson 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 tywk*yg9pq7 f i 0t*elc3q(jl*he 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 a stop aftwzemxljdns3 cmd; *c,b./vadi / 6n+;er 11 s. The car's average velocity during deceleration was 47 km/h. What was the car's decelv. d;wzsn/ib ;c6/*da3mcx,dm+ j e nleration while slowing down?

  An airplane increases its speed from 100 m/s to 160 m/s, at the average rate 5m .2lfj0 /d fhuh1yzxl+n+xcof h2 +5z.l0lxdu 1mnhc+y f /jxf$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerates at the rate , ru8hab1at/k evue42 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 res55 xpn) ukz/vtt 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 fagakc460ac9mc z:l mqnki.xe1: e9. f or 10 s. It then speeds up with a constant acceleration omfle. :9 ckzac: 69 mnace.qxk041iag f $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 4.1ii6nk q +41knfgo.(on m/s experiences a constant acceleration o(6 k1n oinqofn4.ki+gf $4.5 \; m/s^2$. What is the cart's displacement during the first 5.9 s of its motion?

  A bullet moving horizontally to the right (+x direction) h wz;9;jdjk,1hlu 2tr1 rkh7bwith a speed of 510 m/s strikes a sandbag and penetr1r ; hr9;l2kzt 1jh,uhbkw7jdates a distance of 54.28 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on um* 7v 8)zi138kz b serjzd1-ibvda,man aircraft carrier. It reaches a speed of 42 m/s at the end of the catapult, and this requiremzb1zvzdr -,kbvjdai si73* e81 u)m8s 2.0 s. Assuming the acceleration is constant, what is the length of the catapult?

  A car starting from rest moves with constant acceleration of 2cnmvl fd4dx:8;; r6jk0v2h gauh. yy$2.0 \; m/s^2$ 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 d(.iqa: 8 vdz 7 :56bj kxonouiv0jr4uuistance of 200 m. What is its average acceleraku:ozuj5iq vxrud vo(b8.4ji 07 n:6a tion?

  An object starts from rest az 6poovnws; /)nd undergoes uniform acceleration. During the first o pz n6)/o;vwssecond it travels 4.1 m. How far will it travel during the third second?

  An object is moving in a straight line with constant acceleration. Initially it:;gw m. gh tdcswrib;(-.u6mt is traveling at 16 m/s. Three seconds later it is traveling at 1..; 6rshwtb:du t gi;c- gwmm(0 m/s. How far does it move during this time?

  A car starts from rest and acceke:tb;jgq4+im l+ lp6lerates 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 decellr r0fq ;u*9+;sgax iq+z tc3herate 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 beel)q 7zkt v wxz5b20vxx*86ubdn waiting at the intersection starts ahead with a constantx* lvw6zx52dxub tvz0k7 )b8q 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 surface4das ovro;3( v of planet X where the acceleration due to gravity sa 3o4dro;v v(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 surfdspx 0 f9ffcju,.d2-a,2yd tuace of planet X where the acceleration due to -,fd0p.9f fdsxy,ct22ua duj gravity is $1.5 \; m/s^2$. How long does it take for the object to reach the maximum height?

  An object is thrown upwgy6 ju2h n+az9ard with a speed of 15 m/s on the surface of planet X where the accel 6hy 2zn9a+jugeration 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 withmm +m0d0 f1fygb5c ;vrs1xdm6 a speed of 14 m/s on the surface of planet X where tm x+ rdcy5ms10f1m60 bfgm;dvhe acceleration due to gravity is $3.5 \; m/s^2$. What is the speed of the object after 8.0 s?

  Human reaction time ic2k gj3d2o yk-6fr b0fs usually greater than 0.10 s. If your friend holds a ruler between your fingers and releases it without warning, how far can yo2g k fyk-fdjb6r c02o3u expect the ruler to fall before you catch it?

  A ball is thrown upward at a velocity on5c43l1 jd(.t nhoacw f 19.6 m/s. What is its velocity after 3.00 s4. 5caoc3l( 1jwd tnnh?

  A bullet shot straight up returns to its starting point in 13 s.7.o4jsz gv (xg2t-lsl What is the initial speed of the bl(-47svl. j2sztgox g ullet?

  A ball is thrown straight up with a speed of 36.0 m/s. How 2(qhzwcz+6 exn6 om6dlong does it take to return to its 6 owzmd 26h6en+xzcq (starting point?

  A ball is thrown down5ikv e()f j* sn/9jmmbward from the top of a building with an initial speed of 27 m/s. It strikes the ground after 7.9 s. How high is the b9mk5 (bj svinm/)f*e juilding?

  A ball is thrown straight up with a speed of 30 m/s. (only fill 8 c fjerg/aru7tk7f 1+in numerical value ikjrf78r1g /e7uacft +n 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 the air with a speed of 3 zb5wr 09 vdkw1 ny8;w,iqp/ mhrd,lv )n.ug0m8.8 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 9 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 9.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is the velocity a 9)ccxmcl7/ kd.7ba zjt t = 1.0 s?

  In Fig. below, what is the velocvr;96l8)whiz*5k5sveivq. uk cp. fzity at t = 2.5 s?

  In Fig. below, what is theqhbxu ;/jww 9 kqgbmdz:m8(3*s/1esm velocity at t = 4.0 s?

  In Fig. below, what is the velocity aqkqat6 y6z0-rt t = 5.5 s?

  In Fig. below, what is the average ,vcd yskv e*;/velocity from 0 to 4.0 s?

  In Fig. below, what is the average velocity froccd+g7; w,y/q+bm zmsm 0 to 6.0 s?

  In Fig. below, what is the acceldt /l/wg4xx8j62 o apweration at 1.0 s?

  In Fig. below, what is the accelerg3 k*qal+ ytpaqeog*6 b3* m,ylcz*v: ation at 3.0 s?

  In Fig. below, what is the average acceleration from 0 to 5;lj j+/xpi76n zku )yq.0 s?

  In Fig. below, what is the aver rikx qx67y8kmwjjk(12cw :7wage acceleration from 0 to 8.0 s?

  In Fig. below, what is the displaceme(4w ef wx hr2)kxus)c5nt from 0 to 8.0 s?

Does a car speedometer measure speed, vel;y4jkgmz -brw 5uh77uocity? {speed|velocity}

  An object can have a varying speed if its velocity is constanq.: g8.vmny;zahk4r n t.

  The velocity of an object can be negative when its acceleratir.nsmqve3hj/l t 9c-* on is positive.

  If one object has a greatgom.r8(b +n;a kn yy27yl y;9zhvln)gtgz .9eer speed than a second object, the first must have a greater accelerationyzhlt 7y g.)b8.y l a9 eov29rnyn;km;g(z +ng.

  Two cars emerge side by u8 surf rh01bei *)ta3side 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 increasg+6u3:mvl,k 785 jmk uxnhlz eing in speed as its acceleration decreases.

  A baseball player hits u(;v 2n3xwgv*m jdk5ej ,;rp ra foul ball straight up into the air. It leaves the bat with a spmn 3rv v,5u*( er;jk;d2gxwpjeed 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 3- dk(hio+wvlobject speeds up, what is happening to its acceleration, howokihv 3-d+w(l does it change if air friction is ignored?

  As a freely falling object speeds up, what is happening to its ac7 jfkf. mlxc73celeration, how does it change if air friction C.f377fclj m xkAN NOT be ignored?

  An object that is thrown vertically upward will return to its omae9u bda p0s y+et93(riginal position with the same speed as it had initia9 p3ya9us+e em btd0a(lly if air resistance is negligible. If air resistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzero aghse+ 6 wdw:g5( -zwwbcceleration at the same time.

  An object can have nonzes01+q kd(c-cb) yzp,fg(un bsi j,,hc ro velocity and zero acceleration at the same time.

  An elevator moving from the t ggjn;7iesb /pw;s;m4pf-i: second floor to the fifth floor making no stops along the way has zero acceleration all the time weg/s4g:t ;pb;mijnisf7p ;-.

  A rolling ball moves from h9b b-zli lv sy)f7/t-f(6pvx4sc8m d$x_1=2.7 \mathrm{~cm}$ to $x_2=-7.9 \mathrm{~cm}$ during the time from $t_1=2.9 \mathrm{~s}$ 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 $t_1=-4.8 \mathrm{~s}$ is at $x_1=2.7 \mathrm{~cm}$ and at $t_2=3.7 \mathrm{~s}$ is at $x_2=8.2 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete h.+.nw )bgve.ghfz u( laps around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 6.1 min. Calculate (a) the average speed  (数值)  $m/s$ and (b) the average velocity    $m/s$

  A horse canters away from its t(u )h07 bqdhz8g;jqr p: sim/j-ng0ldrainer in a straight line, moving 116 m away in 11.7 s. It then turns abruptly and gallops halfway back in 4.7 s. Calculate (a rjh)gqh ;q0 uliz08db 7pg-n(md:sj/) 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 fro6(vy1 xnxenl 3m $11 \; m/s$ to $25 \; m/s$ in 5.1 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 fromq 0:yos(vrhp( $22 \; m/s$ to rest in a distance of 61 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach alpasx.s((pfy vrn vw 34l(6h7 speed of $31 \; m/s$ 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 ca9n x*wo0nlah *n burst out of the blocks to essentially top speed aboua*hn *lnw x9o0t $10.8 \; m/s$ in the first 13.5 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 spe);*x -t6or qmzqu tqw94(zqjv ed of $19 \; m/s$ to rest in 4.38 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car f gz bp48iw/ -zpr5epfl1.wz6leaves skid marks 92 m long on the highway. Assuming a decelez .ip1 /pp65ger4b wf-f8zwzlration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck gul b*huwtw 1v3gu54+poing $25 \; m/s$ 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 10,00 u obzn5aw)5wj-6 +qia0-m run in less than 30.0 min. After exactly 27.0 min, there are still 1100 m to go. The runnerww6abj)a u5-q z+nio5 must then accelerate at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$