Suppose that an object travels from on6j cwpai,y1a,e point in space to another. Make a comparison between the displacement and the distance trpc ij1,waa 6,yaveled.

  When is the average velocity of an objefm- ,rlvquk71h .gmv 8ct equal to the instantaneous velocity?

  A new car manufacturer advertises that their car can go "from zero to sixty ig(q w(k,duy+/jje 0yon 8 s". This is a d (ej0gyq oyk,wd+ j(u/escription of

  An object moving in the +x axis experienbvo 293y2cqpl ces an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x directsfc *5g;v; lxw9ik *hmav/ 8xtion) begins to slow down as it app/fat9 xw ci*g;8skm 5xv; vlh*roaches a traffic light. Make a statement concerning its acceleration.

  Suppose that a car traveling to the West (-x direction) begins to i:an3e g.dtov s,u1z.slow down as it approaches a traffic light. Make a statement eu1o nid .gta .3,vs:zconcerning its acceleration.

  Suppose that an object is moving with a constant velocity. Mah)ohmx8 z6n e5ke a statement concerning its accelerath)x e6h n58ozmion.

  If the velocity of an object is zero, does it mean that the accelerakduvmi 63(evt6+wzei ;7x.aption is zero? Supdp6vwzm 6i;3i+(. 7eeu xtkavport your answer with an example.

  Can an object's velocity change direction when its azj uu,.)f- wv kx66rurcceleration is constant? Support your ans.w) r6zu, k6vuux-jf rwer with an example.

  Suppose that an object is moving with consj.tea6,h. u (fvniejw :wa h*,tant acceleration. Make a statement concerning its motion:ai,uwhw .en hv.a e6jt*j(,f with respect to time.

  Can an object have increasing spw pn1wr :.db gppj p)17gygq1(eed while its acceleration is decreasing? Support you):1pp. wnwrgppy1 dg (7b1qg jr answer with an example.

  Suppose a can, after an0e rhla:7dpuf k80ex+ initial kick, moves up along a smooth hill of ice. Make a steh+a8kupx 0l:rf7e0d atement concerning its acceleration.

  Under what condition is average velocity equal to the average of the ojqqixk /t j(8.bject's initial and final velq. itk/jx8(qjocity?

  Objects A and B both / .wvb;3q qkyy(t1 nue6s ;lacstart at rest. They both accelerate at the same rate. However, object A accelerates for twice the time as object B. What is the final speed of object A compared to that of object B;y.aev n /6;q3ktclb qyw(su1?

  Objects A and B both start from rest. They both accelerate at th z, cn*vu4iv5be same rate. However, object A accelerates for twice the time as object B. What is the dis, *ubci v54nvztance traveled by object A compared to that of object B?

  When an object is released from rest and falls in .1e uf yahd+m5the absence of friction, which of y1uf5.+haedm the following is true concerning its motion?

  When an object is released from cr7/kz b 1,qtg7dp,el rest and falls in the absence of friction, which of the following is true grkeq7/d ,zbpc,71lt concerning its motion?

  Suppose a ball is thrown straight up. Make a statement about the vel4j) h iszci+ b7*un3hyocity and the acceleration when the ball reaches yb+i7c3hi)s h4j u* nzthe highest point.

  Suppose a ball is thrown straight up. What is its accelerae*yuhjc d )+rcah7 x41tion just before it reachyuejxc d)c ha4+r7* 1hes its highest point?

  Suppose a ball is thrown straight up, reaches a maximum height, thehu,/0v;4z z0d b:7nps1ocd k 2i ojsemn falls to its initial height. Make a statement about the direction of the velocity and acceleration as the ball is goi0z,zd7 nuej0hso4mc svbk1p 2; d/o: ing up.

  A ball is thrown straight up, reaches a maximum-r- f6 i6vh0+uxm3 * ngbyhbdt height, then falls to its initial height. Make a statement about the direction of the velocity and acceleration as the ball is coming 30xmy hg*hbvfb-ir+u-n 6t6 ddown.

  Suppose a ball is thrown downward in the absence of air resistance.w0 n dabut s(qri,(;4x g6 ai;q2sdqk* Make a statement concerning its accelq2(s0g d ;stuaiwqr4 *6 x,k qbd;an(ieration.

  Suppose a skydiver jumps from a high- )j(ec , ik6qn.llepya7p)gv4flying plane. What is her acceleration when she she r a 4l7).p6k,qgc)jp lyevi( neeaches terminal velocity?

  A ball is thrown vertically upward with a speed v. sp 5rzt7;ko pfb,/ezw8. c di1 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 thz 7;ozfc ts 1brdiwp/,5ke8 p.e 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 second later+w8p0fi* t- as e pcb*w5mo*u(ldpb t+, ball B is dropped from the same building. Astpdl tms8*0cbp 5 -i* e+bw*foauw+(p time progresses, the distance between them

  Ball A is dropped from the top of a building. One second later, ball B is drvoxkl/(wtu5b il6.j*+ wi+/dl( zh p sopped from the same building. As time progresses, the *vjo ii x+5b/wp/lh6stz+ luldk(( .wdifference in their speeds

  Two objects are thrown from the top of a tall building. One is thrown up, and t (u9i .rlmbi5the other is thrown down, bou5b(lt i m.ri9th with the same initial speed. What are their speeds when they hit the street?

  A brick is dropped from the top n9q*k.uv1r qmmd2qx y9 otb, c ;k6f,hof a building. A second brick is thrown straight down from the same building. They are released at the same time. Neglect air resistance. Compare the accelerati.d; 1q, xmcftnho vqkr2 9m *6uky,bq9ons of the two bricks.

  An object is moving with constant non-zero velocity in the +x axis. The pos7 nz4ezgm c1 7j(ls+kaition versus l7g mcjszna 4kze71 +(time graph of this object is

  An object is moving with constant non-zero acceleratibl3h9i)fn x h/5xx) pq.chx. xon in the +x axis. The position versus time c/xh ..5xxxx)b)pin l 9qhh3fgraph of this object is

  An object is moving with constant non-zero velocit k f+.itnl/kze: )lep6dshq7*y in the +x axis. The velocity versus time graph kpn ihlk ):z.+seq7/*dt6 felof this object is

  An object is moving with constant non-zero acceleratiosaxodj.yji5j8ge zf12p02e / n in the +x axis. The velocity versus time gra/ e.pd8x2 ej 0 fjyjoza512gisph of this object is

  The slope of a position 922jb* b76:zzh8fef jpbniwg:/uuan versus time graph gives

  The slope of a velocity versus timk go1ou s7ml,9olz :rxf: 9di/e graph gives

  The area under a curve in an acceleration versu0rycc 0m a9i 5d12empgs time graph gives

  The area under a curve in a velocity versus time g8nv1qc7bk on te(fi;y a 5b.i8raph gives

  If the position versus time graph of an object ik 5yd6l 4j6opks a horizontal line, the object i5 kd6y4 jpokl6s

  If the position versus tim1 9t3sibl 1usne graph of an object is a vertical line, the object is 1snls utb93i1

  If the velocity versus time graph of an object is a horizontal line, the gg(lm tyv /jk+cr7z1)object i t) / vgcr1m+k7ygl(zjs

  If the velocity versus time graph of a* x5( jdrj5 imaj7(kn3.z myocn object is a straight line making an angle of 30 degrees with the timeij x7ay (j5(.dmm *3jor5nczk axis, the object is

  An object moves 15.0 m north and then 11n z/pwxf9 w6jgm*fbpv jpl1+8sc q0*1.0 m south. Find both the distance traveled and the magnig6 wf0*xn qf81jm/sl 1vppp+c9 *wbzjtude of the displacement vector.

  A boat can move at 30 km/h in still water. How long will it take to move 1qdmzj 3d/ost:(2q4 to 2 km upstrotj sd2mzq:(4do t q/3eam in a river flowing 6.0 km/h?

  55 mi/h is how many m/s? (1 mi = b- /gk.tf*vqm( 6kjrg1609 m)

  What must be your averager ti78:vgljop(dr7 t/e3m 3 wr speed in order to travel 350 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 km)gm(lotj 9f6po :)+n wl/mqxylcf.s /, in 2 hours and 57 min. What is the average speed of the runnermg.yo/s,fcf:x l pw j(q+tl n9ml/) o6 in m/s?

  A car travels 90 km/h. How long does it vtrcnm+50a dv.y x : 0(1usagjtake for it to travel 400 km?

  A ly (light year) is the distance that light travels in one yea r:(*(wxsqgl 8 gvk0ozr. The speed of light is zgx(k:v *so gw(q0lr8$3.00 \times 10^8 \; m/s$. 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 fo5i ,wsu e:*usxuil 2lgv(p:g-om- 5chr 4.0 s, how far do you travel during this inattentive perlh m5-u-iv* og,p 2xcu:s i g(sew:5luiod?

  If you run a complete loop around an outdoor r)+.wyn)hxo2mrs r/v track (400 m), in 100 s, your average vro) n.+xvr )h/rw 2smyelocity is

  A polar bear starts at the North Pole. It travels 1.0 km south) )6oynmpv, hu(yk6kp , then 1.0 km east, then 1.0 km north, then 1.0 km west to return to its starting point. o v(6up)m n6y,ky k)hp This trip takes 45 min. What was the bear's average speed?

  A polar bear starts at the North Pole. It travels 1rwwj/;e9p uxv 5,n ue5.0 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 be5rnwj/u ;v, wu 9ex5epar's average velocity?

  You are driving home on a weekend from school at 55 mi/h for 110 miles. Iy;wmc-e-xzjf+.jl1 a7-c wd+ot zwq9 t then starts to snow and you slow to 35 mi/h. You arrive home after driving 4 ho-yz-a;+7w-tcq9xmzj. dj cw ewl1+o furs and 15 minutes. How far is your hometown from school?

  A motorist travels 160 km at 80 km/h and 160 km at 100 km/h. Whz6 xsr4;h 2hwgat is the average speed of the motorist for this triz64r;gwxsh 2hp?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/ m9v4cogrg4 ubh3k,g/h. What is her average sbc/u,mr34 4 9gkhgogvpeed for the trip?

  An airplane travels at 300 mi/h south fo6 bv1xki9.l +wu6gtw.i/msmw r 2.00 h and then at 250 mi/h north for 750 miles. What is the average i6+ ux9m 6wbv/ s1lt.gik w.wmspeed for the trip?

  In a 400-m relay race the anchorman (the per+h1k h 3-w/rsns wyqk)son 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 larg3hskr/q) whn+k -y1swest 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 sj gwd0y 2vi:s-top after 10 s. The car's average velocity during deceleration was 61 km/h. What was the car's decelerj: diyvgs02w -ation while slowing down?

  An airplane increases its speed from 100 m/s to 160 m/s, x,o 0hee/glf b)5d r3nhn4 nq;at the average rate of o n)n5eb l0,dhe3r n4;qgf/hx$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accela8nuxk md ,.:kerates 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 rewqky)h+; ,rjn st 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 speeds up with a constantb 1(8hbevmfxq-v(9ym c(mt w4 acceleration 4ev(m8 xybmwqv-bcth1f9(m( 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 ofvq frlk5+.,vv pja58l 2.1 m/s experiences a constant acceleration ofjr5 +kv.,alq 5 vlfv8p $1.6 \; m/s^2$. What is the cart's displacement during the first 5.6 s of its motion?

  A bullet moving horizontally to the right (+x direm79dmbbyq 7hu+rf;-u ction) with a speed of 596 m/s strikes a sandbag and penetrates a dis7b9m-m7hybq ru u +fd;tance of 11.14 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 r9 s.uaguana0 f: 1acby,o,sz,(r( ipqeaches 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 ab:(na9(o1yrqu., sg,up zi0 aafs, cof the catapult?

  A car starting from rest moves with constant c q93r 9;fu;muercrv- 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 distancuo8g)yb md8dxgb fc3xn 806xx*2 o+lp e of 200 m. What is its average accelerao83b+)c882yp df0mdxl6x*ggxux nb o tion?

  An object starts from rest and yo.acv, wrc4-5ow + 6sd;5 n5devyzal undergoes uniform acceleration. During the first second it travels,zocl5ocyvydad+asn r65ve. w;w- 54 1.3 m. How far will it travel during the third second?

  An object is moving in a straight linez0xkkzdklfj++ (. vt5yh/x +h 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 duz5+ jyxhzf0kd(hkv+ lk.x +t/ring this time?

  A car starts from rest and accelev3b3-l/kzx w2 tcv tw *(s-brhrates 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 : kec9.w qm1stroad 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 card/r r lukf(pq 80.sp zs2t(,wk that has been waiting at the intersepfrr8/ luqw 0d( pzss(kt.,k2ction 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/s on the zldo89g nxf dzkd883s(yos66surface of planet X where the a 8f6g soxzkdsln(d8938z do6ycceleration 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 m9 g(n jtc vu9;lrvu/9yt n3px4/s on the surface of planet X where the acceleration due to gravity isuuc9 ;nx9vv3g9t/ nt rjp(4yl $1.5 \; m/s^2$. 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 surfaceaamqvt9u2f 3 3 of planet X where the acceleratiov33m f qt2au9an 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/6jxxz (t. 6rc- zv8cijs on the surface of planet X where the accelerationx6zv8-( jx jrt .zcci6 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 thex sn2s* j+3-pcb*chc an 0.10 s. If your friend holds a ruler between your fingers andc3 *xs+b-j*2e hcscp n releases it without warning, how far can you expect the ruler to fall before you catch it?

  A ball is thrown upward 72vzjx 1m)sa fc0as )yat a velocity of 19.6 m/s. What is its velocity after 3.00 s7v jc)sm z2fa)ysxa10?

  A bullet shot straight up returns to its starting hy0,s,1v 9krzleqwgpl(r+e ifm. -+a point in 11 s. What is the initialrlsylfw(k,e1- h eima, r zvp9 g+.0+q speed of the bullet?

  A ball is thrown straight up with a speed of 36.0 m/s. How 6uo mz0*gvy+jzo(g 8/js6 mqp long does it take to returmo06jy(zg qsupzj8o *v /g +6mn to its starting point?

  A ball is thrown downward from the top of a building with an initial speed pj :f3;uzhgt 59n/rss of 6 m/s. It strikes the ground after 2.9 s. How high is the buipus nj3; 5h9f/:gtr szlding?

  A ball is thrown straight up with a speed of 30 m/sc 8c4q8(9od) lhq sb+tdpre j3. (only fill in numerical value in the tccj88lbd(h + q4 odr)39qpseblanks)
(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 ag x/zcf1e)gvv89gx rf*l,f4o ir with a speed of 41.8 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 7 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 7.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is the veloci +;,tihlvw t5pty at t = 1.0 s?

  In Fig. below, what is tgpruz0h6hzb d90cp 7 :he velocity at t = 2.5 s?

  In Fig. below, what is the ve wtlp*19fxd:,g qf4 my)xi5cjcb+c 7 ylocity at t = 4.0 s?

  In Fig. below, what is the 1ccbwc5*p h6hj wm kcj.o+ k+)velocity at t = 5.5 s?

  In Fig. below, what is the average velocity fr/( 2 btyf tc. 02anona,rdn;siom 0 to 4.0 s?

  In Fig. below, what is the average velocity from 0 to/ ;kxc udt373wt- hjm n*ckwlb9) von* 6.0 s?

  In Fig. below, what td: 4f; gqpu+jw 5b;bbis the acceleration at 1.0 s?

  In Fig. below, what is the acceleration*3-/e.o/y3w7 fhnji 2w kemrqe 1vmrn at 3.0 s?

  In Fig. below, what is the average acceleratiouku2 tk 0o)o6flg,h 5 uk*,qxhn from 0 to 5.0 s?

  In Fig. below, what is the average acceleration from 0 to 8.0qousq9rrs8/ 9nen9rj *(he 2:h yxe2e s?

  In Fig. below, what is the displacement from 0 to q*r pm*rzg )/h4hu-z0q5q79vg c wwj b8.0 s?

Does a car speedometer measure speed, velocity? {s6gpf7 )d/wi1oi .vqtyqyn8g 0peed|velocity}

  An object can have a varying speed if its ac h0o(8x9kft velocity is constant.

  The velocity of an object can be negative when it- d0-n4mgdd40/hmjto p n*xrns acceleration is positive.

  If one object has a greatf4 cn5yzi; fm2er speed than a second object, the first must have a greater acce;cyff5i 42nzm leration.

  Two cars emerge side by side from0kyl dp+6z1xw 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 dea xz;pahpnynf 9jw)t 1r;rwg 0w/h05 6creases.

  A baseball player hits a foul ball straight up into the a:8*d2epzdlo3kg 1xh qir. It leaves the bat wit1kgx*3ze8dlphqod2 :h 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 ic5 ew92kal0troug5 e00 iva9* r0htb object speeds up, what is happening to its acceleration, how does it changar kvu059 at t0i0irhegleo50*wb9 2ce if air friction is ignored?

  As a freely falling object speeds up, what is happening to its acc q0+qm lc2nkc2uzt6h2eleration, how does it change if air friction CANk02 tncq6huqz+ 2mlc2 NOT be ignored?

  An object that is thrown vertically u 8q./z 1yq4dv2g3i po0y/gt;a vw7vx bej*v mupward will return to its original position with 3/dzvav *27e8 u/ji 4wyv.b x tyq0o ;qmgpgv1the 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 acceleration at the ivd/c.**l.cw;+4tzv mp acaysame time.

  An object can have non z6lya)zhcu * s3rc+37ggiv )h-psth,zero velocity and zero acceleration at the same time.

  An elevator moving from the second floor to the fifth floor b+t mu cg/yf+cemhom9sx-8( 0making no stops along the way has zero accelhyut9g+fmm 0 c+mosc/be(x -8 eration all the time.

  A rolling ball moves frov -d x a5sw-d h02k8vamg(ue7tm $x_1=1.9 \mathrm{~cm}$ to $x_2=-6.1 \mathrm{~cm}$ during the time from $t_1=2.1 \mathrm{~s}$ to $t_2=5.0 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-2.6 \mathrm{~s}$ is at $x_1=3.0 \mathrm{~cm}$ and at $t_2=3.8 \mathrm{~s}$ is at $x_2=7.2 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight com a beino-fb /, ;jgz7syi*ls+0plete laps around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 12.4 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 108 m aw0 pc-iw+n0 0 ) mjo96tbsulylgay in 9.2 s. It then turns abruptly and gall+bjm g0llo090)t py-snu w6c iops 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 from;,s cg4w66f/l q yaxxi $12 \; m/s$ to $23 \; m/s$ in 5.2 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 fro8 fhj /p-opto.3)(a)x c6xk,qwivymmm $21 \; m/s$ to rest in a distance of 70 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a spebzh15ev p06e,j )hbiped of $27 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.7 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of the blocks to essentially top zh-9hrdo1+c j+v42bvk eea-d speed abouohdk9b j chd-+2 ea+1-evr4zvt $11.1 \; m/s$ in the first 13.6 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 sp 5 r6d -mekyds:obo0-heed of $15 \; m/s$ to rest in 4.86 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves skid marks 92 ca i d bvmjcqs l5*o90wrua;-y9v6d0 )m long on the highway. Assuming a mul b0y-r*wcia5q06v9soddcv; aj) 9 deceleration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck shb/; .7e aqqwgoing $25 \; m/s$ 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. After exacuk/.d ;i6,ajf r6qzs rtly 27.0 min, irza ,;uj .r6 sk/f6qdthere are still 1100 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?    $s$