Suppose that an object travels from one point in space to another. Make a 0 ksh99zi8twx of ghs0f2.rz2comparison between the displacement and the distance traveh i9rks.g wf08z9ho20 sf2ztxled.

  When is the average velocity of an object equal to the instantaniyta a;r k,10yeous velocity?

  A new car manufacturer advertises that their car can go "from zero to sbn 5iuc:r/; nueaxc p fk/:/m;ixty in 8 s". This ka /ibpf;urcm nue;:: // n5xcis a description of

  An object moving in the +x axis experiencu l8i 04par3zons9/fies an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x direction) beginltt;d6 no;: dus to slow down as it approaches a traffic light. Make a statement concerning it ldu n;dt;t:6os acceleration.

  Suppose that a car traveling to the West (-x direction) begins to fzx/i9o dcgh,0pq i(6 slow down as it approaches a traffic light. Make a statement concerni dh9 fp/6(q0 oxicgz,ing its acceleration.

  Suppose that an object is moving with a constant velocity. Make a statem .nq4nzkvbaft e/y3 o- ,p3msnk*pi;6 ent concerning kypi smfa,o;nq3t n3k -6nb/4.z ep v*its acceleration.

  If the velocity of an object is zero, does it mean that the accelef7iow 4z7o5u6e.pwl h::ld lvjxj+n5 ration is zero? Support your an wi46hu j57 zdj::pon5+f 7xo.lv wlelswer with an example.

  Can an object's velocity change directip+4t fwb sf41g v4v,*(r roirdon when its acceleration is constant? Sup(f rdvo gfpbt*r+4 i14s vrw,4port your answer with an example.

  Suppose that an object is moving with constant acceleration. My v mtruylx1kx0pct4*o 3-t2 z0(v7xj ake a statement concerning its motion0 vym0t xl2v y k3j7z*pt-xrtuco14x( with respect to time.

  Can an object have increasing speed while its acceleration is decreasing? S 6tzemm6t+jm0upport your answer with an 6+tm z m06mejtexample.

  Suppose a can, after an initial kicqb6 lgjk-v8w. 5;:l0xaalrj/k w: fyck, moves up along a smooth hill of ice. Make a statement concerning it-0;:ab r gkjll/l w.k5x qvywa6jf8:cs acceleration.

  Under what condition is average velocity equal to the average of the htor) 5,(rl ww r/j pkpp0qwk m(;f5,vobject's initial and final ve,p(l;rh)tr ( wr0/5vq5pok jkw,p mfw locity?

  Objects A and B both start at rest. They both accelerate at)n ia a0ecz 9-*5lsxth the same rate. However, objectc0x*a)aiz lh9es -5nt 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 from4ej3y noj+,cp/. uq fq 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 compao 4/3+e,yc jqpn ujf.qred to that of object B?

  When an object is released from e.n-x(k n715 8wu aznyyl)vuwrest and falls in the absence of friction, which of the follo8anze75kn.uvx )n-yy w 1w(ulwing is true concerning its motion?

  When an object is released from rkh ,s8+rowy;5+t (s lislfu/ west and falls in the absence of friction, which of the following is true concerning its motion?+t ss/ k;y+lhsi(fouwr5 8lw,

  Suppose a ball is thrown straight up. Make a statement about the velocit2q ymv3 /erkn0y and the acceleration when e/2qmy30 n rvkthe ball reaches the highest point.

  Suppose a ball is thrown straight up. What ishoz9*) tbn t/-sqr 4a*ik 0 yn:fi9avfak8q/v its acceleration just before it rz9t*bihns tka*y)94/f :qqriv k /oanva8f- 0eaches its highest point?

  Suppose a ball is thrown straight up, rea5 67cx 7rnwi wzcxb/ao6 5roor, +ahb1ches a maximum height, then falls to its initial height. Make a statement about the direction of the velocity and accel7+chro6 z r5a6wniobxx c,7 1r/wo5b aeration as the ball is going up.

  A ball is thrown straight up, reaches a maximum height, then falls to its27r*4om1ni1 cnlv,vg tao3 si initial height. Make a statement about the direction of the g7 at,i 113s*no4iovmlr2 cnvvelocity and acceleration as the ball is coming down.

  Suppose a ball is thrown 1uzi5v czp6*rdownward in the absence of air resistance. Make a statement concerning its accel*zcvrpz6 15u ieration.

  Suppose a skydiver juv.an.okl-l z,c ( ed-tmps from a high-flying plane. What is her acceleration when she she reaches terminal tl-l k( ec-z n,a.d.ovvelocity?

  A ball is thrown vertically upward with a speed v. An identicalao2ch 9rjh8rjtnlo3x4/lb 0 1 second ball is thrown upward with a speed 2v (twice as fast). What is the ratio of the maximum h19jtlh on8bc/hl204x o3ajr reight 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 second later, ball B is dfmm9v1ixh*1 e x;h77 x2i7i kbi j/vhmropped from the same building.m m;hiih *v7/m72xx iefv b79hk11jxi As time progresses, the distance between them

  Ball A is dropped from the top of a buildin7i7ljcx 40fb )fji khfe r:r45g. One second later, ball B is dropped frbie70: 4lfkfj7)rrhj 45xfciom the same building. As time progresses, the difference in their speeds

  Two objects are thrown from thx8xw* z d/+qg u gu:s*az(ap 4vyby:m2xp36qje top of a tall building. One is thrown up, and the other is thrown down, both with the same initial speed. What are their speeds when they hit the street/xdxu z6 w(ypmau*j y *ag2q4p v 8g3qxs:zb:+?

  A brick is dropped from the top of 345v/ gjhisyd 5p k vq5u)kv*ja building. A second brick is thrown straight down from the same building. They are released at the same time. Neglect air resistance. Compare the ) hk*j iqv/d35 sgpvyju5kv45accelerations of the two bricks.

  An object is moving with co1j981adox 8 fu *l0pxoigag+tnstant non-zero velocity in the +x axis. The position vers8*x1gp +xft j 89ld au0goo1iaus time graph of this object is

  An object is moving with constant non-ze0hoe /gj6q+2qgdat 8fro acceleration in the +x axis. The position versusad+j6qft gh0o2eg/8q time graph of this object is

  An object is moving with constant (l7 bmnhip pnk*/; f+tnon-zero velocity in the +x axis. The velocity versus tipbkm/ 7 ft lhi*p;n+(nme graph of this object is

  An object is moving with constant non-zero acceleration in the +x axis. *mhkh:,lmml*vhk8 h.The velocity versus time graph 8,l. h:m*lkv*hhmhmkof this object is

  The slope of a position versus time graph gives lh cdg+6.2uzawmg73d

  The slope of a velocity versus time graph tiwquk2/k3g vmr8/t- gives

  The area under a curve ind,yf3fq.p - x7mu a9of an acceleration versus time graph gives

  The area under a curve in a velocity versus tim)6erul5(n+rn z iwl *b7u6vxme graph gives

  If the position versh)l o1n- o9yww: ew1eius time graph of an object is a horizontal line, the object isl 11o)9ey-:ww hnwie o

  If the position versusgsawu:/p 1 6iec(b g7m time graph of an object is a vertical line, the object is/ w 7c6pag1e( m:sbuig

  If the velocity versus time graph of an object is a horizontdu1pn tpm u:. +8emmeto/ sf6 l-p7.ffal line, the object is-.1 /lpdfsm pfnmf uto:8e6+. m7ptue

  If the velocity versus time graph of at4oid* e:+9t ,ndprlzn object is a straight line making an angle of 30 degrees wi 9t:o ized4+*rtd,lpnth the time axis, the object is

  An object moves 15.0 m north and then 11.0 m south. Find botu)fva-d, ao )e ms7fz eu*ri/9h the distance traveled andd/m vei e)f) zuusar9-oaf7*, the magnitude of the displacement vector.

  A boat can move at 30 km/h ;./w 3.c5dawpy eztzk in still water. How long will it take to move 12 km upstream in a river flowing 6.0/p..te3zkw 5z;y cdw a km/h?

  55 mi/h is how many m/s /zp34ebxo k-m? (1 mi = 1609 m)

  What must be your average speed in orde*ng a(cfn;/oteclz5 lj )yd2u)3 4j air to travel 350 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 km) in 2 hours and 57rez+*k9g ;yo n min. What is the average speed of the runner in m/s? e9*ozyrn;+ kg

  A car travels 90 km/h. How long domzd:2x v60c nhes it take for it to travel 400 km?

  A ly (light year) is the distance that light travels in (5d0 odzhd m-uone year. The speed of ozh-dd(u m50d light 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 yadprw94pu5mhm3 ) 3h look to the side for 4.0 s, how far do you travel during this inattentive uhrh y9p)dawpm334m5 period?

  If you run a complete loop around an outj2zx5i) 2 dc ujrfr4+sdoor track (400 m), in 100 s, your averau)2d2zcxjf 4i r+5jsrge velocity is

  A polar bear starts at the Northx q1;k5 8 2ylfdnn 7dhh,nfyz7 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 startzhhkfd x57,q87d; flnny2n y1 ing point. This trip takes 45 min. What was the bear's average speed?

  A polar bear starts at the North Pole. It travels 1.0 km jy8da fyi2))5,t ieeq-m+ tjksouth, 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 velocity?d2ie)qtf a j8j ,5+i-ymykt)e

  You are driving home on a weekend from school at 55 mi/h for 110 milby- sa lx1i1;hijv2cs;wm3 r-es. It then starts to snow and you slow to 35 mi/h. Yo1x1iwa2-y l; ;vshm-brj ics3u arrive home after driving 4 hours and 15 minutes. How far is your hometown from school?

  A motorist travels 160 km 7 pect5ee 6hk/at 80 km/h and 160 km at 100 km/h. What is the average speed of h/e6 c5tpee7 kthe motorist for this trip?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h at 1*pbowg+3;ox r:gwwn)00 km/h. What is her averx;pngo:wrb+3 w *)gwoage speed for the trip?

  An airplane travels at 30veu )ukr-upu3dv71 *l0 mi/h south for 2.00 h and then at 250 mi/h north for 750 miles. What is the average speed for the k3uvue d-*ru1vpu) 7 ltrip?

  In a 400-m relay race the an76zfqhl;- ; rx kbtdd:chorman (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 tdt -rblq x ;z6k:7dhf;he 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 12 s. The car's averagih+)9ru zmx5dlvhaz7 m t,8p(e velocity during deceleration was 51 km/h. What was the car's deceleration while sldz 8 )hh9tm 5( uvx,i+pmar7zlowing down?

  An airplane increases its speed 28)lli cd v qsuqjm9dx, 3)fd2from 100 m/s to 160 m/s, at the average rate of q82dvj)ddful)mixsl 9q2,c 3 $15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelera5)jkwh qw46ui tes 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 rest and accelerax 2uy)ckcujje urkk17yd.e ,7: z 8w9ztes 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 m53rwl5n :mn07kezt iuu;p k/q/s for 10 s. It then speeds up with a constant acceleration of/mr 5 e5u 0;knpk7nqilw:utz3 $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 3.8 n //(dg,t6p7flvzk5s tzj. xfm/s experiences a constant acceleration ofj/ fxpdfzg,7vtl n .5(/ts 6zk $1.2 \; m/s^2$. What is the cart's displacement during the first 9.1 s of its motion?

  A bullet moving horizontally to the rightblhk b )gn-9 q)q(mslgfvl-c2d1 b*g1 (+x direction) with a speed of 325 m/s strikes a sandbag and penetrates a distance of 88.04 cm. What is the average ac 1hbvsg1bql f))mn d2-g-c9kg*ql bl( celeration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on an aircraft carrz6usm3 mdk( wbg1th*9 ier. It reaches a speed of 42 m/s at the end of the catapult, and muh1 w tdsm (*zb63k9gthis requires 2.0 s. Assuming the acceleration is constant, what is the length of the catapult?

  A car starting from rest moves with constant acce0b slnr,s3n. 0(zi blth /ef5oleration 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 its averagb:iscq9bu +0 u:wbj- xe acceler-xbs:u 9q+ w0bcbj i:uation?

  An object starts from rest and undergoes uniform accelerati9ugh 22hxegt) on. During the first second it trav e22gx9)hhgt uels 8.2 m. How far will it travel during the third second?

  An object is moving in a straight line with constant acceleration. Initially xj97 1ezg euv,j tt7gu9))zwk f*b9mnit is travxgmt,eu kf9e7)t)uz gwj 9j79nv*1zbeling at 16 m/s. Three seconds later it is traveling at 10 m/s. How far does it move during this time?

  A car starts from rest and a)8vxkd p2 h26q bd)j,na)mlduccelerates 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 04uift:*o vg5p6an9h o(y kvudecelerate 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 lp;qg/ mkj2 t1-bket26ye9gw cight turns green, a car that has been waiting at the intersection star62e/ -e y9gmptkb;k jc q1gwt2ts 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 surw ;+ojc1n- pe1 wv6.ga*ylwnrface of planet X where the acceleratiylr*wno-w1c16n +ej;ap.wgv on 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 s;qv6ay +pm 6ze4 d;nigor3ti4peed of 12 m/s on the surface of planet X wher4;n6qi ;dert o34 gmpayzi6v+e the acceleration 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 winnlxq s8i/z3xnud.1t:aqi l 8/(bb 9sth a speed of 15 m/s on the surface of planet X where the acceleration due to gravity q1tn8/nnui.x 89 b/ xlq3 s z(l:sabdiis $2.5 \; m/s^2$. 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 surface l(q72f a6gc3dgnkx9e of planet X where the acceleration due to gravity fl9ng2c6 kd37(qe gax 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 friend holdsbl ./*frv(t yp a ruler between your fingers and releases it without warning, how far can you ex ft pl/rvy*b(.pect the ruler to fall before you catch it?

  A ball is thrown upward at a velocity of 19.6 m/s. What is its velocity aftemoe iyu +-uy/4+zngp 7r 3.00 e +ynm-u7ip+ u 4/yzogs?

  A bullet shot straight up returns to its starting poin)un an uu(s(q2t in 7 s. What is the initial speed of th auqn) (u2un(se bullet?

  A ball is thrown straight up with a speed of 36.0qqibbgq45 6l8 m/s. How long does it take to return to its startin5ibqg bq4 6q8lg point?

  A ball is thrown downward from the top of a building with an initia:ksuc 8- 8thh:xhq0l pv eem).l speed of 27 m/s. It strikes the ground af:se-chm0 lvu ekt8:).xp hqh8ter 6.7 s. How high is the building?

  A ball is thrown straight up with a speed of 30 m/s. (onhi9(w k jy8hx-ly fill in numerical value in the blanjyk8h xi(w9h- ks)
(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 ff us0;t xz5e-a speed of 43.1 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 velocity a+hhnvau66j oy,m */nt85udaw/o otk 3t t = 1.0 s?

  In Fig. below, what is the velocity at t xg2 uel*v;v-* bj n2d2 x+kk6vlq eb)n= 2.5 s?

  In Fig. below, what is the velocity at kjb/ 7t9-gro /w9li k2m kezr6hmj 9l5t = 4.0 s?

  In Fig. below, what is the velocity at t = 5.5 s?- fsg,r l, q*,q9dajsx

  In Fig. below, what is the average velocity from 0 to 4.0 s?2ac zd7/+ ontx

  In Fig. below, what is the avebx jfcczs+3w.h0om2;9oq o g6rage velocity from 0 to 6.0 s?

  In Fig. below, what is the acceleratioo nlzh5nr/ str) l 65rxm694e*2rwwodn at 1.0 s?

  In Fig. below, what is the accet/wh )9g;te8gs sdi1 y0o (gvgleration at 3.0 s?

  In Fig. below, what is the average acceleration from b (oz8h.q*ftpa9nu+ r)* pg sc0 to 5.0 s?

  In Fig. below, what is the average acceleration fr0 8z, yh/rs-evisb y0eom 0 to 8.0 s?

  In Fig. below, what is vs1 9oujk8 ft:/tz9lj aq/fjo/-yuc50bpax*the displacement from 0 to 8.0 s?

Does a car speedometer measure speed, v y0zn cy1nbs8e-j(o s)elocity? {speed|velocity}

  An object can have a v ioi xvc6cw7td;.x ouc:t/ 96gu5wb4 zarying speed if its velocity is constant.

  The velocity of an object can s+t/ xhu: 22,jsy(ss)xjazfs be negative when its acceleration is positive.

  If one object has a greater speed than a second object, the first must have a,s1alcx+// vq )q-dlvl9jke y greater ac, lydlx)/1vcvq -+sakle9q j/ celeration.

  Two cars emerge side by side from a tunnel. Car A is traveling x9xe f5dkma(3-hm /ls* sb qiyo8b2b 8with 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 acct+y(n;:i c0.nt vnyh9c*ks qyeleration decreases.

  A baseball player hits a, r3z,xaa(h ha efz(3r foul ball straight up into the air. It leaves the bat witz3( aha r ,zf(3hxe,arh 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 speeds up, what is hn-.syutzoz7v;+x clsom hf* 4 2y :c1xappening to its acceleration, how does 1tx-;hfyx+2so cn.ys7ov: zmu zl4c*it change if air friction is ignored?

  As a freely falling objec:uiiqa02b/k6pgl b n/ t speeds up, what is happening to its acceleration, how does it change if air friction CAN NOT be iuipqli/ /6ga k:bn2b0gnored?

  An object that is thrown vertically upward will return to its ya)mq,q+3a9n, iibctng) qp6original position with the same speed as it had initially if air resistance is negligible. If air resistance is ab6q mi9yai))p,n ntcgq+a ,q3 ppreciable, how will this result be altered?

  An object can have zero velocity and nonzero acceleraarl2f rvxg(v5i.* f3 xtion at the same time.

  An object can have nonzero velocity and zero acceleration at the 0vx u( u/egk k8cak9,q snp*r;same time.

  An elevator moving from the second floor to the fifth floor making no sto1cnxlh v /f/qab*. ;eops along the way has; .o/aqn/hx l fe*bv1c zero acceleration all the time.

  A rolling ball moves from i un)par1c9 ygbyv43:$x_1=3.3 \mathrm{~cm}$ to $x_2=-7.9 \mathrm{~cm}$ during the time from $t_1=2.3 \mathrm{~s}$ to $t_2=5.2 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-3.4 \mathrm{~s}$ is at $x_1=2.2 \mathrm{~cm}$ and at $t_2=3.1 \mathrm{~s}$ is at $x_2=8.1 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete l(xdp2xf(9n nsn*xt 8u( u eah8aps around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 9.1 min. Calculate (a) the average speed  (数值)  $m/s$ and (b) the average velocity    $m/s$

  A horse canters away from its trask ;axd9 .0dtviner in a straight line, moving 107 m away in 9.7 s. It then turns abruptly and gallops halfway back in 4.6 s. Calculate (a) its a.t vs d;09xkdaverage 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 from5w)qk: xe)0ud7rln u cuc5m2z $10 \; m/s$ to $23 \; m/s$ 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 fro3/psg vs 8qx;lxy5a;t m $18 \; m/s$ to rest in a distance of 68 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must r*3 5*iwcsny mkeach a speed of $29 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.6 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst d2yw -aysa/mfor/xgd: -97 tm out of the blocks to essentially top speed about xs7 yrf-wm2:oga9 a/ dymd-/t$10.3 \; m/s$ 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 uniformlybxfgk -66 h,xm from a speed of $15 \; m/s$ to rest in 5.16 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves skid ma-n1377 spc lpqicze8)s , bzlrrks 92 m long on the highway. Assuming a deceleration ofczr,ei scn81b) ls7p l7z3p-q $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck goin :7n7 ulyh1 l1+roh +bj8pnzgbg $25 \; m/s$ 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 10,0001lhiu ib( ( ,ci .ncuad50cl3b-m run in less than 30.0 min. After exactly 27.0 min, there are still 1100 m to go. The runner must then acceler5dci 3.nihll( ,c ua( ui01bcbate at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$