Suppose that an object travels from one px:7ko jv)3ihgoint in space to another. Make a comparison between the displacement and the d:jhk7gx)oi 3 vistance traveled.

  When is the average velocity of an object equal to the instantaneous veln jmwy+*ku jjti uo/jld)4: :oua/q 39ocity?

  A new car manufacturer advertises t3csey 7fxaid fr4c/ )5)cg+zl hat their car can go "from zero to sixty in 8 s". Thisxfd7ef)cg i r+/a4zcl) 5cy3 s is a description of

  An object moving in the +x axis experiences an ac 27 h24. c.zyvmx bhebjm4l,6x:vws zpceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x direction) begins to se25w(xk/ )q xbbz kp4rlow down as it approaches a traffic light. Make a stateme)rkb2w/x 5b pqe(4kzxnt concerning its acceleration.

  Suppose that a car traveling to the West (-x direction) begisd fsyabk(72p 9n*z r8ns to slow down as it approaches a traffic li bf 2(pyrsz*s7 d8nak9ght. Make a statement concerning its acceleration.

  Suppose that an object is moving with a constant velocity. Mc10qq52o2g zl m nl.hsake a statement concerning iq l sq2z0.hm1l5gn 2cots acceleration.

  If the velocity of an object is zero, does itpox hd u0iaz2-5x9jk + mean that the acceleration is zero? Suppori0zj daph- 2k5ox+ux9t your answer with an example.

  Can an object's velocity change zk 8tdt9-xc t-direction when its acceleration is constant? Support your antc8xztd t-k9- swer with an example.

  Suppose that an object is moving with constant acceleration. M.zm :6n1xh4kb vu n2bfake a statement concerningh:vk4 b .nm 61uxbfz2n its motion with respect to time.

  Can an object have increasing speed while its acceleration is decreas.2 qym xiypkbi(x :-u50japh9 ing? Support your answer with an m.y ua:ip0jxb9 5y(iq-k p2hx example.

  Suppose a can, after an initial kick, moves* ux r75:: excf,vypj:alufy.ec 1x/q up along a smooth hill of ice. Make a statement concerninfucxqf7:rv5ey x.:*1 y,/ cx:u ealpjg its acceleration.

  Under what condition is average velocity equal t;c y9in3wxffoco 9in0nvqmi/5 +ki/(o the average of the object's initial and fi(/qk +i/c n3;oovfxw0mi9n9i ci y n5fnal velocity?

  Objects A and B both start at rest. They both accelerate at the elcj1csuxb; pi 2l pduj (+kk4l0:07osame rate. Howevepl0l lks(2be 0jk7u+4 ojcid1p : c;uxr, 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 from rest. They both accelerate at the same r :eg,r1nd *reyate. However, object A accelerates for twice the time as object B. What is the distance traveled by ordry,: 1e* egnbject A compared to that of object B?

  When an object is released from rest and fal t c4x/dy2;wkels in the absence of friction, which of the following is true concerningey2ct4d ;w/kx its motion?

  When an object is released from rest and falls in the ab7iy7 ku.xazx 8sence of friction, which of the following is truea8.zx i 7kyx7u concerning its motion?

  Suppose a ball is thrown straight up. Make a statk oa1p u v*/1 8h;rikqs53pbsbement about the velocity and the acceleration when the ball reaches t/*vkrsp;3qo1ia 8h1pbu kbs5he highest point.

  Suppose a ball is thrown straight up. cg9)q1 q;;eh x13qt:raghk meWhat is its acceleration just before it reaches ittek:er q gx13aq1h;c;) 9ghq ms highest point?

  Suppose a ball is thrown straighac(1cl , udhfv(j3tfwjc(*p+ t up, reaches a maximum height, then falls to its initial height. Make a statement about the direction of the velocity and acceleration as th,dvpl1f*(acuj+ 3cjtcf( (hwe ball is going up.

  A ball is thrown straight up, r tz9iygyl)26 geaches a maximum height, then falls to its initial height. Make a statement about the direction of the velocity and accel6l)yt 9yg i2zgeration as the ball is coming down.

  Suppose a ball is thrown)l ;wn:uxk/ii downward in the absence of air resistance. Make a statement concerning its acceleration.;/uw nlkxii :)

  Suppose a skydiver jumps from a high-flying plane. What is her acceleration wh.)s m9bpi-aw7 t/ tpfgen s7)gt f-atp/9bmpi.w she she reaches terminal velocity?

  A ball is thrown vertically upward with a speed v. An identical yyevf:a uyqx/c2:4p2y qm;w, second ball is thrown upward with ay:p:x;, yfmy4w q v c/ueyq22a 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 times higher does the second ball go than the first ball?)

  Ball A is dropped from the top of a building. One second later, bal7jpkuqz;z3x24r f w)a.)ew inl B is dropped from the same building. As time progresses, the distance between t.in e jkaz7; zxw4wq23f)rup)hem

  Ball A is dropped from the top of a t ;sy v4o*xs3abuilding. One second later, ball B is dropped from the same building. As time progresses, the 3 t;y vxos4*sadifference in their speeds

  Two objects are thrown from the top oa+whsu5m/ c/ v g68kutf a tall building. One is thrown up, and the other is thrown down, both with tagh +/v5m su/8c 6ktwuhe same initial speed. What are their speeds when they hit the street?

  A brick is dropped from the top of a buildin9q2t 7pcyt )c k8g3(v5eeypxng. A second brick is thrown straight down from the same building. They are released at the same time. Neglect air resistance. Compare theny7x 8pgt5 cqv)3 tpce2ke9(y accelerations of the two bricks.

  An object is moving with constant non-zero velocity in the +x axin .qaq 1 9p-9js3qilpns. The position versus.ln3aq1-p9 s 9inqjq p time graph of this object is

  An object is moving wit f3 8bmskmma j 6divyoj81*5t.h constant non-zero acceleration in the +x axis. The position versus time graph ofjs a fjm8mk*dmv i16.t ob835y this object is

  An object is moving with constant non-zs,7 r.e gh d2glg1kvp1sgpfxcy 9m197ero velocity in the +x axis. The velocity versus time79p p r.sgm1 e1yhkg2gflg,dsx917cv graph of this object is

  An object is moving with constant non-zero acceleration in the +x axik/bem5 bdr7xtv*8hb / s. The velocity versus time graph of this objh7/ bbevxdt 5 rk*/mb8ect is

  The slope of a position versus time graph tukr5-oc;6y qwm*ca-r pa/1e gives

  The slope of a velocity v2 z nruyrz)t:7on 2pa+ersus time graph gives

  The area under a curve in an acceler*um 7v(qtqy 0uation versus time graph gives

  The area under a curve in gw)qxkd ve5 0f150nj6 +zjfsq a velocity versus time graph gives

  If the position versus time graph of an object is a horizontald;o5om(x2v db line, the object idmx ob;(52vd os

  If the position versus time graph of an objp tskiz 7xh1yq6:ihv +h1c b::ect is a vertical line, the object is7h:kpt 1iic :1b qh+xsv:h6yz

  If the velocity versus time graph of an object is a horizont 353wgn(zml 9jbi9tds al line, the object ibs jn(ldgz9 wmti935 3s

  If the velocity versus time graph of an object )s81i )v8 h8j/runzi2 ilyq cvcg j1j5is a straight line making an angle of 30 degrees with the time axis, the objic25gq8 8lj/z1cvi yhnrisu jvj ))18 ect is

  An object moves 15.0 m2kz dv* r;f2rrw-j( ma-kuv :+sy.xsv north and then 11.0 m south. Find both the distance traveled and the magnitude of the displacement vectvzr-k:+dm (y* vf2 w uxsakrr;v2.-s jor.

  A boat can move at 30 km/h in still water. How long will it take to move 12 q0) 2evsfq44v qc0ajo km ufq2) v0qsce v44qajo0pstream in a river flowing 6.0 km/h?

  55 mi/h is how many m/s? (1 mv2/zx3as/ q8s-ur2mgzxhe4yq 0mk; ii = 1609 m)

  What must be your average speed in order to travel 350 t;6fm tz5llwl4nd:2tkm in 5.15 h?

  A runner ran the marathon (approximately 42.0 ks3wemh4scc 1db,d7 c 9m) in 2 hours and 57 min. What is the averag cd, dc47hb3s9m1we sce speed of the runner in m/s?

  A car travels 90 km/h. How long does it take for it to t 3c c3.i /mhmtv::oxghravel 400 km?

  A ly (light year) is the distance that light travels in one year. The speed of -*8/0 enimu zan:o swxlighza w:im nnx0u-s*/ eo8t 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 angraks(/,uedy2 : 3 altd you look to the side for 4.0 s, how far do you travel duringgs2da3,lta u/ e:ry (k this inattentive period?

  If you run a complete loop around an outdoor tra1sy-a.p3l iti/z gwr 3ck (400 m), in 100 s, your average velocity iz/ - rg i.tyi1aw3spl3s

  A polar bear starts at the North Pole. It travels 1.0 km south, then q/,fu:;qnbzn 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 uf/z ,nq;b n:qbear's average speed?

  A polar bear starts at the North smxl, pt0qjp4w- ,ukxr7-zo3Pole. 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 tq-t7 u30pwzo rj4-xkp m,sx,lhe bear's average velocity?

  You are driving home on4(ha96v dpj83;chyco s)g cjkvk+k/r 2wj5gh a weekend from school at 55 mi/h for 110 miles. It then starts to snow and you slow to 35 mi/h. You arrive home after drsy482c w 5a(;rvo9hk/jp vj+ ck) 6cg3hhdj kgiving 4 hours and 15 minutes. How far is your hometown from school?

  A motorist travels 160 km at 80 km/h and 160 km at 10o cg(z-l gx2 xu/m-yn,0 km/h. What is the average speed of the motorist -gmn ly u2-,cx (/ogzxfor this trip?

  A motorist travels for 3.0 h at 80a,pd z4 ny*cb(rn.+ss km/h and 2.0 h at 100 km/h. What is her averagsnr( c4,.bp*d z s+nyae speed for the trip?

  An airplane travels at 300 mi/h sqhc-27toen9m0 ult d4u(7le b outh for 2.00 h and then at 250 mi/h north for 750 miles. Whe79 q-elhu4d2n 7 l t(tc0bomuat is the average speed for the trip?

  In a 400-m relay race ic 6gb2 45sfj )mrydi52i/lvithe anchorman (the person who runs the last 100 m) for team A c ii)vbr5cid 45i2m yjs/ f6gl2an run 100 m in 9.8 s. His rival, the anchorman for team B, can cover 100 m in 10.1 s. What is the largest lead the team B runner can have when the team A runner starts the final leg of the race, in order that the team A runner not lose the race?

  A car decelerates uniformly and comeoixr/6:o*hkne ea*g bzk)cu2)c zc42s to a stop after 9 s. The car's average velocity during decz*)*g4occaez b/n22 ke6k:our chi)xeleration was 55 km/h. What was the car's deceleration while slowing down?

  An airplane increases its speed from 100 m/s to 160 m/s, at the aw6 tora , kpq*-ynuul 73j1k:mverage rate of ,ku:n q-ylo3 mu1*w aj r76tkp$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h k9lg n:cbu:2b accelerates 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 accelerates at up k ;gktecrq2x/0t93+*exq m$4.0 \; m/s^2$ 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 cons d9gcp3w i,,q0a kr-npah*cf*6 a 5ceitant acceleration oe pc,6- i50*ra*3qcadhf9ia wn, kpcgf $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 1.5 m/s experiences a constant accelera+jb 4d/d*ro4 .joet:jxdjj n1tion of+4ebd1djtor no *j jx4jj:d/ . $3.7 \; m/s^2$. What is the cart's displacement during the first 9.9 s of its motion?

  A bullet moving horizogilm*g6 aen/; 9frnq4ush/q5ntally to the right (+x direction) with a speed of 557 m/s strikes a sandbag and penetrates a distance of 38.88 cm.n4*a q mqnug 65/;9ges /hilrf What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launchxv(h 6efres+27jjazib 6p5: s ed from a catapult on an aircraft carrier. It reaches a speed of 42 m/s at the end of the catapult, and this requires 2.0 s. Assuming the acceleration is constant, what is the length ofespjx +57jb(fiar6 v 6he:z2s the catapult?

  A car starting from rest moves with co-,a)a jsbo6fujy h75;feu7eod 0q lj0 nstant 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/mme.yf1i qbd) 0k7ne )s in a distance of 200 m. What is its average acceleration.m bi m)1 y0)keedq7fn?

  An object starts from rest and undergoes uniforjb9b:h4/ z cphm acceleration. During the first second it 94/zbh h:bpjc travels 2.0 m. How far will it travel during the third second?

  An object is moving iq7r5zbu +j9h)9+l yr zn l;gqa,p ih6xn a straight line with constant acceleration. Initially it is traveling at 16 m/s. Three seconds lat rzy59 7 +6 qq)rbhuxa;nphz9j +,llgier it is traveling at 10 m/s. How far does it move during this time?

  A car starts from rest bfd1fyj(n8b ; and accelerates 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 decelerate atkfy j1 dh,,+nrdi/pu 17xzd w7 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 lzoj0.yd7b;5s m d k8jqight turns green, a car that has been waiting at the intersection starts ahead with a constant acceleration of 0o jbk8zqjsm . ;y57dd$2.00 \; m/s^2$. 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 wieo5+y 8i ifb 05lho-yhhu0*unth a speed of 12 m/s on the surface of planet X where the acceleration due to gravity is0+ n50-yolu h ho hief8b*uiy5 $1.5 \; m/s^2$. 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 planet X wcn4bf;)u*inf yv ts(t .2n)uohere the acceleration cb.ntvy;2 4ous ()ft) inn*fudue to gravity is $1.5 \; m/s^2$. How long does it take for the object to reach the maximum height?

  An object is thrown upward with a speed of zi- bn;x g/fh6f jwem 6qk(+z;15 m/s on the surface of planet X where the acceleration duzmk+;zqfibfnewh6/x g( -6j; e 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 cnx(-nc6k*zonx -d w) speed of 14 m/s on the surface of planet X where ndk)o-n*c x(x - w6zcnthe acceleration due to gravity is $3.5 \; m/s^2$. What is the speed of the object after 8.0 s?

  Human reaction time zn1b : ;2fj1hseo*. nnfm 9wkgis usually greater than 0.10 s. If your friend holds a ruler between your fingerwg2 es911*f b;nk:ho fnnzj.m s and releases it without warning, how far can you expect the ruler to fall before you catch it?

  A ball is thrown upwoutn7wp,* p+i *l b)xbved.lo1 x9a+w -yhyo7 ard at a velocity of 19.6 m/s. What is its velocity after 3.0yp9 db ex.b +7 wo* xn, i*yo1ul-+7)tpwlhova0 s?

  A bullet shot straight up zpder7lo 8 i35c+oql)xmo*r7 returns to its starting point in 18 s. What is the in+87 7i zx e)lp3ocr*5dlqoromitial speed of the bullet?

  A ball is thrown straight up with a speed of 36.0 m/s. How u-d3ove7ajh .hxery xi 4l1n(*gu c3;long does it take to return to its starting 73dloxerynhu hc3v4i e - (j1*a;u g.xpoint?

  A ball is thrown downward from the top of a building with an initial sk)gqr c2/ ,mwqpeed of 11 m/s. It strikes the ggw , kqr)q/cm2round after 4.3 s. How high is the building?

  A ball is thrown straight up with a speed of 30 m/s. (only fill in numerip)s1fcfddnns:842 g e iwk2,gcal value igkf2pw d1)sde,ifc:nng 2s84n 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 tc ),s eewt( x+it9nv+lpxw6k( he air with a speed of 41.5 m/s. (use $g=10 \; m/s^2$, only fill in numerical value in the blank)
(a.) Calculate the time required for the ball to rise to its maximum height.  (数值)  $s$
(b.) Calculate the time for the ball to fall back to the height at which it was hit.  (数值)  $s$
(c.) Calculate the maximum height reached by the ball.  (数值)  $m$
(d.) Calculate the ball's speed 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 velocity at t = 1.28k1of6yj ubs1e f( lk0 s?

  In Fig. below, what is the velocity atap -;; mj9hrhk t = 2.5 s?

  In Fig. below, what is the velocity at t = 4eq+guvojwb); o1ebteb*0 nio/7 u k+o2k3cx . .0 s?

  In Fig. below, what is the velocb9)tg m .x) erf.;ejrxity at t = 5.5 s?

  In Fig. below, what is thu1h *l-d;y/hqcavs:k e average velocity from 0 to 4.0 s?

  In Fig. below, what is the average velocity from 0 to 6r1k qovc2-ek+d9;y sh.0 s?

  In Fig. below, what is the accelera 04u7usyt1r:yaak(a ktion at 1.0 s?

  In Fig. below, what is the accelep f+v )/kv*qxsu7:w imration at 3.0 s?

  In Fig. below, what is the average acceleratwr h2v9zctmss2izfzc 73i5y.6 6qm g+ion from 0 to 5.0 s?

  In Fig. below, what is the average xbjfg-)1 q q39ff az+k stlaj s33k(-gacceleration from 0 to 8.0 s?

  In Fig. below, what ispc p ,im/)xr1q;3*y i(nqc zps the displacement from 0 to 8.0 s?

Does a car speedometer measure speed, velocxw8zep+g 8puk, 0vqobkh . je(w/7 bm5ity? {speed|velocity}

  An object can have a varying speed if its velocity is cons +mzurnsh8 e)3tant.

  The velocity of an object can be negative when its acceleration is zkt:y,oson.p a9;vb adz +i: /positive.

  If one object has a greater 3kwstu swqa(gra,p,1 j4. 2 hkspeed than a second object, the first must have a grew(uqp 1 ,a hr,wgk .3sjsat24kater acceleration.

  Two cars emerge side by side from a tunnel. Car A is traveli:si4 7c0 nd;lfvm)zft ng 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 accelerationh:i0 hpl*a hm1 decreases.

  A baseball player hits a foul ball straight up into the air. It leaves t3 pt z 6y i(*ys;+j6ualm:5f0tkeuy behe bat wi;sum5u6(*a+:fy 0tklbje iyz6yp et3 th 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 happening to its accelwzg e122p v8raeration, how does it change if air friction is ignorwg82vpz1ar 2 eed?

  As a freely falling object speeds zqr- . cu q;6;iufg+mgup, what is happening to its acceleration, how does it change if airu;.rqi;g m gq-f6uz c+ friction CAN NOT be ignored?

  An object that is thrown vertically upward will reb,n 82feizp st()kjbt lpw*zt8 49wu0turn to its original position with the same speed as it had initially jitw2( 9,pbzep8) lbz 0t4stfn8u k*w if air resistance is negligible. If air resistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzero accele0 9oym+ a wnxqtm7qo8:-rywm /ration at the same time.

  An object can have nonzero velocity and zero acceleration at kce;vksiupjv 1/j mjw5-vfx;w/ p37, the same time.

  An elevator moving from the second floor to the fifth floor makiy vnrdjrs a: a8). ff7xsl(c04f6r4agng no stops along the way has zero acceleration al4 n)s8gac0f :vfayax f(jr7l. s4rr 6dl the time.

  A rolling ball moves fr ,/om oll prt8,fx-e/zom $x_1=3.3 \mathrm{~cm}$ to $x_2=-7.8 \mathrm{~cm}$ during the time from $t_1=2.6 \mathrm{~s}$ 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 $t_1=-4.2 \mathrm{~s}$ is at $x_1=3.0 \mathrm{~cm}$ and at $t_2=3.3 \mathrm{~s}$ is at $x_2=7.8 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete lap*(bqg*rp ,lar, tg yx*s around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 9.8 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 p1;adpg c61q ujv ic7gau3, ysh+a5/j5g(mly103 m away in 10.5 s. It then turns abruptly and gallops halfway bac7c , gpui jm+u(y1y6vlcqa 31apd;h ag/ s55jgk 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 froq8 eg5e;l9f eom $11 \; m/s$ to $25 \; m/s$ in 4.8 s. What was its acceleration?  (数值)  $m/s^2$ How far did it travel in this time?  (数值)  $m$ Assume constant acceleration.

  A car slows down from 5l1y44+cjl) pgj4,msm cupob $20 \; m/s$ to rest in a distance of 80 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a speed ofi7: -)atvd wsp $33 \; m/s$ 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 a*urr ,a0lcw: of the blocks to essentially top speed abouarwu:,crl *0a t $11.0 \; m/s$ in the first 11.5 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 csy,;3 l4svpd a speed of $19 \; m/s$ to rest in 4.75 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves skid marks 92 m long on tbf*dzu 7f01gc he highway. Assuming a deceleration of bf f*czud017g$7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck going3mah*9s)(d ; n ipxlbmgyzay n9)7 hi1 $25 \; m/s$ 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 r 8w, qwrvc-*zmnk4oxc1cbhx4 5)y u)dun in less than 30.0 min. After exactly 27.0 min, there are still 1100 m to go. The runner must txw,*k-zoy d8m xwq c)nch)u15rc44 v bhen accelerate at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$