Suppose that an object travels from one point in space to anb-tzv th(o5c. other. Make a comparison between the displacem t5(o v.tbhcz-ent and the distance traveled.

  When is the average velocity of an object n,f:jyzs 2ykoe1 n*9 iequal to the instantaneous velocity?

  A new car manufacturer advertises tytvb1ghe0 5x7 hat their car can go "from zero to sixty in 8 s". Thisgeth5byv17x 0 is a description of

  An object moving in p1qp ij v4d*bt(2 m t6xw9zg/casi)5b the +x axis experiences an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveli9tgx b+9g ucu57:tcon(w2e wp ng to the East (+x direction) begins to slow down as it approaches ag9u(:57wetxu 9 c+2tpbncgow traffic light. Make a statement concerning its acceleration.

  Suppose that a car traveling to oh 1+e* kqttv w-z1.xj7*jemqthe West (-x direction) begins to slow down as it approaches *t w*eozv17-k qh+ej.qjm1xt a traffic light. Make a statement concerning its acceleration.

  Suppose that an object is movingiquq(* n m*8q c/4ss* ,nxolix with a constant velocity. Make a statement concerning its /(q* l x*sqxc m4q u8non,s*iiacceleration.

  If the velocity of an object is zero, does it mex80m e r.nh-qoan that the acceleration is zero? Support your an0hem8rqo-. nx swer with an example.

  Can an object's velocity change direction when its acceleration is constant87rpv1.pb qzat v /ry3? Support your answer with an examply/vtv.37qb pr1 8zrpa e.

  Suppose that an object is moving with constantm a qs/b)4h uf/g5lxz( acceleration. Make a statement concerning its motion with resp(almhxq/ g4 5fs)uz/b ect to time.

  Can an object have increasing speed while its acceleration is decreasing?fn a9+vlgeqd, qz 249y Support your answer with an exa9q2 ydva4 9lzq,f+ngemple.

  Suppose a can, after an initial kick, moves up alosvj /gv9h.gr2 ng a smooth hill of ice. Make a statement concerning its acces.r jvhgg/ 29vleration.

  Under what condition is average velocity equal bwjn8w9*p tvc9g;fo; to the average of the object's initial and final vg ;ctf pwjb8*9w;9novelocity?

  Objects A and B both stal (pvz 8d1fdfhrr 268xrt 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 f8f6 (rdrl hz8d p2v1xB?

  Objects A and B both start from rest. They both accelerate at thjkh +7(*l+j l4fyh 7gee8wjwojt.zr- e same rate. However, object A accel(hlz 4+l e jgj+7jtwy7ojr k*-fh.w8eerates for twice the time as object B. What is the distance traveled by object A compared to that of object B?

  When an object is released from rest and falls in the absence ofw) 3 j zb((zps3rawpp. friction, which of thrpasw pb3p 3)zwz.((je following is true concerning its motion?

  When an object is released from rest and falls in the absencib72/c q+ebs7skce*h108nv q8ft vdpe of friction, which of the followingb q7h nv8 cei sbs0pk+v2/17d*ceq8tf is true concerning its motion?

  Suppose a ball is thrownst -7xi0t wa*eecsx5 ) straight up. Make a statement about the velocity and the accelera a xt w*)cse7te5ix0s-tion when the ball reaches the highest point.

  Suppose a ball is thrqml 7n2xu4ef1 own straight up. What is its acceleration just before it reaches its higheu1le72nxmqf4 st point?

  Suppose a ball is thrownh(scsw (bi*i7i3t wc22)s.hoiltxs / straight up, reaches a maximum height, then falls to its initial height. Make a statement about the direction of the velocity t3 i(w)sbsi h7c (x i2otcs./liw h2*sand acceleration as the ball is going up.

  A ball is thrown straight up, reaches a maximum height,5jpei(foquj kk10 /xph+r/; q then falls to its initial height. Make a statement about the direction of the velocity and acceleration jpeqpuo5ih rkq0;j/f/k+(x 1as the ball is coming down.

  Suppose a ball is thrown downward in the absence onvve5oz g; mv,fzeg 9g6t61v 5f air resistance. Make a statemef v5zng;o5e, gm91 vv6z gvt6ent concerning its acceleration.

  Suppose a skydiver jumps from a high-flywr-68kxsq :tbls( 3qking plane. What is her acceleration when she she rea 8l -(tk:rx3sbw qkqs6ches terminal velocity?

  A ball is thrown vertically upward with a speed v. An identical seck iy9 w8sdyl(97dk f1wdj. wt4ond 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 the first ball? (How many times y.89 d7wi(lfwy dkj1kt4d 9wshigher does the second ball go than the first ball?)

  Ball A is dropped from wdc/(5wqsn.3sfu m*o0x1tdi the top of a building. One second later, ball B is dropped from the same bui13ifm(0sw uo/ dqc.t dw5nsx *lding. As time progresses, the distance between them

  Ball A is dropped from the k ,dfae.u*pvy4uppo+c k6k87sh20 gs top of a building. One second later, ball B is dropped from the same building. As time progresses, the difference in the 8y 6pu7eofvu *+ka s4pd0k.khp,2 csgir speeds

  Two objects are thrown from the taxip ( y)mp9vm--ogoi-c*9 mvq5n nezzm::r 3op 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 th oe gpamr mnmq(x9-: i-no:z 5 yiv-m93vz*p)ce street?

  A brick is dropped fromfv uts3w3a0 16ldy8 tt the top of a building. A second brick is thrown straight down from the same building. They are released at the same time. Negle3tat1ltw u8f ds0v6y3ct air resistance. Compare the accelerations of the two bricks.

  An object is moving with constant non-zero velocity in xxgt1v,l35 q: 9 pl5,jsumash the +x axis. The position95pxau:jhlmxlg3 v,q ss5t 1, versus time graph of this object is

  An object is moving with constant non-zero acceleration in the +x axnb:t.s 532ozf 5kjefw is. The position versus time graph of this obj 5.f32 sw n5kez:joftbect is

  An object is moving with ..im:wjjohjha49 .ezpcu) jopd::a+ t,0 pcnconstant non-zero velocity in the +x axis. The velocity versus d0ijwh:puo.. ::a pjph.t ccjn)a+ 9,emoj4ztime graph of this object is

  An object is moving with constant non-zero acceleration in thwc . +rn zf+zyc)y3b+te +x axis. The velocity versus time graph of this objewzrytz)3.++y f n cc+bct is

  The slope of a position versus time graph giv ha kd)3;fkgm6es

  The slope of a velocity versus time graph gi92-s 9 llvxr csy,xyi9ves

  The area under a curve in an acceleration ve+kh *,qsp jli/j 0: ff-xd/gyjrsus time graph gives

  The area under a curve in a velocity versus time graph qmj.e/t : -)fkwxgvr5gives

  If the position versus time graph of an object is a horizont *i-godo+ )+82afhmfk an -hkoal line, the object -afk2m+ai *fo 8h-+kognd)hois

  If the position versus time graph of an object wgdzxc *b rwwe5*tl0 a*8+- zxis a vertical line, the object isd*w*xe8wg* a-cb +l 0t5z xzwr

  If the velocity versus(ye)14 np0lz* 5bwbqz*djj dp time graph of an object is a horizontal line, the object isjz1*q dpl d)b0py(zb54wn j* e

  If the velocity versu--*q z4pesn cug-rxy 1s time graph of an object is a straight line making an angle of 30 degreeyzup*4c r 1 gxn-s-e-qs with the time axis, the object is

  An object moves 15.0 m north and then 15y9/zp6rst);w z txz)+h s brg1.0 m south. Find both the distance traveled and the magnitudt /+ z)hz9;)xrwsbst rypgz56e of the displacement vector.

  A boat can move at 30 km/h in still water. How long will it q/zd3bg sc q/m(ms6x/ take to move 12 km upstream in a rive g6mmx/sc/ (dzq q3b/sr flowing 6.0 km/h?

  55 mi/h is how many m/s? (1 mi = 160fb(ohk1g./p 1h zgk ;t9 m)

  What must be your average speed in order to travel 350 km in 5.15 h?9br42cui) d, 5/fnkwqyrb ak+(1tl ga

  A runner ran the marathon (approximately 42.0 km) in 2 hours and 57 min. Wkyo i+9meiy:-jy(hr tx: *(ulk pm+p fr72h+nhat is the average speed h+fr*+imore: y:lyhp (nu7+ px2yt jik -k(m9of the runner in m/s?

  A car travels 90 km/h. How long does it take for it to travelq;2wbc +p6 boc 400 km?

  A ly (light year) is the distance that light travels in one year. The speed of gm*1ie4 kuw*x q,ps e,qkwx*, i4ps ,eug*1emlight 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 /x3 7lmseej d 05ac x2hmi51irkm/h along a straight road and you look to the side for 4.0 ec 2mxs5rl/hj 7di15aemx 3 0is, how far do you travel during this inattentive period?

  If you run a complete loop around an ou.o o;gv 6 . tmcp1av;r.4+rnopl .kldatdoor track (400 m), in 100 s, your average veloci14.at;+;r.nr kmd6ollopv avo.cp g.ty is

  A polar bear starts at the North Pole. It travels 1.0 km south, thm; zq0rq5c axa)sqymg,vxj8t5 9(yh+en 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 warq g tymy 9vc)z0qxaaj ,8xs+;qm(5h5s the bear's average speed?

  A polar bear starts at the North Pole. It travels 1.0 km south,lhz/4t0jkw- q then 1.0 km east, then 1.0 km north, then 1.0 km weswz j04klt/h- qt 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 school at 55 mi/h for,8tr: k6rcgi e mz/3us 110 miles. It then starts to snow and you slow to 35 mi/h. You arrive home after driving 4:g rzu3isckr,te 6/8 m hours and 15 minutes. How far is your hometown from school?

  A motorist travels 160 km at 80 km/h and 160 km a gsw*9r4dl-sq rpe 2u2t 100 km/h. What is the average speed of the motorist for th -4*p2qsr lwu9sgdr2eis trip?

  A motorist travels for 3.0 h at 80 km/h and *0j ifzj0fsul1ys9w+go7iuo7h x g) +2.0 h at 100 km/h. What is her average speed for tufifw 0s)+ 71lxju+s7giogz 0j9h y*ohe trip?

  An airplane travels at 300 mi/h south for 2.00 h and then at 250 m t9y7t.us( wwc9zz gd7i/h north for 750 miles. What is the average speed for y 9zg(t.w 97dzcs 7uwtthe trip?

  In a 400-m relay race the anchormhey4p.v/+xi (.bhqypan (the person who runs the last 100 m) for team A can run 100 m in 9.8 s. His rival, the anchorman for ty py4hvh exqb(+ i/.p.eam 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 comes to a stop after 10 sdf( v wnme36z). The car's average velocity during deceleration was 56 km/h. What wa)wnfzv3e6 (dm s the car's deceleration while slowing down?

  An airplane increases its speed from 100 m/s,kn wma1/9.m ooqvmc, to 160 m/s, at the average rate of qnm k.mo1,v /c,wa 9om$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h 1raex3phc rgk:rkd,fekz jvkql 8096z ;/6/ kaccelerates 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 accelercaw)v;uznu; r3jz1 ,m e curo)x hy.7/ates 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 constant accemaweod*tq,r 2pge/7 (leration ofgp, *eo(wtdqea27 /rm $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initia edq(r 0ntfq8 4tap52kl velocity of 3.7 m/s experiences a constant acceleration of 4q5en2 tt0d pa(fqrk8$4.9 \; m/s^2$. What is the cart's displacement during the first 6.8 s of its motion?

  A bullet moving horizontally to t8; mpu9e/uyh qe cq..the right (+x direction) with a speed of 296 m/s strikes a sandbag and penetrates a d h9/qmque.;. yupc8teistance of 37.62 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is6qmp-bf*i5)z iycmn( /hvv5ota1xb 1 launched from a catapult on an aircraft carrier. It reaches a speed of 42 m/s at the end of the catapult, andhz5*nv 1c/1tmi )bqmo 6xf(5-yv ipa b this requires 2.0 s. Assuming the acceleration is constant, what is the length of the catapult?

  A car starting from rest moves with constant accelerat 3.aumk crk*1fy;z3tj ion 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 ic/ fm2zgu5z/ 2:fqj lmv4yt e1s its average ac f 5/q :gyme1lf4 juzmzv2c2t/celeration?

  An object starts from rest and undergoes uniform accel.gagrx*p k p t7t,i;:bg*m5 zmeration. During the first second it travels 9.3 m. How far will it travel . 5 g:, i7tkgmtp*zrx;am*bgp during the third second?

  An object is moving in a straight line with constant acceleration. Initially a.p /tvf a rk/zbrinqn;,q.;iq7a.w3 it is traveling at 16 m/s. Three seconds later it is traveling at 10 m/s. How far does it move during this tiq/i a.. fnwq/ ,ka7nra tzv;3bq;i.rpme?

  A car starts from rest and accelerates u.;ad ctk-z0uwj2nnt0 niformly 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 u jsa8om*l,c ,drp))z 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 greensjtwsxna u8;3x1o / b-, a car that has been waiting at the intersection starts ahead with a constant acxsb ts ownuj8/; 1-a3xceleration 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 surfu;nv.p: 1vqck ace of planet X where the;u k:vnc.q1p v acceleration due to gravity is $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown upward with a speed of 12 m/s on the surface of planet X wp )sxk d)f65dthere the accelerdxt6)) p5k fdsation 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 with a speed of 15 m/s on the surf-q1 ozkddq l(7ace of planet X where the acceleration due to grz k-l1dqqd7(o avity is $2.5 \; m/s^2$. How long does it take for the object to return to where it is thrown?

  An object is thrown upward with a speed of 14 m/s on the surface of planet Xmsi dj*o7mi(8 oh6pq3 where the acceleration due to g mjm 7s*i8 o6dohpqi(3ravity is $3.5 \; m/s^2$. What is the speed of the object after 8.0 s?

  Human reaction time is usually gree2fx z(nk11edpt 9c7v ater than 0.10 s. If your friend holds a ruler between your fingers and releases it without warning, how far can you expect the ruler to fal(ken cet1x92pz v f71dl before you catch it?

  A ball is thrown upward at a velocity of 19.6 m/s. What is ilq qj,)2 tiwo+iej;p; ts velocity after 3.0j o;)iql +te,;w2j ipq0 s?

  A bullet shot straight up returns to its starting point in 9 s. What is the5n vhw.z(bfg8mbb4 4dukd7o * initial speed of the bullet?bb4 8v475.gb u d*wko(nfm zdh

  A ball is thrown straight up with a speed of 36.0 m/s. How long does0*nk + ppsjva-7vvflwy q* fr4l0rk5 y3xa :d1 it take to return tofl 7* k51y4dp:*r-3+x0vf0slak nqrapy vw vj its starting point?

  A ball is thrown downward from the top of a building with an initial speed of 211ttda a53n 6u ldv-ei4 m/s. It strikes the ground after 7.9 v-4tt ud 1al 3eni6da5s. How high is the building?

  A ball is thrown straight up with a speed of 30 m/s.*/ pr qsmou51a ur4jget d-+q0 (only fill in numerical value in the blanrqje 0sptard4q /+ mo-uu51g*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 intoblzm8fpd9 qq)4/wsakn0m9 e , the air with a speed of 20.9 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 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 xuxvs h a8l:8 :e,mo)+; rqkaohlg3: xis the velocity at t = 1.0 s?

  In Fig. below, what is t ncbw,w/ n*e,-zj3cughe velocity at t = 2.5 s?

  In Fig. below, what is thbu1c5 xm4fl+xe* vyj; e velocity at t = 4.0 s?

  In Fig. below, what is the velocity at t =0lqc:vtb:8ssgt - r0 i 5.5 s?

  In Fig. below, what is1gx/ihg;j 6)/a q n7 ygwf4uhg the average velocity from 0 to 4.0 s?

  In Fig. below, what is the average velocity iedhlj*r. 4ibw+br-tg/st /msz20 0pfrom 0 to 6.0 s?

  In Fig. below, what is the accelerate v3zp7.3nhuqwjr .9o r1c)w t2s b0suion at 1.0 s?

  In Fig. below, what is the vg 6uq u h6h:0tey1f4zacceleration at 3.0 s?

  In Fig. below, what is the average accelerakm . vg-e: shbp1,dzf ..8tbvrwc :1fltion from 0 to 5.0 s?

  In Fig. below, what is the average acceleratiocn-+wmw .u gv1p0hw9hn from 0 to 8.0 s?

  In Fig. below, what is the displacement ecxdqzv6 ol/p *lc;ph.q2vg2fu:9:3lu 9g nlfrom 0 to 8.0 s?

Does a car speedometer measure spe7 xb)gm7 84icwix / myecjtc3*ed, velocity? {speed|velocity}

  An object can have a varying speed iihw1dc9dk :c n1qvyg:k:+ 9mnf its velocity is constant.

  The velocity of an object can be negative when its acceleration is posi8ynr-vn+j6-zn p wol.tive.

  If one object has a greater speed than a second object, the first must have a griq3 caguc4qx(u649+ txqsbu ; eater accel+qugcu b3 9qc4us(6ixatq;x 4eration.

  Two cars emerge side by side from a tunnel. Car A is travelin e7-1u,rijx xog 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 incr bz*,h*yaa y dx: wlg6p2:+ucheasing in speed as its acceleration decreases.

  A baseball player hits a foul ball straight up into the air. It leaves the by6 ccaf2fj (m,.t8 i4/hv3kagnegtp . at with a speed.tg.2nh6t,fmc3fv( 4a/8e apcjkgi y 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 acc q76yn qg9k1n4e ls*hveleration, how dovys q64n7kg9n lheq* 1es it change if air friction is ignored?

  As a freely falling object speeds up, what is happening to its acceler4sq72 bk xm0fjation, how does it change if aifbx sq04mk 2j7r friction CAN NOT be ignored?

  An object that is thrown vertically upward will return to its origikyhd(kh8b9(,swpw 5 knal position with the same speed as it had initially if air resistance is negligible. If air resistanc8wk(y 5s( kbd 9hhpkw,e is appreciable, how will this result be altered?

  An object can have zero velocity and nonzero acceleration a()yap*(f2f,gm /z2gnuk1h p y 8 y)nnhp aiq,at the same time.

  An object can have nonzero velocity and zero acceleration at jwsf). 589 (ju gl dbnbcx6.zctz ;nc7the same time.

  An elevator moving from the second floor to the fifth floor making no stops al u1wp5,kjlan (ong the way has zero acceleration a (a5wnuplk, j1ll the time.

  A rolling ball moves from2vyl7x.im uncoq:l )gc c .05e $x_1=2.0 \mathrm{~cm}$ to $x_2=-4.3 \mathrm{~cm}$ during the time from $t_1=1.6 \mathrm{~s}$ to $t_2=5.6 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-4.6 \mathrm{~s}$ is at $x_1=3.2 \mathrm{~cm}$ and at $t_2=3.5 \mathrm{~s}$ is at $x_2=7.5 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps around a quarter-;her, 3tn9wqsmile ($1 \; mile = 1609 \; m$) track in a total time of 10.8 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 103 m awa /6-d0u *ykv,a w/l9szczx gioy in 13.6 s. It t/z/69 x adyu -0wc,k*voliszghen turns abruptly and gallops halfway back in 4.7 s. Calculate (a) its average speed  (数值)  $m/s$ and (b) its average velocity  (数值)  $m/s$ for the entire trip, using “away from the trainer” as the positive direction.

  A car accelerates fro0 s8kqf/kb qf hq1d: mzm601zqm $11 \; m/s$ to $24 \; m/s$ in 5.7 s. What was its acceleration?  (数值)  $m/s^2$ How far did it travel in this time?  (数值)  $m$ Assume constant acceleration.

  A car slows down from wl4b(e-3smx s$16 \; m/s$ to rest in a distance of 83 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a jjjl ob813 -o:k logt2speed of $27 \; m/s$ 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 can burst out of the blocksl +sl/9i mhg l-pr7 i0j5v,svm to essentially top speed abou+p-vjis7, hmvslrl9l /05m git $10.5 \; m/s$ in the first 11.8 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 speed ofwr o+mi8+ 2ztt $15 \; m/s$ to rest in 4.66 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 theyhbsr qr2 k+19 highway. Assuming a decele9+h1rqb rsk2y ration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truckz5o ily2-(p .doa t+nrba7hz 5 going $25 \; m/s$ on the highway. The car’s driver looks for an opportunity to pass, guessing that his car can accelerate at $1.0 \; m/s^2$. He gauges that he has to cover the 20-m length of the truck, plus 10 m clear room at the rear of the truck and 10 m more at the front of it. In the oncoming lane, he sees a car approaching, probably also traveling at $25 \; m/s$. What is the closest distance of the approaching car that he can still sately make the attempt to pass the truck? (without hitting the approaching car).    $m$

  A runner hopes to complete the 10,000-m run in les1hql 5+zsowa wd c+)/kac a34ts than 30.0 min. After exactly 27.0 mint)lkza13/dsa w+h5 ocw4+a q c, there 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?    $s$