Suppose that an object travels fr81bpvg.fdsx 7om one point in space to another. Make a comparison betweend.f 7pv1 x8bsg the displacement and the distance traveled.

  When is the average velocity of an object equal to the instantan/ qozzkvhp7m ebiwp942s 8:5 neous velocity?

  A new car manufacturer advertises thadc9u36 k-rxu at their car can go "from zero to sixty in 8 s". This is a de3 u9k dc6uar-xscription of

  An object moving in the +y7 bx) p9e0k(rhcayr 0x axis experiences an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x direction) begins to slow down asu;y vmv.7dwxfew- 5/ d it approachesdd xf;vm-v.we5w yu/ 7 a traffic light. Make a statement concerning its acceleration.

  Suppose that a car traveling to the West (-x direction) begins tns6w(4fyrd9m o slow down as it approaches a traffic light. Make a statement concerning its acsfy9n dr6wm(4celeration.

  Suppose that an object is moving.tvuunn,s;c r 9ma)f qa67tn, with a constant velocity. Make a statement concuqusrt;n f nmtc79v,aa .6n,) erning its acceleration.

  If the velocity of an object is zeror. kez 2a2pj7yw 0/w,i y*og ty2dbmu5, does it mean that the acceleration is zero? Support your answer with agyy.2weuyp02b2mziwt k5 /*r 7o,jd an example.

  Can an object's velocity change direction when its acceleration is constant, 42 p:l9kp k0-kkd bbl5lpavj? Support your anak,: jpkpkl904v l bdk lb2-p5swer with an example.

  Suppose that an object is moving with constant acceleration. Make a q yk95pje 19kd7-qeba statement concerning its motionpd e17qj- b9kkeqy59a with respect to time.

  Can an object have increasing speed while it/wlkel kghp4nh ,/.+vs acceleration is decreasing? Support your answer wit hlgv/e4hw/.n +p k,klh an example.

  Suppose a can, after an initial kick, moves up along a smooth hill of ice. Makfzx9b,r 0:d vke a statement concerning its accelerat9b rz0dx v:fk,ion.

  Under what condition is average velocity equal to the average of t+to/4y0eh6y, aqkz mh he object's initial and final velocity?h,0y t+hma4/ez 6oykq

  Objects A and B both start at rest. They both accelerate at the same rate. Hnb 9,u:2mlylget)b)j.aj 1o gowever, objoyjln.9m bt1) 2ue: ajbgl,g)ect 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 accelerz2w)e2bpowo 7 ate at the same rate. However, object A accelerates forz)wpobwe7 2o2 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 t p+ wh0jk.z;n3ny igc-+oemg.he absence of friction, which ofo-+gwhz 3+. eg ;.ik0mnpncjy the following is true concerning its motion?

  When an object is released from rest a zm-d fy/fa9rgs. r/-und falls in the absence of friction, which of the fou.gzs9 ry --/fdmrf/allowing is true concerning its motion?

  Suppose a ball is thrown straight up. Make a b7,ipu1)*plg a0w f2( c7ww0zrzsbf z statement about the velocity and the accelew1ig *f0za plb2wc,7bu szf)pw0 z(7rration when the ball reaches the highest point.

  Suppose a ball is thrown straight up. What is its acceleration just befoqr dpyf),49oe+oh:1 htwr1 o yre it reaches its highest o)fyth1w dp yr qoo,: rhe14+9point?

  Suppose a ball is thr:vxw0n1)mp do own straight up, reaches a maximum height, then falls to its initial height. Make a statement about the direction of the velocity w:0o vnm1p)dx and acceleration as the ball is going up.

  A ball is thrown straight up, reaches a maximum height, then fall-9iu7 fxhzkrks05(nw o7,m-g5 r lsrzs to its initial heinigk9z,7-fzmrk0 o5lsxws - 7rrh5 u (ght. Make a statement about the direction of the velocity and acceleration as the ball is coming down.

  Suppose a ball is thrown downward in th,2 3rym vf2 x2ahy) mvaly9e.le absence of air resistance. Make a statelvry ve9. a23h 2,mfmy )2xlayment concerning its acceleration.

  Suppose a skydiver jumps from an z.ntnz9 *ni* high-flying plane. What is her acceleration when she she reaches termn.9*nzz t*nniinal velocity?

  A ball is thrown vertically upward w9an1uaa p )mh0ith a speed v. 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 the first um)1a 09anhap ball? (How many times higher does the second ball go than the first ball?)

  Ball A is dropped from tjby/ e/h/2zhnhe top of a building. One second later, ball B is dropped from the sambh/ nj/e2yh/ ze building. As time progresses, the distance between them

  Ball A is dropped from h1 (0kji;ae0usdak) x the top of a building. One second later, ball B is dropped from the same building. As time progresses, the difference in their h ()k u0;ax0d1isajkespeeds

  Two objects are thrown from the tog )iw j7;3j25lg,bm1i a m4xgk+b jnejp of a tall building. One is thrown up, and thexjjmg1b 5+7agi3i)kw l gem,;jjn2b4 other is thrown down, both with the same initial speed. What are their speeds when they hit the street?

  A brick is dropped from the top of uv xrt1,x 1p gq0 exy/zp4v)3ba building. A second brick is thrown straight down from the same building. They are released at trqv 43 x1ppb/zytv1g )e xx0,uhe same time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with constant non-zero velocity in the +x axiquv )au(f*mc 34uh/do+ f myedji;e)n;de+y :s. The position versus tfvo+ (;nd)cdyhaqe4 uujm )m e; +fuye*:i/d3ime graph of this object is

  An object is moving with constant non-zero acceleration in the +x x-8ze c u,0n1cg5es;cwb /urmaxis. The positi - sb1 u z;r,xmc0c/85uwegecnon versus time graph of this object is

  An object is moving with con/q 0v)xvbc:(1/cbar *pez at-g7tzjw stant non-zero velocity in the +x axis. The velocity versus time /tbv1:e(0 z*gpb ra axz qj/ct7c-vw)graph of this object is

  An object is moving with constant non-zero acceleration in0j0, 86em0bgw sufeq0+s 0gavzsgs8 n the +x axis. The velocity versus time graph of this jvs,00s b8 0u0 8q0z eeg+smsgnf w6gaobject is

  The slope of a position versus time graph gw 1o 3b,zh. 2pu r3 grt,a5k6k1tuxzusives

  The slope of a velocity versus time graph givenm nqa4v q3vj3.uxd/,s

  The area under a curve in an acceleration versus time graph gi .5:u8xxr :nr c2ryafaves

  The area under a curve in a velbc :dg/)dgz1 qm8 afn ad,(r-yocity versus time graph gives

  If the position versus time graph of an object is9sn oh5xr62pfzy+h)jl1v48po k zt .e a horizontal line, the object sz zv8f12n y4ke.xr+ ph9tl6)5jpoohis

  If the position versus time graph of an object is a vertical line, j-i p:4 poth)mthe object is:o mhptp-4)ji

  If the velocity versus time graph of an object is05bmp* yfurp5 b0p ehfq;dl 3z p599we a horizontal line, the object i q95 e*hp;z5b0p9e0m3plby u pfwr 5fds

  If the velocity versus time graph ofdj e/l4 vrkl ,b55lsh)pg ry-0 an object is a straight line making an angle of 30 degrees with the time axis, the ohlys /dg r5 k04jlebl)-r vp5,bject is

  An object moves 15.0 m nor:g78r+znmm, c:qj+ky cem.s fth and then 11.0 m south. Find both the distance traveled and the magnitude of the diszj:7r m +ec.mn ks 8+cy:mq,fgplacement vector.

  A boat can move at 30 km/h in still water. How long wilyaq-u (yfsuy,em4mdy,y ,cd/5o j48il it take to move 12 km upsyu,(/s ,a, 4 ic-dyyd5mmjeyuyf4 qo8tream in a river flowing 6.0 km/h?

  55 mi/h is how many m/s? (1 mi = 16 p.0tkjs6bt+c 2sve5 f09 m)

  What must be your average speed in order to travel 350 km in 5.15i ,k a56w,fjhyo9z s lw6s(7dn h?

  A runner ran the marathon (approximately waj(b5qm -ie:6; yuct 42.0 km) in 2 hours and 57 min. What iw ybaq -;:utci6(m5je s the average speed of the runner in m/s?

  A car travels 90 km/h. How m::une/nqqgx : l7s1w qg+*nyehl;m1 long does it take for it to travel 400 km?

  A ly (light year) is the distance that light travels in o8l/j2pp vye y5ne year. The speed of light isjy/8 vlp2e5yp $3.00 \times 10^8 \; m/s$. 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 ll 3gu 1ps.vtm(ook to the side for 4.0 s, s.t(v u1lm3 pghow far do you travel during this inattentive period?

  If you run a completecj*lf /ot (r 7vbg/. oy,7jjnc loop around an outdoor track (400 m), in 100 s, your average velocity is orvotcjyjlc g7/ fj(*/,7nb.

  A polar bear starts at the North Pole. It travels 1.0 km south, then a. kj52rb+jln0 nt1q c1.0 km east, then 1.0 km north, then 1.0 km west to return to its starting point. This trip takes 45 min.2r 0ncb5j kja1 t+nlq. What was the bear's average speed?

  A polar bear starts at the North Pole. It travels 1.0 km south, c8 9+mk zm,. klvxng ycda8h:p*9w0n)4kcomv then 1.0 km east, then 1.0 km north, then 1.0 km west to return to its starting point. 8kym4 mv,agvo* 0k)mz9:phdccx+98 n.nklcwThis trip takes 45 min. What was the bear's average velocity?

  You are driving home on a weekend from 3so e7)1 wgszn2zo5zp2 tu2dh school at 55 mi/h for 110 miles. It then starts to snow and you slow to 35 mi/h. You arrive home after driving 4 hours and 15 miu5 oezop1z2 3 7)2wzgnsthd2s nutes. How far is your hometown from school?

  A motorist travels 160 km at 80 km/h and 160 km at 100 km/h. What is the k+7 ( xvjndwopwo;m s 77/b.ieqo9/moaverage speed of thd7;b/qowpoo/7mos vk+ n 79 e.wxjm(i e motorist for this trip?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h. What is hembtisv6 vo+.1jtfe 32 r average speed for the trip stmitv316b 2jfvo+ .e?

  An airplane travels at 300 mi/h south for 2.00 h and th1f i;vn udu+6hen at 250 mi/h north for 750 miles. What is the avni f6u;u1h+dverage speed for the trip?

  In a 400-m relay race the anchorman (the person who runs the last 10l*w7vv7v+jxlz c(c:rbkf *5 w0 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 the team B runner can have when the team A runner starts the finjcw(z 7*7 +:lvxcfblkw5*v rval leg of the race, in order that the team A runner not lose the race?

  A car decelerates uniformly and comes to a sto/vq.e4: xlihtp after 10 s. The car's average velocity during deceleration was 65 km/h. What was the car's deceleration while slowx.v/h tl:4q eiing down?

  An airplane increases 6;akam-a. ehar0oo7h its speed from 100 m/s to 160 m/s, at the average rate of aer0ao-.h67k h oa am;$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h acc9;zv4++5 uy pepqre k t3waxd7elerates 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 an4ax/2i20bvaz q zyyc 7d 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. 1y/+iteyi;ux7 t4ql khr v42xIt then speeds up with a constant acceleration v7 e+2itq/txu4x hr 4iy kl1;yof $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 7.7 m/s experiences a constant accelerat;q tik)e4p 2y:8 bi,rwg3oz epion of w4g )ko be8 ;rqi3zpiet:yp 2,$2.4 \; m/s^2$. What is the cart's displacement during the first 6.1 s of its motion?

  A bullet moving horizontally y7 /o9eagecc :to the right (+x direction) with a speed of 452 m/s strikes a sandbag and penetrates a distance of 48.50 cm. What is e:ca/og97ycethe average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on an aircraft carw wns ./ vz2gww1+2jcarier. It reaches a speed of 2a jw wnv ./+wg1c2szw42 m/s at the end of the catapult, and this requires 2.0 s. Assuming the acceleration is constant, what is the length of the catapult?

  A car starting from rest moves wit93i- 5glmg5dis 9)pe,swkv ff sl; ra1h constant 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 distance of 2u gcbi7a*(cn3 00 m. What is its average acceleration?c3(iba n cu*7g

  An object starts from rsbw+0i .5zto pest and undergoes uniform acceleration. During the first second it travels 7.5 m. How far will it travel during the third secondo5ipb wz0 .s+t?

  An object is moving in a straight line with constant acceleration/tv 3bqxv32tbl / 0of n8.u0rg2n64z hwyf cbd. Initially it is traveling at 16 m/s. Three seconds later it is traveling at 10 q63fx v40 20 3/2yh/ wb.cn8zluvfbottdbgrnm/s. How far does it move during this time?

  A car starts from rest and accelera 8f(wm*hw xay(tes 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,pscg03q woc ylho 9:: a dry road 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 car tha2b5 wtld b;q1ot has been waiting at the intersection starts ahead with t1 o; bwqdl5b2a 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 j)c yhoskk/7i15*t t*jj(0fzd+w di k with a speed of 12 m/s on the surface of planet X where the acceleration due to it w0 *sk dd7jk/ij1+f yj()o*ht5kzcgravity is $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown upward with a spen - pdowi.eo-.yl- jt,2z(xwied of 12 m/s on the surface of planet X where the a- ,jdo-ix.tzo(yl- ep wn.i2wcceleration 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 surgo ec5 l y8h3qkee2*v;face of planet X where the acceleratil85 yo2e;3c kghv*eqeon 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/s on the surface of p-18hsynf/s,4mz )3 c rjx sfddlanet X where the acceleration due to gravity is c8hs)4yffs dd/m- nr,z xj13s $3.5 \; m/s^2$. What is the speed of the object after 8.0 s?

  Human reaction time is usually greateryy*))jf -f .6thcr otd 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 fall bj*.y -6trffhtyoc ))d efore you catch it?

  A ball is thrown upward at a velociw f ig,x ;87me.uobm.haoq:1fty of 19.6 m/s. What is its velocity after 3. 8mfe1a:b7xhowu.i m f.,oqg;00 s?

  A bullet shot straight up returns to its sn am:8c13u+o9hb v/)ich jvfrtarting point in 9 s. What is the initial speed of the bull vchr1v+aj)/9h inuoc8:b3mfet?

  A ball is thrown straight up 0mmg:3t*col g2,at ;s pr0kznwith a speed of 36.0 m/s. How long does it take to return rno sc* zt amp lgk3t0;g:m,20to its starting point?

  A ball is thrown downward from the top of a buildingd+8b /8b hoshjrsn8)u with an initial speed of 5 m/s. It strikes the ground after 2.6 s. Ho 8bhn us+s8 8djro/b)hw high is the building?

  A ball is thrown straight up with a speed of 30 m/s. (only fill in numericagy5 4mzcub,5.a 11 xe-adusk+xn uz 5kl value 1 +5d1s,xu eaaxu.5zznb-5mu 4gkcyk in the blanks)
(a.) How long does it take the ball to reach the maximum height?    $s$
(b.) What is the maximum height reached by the ball?    $m$
(c.) What is its speed after 4.2 s?    $m/s$

  A foul ball is hit straight up into the air with a speed of 2bb k93qy 7e . yio,j,lqxb.1tp6 gjso(4.3 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 is the velociacpgj 8o8u h:7ty at t = 1.0 s?

  In Fig. below, what is the velocity atc b-s/+glti 7b t = 2.5 s?

  In Fig. below, what is th :2bwi2+5ck mcdu()vf 6 iaffte velocity at t = 4.0 s?

  In Fig. below, what is the velocity atbn e z3n6ug7:up// dfg t = 5.5 s?

  In Fig. below, what is5;p, 7vmu*3ltx2p*uyam xvj l;2wud d the average velocity from 0 to 4.0 s?

  In Fig. below, what isun64mf; u, 1ypxob(5a/i wo ws the average velocity from 0 to 6.0 s?

  In Fig. below, what is the acceleration at 1.0 s?c3h(4(:u).0bw pda k s4wtdq+lk-aztn;z xrb

  In Fig. below, what is the accelerat+az 1.foqce( sion at 3.0 s?

  In Fig. below, what is the average accelerat2po.(rpfm /arkg3 g -2g+nk* vhkmbe- ion from 0 to 5.0 s?

  In Fig. below, what is the average acceleration from fn a;.fp .inh60 to 8.0 s?

  In Fig. below, what is the displacemg i3n0p,:ba lpp/n:/k vowk(dent from 0 to 8.0 s?

Does a car speedometer )rer1xl/m7ihxc .0k smeasure speed, velocity? {speed|velocity}

  An object can have a varying speed if its velocity5 b5w)6xrhrbv57upk3apu- p c is constant.

  The velocity of an object can bexw-exd9 li*2gs* n9)wt.t mip negative when its acceleration is positive.

  If one object has a greater speed than a second object, the first m 0jl0il5o,rywvblgg;bs u4jx/p c3a075ts)p ust have a greater accelerv xrsio/s twyj3jlup ;4c0070a b55pglg) lb, ation.

  Two cars emerge side by side from a tunnel. Cvfzohxb9zadt- a/z3r+5 )7a f ar 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 increas3x*1t tq0f *ezwa lns5ou:6 aning in speed as its acceleration decreases.

  A baseball player hits a foul ball straight up into the t:b e:)5 *vd:bx,,agoql hruhair. It leaves the bat withlhdx ) ,*rbt v::goh5:u,qaeb 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 acceleyu efv7 ri:2v8ration, how does it change ifv8evi: yu2r7f air friction is ignored?

  As a freely falling object speeds up, what is happgja tf 9odn(.wa mqt(0o*s:*uening to its acceleration, how does it chan(o*aqjn9( 0dwagf t m.tos*u :ge if air friction CAN NOT be ignored?

  An object that is thrown vertixhso6fg)c7q;)xn ; v l:gqvqr;p3/gl cally upward will return to its original position with the same speed as it had initially if air resistance is negligible. If air resistance is appr v v6lg/xhg;7nqf)3x)g;p qsocl:; rq eciable, how will this result be altered?

  An object can have zero velocity and nonzero ac r j8t*ine+opub.,m ,cceleration at the same time.

  An object can have nonzero velocity and zero acceleratio6, t8m6 if6sm/ctvp idehja93n at the same time.

  An elevator moving from the second floor to the fifth flooi;lfa dg,dmjtxs+f)yd8;y g wh(2mhmo738 5br making no stops along the way has zero acceleration all the tis;a 8d 8bdfmx 7;h2yojl3,i5mgyg)t(f+w mh d me.

  A rolling ball moves f ;cq3ecn w3-bkrln,d:rom $x_1=3.0 \mathrm{~cm}$ to $x_2=-8.3 \mathrm{~cm}$ during the time from $t_1=1.0 \mathrm{~s}$ to $t_2=5.7 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-3.6 \mathrm{~s}$ is at $x_1=2.6 \mathrm{~cm}$ and at $t_2=4.2 \mathrm{~s}$ is at $x_2=7.7 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complr,w3y z0t9qj/:c nph aete laps around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 10.0 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 straigrliltt8. 6fh8 zv)du i1ql*,z ht line, moving 107 m away in 10.2 s. I8 flt1*,uhizl6rzd. ltiq )v 8t then turns abruptly and gallops 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 fr(,y fyo vco wl6::1dqhom $11 \; m/s$ to $23 \; m/s$ in 4.2 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 from k/ hmft pe7oq 9.3xd vlb+(9mz$15 \; m/s$ to rest in a distance of 75 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a speed of(jm1gduos. *n $33 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.1 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst oup w gf1mx5(;uut of the blocks to essentially top speed abouw(fp;u 5u1gm xt $10.5 \; m/s$ in the first 13.4 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 unif*.ke iq13 holjjnce4yn 159ko ormly from a speed of $19 \; m/s$ to rest in 4.37 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a3lxq d9k8a:uy car leaves skid marks 92 m long on the highway. Assuming a dex9uda8k:y q l3celeration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a tr..bq0 f,rnil35(tjd pgnetb(app( 6 wuck 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).    $m$