Suppose that an object travels from one point in space to another. Maik4 u/m3m9md1:u a03b jwqp avw iyk390qml6uke a comparison between3qd93wi b0ku46mamap1i vw /:0l3m 9uq yujmk the displacement and the distance traveled.

  When is the average velocity of an object equal to-k18 ma ( q ih52q*j0rgjsapnaaop0n, the instantaneous velocity?

  A new car manufacturer adve* d*ruia:wz,kj*kvh*snd 4th l)9 q8 mrtises that their car can go "from zero to sixty in 8 s". This*i*ar4nmuh * t: ) wd8,s hqdzjl*kkv9 is a description of

  An object moving in the +x axis experiences an acceleratu uh9pa., 1o1qgbkg3w/e e di3ion of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x directionf m d,n8dek*k(8pr on() begins to slow down as it approaches a traffic light. Make a statement concerning itkop(mn8ke f ,nd *rd(8s acceleration.

  Suppose that a car traveling to the West (-x direction) begins to slow dob0- p h8kmiuf+b4z j.qwn as it approaches a traffic light. Make a state8zjbiu-p4k h.qf0 +mbment concerning its acceleration.

  Suppose that an object is mo+ 5aaopf77b:ps ngso01w0qpcving with a constant velocity. Make a statement concerning its accelf ap5awo0n g07 pqobp1s+s:7ceration.

  If the velocity of an object is zero, does it 3rdyg/2rnj s+t/ j+fe mean that the acceleration is zero? Su+e3/ yjd fstrjgr/2n+ pport your answer with an example.

  Can an object's velocity change direction whet8c3 jnl)jeqy ht:1 s3n its acceleration is constant? Support8jeh ql:1)jts3n t y3c your answer with an example.

  Suppose that an object is movin4w) e1eekdew0g with constant acceleration. Make a statement concerning its motion with w)01k4ewe ede respect to time.

  Can an object have increasing speed while itp0 jp r7i3ot8ps acceleration is decreasing? Supporp03tiopj 8 p7rt your answer with an example.

  Suppose a can, after an initial kick, moves up along a smool7tf xpap i5 /(9hi5hpth hill of ice. Make a state7li5pp5i9f ah/ (p hxtment concerning its acceleration.

  Under what condition is average velocity equal to the lt2m5wfiy: 9 saverage of the object's initial and final velitl9s mw25f:yocity?

  Objects A and B both start at rest. They both accelerat: vy m* t9h1meiv-th/le at the same rate. However, object A accelerates for twice the time as object B. h*-hy9m ve/:i1 mvtl t What is the final speed of object A compared to that of object B?

  Objects A and B both start from res aj8,eaiowy /202hywk t. They both accelerate at the same rate. However, object A accelerates for twice the time as object B. What is the distance traveled oih2w,yeaj8y2aw /0kby object A compared to that of object B?

  When an object is released ,cga1)i gx d,3l)tvk72yw sdofrom rest and falls in the absence of friction, which of the x1)lck yt7 w, ig,)as3odd2vg following is true concerning its motion?

  When an object is released from rest and fallsc5)t(r zht+fp in the absence of friction, which of the following is true concerning its motionhttprz5 + cf)(?

  Suppose a ball is thrown straight ;4dkmeqea y ni 0 qb744(.dnucup. Make a statement about the velocity and the acceleration when the ball reaches the highest point.4ne;y4 bc4d7a d qi. eknq0um(

  Suppose a ball is thrown straight up. What is its acbcsj b0.l-e u(celeration just before it reaches its highest 0 (.-elcub jsbpoint?

  Suppose a ball is thrown straight up,g ipfba-3hbht1ks h/9e2k 2a ( reaches a maximum height, then falls to its initial height. Make a statement about the direction of the velocihg-pabf/t(ih3bse2 k k2 h19aty and acceleration as the ball is going up.

  A ball is thrown strai2t,ha f ,psn)ult+x 7aght up, reaches a maximum height, then falls to its initial height. Make a statement about the directi)7n2,+usf latpx ha ,ton of the velocity and acceleration as the ball is coming down.

  Suppose a ball is thrown downwardsz7-xps. zy*7jk/d hp+xme+nsbal+ 2 in the absence of air resistance. Make a statement concernl+k.x7+ sm7z-s za hyjn/p2bp+ de *xsing its acceleration.

  Suppose a skydiver jumps from a hd nwk fb5p-c68lx1-*wd1s bs vigh-flying plane. What is her acceleration when she she reachfnbdpd5-6x 1 *l8 wskv ws-b1ces terminal velocity?

  A ball is thrown vertically upward with a speed v. y rm:,u/yi(i 5 obrcy8polu-th;g :,f An identical second ball is thrown upward with a speed 2v (twice as fast). What is the ratio of the maximumm (i:p u ,ob gy yfri;cutrly,8/-oh5: 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 to xr8px:)-dz/jd5ugd qp of a building. One second later, ball B is dropped from the same d:r/5z dj8pux -d)qxg building. As time progresses, the distance between them

  Ball A is dropped from the top of a building. One seconlepmn-(slyh *: 4l+86lvhdgl d later, ball B is dropped from th lpsn hl*vl86l4:+dg lhm-e(y e same building. As time progresses, the difference in their speeds

  Two objects are thrown from the top of a zmr5jhr47 qc 4.te* zctall building. One is thrown up, and tr. tc5z4 c 7rhm*q4jezhe 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 a building. A second brick is thrvvc/-gk p y/r/own straight down from the same building. They are released at the same time. Neglect airy-/ /gpvc k/rv resistance. Compare the accelerations of the two bricks.

  An object is moving with constant xbs tnqhw;h,,e13xmr, 1jik 2 non-zero velocity in the +x axis. The position ver,rem ,w2b 3xihtqns kx;,1h1jsus time graph of this object is

  An object is moving with constant non-zero acce rsj6copij 9:4leration in the +x axis. The position versus time graph of this object ijs 6pr o:94jcis

  An object is moving with constant htmbhf*d*w s+22no1r+q i/eu non-zero velocity in the +x axis. The velocity versus time gr d2m**+ fbr/w1 eonhu +hqsi2taph of this object is

  An object is moving with constant non-zero acceleration in the +0pwfrxw 98 i1f nkg/l;:5yacnx axis. The velocity versus ti;i k1fan9 y:xg5p 0wcr/8fwnlme graph of this object is

  The slope of a position versus time graph gi5+nu 7pw 79(qhooov upyp(mr )/ 0dlksves

  The slope of a velocity d;y5ce(pt cqm jp4, .eversus time graph gives

  The area under a curve in an acceleration versus time graph giqsvisz ky.8/ :iu z 1lk.xph -pu0fp(6ves

  The area under a curve in a;, j1 .ooeatjj velocity versus time graph gives

  If the position versus time gra f-bt84 9fkon4zoxzr3 ph of an object is a horizontal line, the object is z3x-zfro9o kbt 44n8f

  If the position versus time graph of an object is awt ,u4mb8d +zs clti .wgo;0)h vertical line, the object iss cwm.b i,0z48 ght;dult+ )ow

  If the velocity versus time graph of an objec6 2f/axh6m iqwt is a horizontal line, the object iix 62awq /6mhfs

  If the velocity versus time graph of an object is a straight tn3fy b79 ta/fline making an angle of 30 degreef/9 t7anf tyb3s with the time axis, the object is

  An object moves 15.0qh (5 .0-k4pjxlhb3 0 gwajfzq m north and then 11.0 m south. Find both the distance traveled and the magnitude of the displacement jz l4hx-pfqb kga.j(0w 5 3hq0vector.

  A boat can move at 30 km/h in still water. How long will it take to move 12 kmsijd4 yr qy8:. upstream i:yisjrd.8 4 yqn a river flowing 6.0 km/h?

  55 mi/h is how many m/s? (1 mi = 1609 2s- i d8azj1.ah)sv bfm)

  What must be your average speed in order toircjmqt)e)pj8 ;u/1 t travel 350 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 km5 xe;m1 nms-ly iw23dj) rt2vm) in 2 hours and 57 min. What is the average speed of the runner ym3;m)n 2edr1t s-xml wj52viin m/s?

  A car travels 90 km/h. How long does it take for+q+yw yra6s ov7*qt ly)c;4fvzg38ao it to travel 400 km?

  A ly (light year) is the distance that light bzs(iaau6p,qt/8 rk 9/ *kidx travels in one year. The speed of light isxpks6bizau* /ia/tq8,d r9k( $3.00 \times 10^8 \; m/s$. 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 m9 7o5 g- x)ow2whwftiroad and you look to the side for 4.0 s, how far do you travel during this inattehtf2 oxw 5o wgw)m-79intive period?

  If you run a complete loop around an oep0oji/yt5* n /:ny rti 5mx.putdoor track (400 m), in 100 s, your average velocity isj 0ppi:y5i y.temor/x/t 5n*n

  A polar bear starts at the Northa(cxu)rdu u )2 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 starting point. This trip takes 45 min. )u()rau x2dcu What was the bear's average speed?

  A polar bear starts at the North Pole. It travelsg,ep3tbb4: )(jcalu5 k0 vib w 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 the bear's j,up 4 w l :bg3civ)k(0et5babaverage velocity?

  You are driving home on a weekee/ynms2)f hi:(3uh98grmna(gig h6f nd 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 driving 4 hours and y(( 3i9:nuam8 f6)g/h sm ggh2i ehrfn15 minutes. How far is your hometown from school?

  A motorist travels 160 km at 80 km/h and 160 km at 100 km/hsg8/hxve/5)4th 6 pyepohif (. What is the average speed of the mote) pf4tiyvho h/(s8pegh 6/ x5orist for this trip?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h at(ax 2va;x. 76lh8/uviiotq al 100 km/h. What is her average speed for tlo t7h2ui;al x/6a ax.8 qv(ivhe trip?

  An airplane travels at 300 mi/h south for 2.00 h and then at 250 mimd7h8z 3 lgs5d/h north for 750 miles. What is the average speed for tz5 7m8sdhdg l3he trip?

  In a 400-m relay race the anchorman (the person who runhgve-f 3 6tof9s 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 the team B runner can have3g h9te-fvo f6 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 afte9vihh s(h1ba;ot )ss5r 13 s. The car's average velocity during deceleration was 65 km/h. W bis sh1v)os (ha9h;5that was the car's deceleration while slowing down?

  An airplane increases its speed from 100 m/s to 160 m/s, at the average rat3qq0v0ug fv 9te of 0 qtvg vqu30f9$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h acceleratespwv5 fh),1fo m 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 resfqsf m j2p;5e)/p3uxat and accelerates at $4.0 \; m/s^2$ for 5.0 s, then maintain that velocity for 10 s, and then decelerates at the rate of $2.0 \; m/s^2$ for 4.0 s. What is the final speed of the car?

  A car travels at 15 m/s for 10 sznh+tnf* i -bs))kn-y. It then speeds up with a constant acceleration ohn)bnnfkyz +i-ts-) *f $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 5.5 m/s experiences a constant ac xj9hl3sor1yjpoo/fjj ) /i13celeration of sy1jojx f91h)i o/pljj ro/33 $2.0 \; m/s^2$. What is the cart's displacement during the first 9.3 s of its motion?

  A bullet moving hori jei;6; cvoo5izontally to the right (+x direction) with a speed of 212 m/s strikes a sandbag and penetrates a distance o6oveoi5 c; ;ijf 81.68 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on an airc:e* *q zuzy,s7dcsje7;*nte a raft 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 c ;jz*e*snz7s e:ade7cy u,*qtonstant, what is the length of the catapult?

  A car starting from rest moves with constant accelerationbbz d(1xq14 wb r wre7b63v tvkam*6x7 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. h+496 vfrovez What is its average accezr4vh 9v eo+f6leration?

  An object starts from rest aczekfya8o*yn69 yf2t0ub)q 5nd undergoes uniform acceleration. During the first second it travels 5.6 m. How okqn6z20)yaf8yu*b5 yf ct9 efar will it travel during the third second?

  An object is moving in a straight line with constant accelerwn r*+lr) vot.ks*4tcyr2+w x ation. Initially it is traveling at 16 m/s. Three seconds later it is traveling at 10 m/s. Ho *wsyt*ckv2t+ wn lo.+rr)rx4 w far does it move during this time?

  A car starts from rest and acce2+ip.gw, hzn wxz1nw7c tfr: u4a.,,ikn v g3alerates 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 jg lyfo0d f0u8 n,t1)mdry 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 that has been waitinr)trin:xwvctquazo726 +)o o ir. : .tg at the intersection star.rq)noa62 7+ i i)xut tcov:or.trwz: ts 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/ vg-.r:gs8tj .d+s faws on the surface of planet X where the accelesraj -f sw8.vdg+:.tgration due to gravity is $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown upwarem u daf6m5w.ej5fni-ku5l99 d with a speed of 12 m/s on the surface of planet X where t5eaf 5 kij9du9uem l6 5n-f.mwhe 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 with a speed of 15 m/s on th c6 o(x5in ips5wowl9 pzq3 w64ut7kx2e surface of planet X where the acceleration due to grav69icwl x5qxizo 2wupnp w6st735k 4(oity 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 14nu +ot7kict4nm fmf) z9l5 89d m/s on the surface of planet X where the acceleration due to g+9c4u7)f5 ifzmktlnmd t9o8n ravity 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 you yvyt,2d9rczj( jbu0pp, 5i upzz( s99r friend holds a ruler between your fingers and releases it without warning, how far can y i9s5p9r ptyz(puj u 2(0zybdz9,,jvcou expect the ruler to fall before you catch it?

  A ball is thrown upward at a velocity of 19.6 m/s. What is i6r/9 /jvjv e.l. ipb.kye nj.pts velocity after 3.00 s?.6p 9/e yp.rj.vel v nbijj./k

  A bullet shot straight up returns to its starnbw6799jc fxsn 2z/gv r7 oop4ting point in 17 s. What is the initial speed ofn9fog67xb 4p vo72z9wcj r/sn the bullet?

  A ball is thrown straight up with a speed of 36.0 m/s. How long does it take t f)sofjm 0u+8lo return t+mfsol8u f j)0o its starting point?

  A ball is thrown downward fro 4,vql+z19* 0w wfps/prvgtdk+begc -m the top of a building with an initial speed of 13 m/s. It strikes the ground after 4.6 s. How high iskevdg 09,4st vz++p- w*r1/wq gflbcp the building?

  A ball is thrown straight up witj w :l 6b),oc7jmgzd+uh a speed of 30 m/s. (only fill in numerical value in the zc d6o:7lj j)mb+gwu, 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 35.1 m/ h5*-jkpit2y rs. (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 3 seconds later.  (数值)  $m/s$
(e.) Determine the time at which the ball pass a point 10 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 10.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what ioqj+4 m7t.kf vs the velocity at t = 1.0 s?

  In Fig. below, what is the velocity23jru: hcvb p- at t = 2.5 s?

  In Fig. below, what is the velocity ates(d6um; ,rm;voxs q/ t = 4.0 s?

  In Fig. below, what islm;,, qrxg.l x the velocity at t = 5.5 s?

  In Fig. below, what is the average velocity from 0 to 4.0mnws5 sgbc6mb4f f,y4y /34x8sef(t r s?

  In Fig. below, what is the aveeuzsel7; 8 n,crage velocity from 0 to 6.0 s?

  In Fig. below, what is the acceleration at 1.0ubbedl2ue*p0m,3 v ,6 ob/l(e4 jnw fz s?

  In Fig. below, what is the acceleration abbcn2i /7n6phw ze8p0t 3.0 s?

  In Fig. below, what is the average accelernxjxzcy;ol8ca.4u 5bv/2 h 3g ation from 0 to 5.0 s?

  In Fig. below, what is the))i;h ysog lzk3;)nw c average acceleration from 0 to 8.0 s?

  In Fig. below, what is the displacement from (qc:k- a7mjmkf xu- o-0 to 8.0 s?

Does a car speedometer measure speed, veakr 8dyz: j0y5locity? {speed|velocity}

  An object can have a varying speed if gxteg9v0e)v6tv; ;emnn 9f .cits velocity is constant.

  The velocity of an object can be negative when its acceleration is ponrbpk/:1y/i :puvc *esitive.

  If one object has a greater speed 4czla3 ux6( xxthan a second object, the first must have a greaaz6 l3x uxc(4xter acceleration.

  Two cars emerge side by side from a tunnel. Car A is trav,7 4nxe2dwg /pxxz d(keling 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 f za,*iby4t+ l;0fz6d/cnxjfspeed as its acceleration decreases.

  A baseball player hits a foul ball straight up into the air. It leaves to; krymq 0p43dhe bat with0;mky4dor3 pq 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, wn 9rbu8xo; it)ec jm ;b7jmu0-hat is happening to its acceleration, how 0 bt7jom9 ;j8eni ubur)x-mc; does it change if air friction is ignored?

  As a freely falling object speeds up, whaigpxd *gkyc-bytja) 92)8t-w t is happening to its acceleration, how does it change cakp gxw -y-bdyt2)9 t)g8* ijif air friction CAN NOT be ignored?

  An object that is thrown vertjcknq9 *0+j waically upward will return to its original position with the same speed as it hj9 aw*+j0knc qad initially if air resistance is negligible. If air resistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzero acceleration at the same oj5;imbvs,5 esv u09r time.

  An object can have nonzero velocity and zero acceleration at9p .eqh 1q4dfi1 2.xlluu *xnv the same time.

  An elevator moving from the second floor l/pe 2gyw:0h(6kt mvn to the fifth floor making no stops along the way has ze06t egh mk:w(p vny2l/ro acceleration all the time.

  A rolling ball moves vibzoqwd; -zy .e:+g8from $x_1=3.4 \mathrm{~cm}$ to $x_2=-5.4 \mathrm{~cm}$ during the time from $t_1=2.6 \mathrm{~s}$ to $t_2=5.3 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-3.8 \mathrm{~s}$ is at $x_1=2.4 \mathrm{~cm}$ and at $t_2=3.2 \mathrm{~s}$ is at $x_2=7.7 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight completsiq k7vhmv7534nh bt-e laps around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 10.7 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 102 m away ipj+ja+ 0aqio tny*)gd:uj h+- n 9.2 s. It then turns abruptly and ga+haytij +nj-:q a * o)pug+jd0llops 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 frorlhj p+ nc0jx*de60; 8)yqstym $13 \; m/s$ to $24 \; m/s$ in 5.3 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 fromg )7dv0fqwn b5t ac7w3 $21 \; m/s$ to rest in a distance of 71 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a speedxey*ytzjewd-9 u7a-2 of $25 \; m/s$ 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 blocks to essentially top speed abn :++/:t w/ pbleybcnzout zpctnbe ://+ nw+yl:b $10.3 \; m/s$ in the first 10.9 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 (v0f9mp a*ytumt.wp5 of $18 \; m/s$ to rest in 5.81 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 onsyvy8l9ulg ( ytl5dj /8+f6 ,oq1brwp the highway. Assuming g(u 6+y,t8jo1d fpwvyl9r8bq5 /sl yla deceleration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a tru q56bment2v w8ck 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 less than 30.0 min. ;9 z* bq4xrercAfter exactly 27.0 min, there are still 1100 m to go. The runner mu 4b9erc;xq*rzst then accelerate at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$