Suppose that an object tra 2tfxi, gavjf69x5km*y cd4c .vels from one point in space to another. Make a comparison between the displac.9i*6v5fkt4fjccxm,2ax dg yement and the distance traveled.

  When is the average vel0d vpmnd l71x5ocity of an object equal to the instantaneous velocity?

  A new car manufacturer advertises that their car can go "fron -cx+ou6 *dbx0egc o.0m9vgb m zero to sixty in 8 s". This is a dbo*. xn0cdu 9+- g6gve0xcbmoescription of

  An object moving in the +x axis sun* mr9wz5( exz+ua+u 0+ qitexperiences an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the Eascrdbi:myz: 2+nf 7ht3t (+x direction) begins to slow down as it approaches a traffic light. t:yr3 b27h dfnz:ci+mMake a statement concerning its acceleration.

  Suppose that a car traveling to the West (-x direg,cnc;wm* ks *ction) begins to slow down as it approaches a *cnw k*cs mg,;traffic light. Make a statement concerning its acceleration.

  Suppose that an object is movin4h3xylzy .y,/p/*pwnh5 cp nrg with a constant velocity. Make a statement concerninp*nh y,/h n4y5.rpy w3zl/pcxg its acceleration.

  If the velocity of an object is zero, does it mean that the acceleration is zj qndr+3 zp5+i) uqak;ero? Support your q+iu5 )+kn j3zaq pdr;answer with an example.

  Can an object's velocity change direction when its accer r81 4tdnm4y.qmgba +leration is constant? Suppor gmd1a.mb4r qr8n+t4yt your answer with an example.

  Suppose that an object is moving with constant ap sm(+3j,5b-xwx.s o6m r fh tmfubg()cceleration. Make a statement concerning its motion with respect to timsforbxmx3 .(wsu )+6gp h 5 fj(tmbm-,e.

  Can an object have increasing speed while its acceleration is decf c5iw,mtx ffa2 (6vi2reasing? Support your answer with an exf5 fc,xw(it2 62vmi faample.

  Suppose a can, after an isrhdrd)0 n2mkz z*(vk6e8i+ p nitial kick, moves up along a smooth hill of ice. Make a statement concerning its acceleration8rkdzs*mi2ezhd k0+6 rp()nv .

  Under what condition is averagujrl;kznmxl.k6538 d.kn x qm g2 24pee velocity equal to the average of the object's initial zmk3.l;2jnnledux8 .xk k g2r4m q56pand final velocity?

  Objects A and B both start at rest. They both accelerate at the sam )o/e,(ayh tuge rate. However, object A accelerates for twice the time as e/youhgt a (,)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 apogsthqa)8 6 1ccelerate at the same rate. However, object A accelerates for twice the tig6 o1 hqp)st8ame 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 absence6/h8-sa m ibze of friction, which of the following is true concerning -/abhs zeim86its motion?

  When an object is released from re9 j+4u0h-+sw1d u(d yp6 fsv z;enygrcst and falls in the absence of friction, which of the following+ gdu1 fzdj6 +n-0whrpeycu94s syv;( is true concerning its motion?

  Suppose a ball is thrown straight up. Make a statement c3zpceb yh qwy2542s0sd5+pa about the velocity and the acceleration when the ball reaches the highhes2z 0 ab3cyqp42c5sy +d w5pest point.

  Suppose a ball is thrown straight up. What is its acceleration just befor,+l4n9ke er nxe it reaches its highe 4nr9ee+l nx,kst point?

  Suppose a ball is thrown stra n ry )r4(vbk-qwy9j*s;nfo9q ight up, reaches a maximum height, then falls to its initial height. Make a statement about the direction of the velocity and accelerrfo 4ynn-rwbvj9 ks(qy ;)9q*ation as the ball is going up.

  A ball is thrown straight+ (wluelyh,b* up, reaches a maximum height, then falls to its initial height. Make a statement about the direction of the velocity and accelerationu* w, e(hlby+l as the ball is coming down.

  Suppose a ball is thrown downward in the absence of aeobhd o;l(,4e.y+0 d 7ug ieosir resistance. Make a stateo 7u0ygb; h sed,+eod(il 4eo.ment concerning its acceleration.

  Suppose a skydiver jumps from a high-flyin mj k,,x2 8sxztja.br,g plane. What is her acceleration when she she reaches termizjmx.jst 2 rb,,axk8, nal velocity?

  A ball is thrown vertically upward with a speed v. An (kzu /k ka4 irsnc3q4mx0,+dkidentical 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 ball? (How mazud4/rc3xkqi,(mnk0k s+ k 4any 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 ddbl2/il5y15u4uc s dos )j9464cf olqqwr.ygropped from the same building. As time progresses, the distance betweeng4/c)c sowyfl9i4ddl42 q yul 1.65bo5juqsr them

  Ball A is dropped from the top of a building. One second lai - kksw 2l4 bu4u1jwrnhhj6;1ter, ball B is dropped from the same building. As time progresses, the difference in their speeds 2h4l 6 juk;whjwi4-b1ruk1n s

  Two objects are thrown from the topxy(*9;dgr+bnt. h r qi 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 ttdhr*yni+;.x(gq9 rbhey hit the street?

  A brick is dropped frr8h 3 li)s ua4h5gzdwogkfj;- yb1/n+om the top of a building. A second brick is thrown straight down from the same building. They are released ati/3au l+ zg- ; f rs1)kndw85ygjhob4h the same time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with constant non-zero velocity in the +x axis. Thejxh3iyr9 u35duf( mw- position v 3xr m-ui 3hf5uywdj9(ersus time graph of this object is

  An object is moving with constant non-zero acau0m f96/vbe iceleration in the +x axis. The position versus timeb feivu90/ 6am graph of this object is

  An object is moving with constant non-zero velocity in ther yfa 7e96-gbavr1 5;jea8ggm +x axis. The velocity versus time graph of this obje5gb9r;fe7vm a1g rey86-aagjct is

  An object is moving with constant non-zero acceleration in the +x axis. Tgrn4/p16 h 9jactp 7jwm(v/wh q+ ,kxrhe velocity rr h4(mht+p79 q6/wjwcnkja xpv/ , 1gversus time graph of this object is

  The slope of a position versus time graph givesjzt,+p;aak1b

  The slope of a velocity versus tim*6tv 9xcazi + y-y1im5ffu w/pe graph gives

  The area under a curve in an acceleration v8cgia:zp 4vd6*ab 4sgersus time graph gives

  The area under a curve i ej9b90wrtanwgb m;6ay q.j(hp6 p-)u n a velocity versus time graph gives

  If the position versusfqj:mk6mq36 xgol 4q- time graph of an object is a horizontal line, the object i6f gm36:4mqqj xq-kl os

  If the position versus time graph of an object is a vert4pn91h8 kmjqxical line, the object is p1nx j94khm8q

  If the velocity versus time graph of an object is a horiz/87a8 jnpp0(pn0ts hvfqi0 pgontal line, the object ig0h8s8f a n7np/pvt0(qp pji0s

  If the velocity versus time graph of an object is a straight line mmhpi,fw ys-+hl91 7n saking an angle of 30 degrees with the time ah pi 9ws17 mf+ylsn,-hxis, the object is

  An object moves 15.0 m north and then 11.0 fn r34tmdy0s5 6dkg;e m south. Find both the distance traveled anen4ydgks 3 r0 dtfm6;5d the magnitude of the displacement vector.

  A boat can move at 30 km/h in still water. How long will it take6ezvn cfo) zb1 no,)i76 zamw2 to move 12 km upstream in a ro) vw1zmiben6 o26zn,ac)7fziver flowing 6.0 km/h?

  55 mi/h is how many m/s? (1 mi = 1 9.(ovu o7qkhg609 m)

  What must be your average speed in order to trave*9jmn4m z q-bntw5 x7xl 350 km in 5.15 h?

  A runner ran the marathon (approxima .c9s6 lsd8uuately 42.0 km) in 2 hours and 57 min. What is the average speed of the 9.ld6uasc u8s runner in m/s?

  A car travels 90 km/h. How lo91 :sccr 6ceuzng does it take for it to travel 400 km?

  A ly (light year) is the di o2+dvh pf3ry k*c5fm1stance that light travels in one year. The speed of light yv*o3+ cf1f dmp2krh5is $3.00 \times 10^8 \; m/s$. How many miles are there in a light year? (1 mi = 1609 m, 1 yr = 365 d.)

  If you are driving 72p/ tr7rx8gtd l.b( )kctpdtbee u 6,0* km/h along a straight road and you look to the side for 4.0 s, how far do you travel during this inattentive./p)tt,et(ret8 ub dx6b07p*gcl kd r period?

  If you run a complete loop around a fdo.mstzp9r60hs+ .w+bzk /d n outdoor track (400 m), in 100 s, your average versb ++pdh.9 0k.mzot/6fwsz dlocity is

  A polar bear starts at the North Pole. It tr0)ybxz6sf1 vnavels 1.0 km south, then 1.0 km east, thenvn6xzsb) f0 y1 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 speed?

  A polar bear starts at the North Pole. It travels 1.0 km south, then 1.ba o/j)s9pr0 qmee5)gmnci;g7 w tq1+0 km east, then 1.0 km north, then 1.0 km west to return to its starting point. Thi51+pj;7/ rgbnei t))saqeq0 w9 gomcms 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 110 milesrzz7 df yi,ct8 10qj2g. It then starts to snow and you slow to 35 mi/h. You arrive home aif780 d t,yzqj 1rgzc2fter driving 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 100qt u7u2 z,dqgvjz5v5 0 km/h. What is the average speed of the motorutgv v52u 5z7jd,0qqzist for this trip?

  A motorist travels for 3.0 c77 ov /:2 +9z t nwnlpynfzibrqs;q79h at 80 km/h and 2.0 h at 100 km/h. What is her average speed for pvowr7fn n ;q z/sicbqyz:nt7l2+997 the trip?

  An airplane travels at 30 d jg19b4lo6ap0 mi/h south for 2.00 h and then at 250 mi/h north for 750 miles. What is the a6ga 9p1b4ldo jverage speed for the trip?

  In a 400-m relay race the anchorman (the person who runs the last 1m19tc p(fc 5d x y4yvpgrup:;;00 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 final leg of the pc ;1t g5(d c:f49xu;p myvpyrrace, in order that the team A runner not lose the race?

  A car decelerates unib 50k tbr pba(aa2x).jlpq84rformly and comes to a stop after 9 s. The car's average velocity during deceleration was 35 km/h. What was the car's decelerati5xb. 8r0a )4a2p(jrqb blatpkon while slowing down?

  An airplane increases its speed from 100 m/s to 160 m/s, at thexy bht.8rgw1i* ;x pune4)2fn average rate of *.n4 1twhp)u8yxibf2rx; gen$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerates at q5lzebr 1* 9wmthe 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 1mqjzj7 r 61aj/w1 bp70ynme2d1uv ia 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) ,la9e dum/wc then speeds up with a constant acceleration of ma/u)dlwc,9e $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 4.8 m/s experiences a constant accelerati)n7s as hno3a e/y,f6oon of aeo,aso 7)/f n hyn6s3$2.6 \; m/s^2$. What is the cart's displacement during the first 5.2 s of its motion?

  A bullet moving horizontally to the right (+x direction) with a spe5c8nfgg) 7ck cl(5b-d6isv s aed of 556 m/s strikes a sandbag and penetrates a distance of 59.3f( dcc) g 6gsbs7a cnl8-iv55k0 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on an aircraft carrier. It revs:gd:o tn(/n aches 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 lengthg:vn o n:/(dst of the catapult?

  A car starting from rest moves witq,; uzzv uj*x .47fknqx,h n.zh 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 +arxa nyt1 ,(x80 m/s in a distance of 200 m. What is its average accelerati r(ya a1,tn+xxon?

  An object starts from rest and undergoes uniform acceleration. Duriz. /6bnu* juajng the first second it travels j*na.u /jz6b u1.1 m. How far will it travel during the third second?

  An object is moving in a straight line with conse9e q vikcx4k 9(nt35ttant acceleration. Initially it is traveling at 16 m/s.x(e 5 nq c9tketk4i3v9 Three seconds later it is traveling at 10 m/s. How far does it move during this time?

  A car starts from rest and accelerates uniformly z94a9up -iop mat $3.0 \; m/s^2$. 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 at abo0f).k fnl ngtx4-)ye39 ivzd iut $5.0 \; m/s^2$ 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 cs3fv3xq i. mi1ar that has been waiting at the intersec m3qvix .1fs3ition starts 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 buauhqf(s,k74bzq5dd/ 1,sz 12 m/s on the surface of planet X where the acceleraqds7ad1s,u 5zzk h/fu4 ,b (qbtion 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 p9xp7ulv d8;+2vew ml12 m/s on the surface of planet X where the acceleration due to grav+v8l d;2melx9 wvpu7pity 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 surface of planet X vbm4l:tz. tx) where the acceleration due to gravi.mz )ltvbx t:4ty 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 X whh67utt,hwr4fj ;f o(qere the acce o(hj74f 6wuqtfh ,rt;leration due to gravity 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 y3 lbnqyn4o :0cour friend holds a ruler between your fingers and releases it without warnn: q3yb0l4c noing, how far can you expect the ruler to fall before you catch it?

  A ball is thrown upwa 7yzz/u 9:gjcord at a velocity of 19.6 m/s. What is its velocity after 3. j :ozgcy7/9uz00 s?

  A bullet shot straight up returns to its starting point in 8 s. * 0r vs--am -jr*7 bmnn1prgpjWhat is the initial speedn-r1ngv-j r jap *m0s-rmpb *7 of the bullet?

  A ball is thrown straight up with a speed of 36.0 m/s. How long does it t 7l;cyknks7e* : hm,xtake to return to7 che,yk;m7slx*:ktn its starting point?

  A ball is thrown downward from the top of a buildin +az)t cyka:4jl 8wld5g with an initial speed of 23 m/s. It strikes the ground after 6.7 s. How high is the b5+zajtc d:4 aywl k8)luilding?

  A ball is thrown stra6xq7z/j h4xl uight up with a speed of 30 m/s. (only fill in numerical value in the b7/l4 zqxux 6jhlanks)
(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 s50mi x1ml0, o5 twkpcjtraight up into the air with a speed of 27.9 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 14 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 14.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is the velocity at t = 1.etpd0p 4z/5w kktb 8may8 l;+x0 s?

  In Fig. below, what iqv-k79qh xqm i(30gtf s the velocity at t = 2.5 s?

  In Fig. below, what is the velo)8j6sx- /y mi t,w8hrn/ oirnccity at t = 4.0 s?

  In Fig. below, what is the velocity a8*fk xo0kh-6pn ,b b o81ncmtdcv1j1et t = 5.5 s?

  In Fig. below, what is the ave wj*mgv8p,gr(jy,ob 9 rage velocity from 0 to 4.0 s?

  In Fig. below, what is the average velocity fr.6 : em uib(waimka(;dom 0 to 6.0 s?

  In Fig. below, what is th cggz nt1mh (v2e+d,cdb05 (tbe acceleration at 1.0 s?

  In Fig. below, what is the a-pla6a/47/m 9dq-2 5kmtxm ckgmj koqcceleration at 3.0 s?

  In Fig. below, what is the average acce/ a6wia27kddzu 1ttscnn6 68zleration from 0 to 5.0 s?

  In Fig. below, what is the average ac0(z7tfs) y+ hvk;eopnceleration from 0 to 8.0 s?

  In Fig. below, what is the displls5oh57 nrai- acement from 0 to 8.0 s?

Does a car speedometer measur/ i xfgt qta34+ni 8q,lcrwk/*e speed, velocity? {speed|velocity}

  An object can have a varying speed if il0lzhri(bsusb 98 9z,ts velocity is constant.

  The velocity of an object can be neg9o qa-f(i5 4tpn wt)slative when its acceleration is positive.

  If one object has a greater speed than a sehdzad2 t.;hnamsv 66;cond object, the first must have a greater accel;t sm6dz 6vnd2a;a.hheration.

  Two cars emerge side by side from a tunnel. Car A is traveling with a spz/b; apf2 l43*shw wfreed 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 its am;)roa*;/+ phw0qd avx 7kn speed as its acceleration decreases.

  A baseball player hits a foul ball straight up into the air7 jij)v0jdtpy,e+aze2j 74m d. It leaves the bat with a jd7vp0aj yz4 em,et di+j 27)jspeed 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 acce 5a.ql dx;tb4dleration, how does it change if aixdl5bq d4t;. ar friction is ignored?

  As a freely falling object speevn us52mn5v.( crid) :, fvwmyds up, what is happening to its acceleration, how does it change if air frictio,(2vw.)u ic vvr fd5:n ym5nmsn CAN NOT be ignored?

  An object that is thrown ver cyy6on-a) 2cxtically upward will return to its original position with the same speed as it had initially if air resistance is negligible. If air resistance is apprecx-) yn2oayc6ciable, how will this result be altered?

  An object can have zero velocity and nonzero acceleration at the same tim3 50 tyes.mqfas: .9stxswa avd 2i,3qe.

  An object can have nonzero velocity a/ 63tt* iptkvlp-ndc .nd zero acceleration at the same time.

  An elevator moving from the second floor to the fifth floor maki ln*6yq4q tfqsck1 ;1qb rq).wng no stops along the way has zero acceleration *q qqsbfqq4)1 ;lykr.cn6w1tall the time.

  A rolling ball moves oc5wuug g;a r89y i)1hfrom $x_1=2.7 \mathrm{~cm}$ to $x_2=-6.7 \mathrm{~cm}$ during the time from $t_1=1.9 \mathrm{~s}$ 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 $t_1=-2.4 \mathrm{~s}$ is at $x_1=2.4 \mathrm{~cm}$ and at $t_2=3.0 \mathrm{~s}$ is at $x_2=8.3 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps around a quarter-mile (ibv m;pb6 :ob(.:g.qqpn9zy q$1 \; mile = 1609 \; m$) track in a total time of 11.7 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 116 mifu1 z aqv-a;4h4pjy 2 away in 9.9 s. It then turns abruptly and gallops halfway back in iuzj4- aa4yfh1 ;2qpv 4.8 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 frofu,eqp4b +rh qh x18d5m $10 \; m/s$ to $22 \; m/s$ in 4.5 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 fromjou psnx5gh5p:v a1 03 $16 \; m/s$ to rest in a distance of 84 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach aucwcgkbv.u-.g, 35*r;zfc y i speed of $28 \; m/s$ 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 out of the blocks to essentially f 3mp3 ;q o2hdr3gz5 k8l/impmtop speed abouog2m8phpz/35lf k mqd 3ri;m3t $10.9 \; m/s$ in the first 13.0 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 4t8o t.vi771ch2zrra iw e)oxof $19 \; m/s$ to rest in 5.25 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves skid marntvpiy),yfo( )n .4o)qny+q rks 92 m long on the highway. Assuming a deceleratioqnfi.)q np t(y r)oyoy,)4vn+n of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a tru3sxd ,5m )+t hfwj7o1 xjoc4oick 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-. eg shz/yr9p4m run in less than 30.0 min. After exactly 27.0 min, there are still y4eh.p rg/z9s 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?    $s$