Suppose that an object travels from one point in space to another. Maoy utq22vcn-( zkt0x.zi s4m2ke a comparison between tt 2.m2zc(tizxs v4 0ykqn-ou2 he displacement and the distance traveled.

  When is the average velocity of dgbmn ro;26kc4nw0 /a;z e:f /qj.kok an object equal to the instantaneous velocity?

  A new car manufacturer afav-f/d4 m:0q/p 7y js5arum jdvertises that their car can go "from zero to sixty in 8 5m7fu/ards / pyfmvja4 qj:0-s". This is a description of

  An object moving in the +x axis experiences an c: r+*b 6m0iyxjq0ecwacceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x direction) begins to sloa8ujx xmik.phd r7*.g(-w/ gv w down as it approaches a traffic light. Make a statemenju*(.hwr8gd/ap i kxgv 7-.m xt concerning its acceleration.

  Suppose that a car traveling ;8gv jn9jo skcf,r h14to the West (-x direction) begins to slow down as it approachekcr1n hjvjf;o8 ,s 94gs a traffic light. Make a statement concerning its acceleration.

  Suppose that an object is moving with a constant velocity. Make a statement cov3oia wu 11o 4a+b8-+8eh,faict se glncerningwb4la ucg+o8 ov3,ht1i18afa -s +ee i its acceleration.

  If the velocity of an object is zero, does it mean th9bhrbdf g*z48hwby+j7rf, (vh . q8neat the acceleration is zero? Support your answer with an ev d(ehr.f7y +f4wrbh,bnqj8hg89*zb xample.

  Can an object's velocity change direction when its accekcw; fusm0v1 7xd njr 2/9c7hqleration is constant? Support your answer with an examplvnm 9 rf s7/jw17q c;u2xdchk0e.

  Suppose that an object 27mt9 b9bvpye mh)z7mis moving with constant acceleration. Make a statement concerb 7m9)py 7mehb9tzv2mning its motion with respect to time.

  Can an object have increasing speed while its acceleration 1u.vzto7k1 ssis decreasing? Support your answer with an exskv .1o71zustample.

  Suppose a can, after an initial kick, moves up along a smoothnpzht k;7 yy;- hill of ice. Make a statement concerning its accel hyt 7n;ky-;zperation.

  Under what condition is average velocity equal to the average of the. i*wrck7oq:dx9 cab+as4 kn3l,ojy* object's initial and final ves*b,o9 37j4anolw:.k*x+a ry ckqdci locity?

  Objects A and B both start at rest. They both accelerate at the same rate. ro)wm uhs;0g+ However, object A accelerates for twice the time as object B. What is the final so+mgr wsh )0;upeed of object A compared to that of object B?

  Objects A and B both start from rest. -kd 1qe( uv.xmThey both accelerate at the same rate. However, object A accelerae. (-qxvkum 1dtes 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 if n57i: coymw,n the absence of friction, which of t :y7o5ifwn,cm he following is true concerning its motion?

  When an object is released from rest and 5u)gs- t2zj 8zt,r vr, vgp(difalls in the absence of friction, which of the f2s-irujzzt, 8rd ),(gg tp 5vvollowing is true concerning its motion?

  Suppose a ball is thrown straight up. Make a s6; 8h8 htlc(l 9(i mlogcskp:atatement about the velocity and the accelh sklacp6:o(h( c8 lmtl8i9;g eration when the ball reaches the highest point.

  Suppose a ball is thrown straight up. What iy7b bnadn*9( qs its acceleration just before it reaches its highest point?dq(na* y9nbb 7

  Suppose a ball is thrown straight up, reaches a maximum height, then falls toz0s abpgsj ui-. )xt+t:yyj 88 it b+zijsgyy8 t)u.xs0a8 -: tpjs initial height. Make a statement about the direction of the velocity and acceleration as the ball is going up.

  A ball is thrown str2s tcy5 c,ett8aight up, reaches a maximum height, then falls to its initial height. Make a statement about the direction of the2tc,85ct st ye velocity and acceleration as the ball is coming down.

  Suppose a ball is thrown downward in the absence of aidx ,xsb1,wi7ar resistance. Make a statement concerning i x, wd7b,ai1sxts acceleration.

  Suppose a skydiver jumps from a high-flying plane. What is her ac604qvmnu5mv iceleration when she she reaches terminamn mv45 uiqv06l velocity?

  A ball is thrown vertically upward with a speed v.-b p2b0 r+canm 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 ball? (How many times higam b0rp2c +-nbher does the second ball go than the first ball?)

  Ball A is dropped from the top of a building. One second later, - vo:t w8ed9kvball B is dropped from the same building. As time prt89:vw kov de-ogresses, the distance between them

  Ball A is dropped from the top of+ j9);r 6rqnkzfuq ib* a building. One second later, ball B is dropped fr*iku r;nj+q6b 9fq )rzom the same building. As time progresses, the difference in their speeds

  Two objects are thro zojil6)ucn.g *utw;5p4wti2v) ifl7wn from the top of a tall building. One is thrown up, and the other is thrown down, both with the same initial speed. What are their speedswt twl i 2i5lj;).v p 6g)*4u7uzfonic when they hit the street?

  A brick is dropped from the top of a building. A second(7pm,h0t6 ovn 1 )ajqueo7viz brick is thrown straight down from the same building. They are released at i70qm61pv , ahe7jvu)on( z tothe same time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with constant.21b gklv+yd v+o,o) w za,mfx non-zero velocity in the +x axis. The position versus time graph of thlxo+z kba 1,vm2. v y,)+gowdfis object is

  An object is moving with constant non-zero acceleration in the +x a72aubo +sru+o xis. The position versus time g7o2uu ao+sb+rraph of this object is

  An object is moving with constant non-zero velocity in the +x axis. T6nb dc:4had7r he velocity versus time graph of dnc4 7ar6:dh bthis object is

  An object is moving with constant non-zero a.nm*lgktj9m ux lxa88z x-5/er 0xka ;cceleration in the +x axis. The velocity versus time kg le t 5x8j .ar*uzl/k ;xa8-9xmnm0xgraph of this object is

  The slope of a position versus timevv ea/xm7;+pu8i9 d6 czyuu 1e graph gives

  The slope of a velocity versus time graph givesywnag7zv jid(y; ,.8z

  The area under a curve in an acceleratihqw p)9u2+zs+ t0ejmjon versus time graph gives

  The area under a curve in a velocity versus time; pnd,x:p ki.u graph gives

  If the position versus time grauz 53pwqw;nb/ 4 tlpmxa7nf1 ; szwsq(io(8/wph of an object is a horizontal line, the object isba 8 fut;q3n5li( wm w47nssw(p;wzq/ x1/p zo

  If the position versus time graph of s0cp e1*zk+wy; d5bju(j-hqdw*3o uian object is a vertical line, the object isks* e+c1qj;wj(uh ioyd*dp-3b 5 u0zw

  If the velocity versus time graph of an object is adj+e b rs k;khopxkawo-6(q2yj:q4 ;8 horizontal line, the object jrj k-s( kephxbkqyo +684;a: qdw;o2is

  If the velocity versus time graph of an objects9pf :5k trq:c ).tovc4uwy3t is a straight line making an angle of 30 degrees with the time axis, the object itkotcv53 r.q):ys:cw 4 utf9p s

  An object moves 15.0 m north and then 11.0 md(7u8 6sqls y1ri )dva6ueq0f south. Find both the distance traveled and67yls)dv8dqq0 seuaurf1 i 6( the magnitude of the displacement vector.

  A boat can move at 30 km/h .2-l b80 vnznfnu )qoo(zg nk76( lqobin still water. How long will it take to move 12 km upstream in a river flowing 6.0 km/qq)nf6- (l o nv.zbz0gono( k bln27u8h?

  55 mi/h is how many m/s? (1 mi i sxu0zehh 400 gfg8(l= 1609 m)

  What must be your average speed ina -s 2zk5u3pxn order to travel 350 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 km) in 2 hours and 57 min.ub7jh 1g9,nt jr,c 0tk What is the avera tj urj,n0 97gc1thb,kge speed of the runner in m/s?

  A car travels 90 km/h. How long does it( xz d(-slcfn2 o1mlk2 take for it to travel 400 km?

  A ly (light year) is the distance that light travels in one year. The bzts933i1o 2 )n3w7aue wxqqc speed of light bcx o3enz1uwtais3 2w7 q)93q 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 and y+vy q9gr6m ,kkou look to the side for 4.0 s, how far do you travel during this inattentivekkq+mg9v r6y, period?

  If you run a complete d jeek07:*gc jxpp+ohel50 o5loop around an outdoor track (400 m), in 100 s, your average velocity iso ojkpp*5l cj0d7:he 05 e+gex

  A polar bear starts at the*o m )p7l5kz 7ll)pudu North 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 mmpul7uo)5 ld lkzp) 7*in. What was the bear's average speed?

  A polar bear starts at the North Pole.jq7gpb ;3 fut5 It travels 1.0 km south, then 1.0 km east, then 1.0 km north, then 1.0 km fj ub73tq5gp;west 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 mh6xmwl)6u8p8k ,oa ngopkn loi8+( +li/h for 110 miles. It then starts to snow and you slow to 35 mi/mnkix 68ao ,8) up+ pw+ lok(glo6ln8hh. You arrive home after driving 4 hours and 15 minutes. How far is your hometown from school?

  A motorist travels 160 km at 8b;czmapd5 ny2ab9x;e k;5 mp80 km/h and 160 km at 100 km/h. What is the average speed of the motorist for this dxmc y59;52;amkb bpzn8eap;trip?

  A motorist travels for 3.0 h at 80 km/h and 2.0i j76w :eahc2m2.f b6 fwsyp 2z,zavi0 h at 100 km/h. What is her average spajy6p 72i, 6 bsmwf:f.a2v2h 0ciezzweed for the trip?

  An airplane travels at 300 mi/h south for 2.00 h and then at 250 m4(4( c xyaojeii/h north for 750 miles. What is taj4 i(co (4exyhe average speed for the trip?

  In a 400-m relay race the anchorman (the person who runs the last 100 a.m0/yg 6xjrpt,cz zhc5h w*;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 hr;/*ym z6ptx5. jgaw, chcz 0runner 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 arqm1kzbv87 .a8 jp 2pffter 12 s. The car's average velocity during deceleration was 77 km/h. What was the car's decele 7jav18z2 .fk8mqrbp pration while slowing down?

  An airplane increases its speed from 100 m/s to 160 m/s, at the average rate gwy1fqr90 (cs/e pm t0of g/rcyp091 0 wsqft(me$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerates at 4t sf2fm7dos rd(b*ux l*.x4rthe 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 andcy / gd0x31.aw apypiwda/r)( 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. It then speeds up with a constant acrlrv,s.w20u nceleration s2,.l 0rnurvw of $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 5.4 m/s experiences a constanth4t wpbz;enaz ohdj5 a5s90 )48lbo3 p acceleration ob lw505tzsn 4p 3j;o)9zab48eapodhhf $1.0 \; m/s^2$. What is the cart's displacement during the first 9.4 s of its motion?

  A bullet moving horizontally to the yd(5 .mmunpy4d raju)81nfv3right (+x direction) with a speed of 289 m/s strikes a sandbag and penetrates a distance of 64.75 cm. What is the average accelerationvd4d)r1juayy3(5 8m.fu npm n, in $m/s^2$, of the bullet?

  A jet fighter plane is launcv wj mllfv2aw),b k6,px 5,xx,hed from a catapult on an aircraft carrier. It reaches a speed of 42 m/s at the end of the) f,vx6l,,xwv 5p2mwk,l abjx 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 with conyx.xskzky; 4fao6 c(, stant 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 200 m. What is its aver,7)cxr*c rn psage acceleratioc r*)spcnx,r7 n?

  An object starts from rest anva +b f:x(:yts/om2q fd undergoes uniform acceleration. During the first second it trb :xaf+sq(mo/ftyv2: avels 4.8 m. How far will it travel during the third second?

  An object is moving in a straight line wit.szcwc 50dbns5 vtl0o ;7wl9th constant acceleration. Initially it is traveling at 16 m/s. Three seconds later it is 97;vc w.tcl5 st5ndzl bo s00wtraveling at 10 m/s. How far does it move during this time?

  A car starts from rest and accelerates uniforml 8rwft/ivcm u .qxblt9 z5f3)/y 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 -l owj)yzv*2c 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 waiting ate -f3skokkd3f 7t., go the intersection starfgk3, e-d.3 tso7kokf 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 upwaf:l4u)3qtx 6z 7qet eard with a speed of 12 m/s on the surface of planet X where theq4e)e7qz fl xut 3:t6a acceleration due to gravity is $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown upwx9z:kl 50,ctw +wzoy lard with a speed of 12 m/s on the surface of planet X where the acceleration due to gravitc+,9:twxzlo z5l ky0wy 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 m1q7 rxjs5i+vupgz 5 8p/s on the surface of planet X where the acceleration due to gravi5urv zj1xpip57+ q8 gsty 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 o84j9ts6c qgdu f planet X where the acceleration due to gravitytdug 94s6c 8jq 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 your*y.sfqr3 o 1rmd8oz v( friend holds a ruler between your fingers and releases it without warning, ho.z1f8 vqy(smor*r3d ow far can you expect the ruler to fall before you catch it?

  A ball is thrown upward at a velocity of 19.6 m/s + vv3js7vxfp)u7hrq3. What is its velocity after 3.03qus p)xjrh7v 7vfv3+ 0 s?

  A bullet shot straight up returns to its starting point in 5 s. Wl+wa3 y,p hzr/;)7 l*j3vkc6fviw xcrhat is the initp*cwyfl3 +ar,6rk; i/z37) jx lcwhvvial speed of the bullet?

  A ball is thrown straight up with a speed of 36.0 m/s. How long does it take r4am eyz8,9ia to returiz ,a8ery49amn to its starting point?

  A ball is thrown downward from the top of a building with an initi0 pk gbv/bktj(*297ec lsi *xial speed of 23 m/s. It strikes the ground after 5.6 s. How higi/bs t pc9gxekljivb( 0*k 7*2h is the building?

  A ball is thrown straight up with a speed of 30 m/s. (only fill i2ev16l22.uabbt d ag mn numerical value in the vdalgmu22a62 bte. 1b 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 42.4 m/s 0 :7cdpzr/scj. (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 8 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 8.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is the velocity at8v va:m8utk0d t = 1.0 s?

  In Fig. below, what is the velocity at t = 2.5 hm yyf,/ih,rj2-( yai s?

  In Fig. below, what is the velocity at t = 48 alyi4bkeh-w5b, i1/m g4n rn.0 s?

  In Fig. below, what is the velocity;;hr e-mddm hv31y g/l t*s5 )d6alahu at t = 5.5 s?

  In Fig. below, what is the (n(s( bak*vun g ktxx2qe4 y*:average velocity from 0 to 4.0 s?

  In Fig. below, what is the average veprd51an xh: g:locity from 0 to 6.0 s?

  In Fig. below, what is the accma b5j0e( ti-zeleration at 1.0 s?

  In Fig. below, what is the acceleratioa(p56aasc ;n fn at 3.0 s?

  In Fig. below, what is the average accelerat-il1po jr2f .g-m :n0x)zwvotion from 0 to 5.0 s?

  In Fig. below, what is the average acceleration from 0v b jr,6/jndo9coeni 3;j *nv6 to 8.0 s?

  In Fig. below, what is the displacement from 03j (bpov.wq yvvh.k 57r dk7*f to 8.0 s?

Does a car speedometer m e*wrk)7h1rrn easure speed, velocity? {speed|velocity}

  An object can have a varying speed i fw83wf cymzqoqq-27 0f its velocity is constant.

  The velocity of an object can be negative when its av19u -x(cq, ;e lf ljm+rge(d;zqynn2cceleration is positive.

  If one object has a greater speed than a second object, the first must have.q1y-at ,udgm a greatert qg1-yu,dma . acceleration.

  Two cars emerge side by side from a tu k6f vo5-;r*sa (xno p+segeq+nnel. Car 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 incribgok cgi tg30x*8dd1 9b z;s63uk h:deasing in speed as its acceleration decreases.

  A baseball player hits a foul ball straigv*hss :qw x:mdd/s .u-ht up into the air. It leaves the bat with :q/xdm - dssvs.huw: *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 acceleratiob/8 - /0figu jzqtp+won, how does it change if air frictiojo+i u/fb8/t z- wgq0pn is ignored?

  As a freely falling cd0*vo+o )5gdmov2 x vobject speeds up, what is happening to its acceleration, how does it change if ad+v c5xo)od0v vmo2*gir friction CAN NOT be ignored?

  An object that is thrown verticallo)5c u o9x9f*e)rhxjl y upward will return to its original position with the same speed as it had initially if air resistance is negligible. If alhxrx9 ecj9 ofo))u*5ir resistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzero acceleration at thbj1(j lbi2x68v c0tx me same time.

  An object can have nonzero velocity and zero acceleration at the same time abwf4eeva/kj 3e 8m 0( o2knt56x7spw.

  An elevator moving from the second floor to the fidotw7g ,j v8m:)g;nfu fth floor making no stops along the way has zero accel gwdg8u fto ;mv,:7)jneration all the time.

  A rolling ball moves from7x)0f4m ue 2k*m-peoy bd4gq;vac yg* $x_1=2.4 \mathrm{~cm}$ to $x_2=-5.8 \mathrm{~cm}$ 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 $t_1=-3.4 \mathrm{~s}$ is at $x_1=3.2 \mathrm{~cm}$ and at $t_2=4.1 \mathrm{~s}$ is at $x_2=8.4 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight liv,yui/ av. 29yrth 9complete laps around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 7.4 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 straio5qy .5:j0+ts-a0bd ecorm fl ght line, moving 104 m away in 11.5 s. It eym0: lt qo r0+s55c.a-jodfbthen 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 frourri *saj 44ymv, vi7+m $12 \; m/s$ to $24 \; m/s$ in 4.6 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 frol nbv4hl: f*hv;m i2+um $20 \; m/s$ to rest in a distance of 64 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must ry+r i8p lujlh1*xhk8. each a speed of $28 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.3 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of the blocks to essentially top speed aboud 16caph:4*t (duaqpdtdua 1p4q :ta(h6c*ddp $11.2 \; m/s$ in the first 13.3 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 uniformlyb4ok5c+n0+ a)hfgiss)yg 1 zjc 2e -qn from a speed of $19 \; m/s$ to rest in 5.09 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 the highway. Az(rm9 k- fere6ssuming a (r6fekze9-mr deceleration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck goindh1y- b hx(n9d*q0w qwg $25 \; m/s$ 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 compnqfi* 4ya45w vlete the 10,000-m run in less than 30.0 min. After exactly 2wi*na5 y 4qv4f7.0 min, 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?    $s$