Suppose that an object travels from one point in space to anv-9wcxfu7f8;u5 y z,qs.m9sgdme 2 sqother. Make a comparison betwe,7 qy9-xeus5 s;c s2m dfg9wq fmuz8.ven the displacement and the distance traveled.

  When is the average velocity of an object h/,pnt5 3:yr1lak jfj equal to the instantaneous velocity?

  A new car manufacturer advertises that their car can go "from zero t. )jtt pu06rjho sixty in 8 s". Thish jt )t0j6.upr is a description of

  An object moving in th4 b82dss99nhen4ugz(qa (a sk e +x axis experiences an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to thst)v.zhpl u0y 2(v s(i a+pfw5e East (+x direction) begins to slow down as it approachsz)y0lp5i.huv(fa ( p 2s+vtw es a traffic light. Make a statement concerning its acceleration.

  Suppose that a car traveling to the West (-x direction) begins to slow down 5*habtif 0k:5up 2glj as it a0*ith apug 2lkfj :55bpproaches a traffic light. Make a statement concerning its acceleration.

  Suppose that an object is moving with a constant velocity. Make a sxrs)17q kt x*l( p i9nqi-2ptitatement conc)7n1s pki *9tr2qti x-x (ilqperning its acceleration.

  If the velocity of an object is zero, does it meanmv3wapzyz/ o *z61j:v x22vai6 zk4fs that the acceleration is zero? Support your ans*z/w1azjmvpov6k y4zvz2x2f :s3i6a wer with an example.

  Can an object's velocity change direction when its acceleration i(t - m tf/wceo*/bj)zws constant? Support your answer with an exw*/-ztew) tcbfoj(/ mample.

  Suppose that an object is moving with constant accelerati*sq g5 kwm2ol6on. Make a statement concerning it6qoglk* wm2 s5s motion with respect to time.

  Can an object have increax ol g(esv)8.using speed while its acceleration is decreasing? Support your answer wite 8vo.xgsu)(l h an example.

  Suppose a can, after an initial kick, moves up along a smooth hill;n3domm o,; e tmdn(9 wgf-).mfu/ ynb-0hld a of ice. Make a statement concerning its ay(gltd mew; ;omdh-mn)ba, u 3on.-/n9dfmf0 cceleration.

  Under what condition is average velocity equal to the average of the objec5djc z/vl9 u6a2 hgr(xt's initial and uarzx 59j 2vgld(ch6/ final velocity?

  Objects A and B both start at rest. They both accelera:xsmjcijty 8k:24n0i 6w +tkute at the same rate. However, object A accelerates for twice the time as object B. What is the 0icuj :it t682xm+sjnwk4k: yfinal speed of object A compared to that of object B?

  Objects A and B both start from rest. They both accelerat2ciwi/ eq;8 lbe at the same rate. However, object A accelerates for twice the time as object B. What q w/eb82ic;liis the distance traveled by object A compared to that of object B?

  When an object is released from rest and falls in the absence of frict 75y7) ryhl,iv, idwlnion, which of the following is true concerni7,yyhv r)li7n li,w 5dng its motion?

  When an object is released from rest and t5g;; m;arevp falls in the absence of friction, which of the following is true concerning its mep;;v5m; rtagotion?

  Suppose a ball is thrown straight up. Make a statement about the hsqyg(7x05 b0 inn3gavelocity and the acceleration when the g b5g(qanx iy73ns0h0ball reaches the highest point.

  Suppose a ball is thrown straight up. What is itiewgi /93 4mdks acceleration just before it reaches its higdg /mei 3k94wihest point?

  Suppose a ball is thrown straight up, reaches a j 8, mote71l,f nh,vfbmaximum height, then falls to its initial height. Make a statement about the f,1,m ,bo f jt7lv8nhedirection of the velocity and acceleration as the ball is going up.

  A ball is thrown straight up, reaches a r16l /z,4y sc;cj1oyhi+ ppsfmaximum height, then falls to its initial height. Make a statement about the direction of the velocity and accelerap1 cy1j,hc zly;4sisr6f/po +tion as the ball is coming down.

  Suppose a ball is thrown downward in the absence et qu3)56i2mkp osoa3 of air resistance. Make a statement concerning3m tk) oiqs2u3e56 apo its acceleration.

  Suppose a skydiver jumps from a high-flying plane. What is henxkl+;b a 4 5 es37uexy4 lwmz-ves*.rr acceleration when she she reaches termi.rsw4 ay +uxlxsb 7 -l 4znk;3*mveee5nal velocity?

  A ball is thrown vertically upward with a speed wq1q qg/ve u)/v. An identical second ball is thrown upward /q)gu/e qwqv1with 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 higher does the second ball go than the first ball?)

  Ball A is dropped from the top of .i2spc 9ft -;indt,ee a building. One second later, ball B is dropped from the same building. As time progresses, the distance betd s, 9;fpii2eectnt. -ween them

  Ball A is dropped from the top of a building. One second later,kw d2 yl(h o2fgr4n75)y8mbru ball B is dropped from the same building. As time progre5)ndw f7h rrob28gymu l4y(2ksses, the difference in their speeds

  Two objects are thrown from the top of a tall building. One is eom 357 ac97q me. swlzsl+kmwm3)p:ethrown up, and the other is thrown down, both with the same initial speed. What are their speeds wh ee+ls)3 m ozm ms.37e5wlma 97qw:cpken they hit the street?

  A brick is dropped from the top of a building. A second brick is thrown straig93 i2dc,z7nr vfpb8 lrht down from the sa3f,izlbvc8rd n2 7p9rme building. They are released at the same time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with constant non-zero velocitw ga*3s9ru f) ryd/ yo)19klfpy in the +x axis. The position versus time graph of/d9 ry )fylpfo3rw1k*sag 9)u this object is

  An object is moving with constant non-zero accelerationw ersm7;2d62, dgm at1rhcv*c in the +x axis. The position versus time graph of this object i *wmrv 1;6acrd7d2egmtch2 ,ss

  An object is moving with constant non-zero velocity in the +x axis. The velocietl2; o9sd*kgty versus time graph of this obj lk;dogs92 *teect is

  An object is moving with constant non-zero acceleration in the +x axis. The velwjggcwnea h87 1ze*00 ocity ve 07we1z w8 *e0ngjhcagrsus time graph of this object is

  The slope of a position versus time grawo lh zp2d eg7wfc97,ypb3u85 ph gives

  The slope of a velocity versus timet,u5vvl4atw9g 3 k1 qq graph gives

  The area under a curve in ansnr.q.2rwa 7 x acceleration versus time graph gives

  The area under a curve in a velocity versuswe4 r+-4+6 nijadutw r time graph gives

  If the position versus time graph of an object is a horizt-(-bww/k hj kontal line, the object bh--(wj k/twkis

  If the position versus time graph of an obj oit, ub-dy p,8k:yl.8wu) yghect is a vertical line, the object isk8u , bwl pg,-8tihyy)ud:o.y

  If the velocity versus time graph of an object is a horizontal line, the objec;jclvvr ns,( 5m gb4rl7h 8sl:t 7 ,jbn s (vmhlr:cv ;4g5srll8is

  If the velocity versus time graph of an object is a straight line making an g(wz5( 1 :cs3*fp9burwuqszu angle of 30 degrees with the time axis,(qsrc193sgzf (p*wzuu: w ub5 the object is

  An object moves 15.0 m north and then 1v3wbt8 f (ud1uffna7j2o*b(i1.0 m south. Find both the distance traveled and the magnitude of the displacement vector.fa1(2jfbu u*dwnif(7otb v38

  A boat can move at 30 km/h in still water -dh55dz7javk k 2;gzz. How long will it take to move 12 km upstream in a river flowi zd52hkda v5;- gzkz7jng 6.0 km/h?

  55 mi/h is how many m/s? (1 mix4p jxc6 9nm ayve74 s-3vqr)gjv j.5h = 1609 m)

  What must be your average speed in order to travel3 j..zk7o7wy a7boau n 350 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 km) in 2 hourzcfq1 rv n;7lboh3+3ss and 57 min. What is the average speed of the 3;lh crszv+b f1 qno73runner in m/s?

  A car travels 90 km/h. How long does it take for it to travel rw /oabtl :7ahhk+0,3wqmcr4 400 km?

  A ly (light year) is the distance that light tran) glzn9 d:.g e9;1u)uwkqr eavels in one year. The speed of li z)9e rnagkw9u)d neuq1.l;:g ght 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 strme6l3hf d.h ew )ez;:laight road and you look to the side for 4.0 s, how far do you trw e: 6).f3mlehd;helz avel during this inattentive period?

  If you run a complete loop ar, h9jsrf;)c nvound an outdoor track (400 m), in 100 s, your average velofr9j,)hcvn s ;city is

  A polar bear starts at the North Pole. It travels 1.0 km south, then 1.0 k6:xzwp ht8 x,xm east, then 1.0 km north, then 1.0 km west to return to its starting point. This t:t8 zpxx,wx6hrip takes 45 min. What was the bear's average speed?

  A polar bear starts at the North Pole. It tr)n(bm-j03 abbqbt bsc;si;f::bm7h savels 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 average velocit) -s jbhbb:sacn3m0s; q7(bbi: ;fbtmy?

  You are driving home on a weekend from school at 55 mi/h for 110 miles. It then aj (ti0x/u;an0* 7jov vrin.u6o0vnf starts to snow and you slow to 35 mi/h. You arrive home*;nviju0 xinr a u6/v7.jf n 0taoo(0v after 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 100 km/h. Whz0xgv d3k,*n yat is the average speed of the motorist for this tri*y zdv, 3xgn0kp?

  A motorist travels for 3.0 h at .o:h,ohp3gvf 80 km/h and 2.0 h at 100 km/h. What is her average speed for the tr:o ph h3v.,fgoip?

  An airplane travels at 300 mi/h south for 2.00 h and then at 250 mi/h north for3; czn;orcq6ll8 q+bk 750 miles. What is the average speed q cqz6c8rok3;n; l+b lfor the trip?

  In a 400-m relay race the anchorman (the person who runs the last 100 m) grhh/* ;cpz i ,y7:iuh-8povhfor 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 iph*7c- /:irh g; u 8y,zhpvhorace, in order that the team A runner not lose the race?

  A car decelerates uniformly and comes to a stop after 10 s. The capgdfi*swa g1n cy26-;r's average velocity during deceleration was 43 km/h. What was the car's1w2-*ig dg6y;cn fsap deceleration while slowing down?

  An airplane increases its speed from 100 m/s t*aa g/6vk f3h0fiuyy )o 160 m/s, at the average rate of yuagfk/v)af *i 60hy3$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerates at 9)r l,86d z(,wvrh mspqc)olnthe 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 a)5gqjc ku k;)+lfiu 1ju el/2vt $4.0 \; m/s^2$ 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 speemd e*6nu p 7co:ag;zj8ds up with a constant acceleratiou7opndjaeg 8*6 cm:z; n 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 constan m3p6,.fsrib8gll2c3zs m5ei t acceleration of smgrlc3ml5p si26 e f3,bi8.z $3.9 \; m/s^2$. What is the cart's displacement during the first 4.2 s of its motion?

  A bullet moving horizontally 7-rotob (n )tfto the right (+x direction) with a speed of 358 m/s stri bt-ro(nof)7tkes a sandbag and penetrates a distance of 63.53 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is laua nuspwiv2d* x+qyka:lyl ,a z0/ 227enched from a catapult on an aircraft carrier. It reaches a speed of 42 m/s at the end of the catapult, andda 0e2:kya+pal is2z,u*n/ ylx7qw v2 this requires 2.0 s. Assuming the acceleration is constant, what is the length of the catapult?

  A car starting from red yc f/5v3sob/,k n d4fh.et6lst moves with 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 b8wlikxd8e*in6 :x 8hxm,j;j of 200 m. What is its average acceleration* ilxx:k hj; m,ixe d88w6nbj8?

  An object starts from rest and undergoes uniform acceleration. k, tcoh k0g w8v;+g2gm ;8enxf During the first second it travels 7.3 m. How far will it ;xgg 0e o8+wv,kfn2;m8 gthkctravel during the third second?

  An object is moving in a straight line with constant acceleration. Initially it j+h 2aw*hd ou 7av;vm8wpo.k+ is traveling at 16 m/s. Three seconds laterw *hwamu +k.2a opd7v;v o+j8h it is traveling at 10 m/s. How far does it move during this time?

  A car starts from rest and accelerates uni eyy/gr8x +bzn*e .s,0gyv)wz dz:9ug formly 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 roace8 yzg0l0)d dd 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 ligb+ 8fpm ;xq,/h.wumkeht turns green, a car that has been waiting at the intersection starts ahead k8.mb;,+x/ mu qehpfw 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/s ug6 4i 0t5pyey l0gh)jon the surface of planet X where the acceleration due to gravit4iuj)yp 6gh0 ly5eg 0ty 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 ;bex m2taf 7eh4oi 0p5m/s on the surface of planet X where the acceleration due to gravef;i ep074 2b5hoxm atity is $1.5 \; m/s^2$. How long does it take for the object to reach the maximum height?

  An object is thrown upwh7) dx/r6*v gq+ibzhbc dl 37tard with a speed of 15 m/s on the surface of planet X where the acceleration due to gravity is r v/) dzh 6cb7di*73lhxb+ qgt$2.5 \; m/s^2$. 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 owcu-0bjb8+ * igli-b sf planet X where the acceleration j *si -w+uic8gb0b-bl due to gravity is $3.5 \; m/s^2$. What is the speed of the object after 8.0 s?

  Human reaction time is usuallyd.g/dluc*8 b x greater than 0.10 s. If your friend holds a ruler between your fingers and releaseuxdg*8/c dl b.s it without warning, how 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. What /(; jx fkjpj*9w4jqxt is its velocity after 3.px ;t4/*jjwjq9j( fkx 00 s?

  A bullet shot straight up returns to it dxow- h0jij.xp3ju/ .s starting point in 15 s. What is the initial speed of -/hwjui .x poxj03jd.the bullet?

  A ball is thrown straight up with a speed of 36.0 m/s. Hopa nl:q b7e9h-gwaxwq.*g6t 5w long does it take to *qg:-. qt h56nalwp7ax9bwegreturn to its starting point?

  A ball is thrown downward from the top of a building wit,tr* ;sp )ezcd1ig. w burea:s)x.:ubh an initial speed of 16 m/s. It strikes the ground after 1.7 s. *tu:)icr se psbb)xe. audrg ;: 1.w,zHow high is the building?

  A ball is thrown straight upg9.t 7o v6pph1 wutf,y with a speed of 30 m/s. (only fill in numerical value in the blh9,g6 p1uof ytvpw. 7tanks)
(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 p+gai2-ci2-at0x tiu7uomm i0 sxd 0f5jw, s4air with a speed of 39.6 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 2 seconds later.  (数值)  $m/s$
(e.) Determine the time at which the ball pass a point 7 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 7.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is the velocity at tb.hx. dwi9n :o = 1.0 s?

  In Fig. below, what is the veloc--na6dgpjy mc /d (ze2ity at t = 2.5 s?

  In Fig. below, what is the velocity a yx( w. k7(oi.z8uoxgih8 .lljt t = 4.0 s?

  In Fig. below, what is the velocity at t = 5cc.u8 sg9(m: 7uw lav*3hlvkj.5 s?

  In Fig. below, what is the average velx t:i . u79xcikp4cvk7ocity from 0 to 4.0 s?

  In Fig. below, what is the average velocity fz2bc( ndst )8qrom 0 to 6.0 s?

  In Fig. below, what is the acceleratifspy jt 8r:8v3e +i(ajon at 1.0 s?

  In Fig. below, what is the acceleratiopmw6)eh y4uedyga axse/,/)5 n at 3.0 s?

  In Fig. below, what is the averawnj+b *8j; kp tf-n.bmge acceleration from 0 to 5.0 s?

  In Fig. below, what is the average acceleration fl4j da s1*bx5 byq2et,rom 0 to 8.0 s?

  In Fig. below, what is the displacement from 0 to 8dco l1r(apzi l9m:hhv2ox.- 8.0 s?

Does a car speedometer measure speed, velocity? {speedvkgu+wr)/g: :y*wzof |velocity}

  An object can have a varying speed i0fc-cbxe.(v flnkyj(c ,-, khf its velocity is constant.

  The velocity of an o) z0xp(xs;khv bject can be negative when its acceleration is positive.

  If one object has a greater speed than a second objectm.,unb1drb g 9h 8oi2w, the first must have a grea,bdw281.on rb i9g umhter acceleration.

  Two cars emerge side by side from a tunnel. Car A is traveling with a speed lxg :;e9zbxdj fq8nz3x)2c;rdl0 x3 iof $60 \; km/h$ 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 speed as its acceleration d w3qug3a(4hy(;pzvi xecreases.

  A baseball player hits a foul ball straighty-vrk;,u ben ) up into the air. It leaves the bat with anb;)- vykeur, 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 sp-k1qutl pvzoi1a a,),eeds up, what is happening to its acceleration, how does it change if airq)l1,azp ut1kaio v ,- friction is ignored?

  As a freely falling object+705p0z iuz 7cssly-n8 x jtimw6)sb t speeds up, what is happening to its acceleration, how does it change if air friction CAN NOT be ign0syn )ilm6 isuj c7-75t8zp0z s+x wtbored?

  An object that is thrown vertically upwaxmfe , app-4;b.6sglbrd will return to its original position with the same speed as it had initially if air resistance is negligib x;g-6s bapm.lebf 4,ple. If air resistance is appreciable, how will this result be altered?

  An object can have zero velocity )lj;t1m1 l tmcand nonzero acceleration at the same time.

  An object can have nonzero ve6r ;lggeui2 o/locity and zero acceleration at the same time.

  An elevator moving from the second floor to the fifth floor making no sf6;31dr lba4 va 5fqbux7w9dftops along the way has zero accel65dqfalav;w x 9b 47r3fbudf1 eration all the time.

  A rolling ball moves fromxrx v tp(zkj1ccyj w7/9qe5j -:irr//p2bvk* $x_1=3.2 \mathrm{~cm}$ to $x_2=-6.2 \mathrm{~cm}$ during the time from $t_1=2.0 \mathrm{~s}$ to $t_2=5.2 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-2.2 \mathrm{~s}$ is at $x_1=2.4 \mathrm{~cm}$ and at $t_2=3.2 \mathrm{~s}$ is at $x_2=7.4 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps around a quarter-mile (5 ux:ados9a o/ ril:m3mxc9+- an27 sv(fruon$1 \; mile = 1609 \; m$) track in a total time of 7.7 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 strn xzwb+j5 fg*(aight line, moving 97 m away in 11.6 +z5gj fnwb*x (s. It then 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 fro /0o ); shd*4k(a fllg)ks-rcir hco;om $10 \; m/s$ to $23 \; m/s$ 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 fros0;edqv4wlf48 vvq a:m $18 \; m/s$ 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:zr qcai1 2i8l:gdd*k0rv*v y of $33 \; m/s$ 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 outilcd+27 y,cto b; kw1)dnbbx* of the blocks to essentially top speed abouwy o2 cxcktbdi n;7ld b)*b,+1t $10.4 \; m/s$ in the first 14.9 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 unifso(qp,o kv g/:fn* oh,ormly from a speed of $16 \; m/s$ to rest in 4.02 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 h)nt*x/e7s 5eiqf9egwighway. Assuming a decelerati ei*qee)n 79sgt wf/5xon of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck goiz;h e.1-hmg -;m)hven a 9uaqwng $25 \; m/s$ 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 than5nz*f n. +ttvm 30.0 min. After exactly 27.0 min, there are still 1100 m m5nvn*f+ .ttzto go. The runner must then accelerate at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$