Suppose that an object travels from one point in space to av+k hl0e ;-cmdnother. Make a comparison between the displacement andl+ev- k;hd0 mc the distance traveled.

  When is the average velocity of aer8shwg(o ivxw599iqd+ t02 yn object equal to the instantaneous velocity?

  A new car manufacturer advertises that t5g:u:d x5ht( ueg)v buheir car can go "from zero to sixty in 8 s". This5 (e5vu :)tx:uggudh b is a description of

  An object moving in the +x axis exp(i0,p i ceelo8eriences an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x directionj mzi(:* 58 utsig8maue0x/ gw) begins to slow down as it approaches a traffic light. Make a statement concerning its act a8(emzsu* m5 0iiw 8g:g/jxuceleration.

  Suppose that a car traveling to the West (-x direction) begins to slow down as ifs bza / 9*a7s c5vnwqi5n24ydt approaches a traffic light. Make a statement concernf5745vc nyas*n29 bwaiqd/s z ing its acceleration.

  Suppose that an object is moving with a constant velocity. Make a f;9yhnqt9x d c :cpao*4 :mwt9statement conce*9:99odm wcc4 hqa nt;:fxptyrning its acceleration.

  If the velocity of an object is zero, does it 0(q apf wppyb;;js3+sc et(h/mean that the acceleration is zero? Support your answer with an s3q jbpa;(/phe wf0 ts(c+y;pexample.

  Can an object's velocity chag *h;pjmt/4grjk 0jdq 6go0a7nge direction when its acceleration is constant? Support your answer hqa70jr;k6/mjg 4g0tpo g*d j with an example.

  Suppose that an object is moving with cojhu0lky.utp250 r vtb+s c2z0nstant acceleration. Make a statement concerning its motion with r .0y bkhszc+tputu20l2 5j0 vrespect to time.

  Can an object have increasing speed while its acceleration ;d j5xis0bb2m . fao+yis decreasing? Support your answer wit2md 0; ofx ajb+sy.i5bh an example.

  Suppose a can, after an initial kick, mon0 r:mqa4b-o mves up along a smooth hill of ice. Make a statement concerning it0 rm-bnoa:q m4s acceleration.

  Under what condition is average velocity equlsd1 r rd ct1pni6m36+al to the average of the object's initial and finalm16d3p src+6l inrd1 t velocity?

  Objects A and B both start at rest. They both accelerate auw 1if,c/3aklt the same rate. However, object A accelerates for twice the time as object B. Whu31alw fci,/ kat is the final speed of object A compared to that of object B?

  Objects A and B both start from rest. They both accelerate at the same rate. ,m idu4c+:sp fa0r8ykr wo+lo-y x:y- However, m0,ixfr-+yp:8lwr d+kysao -4y:uco object A accelerates 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 i(c3acnmow72sbcvp t0splm ) n.q4 6,j n the absence of friction, which of the following is true nj0)4co ctqpmbw7c m,2p.(na6s v3 lsconcerning its motion?

  When an object is released from rest and falls in the absence of fr:mj )p +(2ssjn xn8ynmiction, which(snx m :m2y+j)p8jsn n of the following is true concerning its motion?

  Suppose a ball is thrown straight up. Make a statement j/yycxf0q :q- about the velocity and the acceleration when the ba c0-fyqjx qy:/ll reaches the highest point.

  Suppose a ball is thrown straight up. What is e+ bfhhxi5t16 its acceleration just before it rbx+5thfie1 6 heaches its highest point?

  Suppose a ball is thrown straight up, reaches a maximum height, then4,cer 0 uthe+w3x/c8/r gopcm falls to its initial hp 0h /rc 4xemectrgu+3cwo8,/ eight. Make a statement about the direction of the velocity and acceleration as the ball is going up.

  A ball is thrown straight up, reaches a maximum hi e *kx3zmodr* s+p,v8eight, then falls to its initial height. Make a statement about the directionmerd zik,s3ov x8*+p* of the velocity and acceleration as the ball is coming down.

  Suppose a ball is thrown downward in the absence of air pc 8xdd9hv4zpvi 65h; resistance. Make a statement concernp56hcvxip4 ; zv 98hdding its acceleration.

  Suppose a skydiver jumps from a high-flying plane. What bu /olrjyj4- 2is her acceleration when she she reaches terminal velociy j2-/u4 lojrbty?

  A ball is thrown vertically upward with a speed v. An ep.pun*dg6mm;lyn0t3)h to/ 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 mhol 6/0 d*mytue )pg.;npn 3tthat 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 a building. One second later, bal/4p;jgwf-nsj iu) d 7ez+dob (l B is dropped from the same building. A7gbud-/zf s)jw+ i;enjd( o4p s time progresses, the distance between them

  Ball A is dropped from the top 2no ;-gwymuj(yx :kr)of a building. One second later, ball B is dropped from the same building. As time progresses, the difference in their yjy-r2u xgk)wmn;(:o speeds

  Two objects are thrown from the top of a tall building. One is thrown up, a rfi rly6999dpnd the or6 lrp i9yf9d9ther 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 thrown straigu j + y0jrg** //q,lju mqmg+q58oalejht down from the same building. They are release mej0/+y+ *lru 5o *jl q/uq8g,jqamjgd at 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. Thby2fn b j.9,txe position versus time gf2, 9nxt.yb bjraph of this object is

  An object is moving with constant non-zero acceleration in ygnup; f0yd2,o c7t:e the +x axis. The position versus time graph of th tf:0 n,e2gycd;y7puo is object is

  An object is moving with constant non-zero velocity in the +x axis. The veloc ,*.p)43pq lr0d 6kstuxegediity versus time graph of this objedkpetuxs,4dl)e 6q0 .p i3rg* ct is

  An object is moving with constant non-zero acceleration in the :r73bsj ls/;luo d lhl h;it w7sj+)b/+x axis. The velocity versus time graph of oj7l):;brlliw/lu 3hb shjs+ /s;td7this object is

  The slope of a position vevu7uq,am ujj v51-,lmrsus time graph gives

  The slope of a velocity ve2zjpugqxx:(fbc7)dywj 1. ; lrsus time graph gives

  The area under a curve in an accelerag4*8x+ bk meeo vq,wl5tion versus time graph gives

  The area under a curve in a /fio1wej.hyf* 60nf yvelocity versus time graph gives

  If the position versus time graph of an object is a horizontal line, the objqnq:h o;g+1znn*l7u j ect iso1n :z+jg qn;hq* ln7u

  If the position versus time graph of an objey;4( hae en7*m-xfgrcct is a vertical line, the object is-h; (7yngcxe4r fm ea*

  If the velocity versus time graph of an object isc s3/gana+ er4 a horizontal line, the object isc4aeg r 3/n+as

  If the velocity versus time graph of an object is a straight line making ap 8mnyazp84-vdlhf+( n angle of 30 degrees wihfm4da8 z ( nyv+p-p8lth the time axis, the object is

  An object moves 15.0 m npp+81j tyoqi4gd:/r north and then 11.0 m south. Find both the distance traveled and8g/d1qntrpyj:i p o+ 4 the magnitude of the displacement vector.

  A boat can move at 30 km/h in still water. How long will it take to move 12 km ,fmff9 g b)kg qhl18oo fq3+n5m)g 3hfn,glo+1fq8o q 5f 9kfbupstream in a river flowing 6.0 km/h?

  55 mi/h is how many m/s? (1 mi = 1609 giw3u2g79c56xjkv )v jr :cffm)

  What must be your averapk/)bfzj+cooldc/y6b xy.*6b 5l0 fo l 2zq9age speed in order to travel 350 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 km) in y ( qsq+ q5w (:x7m+uuzcurdw22 hours and 57 min. What is w u+qduq z:m25 cw(y(7sr q+uxthe average speed of the runner in m/s?

  A car travels 90 km/h. How long does io8 8wcil .i8/(stah vlj p 7rsxczg394t take for it to travel 400 km?

  A ly (light year) is the distance that light travels ilpnnp5 0i1 sf1n one year. The speed of light inpp 11 s5fi0nls $3.00 \times 10^8 \; m/s$. 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 look to the s deyb 8(akmjj;3/q b9mide for 4.0 s, how far do you trj3;em9qbdm ya( / bkj8avel during this inattentive period?

  If you run a complete f-fxtj+6 gc4aloop around an outdoor track (400 m), in 100 s, your average4a- g f+xfctj6 velocity is

  A polar bear starts at the Northzfwld: qanl.(qwp9k20)1z d b Pole. It travels 1.0 km south, then 1.0 km east, then 1.0 km north, then 1.0 kma1qlq:w)bf9 2p l0zw(n d.zdk 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 1d9 y(zd;cwm-ma g s2t57 lh2nh.0 km east, then 1.0 km north, then 1.0 km west to return to its starting point. This trip takes 45 mim w s5mz7aldnh9 -(y2d; 2gcthn. What was the bear's average velocity?

  You are driving home on a weekend from school at 55 mi/h for 110 miles. It.ye ksg se0 .dyaad.rs:lbsmn14)s8+ then starts to snow and you slow to 35 mi/h. You arrive home a 1aa n8edy sreyss).+.gsm.dl0:s k4b fter driving 4 hours and 15 minutes. How far is your hometown from school?

  A motorist travels 160 km vwmuep -+7lf3 +3gd hfxc)zu *at 80 km/h and 160 km at 100 km/h. What is the average speed of the motorist for thvu)33xw*ldfmu+cp f+ -7ze gh is trip?

  A motorist travels for 3.0 hm c/(l9 9gndef at 80 km/h and 2.0 h at 100 km/h. What is her average speed for the trip?m 9n9cl (ged/f

  An airplane travels at 300 mi/h south for 2.00 h and tim 6ozp/b qrjy)ec7: 5 -) s,bailty0ehen at 250 mi/h north for 750 mio/rs ej6q a57 te i cbzbpymli,0):y-)les. What is the average speed for the trip?

  In a 400-m relay race the anchorman (the person w yh-(3g,yy5 73u mikpyyavzji;9( hzdho runs the last 100 m) for team A can run 100 m in 9.8 s. 3a y(7pu -ivj,;yhk( y yzgid95my3zhHis 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 race, in order that the team A runner not lose the race?

  A car decelerates unifor 8 f3hxojfwi*j 9+ip8cmly and comes to a stop after 11 s. The car's average velocity during dei8jo+ cf f 3hwj9x*i8pceleration was 34 km/h. What was the car's deceleration while slowing down?

  An airplane increases its speed from 100 m/s to 160 m/s, at the average rtj(/vu(aac 3l 42 gbyeate of av(etb3(lcu j2g y4 a/$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerates at rua) i k/mw.1pthe 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 at -zf1 xu 9wmz+w$4.0 \; m/s^2$ 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:tva*- 4 g7fnyjk .jri constant acceleration jf krt*4:ag 7i. vn-yjof $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial veloc .ppji5qlw9 hh1ut 7m ;x,qw+aity of 7.1 m/s experiences a constant acceleration of mp+wxli u; q .ap971jhwt,h5q$2.5 \; m/s^2$. What is the cart's displacement during the first 9.8 s of its motion?

  A bullet moving horizontally to the5 (4t/s -jc cb1akjarx right (+x direction) with a speed of 314 m/s strikes a sanj5bx tc41ck- r( s/aajdbag and penetrates a distance of 52.82 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult ovs2+:j ot95kd9d77uy c)apj(yc l *s3jfuhdrn an aircraft carrier. It reaches a speed of 42 m/s at the end of the catapult, and th *cu5atjc r vuo d7:shjf7(+3 s2d)dj9ply 9kyis requires 2.0 s. Assuming the acceleration is constant, what is the length of the catapult?

  A car starting from rest moves with constant acceleratio:6m8; 0t:fta flarl.dd-hvxor ps7b )n 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 n p:25g,z l.(b-tyznu 1b ju1slmpqe7a distance of 200 m. What is its average accelezep,npsn2 y1l5ugjz bqu. tm7l 1b- (:ration?

  An object starts from-rcpd 9v 7s6ox rest and undergoes uniform acceleration. During the first secondx9d pvc-s 7or6 it travels 7.8 m. How far will it travel during the third second?

  An object is moving in a stra,z9 xqcacn+ x-g,)hiaight line with constant acceleration. Initially it is traveling at 16 m/s. Three seconds later it is traveling at 10 m/s. How far+hqgz) aac 9nx,c -i,x does it move during this time?

  A car starts from rest and acceleratkpik:)x/o:ow0ubmv ;es 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 dry road can decelerate at wa*fwsz/g)k; 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 t0 5--,rfho jd2kkqqjhurns green, a car that has been waiting at the intersection starts ahead with a constan -rqj5o ,k- k20hqjfhdt 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 upwafclaru /uy6m56d(u : ard with a speed of 12 m/s on the surface of planet X where the accelerlrc6u:d fyu(m/uaa 65 ation 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 12 m/s on the oft.y 8mli*ra-ude2wi8 ye ;3surface of planet X where the acceleration due to gravity isw etdrmy; 8eoi a.luy8i32f*- $1.5 \; m/s^2$. 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 ;g .ecuksq9.oe surface of planet X where the accelerse.9c. ;q kguoation 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 o)my8ju1 v2gzr cs.5cy f6-mwq5 r+burf 14 m/s on the surface of planet X where the acceleratcm-m.r8w2rczu jy )qs +vu55gfr1 6byion 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 6 y9(qp)splcz 0tr(g y0.10 s. If your friend holds a ruler between your fingers and releases it without warning, how far can you expect the ruler to fall befor (0y srg)6lyp(zpc 9qte you catch it?

  A ball is thrown upward at a velocity of 19.6 m/s. xe6jx b ,qr07m xbeucmv*wsz)-6w )f8 What is its velocity after 3.08sx* ejfu-6 0b,mmw6c)ewxv7 )bzxqr0 s?

  A bullet shot straight up returns to its starting point in 9 (m*tj8di *b qss. What is the initial speed of theb(m*dtiq* 8sj bullet?

  A ball is thrown straight up with a speed of 36.0 (x9nq s)g (p3b8,ycjc .lbrbtm/s. How long does it take to retbyrbqpc lcx39.stb j,8n(g) ( urn to its starting point?

  A ball is thrown downward from the irkl,0obm fq kkg:);4top of a building with an initial speed of 23 m/s. It strikes the ground after 6.1 s. How high is the f);r,qikg bk o0:ml4kbuilding?

  A ball is thrown straight up with a speed of 30 mpu)db uz6-lm dr)9 2rj/s. (only fill in numerical valu6d)zrrlp- 9ju)m2bd ue 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 witj ):60bm -vel hz+vbuhh a speed of 36.6 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 1 seconds later.  (数值)  $m/s$
(e.) Determine the time at which the ball pass a point 13 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 13.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is the ve ep 2ah)tez*d3/qcn r6locity at t = 1.0 s?

  In Fig. below, what is the velocity at t = 2.5 m xl)mg:w (3iqil0+9vujrxond 5in 1.s?

  In Fig. below, what is the velocity at t =3u ) l pou3e.ghl1/rlt 4.0 s?

  In Fig. below, what is the velocity at t = 5.5 2 .yh3yorzmf2oqv: /ls?

  In Fig. below, what is the average velocity from 0 to 1qw mg03- rsxj4.0 s?

  In Fig. below, what is the average velocity from 0 to 6 bv.c t/fc ic*:ufls y**skl01.0 s?

  In Fig. below, what is the accelerati9kthak7mti 86/8tffg on at 1.0 s?

  In Fig. below, what is the acceleration at 3.0 j c+vcwy4 kx *e8nhpo611o- ,eh ora*gs?

  In Fig. below, what is the average acceleration from 0 to ihymkb l;x )(axzh(s1/1w-v z5.0 s?

  In Fig. below, what is the average acceleration from 1;erc 6wq7t q5 2axlzg0 to 8.0 s?

  In Fig. below, what is the dqyr:q . n,clr3*gih:qisplacement from 0 to 8.0 s?

Does a car speedometer measure speed, velocity? {speei vn* )n y0q-pb/3zucvd|velocity}

  An object can have a varying speed if its velocity -u48vlu 3xdup is constant.

  The velocity of an object can be negative when its acceleration is pdp16l nsvgz 3ab*k+ (positive.

  If one object has a greater speed than 6 mx4ou,ww(e3a zt5lchza4db*1as c-a second object, the first must have a greater accele4w m6s3tc15zua 4xe ,*lc( dwoaa- zbhration.

  Two cars emerge side by side from a t rrz2w+ ;yze*/ koo9jeunnel. 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 increasing in speed as its acceleration mv6es(m/.w m8hhs6y gdecreases.

  A baseball player hits a foul ball straight up into the air. It leaves the bat 4d4/:hwqtyk/aw qii1w ,6j zcwith a sdwa, icq 1kw6/ yiht4j4w/:qzpeed 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 (berf1oa,h7hits acceleration, how does it change if air friction is ignor7ha f,( eohbr1ed?

  As a freely falling object speeds up, what is happening tyabw:s :*x(iwo)u iu1o its acceleration, how does it change if air friction CAN NOT be ignored?w*:si(wxyu: aio1 u b)

  An object that is thrown very6k z so:f3k,ado; yb;tically upward will return to its original position with the same speed as it had initially if air resistancd:b,k 3y;sfoy6 z oak;e is negligible. If air resistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzer8hen)j2:s1 jolsi+fu o acceleration at the same time.

  An object can have nonzero velocit) 6hm-g tus)lwg 6av4uy and zero acceleration at the same time.

  An elevator moving from the second floor to the fifth floor making2uic e*0 9cnbo7dr .xyd9inl6 no stops along the way has zero02i9x.l9 7 yccbre*u ddnn6io acceleration all the time.

  A rolling ball movesr(x i6cv-zt (u from $x_1=2.8 \mathrm{~cm}$ to $x_2=-5.9 \mathrm{~cm}$ during the time from $t_1=1.1 \mathrm{~s}$ 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 $t_1=-4.5 \mathrm{~s}$ is at $x_1=3.3 \mathrm{~cm}$ and at $t_2=3.4 \mathrm{~s}$ is at $x_2=8.0 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps around a quar -.z,0ebnt4x i4x3 kg7cej vrdter-mile ($1 \; mile = 1609 \; m$) track in a total time of 9.1 min. Calculate (a) the average speed  (数值)  $m/s$ and (b) the average velocity    $m/s$

  A horse canters away from its traineg -zw5zz: nn8kildx-* r in a straight line, moving 101 m away in 11.7 s. It thenz gl*i8d n5x-n zz:-kw turns abruptly and gallops halfway back in 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 from o( rm16y ij2ib rp.1:jgyklc5$12 \; m/s$ to $25 \; m/s$ in 5.9 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 fro/wk8o.s e8vcn m $20 \; m/s$ to rest in a distance of 76 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a speed off+xf.r hcz8 s+zw2a /y $28 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.4 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of the blocks to essentially top speel-w*zn2s2 5vyzt 8k vvd about yz2-n zkstlw v2v*5v8$10.8 \; m/s$ in the first 10.0 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 ake3+ h5 ij9 cavgv:9du speed of $19 \; m/s$ to rest in 5.00 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves skid markl /;5yir2;cr bonyl5(h; behds 92 m long on the highway. Assuming a deceleratiod( ; l5/;rc2nyhoey5b hbr;iln of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck(g un -z6j ihwrr,u3h3c5cz- p 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 leshp/-afnw14 +:mf auizs than 30.0 min. After exactly 27.0 min, there are still 1100 m to go. The runner mu14fum+-wia p/: hzaf nst then accelerate at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$