Suppose that an objectf6m+yr /km:bge 0u*a o travels from one point in space to another. Make a comparison between the displacementro+ag*6 bm ku:fe/0ym and the distance traveled.

  When is the average velocity of an object equal to the instantaneouto9i, .mqyh *ws velocity?

  A new car manufacturer advertises that their cl, r9y8wqyfqth z 9t70ar can go "from zero to sixty in 8 s". This is a descriptio9 w8 r,hq7z90f yttyqln of

  An object moving in the +x axis experiences an acceleration of klb5+ 7oqozt,;b;tqlv 6zw/ j$2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x direction) begins to slowqe:y n5zsw8d s ,*clb7 down as it approaches a tr ew* scndy8sq,:5lzb 7affic light. Make a statement concerning its acceleration.

  Suppose that a car traveling to the West (-x direction) begins to slowm(;s ehvi ly,. down as it approaches a traffic light. Make a statm (,y vhe.li;sement concerning its acceleration.

  Suppose that an object is moving with a constant velocity. Makef3htf 28+ia,tm dgn p- a statement concerning its acce8dni-3a2f+ g,tpfm t hleration.

  If the velocity of an object is zero, does it meaau .2f/:yg.k sql0d kpn that the acceleration is zero? Support your/q.ky.ldu2 fas gk:p0 answer with an example.

  Can an object's velocity change direction when its acceleration is cd cc)l6:pqrq 5onstant? Support your answ cq6qdpr cl5):er with an example.

  Suppose that an object is moving with constant accelera3 ueg wj9bp)m9tion. Make a statement concerning its mo gju 9p93wmb)etion with respect to time.

  Can an object have increasing speed while its acceleration is decre xk22cubdr 80-brk4j) u flde6/vi4lgasing? Support your answer wxd8jc6drv2 2li4rubule) gk 0kb - /4fith an example.

  Suppose a can, after an initial kick, m4.v/c1 sas6yg inw -f9d(cqlh 7+d wxr(et5qooves up along a smooth hill of ice. Make a statement conceriw6qslq/e c(a7+w5 n g v4s.r 9fdy-c1d (xthoning its acceleration.

  Under what condition is average velocitklf.x04v l u.iy equal to the average of the object's initial and final . lxli4kv0fu .velocity?

  Objects A and B both start at rest. They both accelerate xl)n/i f trs 7wuo1y+/o82wtz at the same rate. However, object A acz1/xrti yf8n) tsl/ou +27wowcelerates for twice the time as object B. What is the final speed of object A compared to that of object B?

  Objects A and B both start from rest. Theuq n.ta:7bs8sc+g hc5 0qo3qby both accelerate at the same rate. However, object A accelerates for twice the time as object B. What is the distance traveled by object A cgsq83:a . q uscn7+bo 0hcbtq5ompared to that of object B?

  When an object is released from rest and falls iaboyt rj6,g;7 tm-v4jn the absence of friction, which of the following is true concroj ,7tyv-4tbm;g ja6erning its motion?

  When an object is released from rest and fal (wwdxtbgg-:4 ls in the absence of friction, which of the following is true concerning its g:b g(wx4-tdwmotion?

  Suppose a ball is thrown strauk 9(nfhu7we,d 9qk 2sight up. Make a statement about the velocity and the acceleration when the ball reac 92,fwnk(ku9dh uq s7ehes the highest point.

  Suppose a ball is thrown straight up. What is its acceleration)zoqzz; 9o6ip just before it reaches its highes9zo zi6)zp; oqt point?

  Suppose a ball is thrown straight bi s6lo2)pgyp,q6di ,up, reaches a maximum height, then falls to its initial height. Make a,,ip6i )6sqd oplgby2 statement about the direction of the velocity and acceleration as the ball is going up.

  A ball is thrown straight upsdtmr ay6h8 p)z5 y36smvkr :7, reaches a maximum height, then falls to its initial height. smrhm v)k:8z6ry53t7y6ps da Make a statement about the direction of the velocity and acceleration as the ball is coming down.

  Suppose a ball is thrown downward in the absens52 kloay(c 7ace of air resistance. Make a statemy( sc2ok7 5laaent concerning its acceleration.

  Suppose a skydiver jumps from a high-flying plane. What is her acceleration l:*xe -v l-/spli 5gdpwhen she she reaches terminal velocity?- e:s*l-lld/px5pig v

  A ball is thrown vertically upward with a speed v. An identical second rz n1mq7 7bc0dball 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 higher does t 1q d7mn7z0rcbhe second ball go than the first ball?)

  Ball A is dropped from thef)3yydj ) 9gsx top of a building. One second later, ball B is dropped from the same building. As time progresses, the distance between thefx3y y gd9j)s)m

  Ball A is dropped from the top of a building. One sr0 ak5dxx,og 5econd later, ball B is dropped from the same building. As timr, 50xkx5dgoae progresses, the difference in their speeds

  Two objects are thrown from the top of a tall building. One is thrown up, anh+0cz-ahoby6 d the other is thrown down, both with th-+zbo 6c0hhay e same initial speed. What are their speeds when they hit the street?

  A brick is dropped from the top of a building. Ap0yksxy:63vz6 v pdv9 second brick is thrown straight down from the same building. They are released at the same time. Neglect air resi9kv0d6:yzvpy vs 6px3stance. Compare the accelerations of the two bricks.

  An object is moving with constant non-zero velocity in the +x axis. wwysovzkz*x :k0z70; 4f s t;iThe position versus time graph of this object0*ysz: kzkx;7f w;t0zovs4 w i is

  An object is moving with a9cnl -h( 7(fxh(faxm y9r 7yyconstant non-zero acceleration in the +x axis. The position versus timry7((79ha(ylfa-n 9 x xc fymhe graph of this object is

  An object is moving with dasklszo4o6jnm1 qc,3 /4a.q constant non-zero velocity in the +x axis. The velocity versuss nosl436a m4qaz/1ok cd,.jq time graph of this object is

  An object is moving with constant non-zero acceleration in the +x axis. The vuqrnnq/mgb s/.*a2jgoda)8fci d ;26elocity versus time graph of this obje6argsbdin f .) 2ogd ;uancq/m8/qj*2ct is

  The slope of a position versus time uk+vsu2ihzj bm+(s34ao.;t sgraph gives

  The slope of a velocity versus timev.;sh vhk vs:;ncqxn+c 5x:*m graph gives

  The area under a curve in an acceleration versus timh7eg)ds 59uy y o7o.cee graph gives

  The area under a curve in a veloxbix37,el.xjwfl 0 y1city versus time graph gives

  If the position versus time graph o3 nc 3bb.8rnxvj*s5qcf an object is a horizontal line, the object 8j* . bcn3xbvrsq3 n5cis

  If the position versus time graph of an object is a mmxx7,v7i o5 5s d3lrotp-.b hvertical line, the object isd7oh7p35x trlm5,. bsmov-ix

  If the velocity versus time graph of an object is a hor8 kt 63 z uan4ho+1a7:ejd4e dnynyq5dizontal line, the object isnhn1 5+u7z8 4j4dya6:e qt ekdyon3da

  If the velocity versus time graph o x8w0vf4kq/+ tgd68cbzwxtz8f an object is a straight line making an angle of 30 degrees with the tim8w8 04vz6k8/x zq +txt dbcwgfe axis, the object is

  An object moves 15.0 m north and t )g9w mxtkz rlk.wmcpgk:;y2m; ua-5 y)+sdu:hen 11.0 m south. Find both the distance traveled and the magnitpg5du; ws:2ac rg- ky)wm yml9+;) :zm.u ktxkude of the displacement vector.

  A boat can move at 30 km/h in still water. How long will it tak ;)bbykhr r g-whv,bs29.j a0je to move 12 km upstream in a river fy wahb- r9 jk20;rj.bbs hg,v)lowing 6.0 km/h?

  55 mi/h is how many m/s? (1 mi =ec( *)w2 jjejb 1609 m)

  What must be your average speed in order to travel 350hrwg7)ox9r (*mde el( 8)tyq a km in 5.15 h?

  A runner ran the marathon (appi/-t+l0l9r1i y:sz0gl x pypproximately 42.0 km) in 2 hours and 57 min. What is the average speed of the rup is trlp:pyi+ x/lzy0 1gl09-nner in m/s?

  A car travels 90 km/h u7h kj5ab6o;j. How long does it take for it to travel 400 km?

  A ly (light year) is the distance that light trhsjl),nqd y ;k o6 p7jftr99-/ioryr+ avels in one year. The speed of light isyrhp nt r jy;q9,i-d9+kj/l ro)o76sf $3.00 \times 10^8 \; m/s$. 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 loj43u g 9fxna7ook to the side for 4.0 s,fa49u nxo g3j7 how far do you travel during this inattentive period?

  If you run a complete loop around an outdoor track (400iwi -x)n,hzhs3l)p9h m), in 100 s, your average vel)sh xii )3 n-,9pwhhzlocity is

  A polar bear starts at the North Pole. It travels 1.0 km south, th6:jv k9 vxun :e,mnj6len 1.0 km east, then 1.0 km north, then 1.0 km west to return to its starting poi: knxuv 6j6em9,n:j lvnt. This trip takes 45 min. What was the bear's average speed?

  A polar bear starts at the Northohw 7tj h.,zt x5lzy7+mh, .au Pole. It travels 1.0 km south, then 1.0 km east, then 1.0 km no,75mz. +h7owlx jatu z,thy.hrth, then 1.0 km 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 se kzru42 lwtou7 ,h14mchool at 55 mi/h for 110 miles. It then starts to snow and you slow to 35 4 km 7,zro1 u2lh4teuwmi/h. You arrive home after driving 4 hours and 15 minutes. How far is your hometown from school?

  A motorist travels 160 km at 80 ;jxuiwi 7r7sxw+ s;4akm/h and 160 km at 100 km/h. What is the average speed of the 4 sxu;a7wjiwx+is 7r; motorist for this trip?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h. What is her aver(nj p vbwru7v /w-,7pw7v b/u,nwpj-vr (w pw7age speed for the trip?

  An airplane travels at 300 mi/h south for 2.00 h and then at 250 mi/h north for yj*x kdp -xw3175wx*jxk-p31 yd0 miles. What is the average speed for the trip?

  In a 400-m relay race the anchorman (the p-a4- :bjw ula/e w(lzz:z6draerson who runs 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 have when the team A runner starts the final leguza/z(dlwbj w6ra:ze4a l- : - of the race, in order that the team A runner not lose the race?

  A car decelerates uniformly and/ i+bhkzyx:h + comes to a stop after 13 s. The car's average velocity durinkyxbh/z ++:ihg deceleration was 76 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 rate o2h1 w+qfnryr- f w2rry+qh1 -fn$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h acceleramv9(a-xngn3i30 cqh xih+e+i tes 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 rest and acceleratey01 lvg2lnt+t s 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 consta m7gi*-tkijmhntsfe ,g (k38gz8 0pi.nt acceleration of8khp *3kt im-0gt nigis.mz,7fe 8(j g $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocv -gxme1 .+e,vnhql /7zam p7pity of 3.6 m/s experiences a constant acceleration ofvv +l- p.a ez/xhem n7q7p,m1g $4.8 \; m/s^2$. What is the cart's displacement during the first 6.4 s of its motion?

  A bullet moving horizqenifsq 3(p2 .gkp* l4ontally to the right (+x direction) with a speed of 228 m/s strikes a sandbag and penetrates a distance of 37.99 cm. What is the average acceleration, inql3 fpe(g*qn.kip s42 $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on an aircraft carrier. It y,1q- 0 ieu klvli)j*lreaches 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 length ofv iu)yle i*lk0jl1, -q the catapult?

  A car starting from rest moves with constant ac:7nkk zo4rvz t+w1y1 cceleration 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 dista; ,fal 4/.vc0 qicb zlbo8zk6once of 200 m. What is its average acceleration?fo z/8 c;0.lao6cbiv,4kq lzb

  An object starts from rest and undergoes uniform :b7fsxwehkn5nna41 (acceleration. During the first second it travels 7.5 m. How fx ( n n17:4heb5ksnwafar will it travel during the third second?

  An object is moving in a straight line with constant acceleration. Initiall8) 4mlil/n fbry it is traveling at 16 m/s. Three seconds later it is l4 i8nrl/mbf)traveling at 10 m/s. How far does it move during this time?

  A car starts from rest and accelerates unifp44)9 l df)8kx3-tj ms6sc1ggzvyytoormly 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 alj*l(nvnx rcx s9u 3d,ess5- 1t 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 at the-324v0kxxs3fcz hwch;c c 4sh intersection starts a20 xs3x-whs3c f4z ;chh kvc4chead 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 spum.vn5*ehvwjp5 .jx /eed of 12 m/s on the surface of planet X where the acceleration duemv j.xwnp5 j*v5/. euh 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 surfacenb3* .+ f c9jrok/e4 qgv(irjg of planet X where *3krgj/q4gb+ iv (ofc9r.jn e the 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 withab7g11blvnmr- ylos0v2 m, g. a speed of 15 m/s on the surface of planet X where the acceleration 1bg7rno myvsl1mb. a v2l,-g0due 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 of 14 m/s on the surface of planet X wheqkqs9lw, /x,t;b q9ep 12u3dk eim y/br,qqp2k 1m3e/, s /yt9qidwb9el; x ubke the acceleration 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.:(drta7q,6m2afq; 0won2s 0ite lmdd If your friend holds a ruler between your fingers and relq0se :ad idf6,own2 0 a;(mqd27ttlrmeases 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 is its yu+h 0m jfwad2*z, 2r:zt al99lh6byuvelocity after 3.00 jz 9*62l+ya :dh9bl 0,yfrauwhmtz2 us?

  A bullet shot straight up returns to i 9mt*b m h2abzn8.ir;gts starting point in 18 s. What is the initial speed of the bullnr.z ;tg *i a2mb8mh9bet?

  A ball is thrown straight up with a speed of u1d a+,asx bzi,/ d48umw;fks36.0 m/s. How long does it take to return;4skddau,sa 1 m u+i z/x8bfw, to its starting point?

  A ball is thrown downward from the top of a building with an initial speed of 1 d1(nav5uzztmz 7z;z2 8 m/s. It strikes the ground after 5.9 s. How hign; (z vztdzz571za2u mh is the building?

  A ball is thrown straight up with a speed of 30 m/s. (only fill in numeric 79hs/a l7pjsual valjasl / 7hpu97sue 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 with a spnu3v0g+3 qwl8 ljy6yi+df+wqeed of 35.3 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 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 is the velocity at t = 1b s:2jaup 8n a9)cek,s8ez l6-rirv, i.0 s?

  In Fig. below, what is the velocity at t = 2.5 sx)0pfskoljyx c 6n)x8bt (9(v?

  In Fig. below, what is the velocity at hz bw3e1lv- /yt = 4.0 s?

  In Fig. below, what is the vre 1y)9pk ta6celocity at t = 5.5 s?

  In Fig. below, what is the aveuv.vcgh.e8uk o 5a(sbkh (x(-rage velocity from 0 to 4.0 s?

  In Fig. below, what is the averag6yhs *s a8wgnpc9q :h.,6pscae velocity from 0 to 6.0 s?

  In Fig. below, what is the acceleration at 1.0 -a)x 0z5fyna ogyk2iy 3 np9b3s?

  In Fig. below, what is the acceleration*sy :6arudvm- igfys4 +9u (in at 3.0 s?

  In Fig. below, what is the average acceleration frd1(huqbj x;9 bom 0 to 5.0 s?

  In Fig. below, what is the average acceleratioyfi oo 0a v8p7(c8kqd;vk4v 6in from 0 to 8.0 s?

  In Fig. below, what ieab, yirra08oi - r 28qlr;qh9s the displacement from 0 to 8.0 s?

Does a car speedometer measure bod6 f:ziyh,2 0e 6- hr6tiqhgspeed, velocity? {speed|velocity}

  An object can have a varying speefdoedrd;xmd 8fpp,8, c(scs d087nn3 d if its velocity is constant.

  The velocity of an ofd9/e m3dpp 7nbject can be negative when its acceleration is positive.

  If one object has a greater speed than a second obru1.2ta /: taukke0 tpject, the first must have a greater acceletakk/ 2ua .t urp:t0e1ration.

  Two cars emerge side by side from a tunnel. Car A is travelinnpdtbd g+*p 74wy-n5p g 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 acceleratibq6i-; ix3stgk+ 6mf8vmylm 3 on decreases.

  A baseball player hits aiz3cw 7q3w q5t/hin1 y foul ball straight up into the air. It leaves the bat with z7qc35qi/ywht in31wa 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 happeninfv- *8p een;vxg to its acceleration, how does it chan p-f8ee* vvx;nge if air friction is ignored?

  As a freely falling object speeds up, what is happeninl;ll /cayc: .jg to its acceleration, how does ity lcj:ca/.l l; change if air friction CAN NOT be ignored?

  An object that is thrown vertically upward will xy1aj+d8 g m6hreturn to its original position with the same speed as it had initially if air resistance is negligible. If air resistance is appreciable, how wilgmyx1+a j6d8h l this result be altered?

  An object can have zero velocity and nonzero accele b; fi)hlbj1,sration at the same time.

  An object can have nonzero velocity and zero acceleration at the samn4lb uq4d7 i db/yby04d /wz.ge time.

  An elevator moving from the second floor to the fifth floor making no stops aloht8gdy2+bdv 9ng the way has zero acceleration all + 9t yhd28gbdvthe time.

  A rolling ball moves fromib,*5uug fwvc .,p1rn $x_1=1.6 \mathrm{~cm}$ to $x_2=-6.0 \mathrm{~cm}$ during the time from $t_1=2.5 \mathrm{~s}$ to $t_2=5.0 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-2.7 \mathrm{~s}$ is at $x_1=2.7 \mathrm{~cm}$ and at $t_2=3.3 \mathrm{~s}$ is at $x_2=8.0 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight compleg7 9 b;re/x9ze, bllbnte laps around a quarter-mile ($1 \; mile = 1609 \; m$) 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 s/.jdckz i ,mmp5l.zu9traight line, moving 114 m away in 8.3 s. It then turns abruptly and gallops halfway back in 4.7 s. Calculate (a) its average imjz/95 p.z l,duck.mspeed  (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 vm zar.vox0 wj+-*4xia a) 6lj$10 \; m/s$ to $23 \; m/s$ in 5.4 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 from a 6o zb4v-*b*g)l)dhfl r4 pbk$17 \; m/s$ to rest in a distance of 81 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must rea emch99+asb 3gp(xw83 lu qz6jch a speed of $29 \; m/s$ 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 t3 v7dnv ff;wi2he blocks to essentially top speed aboui2 fvw;3n7fv dt $10.1 \; m/s$ in the first 13.4 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 unifo - 6c7fz6j ncraiz,,68 xntvhtso35zimko6 n1rmly from a speed of $20 \; m/s$ to rest in 5.57 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, k5ttaj. *9db 0k1n mlea car leaves skid marks 92 m long on the highway. Assuming a0k5j9dt * .tne lb1kma deceleration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck goincn0bg:xywk2j-+ nl/og $25 \; m/s$ 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).    $m$