Suppose that an object travels from onr0t6 .:2eb:gdjmestsg kv0ki .0 j7qs e point in space to another. Make a comparison between the displacement and the distance travel 6je tde 0.rv:0skmsgktib.j2s7:q0ged.

  When is the average velociz7n dol7u5pg (ty of an object equal to the instantaneous velocity?

  A new car manufacturer advertises that their car can go "from zero tsoe z:0+s2ov eo sixty in 8 s". Th2 zsve so0o+:eis is a description of

  An object moving in the +x axis experien8map u(8f;a jvod5lk /u(rh, vces an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveli*hzxcj *9w ar8ng to the East (+x direction) begins to slow down as it approaches a traffic light. Make a statemen8x9* wjazr hc*t concerning its acceleration.

  Suppose that a car traveling to the West (-x direction) begins )af 4fqg(l,d*tgwa l6 to slow down as it approaches a traffic light. Make a statement concerning its acceleration.( dlfa,at)f6qw g4*lg

  Suppose that an object is moving with a constant velocity. o2 xuls;v-s09 )pugyn 9ixo6*xir a/ s Make a statement concerning itiiaxn-) s vuxxus9*l/og6;9o 0 yr p2ss acceleration.

  If the velocity of an object is zero, does it mean that the acceleration is za x5x,6vlnzq( ero? 5,qvz l(x 6axn Support your answer with an example.

  Can an object's velocity change direction when its acceleration is 8rs 2b pl 4uuw dwj6h2p0fd 7)*gc 2lhhh7ze(nconstant? Support your7( f 24uhzg0wpuwd)d spb2jnh7 2h cehl6* rl8 answer with an example.

  Suppose that an object is movi 1c-xz)hkv 7ls 1mee:tj6zvv(ng with constant acceleration. Make a statement co16vvlzs jh-:z k71)e cmv(t xencerning its motion with respect to time.

  Can an object have increasing speed while i+fc1pau84cas ts acceleration is decreasing? Support your a8aucsc 14afp +nswer with an example.

  Suppose a can, after an initiall* xej8mvtvtb0z0)* y kick, moves up along a smooth hill of ice. Make a statement concernin*t)y be ztm 0xj0v8lv*g its acceleration.

  Under what condition is average velocity zz gmopdj *uw;vf1,2 /equal to the average of the object's initial andoz; 2,uj gp/fzvmd1*w final velocity?

  Objects A and B both start at rest. They both accelerate at the same rate.h9;a ay. *bq0 crc 7-je.oer/au hh+rt However, object A accelerates for twice the time as object B. What is thet r.bo7jh*ea er9hqhc0;r +c u.a -y/a 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 ratei.ed2 vji: bl). However, object A accelerates for twice the time as object B. What)j.e: 2iil dvb is 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 frictio/0xw:p4 km8gr1cft2sp42d 1pisq 0isnu aal8n, which of the following is true concefrs w 08xs2ius a4ciqm4 p p:dg2tp1la0kn8 1/rning its motion?

  When an object is released from reszu ,/yj7tpjq+ t and falls in the absence of friction, which of the following is true concez/,utj y7+p qjrning its motion?

  Suppose a ball is thrown straight up. Make a statement a6lbw/2 b1 pwtabout the velocity and the acceleration when the ball1lb2ba wtpw /6 reaches the highest point.

  Suppose a ball is thrown straight up. What ii/8 wedj +4kg4w un zm 7,q6(gq)rdwcls its acceleration just before it reaches its highest lq6)g d7ri8/qwz nd4mceu(w4,wgjk +point?

  Suppose a ball is thrown straight m*b/ct+i0vf0p 46cp i6n*qib7 ustqoup, reaches a maximum height, then falls to its initial height. Make a statement about the direction of thei fqc 6bmq* tvi046/c*+ tpo70upbsin velocity and acceleration as the ball is going up.

  A ball is thrown straight up, reaches a maximum height, then f7s3s-prjoqx7pt(t, 5 okrw .oalls to its initial height. Make a statement abo,tjxokwpoqso7 -3. prt(rs57 ut the direction of the velocity and acceleration as the ball is coming down.

  Suppose a ball is thrown downward in the absence of air resistance. d4h6k/djiw1 a Make a statemenaj 4hiw /d1dk6t concerning its acceleration.

  Suppose a skydiver jumps f)7 )y e*zudfgwrom a high-flying plane. What is her acceleration when she she reaches terminal fyg 7eduwz )*)velocity?

  A ball is thrown vertically upward with a speed v. An identical second r) gr uu)kjx:i(s p6q3ball 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 high6:q3kgjip(x ) sr)uruer does the second ball go than the first ball?)

  Ball A is dropped from the top of a building. One secondk71mp wm t8f:b later, ball B is dropped from the same building. As time progresses, the distance be1: tmp b8wkmf7tween them

  Ball A is dropped from the top of a building. One seco8i7*-y e ka9 os3*,6 v 01oxmbcaxesecdrkwr 4nd later, ball B is dropped from the same building. As time progresses, thei7w3,m40av ebk -skydxrao*68rsceo * cx91e difference in their speeds

  Two objects are thrown from the top of a tall building. One is thrown 02+tkjgm 3t)t tjc/ec rbi *e4up, and the other is thrown down, both with the same initial speed. What are their speeds m tr3et+4ki/ *g cbj)c ejtt02when they hit the street?

  A brick is dropped from the top of a building. A second brick is thro q((tk0b4 .fzf5g ceo/ia2zvswn straight down from the same building. They are released at the same time. Neglect air resistance. Compare the accelerations of vqzi ftzc2k 0gbae5 fs.((/4othe two bricks.

  An object is moving with constant non-zero velocity in the +x axis. x) *jcpltt koi- bkm;7k).+vrThe position vero.ivlk+ k );-*p bxmt7j)r ktcsus time graph of this object is

  An object is moving with constant non-zero ac0: t4n( ipxvxxceleration in the +x axis. The position versus time gra :0 (itpxxvn4xph of this object is

  An object is moving with constajq g ,k;waqgl5c2 f()znt non-zero velocity in the +x axis. The velocity versus time graph of tcqg(f,g z25qklwj; )a his object is

  An object is moving with constant non-zero accelerati1legs6.,olpi qv9 zl0cip-1 fon in the +x axis. The velocity versus time gr10 o9.l-z q, fiplpcs1ge iv6laph of this object is

  The slope of a position versus time graph giv*/qwk46a eb 8ni+.;kux j hcpyes

  The slope of a velocity vers6ko xj21)t e/; hwrpegus time graph gives

  The area under a curve in an acceleration e m3ut-9x0puquk+)d 7s0dpfzversus time graph gives

  The area under a curve in a velociuqdfw 7qjs)g9jh (3 rpr.+7bc1km gm 7ty versus time graph gives

  If the position versus time graph of an object is a hor (+jf5gp:5gofy+2 vxpzoq 1gnizontal line, the object i gp1gx+:yfg 55njqov2p f(z+ os

  If the position versus time graph of an object is a t :n78tdmg;j1o.zwu i vertical line, the object is: m.jiwgt;n187 duzot

  If the velocity vers g5,)xdt)2pjx w luso(us time graph of an object is a horizontal line, the object is 52)d(glx pu)tj,sxow

  If the velocity versus time graph ofibfx 90*kep7z+ y:mvs j7moy, an object is a straight line making an angle of 30 degrees okym *+yf,x v7b0ej9siz :7mpwith the time axis, the object is

  An object moves 15.0 m 4klbtn u 8rf+ti:7fk, north and then 11.0 m south. Find both the distance traveled and the magnitude of tku87:t trf4f lk+ ,bnihe displacement vector.

  A boat can move at 30 km/h in still water. How long will it take to move jy:9wg 3jl8*kn5r rix 12 km upstream in a river flowingjxw5y:r 3 8l *jk9inrg 6.0 km/h?

  55 mi/h is how many m/fj dc(v5 b +sv,j5xn/rs? (1 mi = 1609 m)

  What must be your average speed in order to travel 350 . het0y(/azklk bl27x//krnkkm in 5.15 h?

  A runner ran the marathon (approximatelye9d h,:4e6d; bywuyop 42.0 km) in 2 hours and 57 min. What is ydho y ;6w9eu:ep 4,bdthe average speed of the runner in m/s?

  A car travels 90 km/h. How long does ihdujgd439o.r t take for it to travel 400 km?

  A ly (light year) is the distance that ld,i,r*nf) w2lm5dm5v3k oq 4 sdhz5f jight travels in one year. The speed of l,f n4d5rvwd3)jmq ko5 ,lsh*5z2mdi fight 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 stro f1 -b1kp4(cyejr,px aight road and you look to the side for 4.0 s, k,xb-j(cf1 ppe4o1r yhow far do you travel during this inattentive period?

  If you run a complete loop around an outdoor track (400 m), in 100 s, your aver..)m q6 o1idx; m5dr5hcu/zo roiifq.age velocityzxqi/d5i mooq.d fc5iu .rm.h)6o1 ;r is

  A polar bear starts at the North Pole. It travels 1.0 km south, then 1. : 8fl+ 6bzewsktvsl/q (b+w4g0 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 speed?e8sgst+ll+kwwb6 :(vb q/4f z

  A polar bear starts at the North Pole. It travels 1.0 km south6,dtn.o0e k w- oxh.ss, 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. .ho. 0n do,ste6sw-kx What was the bear's average velocity?

  You are driving home on a weekend from school at 55 mi/h +f:xg8x01f : uvrh( j9adsvwdfor 110 miles. It then starts to snow and you slow to 35 m9fv:( hgaw1rux :dxd0vj 8+sfi/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 km/h and 160 km;/olw iy oywv- )kfg03 at 100 km/h. What is the average speed of the motorist for this trwg-;oklyfo w/) 03i yvip?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h a omg8ik es.o.t.oxu3(t 100 km/h. What is her average omsx.ot k o3(e8g..iu speed for the trip?

  An airplane travels at 300 mi/h sdbd+ d ug mhet,1+q5n (bp8n)louth for 2.00 h and then at 250 mi/h north for 750n +)d hnqdp 5b+b,(gmletd 81u miles. What is the average speed for the trip?

  In a 400-m relay race the anchorman (the person who runs the last 100ie5ics.dng ;4 m) for team A can run 100 m in 9.8 s. Hi4cg sin5id.e ;s 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 uniformly and c4edbf9vomzk q2 h710womes to a stop after 12 s. The car's average velocity1o4 kbmwe7zf9d0vhq 2 during deceleration was 65 km/h. What was the car's deceleration while slowing down?

  An airplane increases its speed from 100 m/s to 160 m/sk 0xt19re.*um h(wy3 nm. khrh, at the average rate of e( m.90t xk u1yr nm3k.*hhhwr$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accel n /+ykb kuc. k9qz8y;pdt)s6gerates 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 rdgo98 gnrqn1c3 e*aj zwzzg1..:vkv +est and 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 4a2(lq; ws xvh5w0vjy e(j4f ewith a constant acceleration of eeq4shla(5vjf j 4ww2v0 ( ;yx$2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial wanf:,d k.w i.velocity of 4.7 m/s experiences a constant acceleration ofai,dn: .wfw .k $2.1 \; m/s^2$. What is the cart's displacement during the first 8.1 s of its motion?

  A bullet moving horizontally to the ri)9agxwp4htq r h3x0q0q5v*wr ght (+x direction) with a speed of 208 m/s strikes a r5hpg 94thxaq wv rq*wx03 q0)sandbag and penetrates a distance of 25.41 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on an ai8k sduedb/cix q4+z3. rcraft carrier. It reaches a speed of 42 m/si3 +e4k s/dz qxc.ud8b at the end of the 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 constant acc f9vc l2+qldcci-od 2a+o p9v/eleration 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 tot9,kcxg )dn*i 80 m/s in a distance of 200 m. What is its average accelerationi),9 gt*dxc kn?

  An object starts from rest an j d +l(mqg-vyejzba23qk,2b)d undergoes uniform acceleration. During the first second it travels 10.0 m. How far will it travel during the third secon+ qyqv, bde akj l)zg23(j2m-bd?

  An object is moving in a straight line with constant acceleration. Initiallyev7jv7 thmop1su4s : .t 8vc.o it is traveling at 16 m/s. Three seconds later it is trav47pv:v tm eoos hst7v.1.8u cjeling at 10 m/s. How far does it move during this time?

  A car starts from rest and ad5erkn8 gq8wm5ahp + l52hb9z ccelerates 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 i64tqp(5cmopn y 6fn 7at 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 trawu*cl2l cba5m;ofjq e*4v e:0 ffic light turns green, a car that has been waiting at the interse eb;qwm* jf:calv cl2 405*uoection 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 12 m/s on thl.ebcjlv7 b+ 5e surface of planet X where the acceleration vl+clbj7b. 5edue 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 surface ofcxm .5y t4ko-rv-vis . planet X where the acceleration due to gravity ismsx-4c5y.t.v -ivor k $1.5 \; m/s^2$. How long does it take for the object to reach the maximum height?

  An object is thrown upward wit*:,bhphk amd g l*hd-lxqjig :*6a c0(h a speed of 15 m/s on the surface of planet X where the acceleration d,::x(*aagj m-lhqdh h**kp0 icl6 b gdue 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 speeddx:oti3wa8t zyz sep9.4n .j* of 14 m/s on the surface of planet X where the acceleration dued .8yz4e: o 9pntiw3z*jta.sx 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 sp n9ilo n(7ma+. If your friend holds a ruler between your fingers and releases it without warning, how far can you expecannm(o 7pi+ l9t the ruler to fall before you catch it?

  A ball is thrown upward at a velocity of 19.6 m/s. What is its velo4py v )gvma:4lsao 5a /va(0nhcity after 3.0(v/s5 av pamnayl 4g0:ha) 4vo0 s?

  A bullet shot straight up returns to its starting point in 16 s. Whaugiha 17*(+ f/zo zgwnt is the initial speed of the bh/ (g7gaz in+f*1 wzouullet?

  A ball is thrown straight up with a: /s-u-ki emp9vvcuk-jx 92bf speed of 36.0 m/s. How long does it take to return to its star9v c/m9b- :- k i-x2uesupjfkvting point?

  A ball is thrown downward from the top of a building with an initi:ut ypmgo6g:rkud d vl3 .(y,/al speed of 14 m/s. It strikes the ground after 2.4 s. How high is the built o y6:( dd3vp:uggu ,lyrk./mding?

  A ball is thrown straight up with a speed of 30 m/s. (only fill in num 4pgy8oxzpq2 +erical value in the blanks) q4oy2 +gzx8pp
(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 strsl8s -w+rj 2qbaight up into the air with a speed of 42.3 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 3 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 t = 9flkpee*:( h l.cigumadcp;0 *e8i b.u6hdd+1.0 s?

  In Fig. below, what is q7p1i6c+ih k:nz3rtzthe velocity at t = 2.5 s?

  In Fig. below, what is the velocity at tt,mou*xlab0ade 7q,tyw23 b 4 = 4.0 s?

  In Fig. below, what is the velocity at t = 5.bvn(,5nu5wy b5 s?

  In Fig. below, what is the average velocity from 0 to 45wy*t)bt0 1f:toigwc wj -ov8 .0 s?

  In Fig. below, what *n,pe/b)l)dhj g htm.is the average velocity from 0 to 6.0 s?

  In Fig. below, what is tgnqxu2 :o5,yt he acceleration at 1.0 s?

  In Fig. below, what is the acceleration at 3.9(y+gmv 5 hjlr0 s?

  In Fig. below, what is the ave equh7+*l w kyv;d m9)ud6;ztjrage acceleration from 0 to 5.0 s?

  In Fig. below, what is the average acceleration fb8+ed dhu e;rd/s, w2arom 0 to 8.0 s?

  In Fig. below, what isb/)lw ;4j,ww36 pt jkhpc *mnk the displacement from 0 to 8.0 s?

Does a car speedometer measure speed, velocity? 0ejgb , j4 (m0hf7wgoi{speed|velocity}

  An object can have a vhb sbeapp:lv /t4 p:70arying speed if its velocity is constant.

  The velocity of an object can be negative65ep)yl.lmiyd* ca 6w when its acceleration is positive.

  If one object has a greater speed than a second object, the first m7nvmh f jzp5j 3vx7l+.ust have a greater accelera7+pmnv jjx7 z3vf .h5ltion.

  Two cars emerge side by side from a tunnel. Car A is traveling with a speed ofoj if2h42z3agewb z0. $60 \; km/h$ 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 decrea y/ kruhyl.k3(ses.

  A baseball player hits a foul ball straight up into the air. It le57ol6lc,g p pgaves the bat with a6,l c gp5logp7 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 acceleration, how8g r.g,w 1oc1i,o qstu does it change if air friction is ig,o gt ui,1cw8o.1g rqsnored?

  As a freely falling object speeds up, what is happening to itgqa(f/rr1vvb i m2)f4pf3 po) s acceleration, how does it change if air friction Ci4)b 2mrf3v)pq/g fv aorf1 p(AN NOT be ignored?

  An object that is thrown vertically upwag1/f6q llxf5a0h4fi d ;snu -aiobq,- rd will return to its original position with the same speed as it had initially if air resistance is negligible. If air resistance is apprecix;lsg /of dbh4na6-1u 5 lafiqf-q,0iable, how will this result be altered?

  An object can have zero velocity and nonzero acceleration at the saiyjt+q j 31mp4me time.

  An object can have nonzer(nb:z)frx-c n :; jxago velocity and zero acceleration at the same time.

  An elevator moving from the second floor to the fifthuf8oo v7v -mx: floor making no stops along the way has zeruvmfvo78ox -:o acceleration all the time.

  A rolling ball moves from81q6/ 0 gu5lo-fcrtl3ytdn u+nj i1sg $x_1=2.9 \mathrm{~cm}$ to $x_2=-7.2 \mathrm{~cm}$ during the time from $t_1=1.9 \mathrm{~s}$ 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 $t_1=-3.1 \mathrm{~s}$ is at $x_1=3.3 \mathrm{~cm}$ and at $t_2=3.9 \mathrm{~s}$ is at $x_2=7.5 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps around a quarte:(11qd cuoq 6y6 e0ghe;huxbt r-mile ($1 \; mile = 1609 \; m$) track in a total time of 11.2 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 o ,ur7ul0kijw ecb3 .:a straight line, moving 114 m away in 9.0 s. It then turns abruptly and gallops halfway back in 4.5 s.ur i0.:3o7kewc ,jul b 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 frpqmp kq 41v*new6(;inom $11 \; m/s$ to $22 \; m/s$ in 5.8 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 )06i i;;sw:g-qus+ix tfwb re$18 \; m/s$ to rest in a distance of 55 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a speed ge os1bpg9gkw-9.amdou. k, :of $32 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.2 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of t 1- s5/rj6e rkplwv9fphe blocks to essentially top speed about jrs5epv-9 pw6r k/lf1 $10.9 \; m/s$ in the first 13.8 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 speeh- 5bwrkvg-1km uw,) fd of $20 \; m/s$ to rest in 5.31 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,p/wfew 28lwn the highway. Assuming a decelepw /2w8nel,wf ration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a tr 21b.kf :yz2lzj8acnd uck 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).    $m$