Suppose that an object travels from one point in space to another. Make 84) ha4nxdfae a comparison between the displacement and the distance travel8x e4)adfa h4ned.

  When is the average velocity of an object equal to zx 6x r.cj)9htthe instantaneous velocity?

  A new car manufacturer advertises that their (t mi8:ew5llc;qe bu2car can go "from zero to sixty in 8 s". This is a;clt:iqb(5 2e8 uewml description of

  An object moving in the +x axis experiences an accelez*v ,;lxb7mihfdsxbp:9) pv8f yn:*vpo 9d8aration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car tra 12vx (tyez;y yevtw04uhec46veling to the East (+x direction) begins to slow down as it approaches a traffic liu( t0c4weyv ;2 t vz6yye41hexght. Make a statement concerning its acceleration.

  Suppose that a car traveling to the West (-x direction)noo.k c4 .243cxsbp 7rh1.0aordsmb o begins to slow down as it approaches a or 7o ndbh3xk.soc 4 as2.o4rc.mbp10traffic light. Make a statement concerning its acceleration.

  Suppose that an object is mov0m.zx;d5s o,5ak fw ksing with a constant velocity. Make a statement concerning its acca;w dmk0sxfz.55 o,ks eleration.

  If the velocity of an objen )b)6xtkr4c 6dg+vvcct is zero, does it mean that the acceleration is zero? Support your ans6gnx)c +4t6cbv)dkvrwer with an example.

  Can an object's velocity change direction when its acceleratiof kj/an m k 0)il7axang/emv*c.) ro1n4by1a( n is constant? Support your answer with an exj)m*ncnam./k0lgve )4r n1(oykia/71 aba xfample.

  Suppose that an object is moving wzxz1vx +1d gyby pjf14/u)9fgith constant acceleration. Make a statement concerning its motion with respect to tg1gxj/p194y1fyd +uxvb z )f zime.

  Can an object have incml 2f*kkw dd:(.nqgw r.frn0 xk7+,,gjpwax 7 reasing speed while its acceleration is decreasing? Support your answer with anmn+2 g, fl7.7g0w r:x rjkkdwdxp w,a qnf.*k( example.

  Suppose a can, after an initial kick, mob6 bmn. n59kdaves up along a smooth hill of ice. Make a statement concerning its ac596n kab db.mnceleration.

  Under what condition is average velocity equal to the avi,1(mzqvsp,kv -d l .rb5q og2erage of the object's initiavdv.lq,5qpzmo , (-i r gks1b2l and final velocity?

  Objects A and B both start at rest. They both accelerate at the same mdn uk9-8;,xezr wpd 9rate. Howx9krwezdp ;dm-u8n9 , ever, object A accelerates 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 startec9b+u .wmc w* from rest. They both accelerate at the same rate. However, object A acceleratesbucew m wc*.9+ 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 9 qhb+fj+t9 (r j 6yuv,l bh/6u)zybkzfrom rest and falls in the absence of friction, which of the folb ruz 96 + btbuyz/ljyjq, )h6vf+k9(hlowing is true concerning its motion?

  When an object is released from rest and falls in the absence of frk,;u nsl+v* 11wj) pi.el0v m*efpa ckiction, which of the following is true+ 01nipu.cpe*vew)lsm,fvk;lka1*j concerning its motion?

  Suppose a ball is thrown straight up.zr j5sx g4 ,qrb ;jbexo8aw;-1 Make a statement about the velocity and the acceleration when the ball re5brr4ebw aqjx-zj;; 8,s gx o1aches the highest point.

  Suppose a ball is throsbd :jqj6.,7f : jl,e0m nrlfqwn straight up. What is its acceleration just before it reaches its high j mj .j6lf0r7s d,fq:qbe:l,nest point?

  Suppose a ball is thrown straight up, reaches a maximum height, then famzfqsy u qr-stg9s3bw0:o9 /3lls to its initial height. Make a statement about the direction of the velocity and accelerasu9 :s0wgmb qsy3q/3 zf9otr -tion as the ball is going up.

  A ball is thrown straight up, r08 cmn0(ph3an 7fic -tk) dfjceaches a maximum height, then falls to its initial height. Make a statement about the direction of the velocity and acca n)0mcpfc 8f0n(tjd-h k7c3i eleration as the ball is coming down.

  Suppose a ball is thrown downward in the absence of air ux6b2 t.zoa1wrc;ey+ resistance. Make a statement concerning ior.u16e +y2z w;t abxcts acceleration.

  Suppose a skydiver jumps fr*seoht )7 um5zom a high-flying plane. What is her acceleration when she she reaches terminal *e m)u5zos 7htvelocity?

  A ball is thrown vertically upward with a speed v. An identical second ballvk0 . is*y;. mf2r eewbpm8n-1yus9dg is thrown upward with a speed 2v (twice as fast). What is the ratio of the maximum hri8-be nw2 suk9vep* g .f01 myyd;m.seight 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 a building. One second later, ba k1rfkbf) 7m:onjt/ 7wll B is dropped from 1k7/7t :w)orfkbf nmj the same building. As time progresses, the distance between them

  Ball A is dropped from the top of a building. 1w p91o*i dln a4xm3nlOne second later, ball B is dropped fr39p 1xnm naoll 1*wid4om the same building. As time progresses, the difference in their speeds

  Two objects are thrown from the togm 3ye(p 0sq2q1jn3 srp of a tall building. One is thrown up, and the other is thrown down, both with the same initial speed. What are their speeds when they hit thrqpqyss3 n1gmje0 2(3e street?

  A brick is dropped from the top of a building. A second brick is thrown strai cq;ni),y pvq/m0* eknght down from the same building. They are released at the same time. Neglect air resistance.cqe 0nyp / in)vmk,;*q Compare the accelerations of the two bricks.

  An object is moving with constant non-zero velocity in the +x a.tx:8 kq; j1ri4ly ibjxis. The position versus time graph o8jil1b;k.4j : tiyrq xf this object is

  An object is moving with coc*/glvt ;lk);/1auz ky torz(nstant non-zero acceleration in the +x axis. The position versus time graph of thg at/z)lyk(k/lov ; u;z t*1cris object is

  An object is moving with consta *k*weunqv 4offz+3xj, 8y:cint non-zero velocity in the +x axis. The velocity versus ti +z*kc wnev,y:4xfo3f8ju*iqme graph of this object is

  An object is moving with constant non-zero accep++qe ic vf gmwwo2(.-leration in the +x axis. The velocity versus+m i2 vwc+-gpqew f(.o time graph of this object is

  The slope of a position vtxw7e8vjc y k4.ivk ;k2,akh2ersus time graph gives

  The slope of a velocity versus time grdabh2qsd/ tvar4swz;hv3 f:7w7 3s )daph gives

  The area under a curve in an acceleration versus time ga 5w6rq14vik zraph gives

  The area under a curve in a velocity versus timed r7/zvqa5i/qv4 bwq- graph gives

  If the position versus time graph of an objecs)lf8un .dqz5t is a horizontal line, the object if5 u8lzndqs .)s

  If the position versus time graph of an object is a vertical linrtj(rleqqxb ;1 9 ic-(b xo8 ovq-c52ae, the object isjet cq br(ai(co-2q ;b8 rq1xl o-xv59

  If the velocity versus tq4) lxm6)y z zefk4imb9b7wf 6ime graph of an object is a horizontal line, the object i64)m)y 7m e4qwbz kfx6zi9fbls

  If the velocity versus time graph of an object is a st.z1+e m w0oecj/kjeg9 67vydbraight line making an angle of 30 degrees with the time axis, the ob.o9kzm1jc g7 6/ve 0w+je yebdject is

  An object moves 15.0 m north and then 11.0 ml9f eg1z ic45) nh1p:vvfs3d o)hti.w south. Find both the distance traveled and the 1vwchsofi4 he: id5 g1 9)3ft p).zlnvmagnitude of the displacement vector.

  A boat can move at 30 km/h in still water. How long will it take to move 120rx8 mscc(7 uh km upstrxhcm r0c7s (u8eam in a river flowing 6.0 km/h?

  55 mi/h is how many m/s? (1 mi = 160,nmn/)o9 di)f(zq abokoa +3 t9 m)

  What must be your aver8kcj.))fbg+n b rqp.tjq-/ l yage speed in order to travel 350 km in 5.15 h?

  A runner ran the marathon (appjylw-n8-7efilwu c ,yq*3) cb roximately 42.0 km) in 2 hours and 57 min. What is the 8bul*7wi- n wflecy)c, -jyq3average speed of the runner in m/s?

  A car travels 90 km/h. How long does 2ccz- qma y;+bit take for it to travel 400 km?

  A ly (light year) is the distance that light trmw g+j) ,uqy-kavels in one year. The speed of lig+m, yj qu)g-kwht 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 you look to the side r,wk2q5cl1lq for 4.0 s, how far do you travelwkl,2qr 5qlc1 during this inattentive period?

  If you run a complete loop around an outve8ah(ub 4y4n ,+l9ygskj kz1door track (400 m), in 100 s, your average veybh kn14 gayu z(,4jkesl+98vlocity is

  A polar bear starts at tbhkb; 1bdhq56f(bbg5he 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 min. What was the bear's average s bb g1b;b d5hbf5qk(6hpeed?

  A polar bear starts at the North Pole. It travels 1.0 km south, then0 h7iy7eo haw5 1.0 km east, then 1.0 km north, then 1.0 kmeio5a077hy wh 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 mi/h for 110f4u tad*zqzb2s/ 0 ep5 miles. It then starts to snow and you slow to 35 mi/h. You arrive home after driving 4 hours and 15e0* tz4 s 25/fbzdqaup minutes. How far is your hometown from school?

  A motorist travels 160 km n+g 2 qrfhd0 qjocq cw5ojtu, 5:g04b +hjz5k:at 80 km/h and 160 km at 100 km/h. What is the average speed of the m5j hkcwhj+d 50 qo::2qzubct, oq +rf4n0g5jgotorist for this trip?

  A motorist travels for 3.0 h atf 7;l x ,3f+p8pt qquimlej(/n 80 km/h and 2.0 h at 100 km/h. What is her average speed for the trip ( q,/7;uq83efxtpfn mj l+ilp?

  An airplane travels qn g:s l9a;hs-at 300 mi/h south for 2.00 h and then at 250 mi/h north for 750 mis;-9ln:sahq g les. What is the average speed for the trip?

  In a 400-m relay race the anchorman (the perso2xeif 0 )wr 3pz9spq6vn who runs the last 100 m) for team A can run 100 m in 9.8 s. His rival, the6 ievr p0zf)w 29px3sq 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 comes to a stop after 12 s. The car's bzlz7 xvrm2/*lc80rod9 pze 8 average velocity during deceleration was 74v 0d 8zbmz9 o cl2/xer8zl7rp* km/h. What was the car's deceleration while slowing down?

  An airplane increases its speed from 100 m/s tofc3el 8o vc u-u2r0qt x-bii;. 160 m/s, at the average rate of evi0- qc fuocr-ut2 8b;xil 3.$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accel 9++hjb. qbopberates 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.5 yt2 t7cnztbo6o f4ff+en;*k yap o-go g+:o 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 ;n mlt((hu37o-u -rxs da3 xdpul9ap 3with a constant acceleration of3xdt73ar lu sm 3( u9pu xpohnd;la--( $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 2.9 m/s experiences a constant acceler kg5wz3n/ii8sp0e8)2pbzvaoation of ov0 inkiwg/)2 8 apes3p z58bz$1.9 \; m/s^2$. What is the cart's displacement during the first 9.8 s of its motion?

  A bullet moving horizont bvgo:e ni:f49ally to the right (+x direction) with a speed of 488 m/s strikes a sandbag and penetrates a distance of 51: ienf gv49b:o.23 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is laufzkui(z4j b a+7(*fo pnched from a catapult on an aircraft carrier. It reaches a speed of 42 m/s at the end of the catapult, and this requires 2.0 s. Assuming the accele ( pa+uzofzj*47fbk(i ration is constant, what is the length of the catapult?

  A car starting from rest moves with constant accex a yb8b1rh(o5leration 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 yb jr9u4/ y *e9agxb0om. What is its average accelyry je a9*4 0x9bobu/geration?

  An object starts from rest and undergoes uniform accelerate 7x gh;v*+wpkion. During the first second it travels 1g ;+vkwexp* 7h.6 m. How far will it travel during the third second?

  An object is moving in a straight line with constant acceleratkd ,u cvort79)l4gufp;p3s * gion. Initially it is traveling at 16 m/s. Three seconds later it is traveling at 10 m/s. How far does it move during thp)cu ,fgl rso394;pvtdg*7 u kis time?

  A car starts from rest and accel2 gazij pxs6a3u,); vderates 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 5mlmd:ahu ml0l35u *ldry road 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 b+*rfi kcfo+(f a 1dxlmb,:0jrp*7f slight turns green, a car that has been waiting at the intersection starts ahrb f0c riljf opb1+(:+ *xf7akfdm*,sead 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 ol1 gypw+u:amz. .s:aaf 12 m/s on the surface of planet X where the acceleration due to gravity is.ag+l:p: szu. aa1w my $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown upward with a speed of 12 m/s on the i2+kwobwn vvov)z ; nqg;n,xn,dq;,0surface of planet X where th ;qoo; gv2n0k )+vwq zbdn,;iv xnnw,,e 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 with a speed of 15 m/s on the surfx .cp8- deoe;face of planet X where the accelera c .8;oedepx-ftion 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 s o4h fzra14f7hpeed of 14 m/s on the surface of planet X where the acceleration due to gravity ff4za4 17 ohhris $3.5 \; m/s^2$. What is the speed of the object after 8.0 s?

  Human reaction time is usually greater than 0.10 s. If your frienq/;jgsr ax0(n d holds a ruler between your fingers and releases it without warning, how f /0naqsxr; g(jar can you expect the ruler to fall before you catch it?

  A ball is thrown upward a ):a *(ioqdfo2uotm 48jfja:pt a velocity of 19.6 m/s. What is its velocity after 3pjo)o4 8uif2to:q *(:dfa mja.00 s?

  A bullet shot straight up returns qwz sm.0*bv5-dj o rn+to its starting point in 6 s. What is the ini mdq0sowj *zr.-n +5bvtial speed of the bullet?

  A ball is thrown straight up with a speed of 36.0 m/siys 5 l8jaq;qo l056tl. How long does it take to return to its s qsotl;80lialj556q ytarting point?

  A ball is thrown downward from the top1esh rcivy48gud (7- xtob7o hu.j3 r* of a building with an initial speed of 17 m/s. It strikes the ground aftere8 3ybv otoiuj1 rhs7 d. chr(-74x*gu 3.5 s. How high is the building?

  A ball is thrown straight6.rc0gwf-rmv39o apk( yaav / up with a speed of 30 m/s. (only fill in numerical value in t-oa9 arry/mf3vcv6 (p k.a0w ghe 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 wi//r/8n0k7gjcnkrsclm513p-px ynjc th a speed of 34.3 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 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 velo3 1waaalt u h5dxn8.ltpc .73+dax *lacity at t = 1.0 s?

  In Fig. below, what ih/9a 7 0xczxxts the velocity at t = 2.5 s?

  In Fig. below, what is the velocity at t3gz f0y+b3 fui = 4.0 s?

  In Fig. below, what is the db(p 8b065da*i x,v f6avzklj velocity at t = 5.5 s?

  In Fig. below, what is the average velocity fx 4txoxs; qsz+w:4c0nrom 0 to 4.0 s?

  In Fig. below, what iwne-iacasv1 to qe /fo/ 7p*11s the average velocity from 0 to 6.0 s?

  In Fig. below, what is the acceleratio2fth5rno old-wo;) 2ok *iva6n at 1.0 s?

  In Fig. below, what is the acceleration at 3.g/:ayaadryzx s2v .( c:.2p64hyxtro 0 s?

  In Fig. below, what is the avemn -e ,gbv/+bqw gho.9rage acceleration from 0 to 5.0 s?

  In Fig. below, what is tell fg+*z2qy9 he average acceleration from 0 to 8.0 s?

  In Fig. below, what is the displacement from 0 to 8.0 s)no. * ;1: oet / :ofagt-nlzxbgcyid4?

Does a car speedometer measure speed, velocity? {spbt8gf1mm .*cxs ;kd nf4z*n6eeed|velocity}

  An object can have a varying speed if its velocity is constant. / 5jj-ylfp,ua

  The velocity of an object can be negative wsqf ohb.jk 5jvx /xd0 8g)d39nhen its acceleration is positive.

  If one object has a greater speedwp li2r3g4(dt*.f ayk than a second object, the first must have a greater acceleration.la*dtf pr g(.i4y23kw

  Two cars emerge side by side from a tunnel. Car A is traveling with a spe, tjuvab//tj lgp 242jed 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 yr.83fc8ym cs in speed as its acceleration decreases.

  A baseball player hits a foul by g-s63-*riuww- l; wghnc /qlall straight up into the air. It leaves the bat with a speed of h -i- cn;w3/wg *-llwgys6 ruq$120 \; km/h$. 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 -g3/ o15le gge yzrwn;up, what is happening to its acceleration, how does it change if air fricy 31ggorne5;l/zegw - tion is ignored?

  As a freely falling object speeds up, what is happening to its uienuzj9puf/ * 862blacceleration, how does it change if92uj zlpf u8u/eib6n* air friction CAN NOT be ignored?

  An object that is thrown vertically upwarkx ry:x2ds 6:nd will return to its original position with the same speed as it had initially if air resistance is negligible. If air resistance is apprex rd6x2ks:y: nciable, how will this result be altered?

  An object can have zero velocity and nonzero a+/vkergo(3iytm u 7 43z8z nkhcceleration at the same time.

  An object can have nonzero velocity and zero acyj0pz2(8f 90lfvyk bdvn 7(vmceleration at the same time.

  An elevator moving from the second floor t(a0 wgwahc f5fn.9du(ncc2 n 2o the fifth floor making no stops along the way has zero acceleration all an fn9 cfc2(acw nwuhgd5.2(0 the time.

  A rolling ball moves frw i3rrf t e(jddymeo7/q(; ;k:om $x_1=2.1 \mathrm{~cm}$ to $x_2=-5.4 \mathrm{~cm}$ during the time from $t_1=1.6 \mathrm{~s}$ to $t_2=6.0 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-2.4 \mathrm{~s}$ is at $x_1=2.9 \mathrm{~cm}$ and at $t_2=3.4 \mathrm{~s}$ is at $x_2=7.3 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps arouej2qq1g fe6(g v,o c5 /hfq3hfnd a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 6.1 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 straight line, moving 109 ; liaamefic f+w:0):d m away in 11.5 s. It then turns abruptly and gallops halfway back in 4.5 s. Calm c0if+:e:f alwda;i)culate (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 from0j ycobkpmkj; ut0kt7 2dqt+ i1(wl 1+ $11 \; m/s$ to $23 \; m/s$ in 4.8 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 from7zjlu 0/ct7dm3ii ;bp $18 \; m/s$ to rest in a distance of 61 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reafyx: ; hwv.ikh8ya6hrue3ws k .64/ zwch a speed of $33 \; m/s$ 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 e /+makb o/lw)fzy( f2xssentially top speed aboutk/xoa y+(flb/)w 2z fm $11.5 \; m/s$ 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 uniformly from a *1cu:x 7rol 2jgzmg,espeed of $18 \; m/s$ to rest in 5.07 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves skid marks 92 m 2* q+vbom5smzwf o;:hlong on the highway. Assuming a decele:5w +oh;bmo fvsq2mz*ration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a tru.d+,p:,kls zxz8ch0rcej u-tk k *xx8 ck 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).    $m$