Suppose that an object travels from one point in space to another. fz)yw8tg0 -mk Make a comparison between0 )zt8gy-k wmf the displacement and the distance traveled.

  When is the average velocity of an object equal to the instantaneous velocw).w;h1;jcqz3q vv x r.vk sw1ity?

  A new car manufacturer advertises that their car can go "from zero to sixtye odepb d0 --tj-; cvei-)lss3 in 8 s"i-e e b;-0c3 j-p)dd olsste-v. This is a description of

  An object moving in the +xav2 qlikyrh4hgkuu13-sl o y6:j568 u axis experiences an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (q;s+jvx7 dwxrm6jv05qgf 1 -md3lrd 7+x direction) begins to slow down as it approaches a traffic 7f-sqgj3x rm15dv0dv6 dj 7 ;wqr+lxmlight. Make a statement concerning its acceleration.

  Suppose that a car traveling to the West (-x direction) begins to rw49tyax 4u ;vslow down as it approache;4ux9v4ay trw s a traffic light. Make a statement concerning its acceleration.

  Suppose that an object is moving with a constant velocity. Make g80qk(f 9;hs02qwmyb.xavz2 pprh2 c a statement concerning its acc0(a2q9zxv sgck hh;fm0py 28w r.b pq2eleration.

  If the velocity of an object is zero, does it mean that the acceleration 4fbu(iopgdq :y zi6 9 7uo;0tois zero? Su yu4zqiifut67 ;bp 0o 9oog(d:pport your answer with an example.

  Can an object's velocity change direction wp y;1jf,8h7:4flaowee3 qmid hen its acceleration is constant? Suj:4 f i83mo 7eyw,qfh1pd;al epport your answer with an example.

  Suppose that an object is moving with constant acceleration. 8,ap2aoy apu 0.o)vv a Make a statement concerning itsp8p avav)youa a,2 .0o motion with respect to time.

  Can an object have increasing speed while its acceleration is decre.k.nobz u-t3 oasing? Support your answer with an exa tb o.uz-.okn3mple.

  Suppose a can, after an initial kick, moves upgbq: v0t,xpktyu)9v) 9 g3pug along a smooth hill of ice. Make a statggt09 9y,uk)upqtpv)3gvx b:ement concerning its acceleration.

  Under what condition is average velocity equal to the average of thff wq895zv3bljp-h y 1e object's initial and final velocity zlwfqfj389 v5- 1byph?

  Objects A and B both wf,e9+iwe;-kw:0xh* zww b 3sm- voxeeg 3/ch start at rest. They both accelerate at the same rate. However, object A accelerates for twice the time as object B. What i xg ewz-wbwm:;vc3+- /ew,koxhs wei0f39*he s 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. o .b94sx r;irv utatw y(u*4*lfark v w0,xf:1 However, object A accelerates for twice the time as object B. What is the distance traveled by object A compared to that of objec;,* 4tv ruixr0tw sfkbla.wo4v x:*r( 9au y1ft B?

  When an object is released from r uzchd2et pot9u35q6 1we9p1gest and falls in the absence of friction, which of the following is true cot 9d1u pucqwehp 5g3e1o6t 29zncerning its motion?

  When an object is released from rest and falls in the absence of friction,m64-f q/ fd;e qmegct. which of the following is true concernfmg qe q/f64.ecm- td;ing its motion?

  Suppose a ball is thrown straight up. Make a statement about the veouj3ffyv iuk2au8)9v 4d75ri locity and the acceleratioy a2vofudi8k)j73 fu54ivr 9un when the ball reaches the highest point.

  Suppose a ball is thrown straight up. What is its acceleration just befi3xe3os7tr: (p ksx2pore it reaches its highs7x ( kpri3pxt3o:e2 sest point?

  Suppose a ball is thrown straight up, reaches a maximum height, then falls to itulv)9p xq6g va l+:)pfs initial heightax)+ fgp:)vpqv96lu l. Make a statement about the direction of the velocity and acceleration as the ball is going up.

  A ball is thrown straight up, reachey(t0ippilj.(g*hz *-pt+e vas a maximum height, then falls to its initial height. Make a statement about the direction of the velocity and acceleration as the ball is coming down.-t*pa((ti ei p+vyp gz 0.l*hj

  Suppose a ball is thrown downward in the absence of air retu--xf-xh tw i9v+tga*l+if509rc8jjcpi 3n sistance. Make a statement concerxg3x5ia +9i8 ul 0jpti-vtnff*j h-9-crcw+t ning its acceleration.

  Suppose a skydiver jumps from a high-flyin4jd3yn/ s7qskg plane. What is her acceleration when she she reaches terminaly3skn/7 s4dqj velocity?

  A ball is thrown vertically upward with a speed v. dmb1(kqea6 t 7 An 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 that of the first ball? (How many times higher does the second ball go than the f me61(akdqbt7irst ball?)

  Ball A is dropped from the top of a building. One second later, ball B is droes +z:n op-g; t:t0hdwppedehs;twz0n-tpg+d :o: from the same building. As time progresses, the distance between them

  Ball A is dropped from the top of a building. One second later,( o t/twll gffmq*7 j-i4x+gv, ball B is dropped from the same building. As time progresses, the diffwf(j gf*ixg7mlq,4 -tv+/o t lerence in their speeds

  Two objects are thrown from the top of a tall buildinp9umwpsv8 +-7o0j qdtu3dpvkf7*co3g. One is thrown up, and the other is thrown down, both with the same initial speeu msuw cq3 vjk9tdd7ovpp7f -*p o038+d. What are their speeds when they hit the street?

  A brick is dropped from the top of a building. A second brickkxfj :o/ ruqskgy*13/ is thrown straight doyso3*f ur://gxj 1kqkwn from the same 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 velocity in the +x axis. The posi: k0c *aq5xnbc lo om.v0ak*+dtion versus time graph ofa+qd:b5v. xkacc 0lom*o* nk 0 this object is

  An object is moving with constant non-zero acceleration in the +x axis.(zze1 vhm8 w-m The position versus time graph of this obj w hz8-e(zmv1mect is

  An object is moving with constant non-zero vt+m1f qcr (z.w*ph tc)elocity in the +x axis. The velocity verprq.)w tfcm*h1zt( + csus time graph of this object is

  An object is moving with constant non-zero accelee 6raim(, sbzs 4wup1jebq8;j8c3d p /ration in the +x axis. The velocity versus swujis,4p8p6 mc1 bbed /;e8 j3(qraztime graph of this object is

  The slope of a position versus time gs 9u37ciu+aqq 88v;.gk8w gi ( xtpajrraph gives

  The slope of a velocity v k hej(5y2-ymgersus time graph gives

  The area under a curve in an acceleration vfp)hf(a:;rr yersus time graph gives

  The area under a curve v puf .zchix:y: 263hs;im xjq,i 35jbin a velocity versus time graph gives

  If the position versus time graph of an object is a horizod m 3d+vi):eofntal line, the object if 3:)m+v doieds

  If the position versus time graph of an object is a vertical linebh +k.e w(yr .4drs3,;rfjw-meyg js/, the object iswby( -j kewjh./+4;s3f rs e .ymrdrg,

  If the velocity versus time graph of an object is a a)wm azr, x6u6horizontal line, the object iu xazr6w6 )m,as

  If the velocity versus time graph of an object is a straight lr.a8 8xal7bgline making an angle of 30 degrees with the time axis, the objec l7ag8ba.8lr xt is

  An object moves 15.0 m north and then 11.0 m south. Find both the dista,,sa ( *zyk/nh5 0ig ecdbb1innce traveled and0/s1dge( ,zhc5 niak ybb,in * the magnitude of the displacement vector.

  A boat can move at 30 knmg+w xd25:qc.jzl ;om/h in still water. How long will it take to move 12 km upstream i wq5oln.zmx g2d: jc;+n a river flowing 6.0 km/h?

  55 mi/h is how many m/s? (1 mi = 160jf;fl)n k *o,o9 m)

  What must be your average speed in order to travel 350 km in 5.15 g(*grrd9a db64+zsooz)g6nj h?

  A runner ran the marathon (approximatel ;k237 og qngw77b9yr/iqzncpy 42.0 km) in 2 hours and 57 min. What is the average speiwkbzog77cq72 y;g3np n9r /q ed of the runner in m/s?

  A car travels 90 km/h. How long does it take for x5wau k f h5dpsn9,,j)it to travel 400 km?

  A ly (light year) is the distance tjmvg 5jr8 wu)3hat light travels in one year. The speed of vgu 5wjmrj 38)light 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 alongc qn+ ;nk-n5 qb2vcp5.h tkab ;zoa-b5 a straight road and you look to the side for 4.0 s, how fk 5-2ocn; bc; an5+pk.h aqzbb5tnvq-ar do you travel during this inattentive period?

  If you run a complete loop around an outdoor track (400 m), ib;29c+f2 jabo ) ukpbba91qsrn 100 s, your average velocity ij9o9s bca;r2abq+bukf2 b p)1 s

  A polar bear starts at the North Pole. It travels 1.0 km south, then 1.0 km irrnc)* + czcy)i(38fwuvn 3peast, then 1.0 km north, then 1.0 km west to return to its starting point. This trip takes 45 min. Wv ci)wnui+f 8p()rc3*cz y n3rhat was the bear's average speed?

  A polar bear starts at the North Pole. It travels 1.0 km tnwi t7oz vkj9 c6/d80south, then 1.0 km east, then 1.0 km nootwjt6 n c 9/z7idv80krth, 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 2xiyks()f 2chcg8qw 3h 2y5k xweekend from school at 55 mi/h for 110 miles. It then starts to snow and you slow to 35 mi/h. You arrive home after dri82i(wcf kg3 yx 2q5h)s hxyc2kving 4 hours and 15 minutes. How far is your hometown from school?

  A motorist travels 160 km (y: sxrx4. ksxat 80 km/h and 160 km at 100 km/h. What is the average speed of the motorist for this trixr .ssx:xy( k4p?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h. What is hy7 xkxgmva,*mt46l x- er average speed for the trip?xx,vkxm6 t*la7 y-4g m

  An airplane travels at 300 mi/h southjy6jyw5a9 5 qx for 2.00 h and then at 250 mi/h north for 750 miles. What is the average speed for tya q9j5j6x 5wyhe trip?

  In a 400-m relay race the anchorman (the person who runs t:mz6hq2za:w -62*r hertmt pbxo( (mzhe last 100 m) for team A can ru pm:o:e- bxqht2z(a2r66wz mmzh*t(rn 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 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 c-v/p4uq zf 6x,yx2jzs ar's average velocity during deceleration was 67 km/h. What was the cary4v s-qux ,j/z2z fpx6's deceleration while slowing down?

  An airplane increases its speed from 100 m/s to 160 m yrh9ax6 .sgsra68qeh; m* )lr8,mcly/s, at the average rate of h68c;y. 9sgel al* ) yhr,r 8msax6qmr$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h acceleratesp/2*u.7 lj 0jaczdxpri, g c8x 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 accelerates at 38 slcssma3 x1$4.0 \; m/s^2$ 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. k ) d.5ne 7mpnglyo5df.kx24oIt then speeds up with a constant acceleratiog5)dl xe5nod.fpkk 2 ym .o74nn 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 5.0 m/s experiences,j t/(v4hk)ae mit;ic a constant acceleration of ie(j h4v;ta,c/ mit)k$2.3 \; m/s^2$. What is the cart's displacement during the first 7.7 s of its motion?

  A bullet moving horizontally to the right (+x direction) with a speed .srzn(,00fppl u)o t0 k wki4vof 273 m/s strikes a sandbag a pp r4i00,s.tv k)u(l0kfnzownd penetrates a distance of 91.35 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on anax-xbpi4vh7ub.v 4r7 aircraft carrier. It reaches a speed of 42 m/s rx-a.7px b4vh74bivu 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 nljcg25 r* cw,dpd1npy- (q8vconstant 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 of 200 m. i d c7mzey12-k What is its average acceleration? 1m 2kce7dzi-y

  An object starts from rest and undergoes uniform accelerxh 0m2 p njune9q)oa p(i3qe.2/2z nuq q1r4uhation. During the first jin .n)hp9/nmq1(o422 ruezu eq q3ux qap02hsecond it travels 9.6 m. How far will it travel during the third second?

  An object is moving in a straight line with /oy vn iz5fbgi-.t/1inw2y(kks 2qg8constant acceleration. Initially it is travelingsfbiky5(ytnwz. 8/gk q2 12nv o- ig/i at 16 m/s. Three seconds later it is traveling at 10 m/s. How far does it move during this time?

  A car starts from rest and acceley);t.ax wksa3 rates 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 de;jht:0m* fl8b, m fjducelerate 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 light turns green, a car that;2qvxv agd2 v/wegolrm 4z)8) has been waiting at the intersection starts ahead with a c4o2 2vl)r)vv a wg/gze;m d8xqonstant 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 the surface of plancygi j9x w:5qeqy)gvcc bmz (r7 +4q/4et X where the accelerg iycc+qbwm y97z5 /e:c(g)x rq4q4vjation 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 f1z *s.oi1; tsjaom4 fsurface of planet X where the acceleration due t fz1; .ss4ojmaoi1t f*o 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 wir6g i01t5c hoz v8mbe6th a speed of 15 m/s on the surface of planet X where the acceleration due 65 m86btoch0rvgize 1to 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 e bwl1g c5otp*1q:; szX where the acqc ;*5:1tesglwbpz o1celeration 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 thrhcnm:e4b3n (p+ e5 wwan 0.10 s. If your friend holds a ruler between your fingers and releases it witcwn3e 4p5m+(n we:bhr hout 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 5b/) t7q+ m65cardc2gp qssxuis its velocity after 3.basst 5ud2cpx/)c7+g qrm5q600 s?

  A bullet shot straight up returns to its starting poil. 9l2 wdnhk.nnt in 16 s. What is the initial s hl92nkw.ldn .peed of the bullet?

  A ball is thrown straight up with a speed of 36.0 pb),n8ga k8-bf kohvh4vst+mor , 25a m/s. How long does it take to return to its startingh5 p k,vrm-toos) +vkb, h8b48na2fag point?

  A ball is thrown dowd,k3v qwv3k0hnward from the top of a building with an initial speed of 18 m/s. It strikes the ground after 5.1 s. How high is the building?0k3h k wqvdv,3

  A ball is thrown straight up with a speed of 30 m/s. (only fill s ,p.(k kgt-krin numerical value in t.( p,trkk ksg-he 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 intoo(v vlxcw h6ao:n5tr0je9) x * the air with a speed of 45.7 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 8 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 8.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is the ced +*ls,x2:mp*j at svelocity at t = 1.0 s?

  In Fig. below, what is the velocity 63recnc.1ica at t = 2.5 s?

  In Fig. below, what is the velocb) mc4l8tr)j bka o07oity at t = 4.0 s?

  In Fig. below, what is the velocity l+ )wh/l w*dchat t = 5.5 s?

  In Fig. below, what is the averagex3odb qs0+ -yl velocity from 0 to 4.0 s?

  In Fig. below, what is the ayc.lhi4g zndd8h b lj 6f09m;7verage velocity from 0 to 6.0 s?

  In Fig. below, what is -et z xl.),vvijfzpt7 gw,27(icp6k gthe acceleration at 1.0 s?

  In Fig. below, what is the acceltumqi u8.); o9egcy+leration at 3.0 s?

  In Fig. below, what is the aver /t ,diq-qsp8gg,z9zae 3 wr6xage acceleration from 0 to 5.0 s?

  In Fig. below, what is the averg6 hlvmd8p :m1.eu 7tsage acceleration from 0 to 8.0 s?

  In Fig. below, what is the displacement from 0 to 8.0 s?.yf3.lgn0o1; npoilw

Does a car speedometer b-df1;o f g p)-azpr-zmeasure speed, velocity? {speed|velocity}

  An object can have a varying speed if i ktfmqo,e 1paof6;;2x ts velocity is constant.

  The velocity of an object can be negative when its acceleration i myhg-x1ogd32kjt./ wxx v, )ps positive.

  If one object has a greater speed than a second ou*mg,na0 pznd . o1kgo;t7z)rbject, the first must have a greap z mg);k go,*arn.dt z71no0uter acceleration.

  Two cars emerge side by side from a tuwbwuyr 1i+r q s*.3wy3j+knd9nnel. 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 aszhbj/ 4-u)eqfy 2 de *s/r4dip its acceleration decreases.

  A baseball player hitsh cm/hm d,bl-ex 5x2d4 a foul ball straight up into the air. It leaves the bat with mhxx, l4cdb/- me5hd2a 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 hap4)qq g5sh m1yrpening to its acceleration, how does it change if air friction is igno 1qhm5g4)qr syred?

  As a freely falling object speeds up, wkp5 rotr0(7f93 ws rijhat is happening to its acceleration, how does it 7ptjwo sk 3r50f(9rri change if air friction CAN NOT be ignored?

  An object that is thrown vertically upward will return to its original positiosv-fp1 ag w.0+f.rinq k.3 c 5fyrp8emn with the same speed a51nfw y+q pargpv3r-e .8s .kfifcm0.s it had initially if air resistance is negligible. If air resistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzl qefkoau /,sit)k x) g;)sy)2ero acceleration at the same time.

  An object can have nonzero velocity and zero ;+hj6li l8jst g8o7dr qc c+:cacceleration at the same time.

  An elevator moving from the second floor to the fifth floor icixnz8v8h25 making no stops along the way has zero8in2v c xhz58i acceleration all the time.

  A rolling ball moves from 8/+s xdsvl8es $x_1=2.0 \mathrm{~cm}$ to $x_2=-5.6 \mathrm{~cm}$ during the time from $t_1=1.9 \mathrm{~s}$ to $t_2=5.9 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-3.0 \mathrm{~s}$ is at $x_1=3.4 \mathrm{~cm}$ and at $t_2=3.6 \mathrm{~s}$ is at $x_2=7.9 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps around a x 4 dte77h8fg)ts sep-cqt,p /quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 8.3 min. Calculate (a) the average speed  (数值)  $m/s$ and (b) the average velocity    $m/s$

  A horse canters away fr kp 3b es-9f1o8g 8llno-w:liiom its trainer in a straight line, moving 106 m away in 8.1 s. It then turns abruptly and gallops halfway back in 4.5 s. Calculate (a) its l8-1o 9l- eoi8pg iks3wf nl:baverage 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 dou.rrzprz,uofa c31 b.ek42 14 .gf l$12 \; m/s$ to $22 \; m/s$ 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 froqmbj,o(h re3 91cz5z*o2 iih im $16 \; m/s$ to rest in a distance of 63 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a s3n+p8j;(olqfoqz sc0y 7cu y2 peed of $27 \; m/s$ 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 out5ghu:p:8jx t u of the blocks to essentially top speed aboutg :tp8:juxhu 5 $10.6 \; m/s$ in the first 11.3 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-gx +g9 tiyc;y from a speed of $19 \; m/s$ to rest in 4.28 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves skid marks 4iqa/ i 5gvpc/92 m long on the highway. Assuming a decel/p5caii q/gv 4eration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck vg 6xw(z8xa. wzzy,du:+rw ;k7 hrh ;zgoing $25 \; m/s$ 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 10,000-4i ry37w56r k;p)3,i:gylvfq fsm ympm run in less than 30.0 min. After exactly 27.0 min, there are still 1100 m tomfyylikr73gsq, 63fiyv: r;4 5p)w m p go. The runner must then accelerate at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$