Suppose that an object travels from one point in spa)i o*2r +.azbm m.euns4e ef:8 qfvlb0ce to another. Make a comparison between the displaceme0l)siu eef*.nqe: 824.mzfbb oma+ vrnt and the distance traveled.

  When is the average velocity of an object equal t5jlg*wmb19vivpghp)* r qx,,p6 )nauo the instantaneous velocity?

  A new car manufacturer advertises that their car can go "from zero to svj6hssbsj:x 8yf5+v.ixty in 8 s". This is a 8vy+.bsv6x:s5 j hfjsdescription of

  An object moving in the +x axis exper dd5om pd0)v,9zh l+waiences an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x direction) begins to slow down as eu .l/qsip :l (c/ko9g4 +yqymit approaches a traffic light. Make a statement concerning its ai co(.mq/+s/l4 qyguel 9yk:p cceleration.

  Suppose that a car traveling to the West (-x direction) begins to slow down as kikr) qg 8r5:lit approac) qk:gli8r5 rkhes a traffic light. Make a statement concerning its acceleration.

  Suppose that an object is moving with a constant velorjghe-w) vcz/i2o /) c gi mgx4c7*j(j4 sh6sucity. Make a statement concernh4 csczh6rgg/ *ji 2usxg7v(cj)omw)/e -j 4 iing its acceleration.

  If the velocity of an object is zero, does it mean that the accelera w0md.dg9c1a ution is zero? Support your answd1 .0du9wcm gaer with an example.

  Can an object's velocity change direction when its accelerati:g is(y l*2xlqon is constant? Supporyl: qg2is (x*lt your answer with an example.

  Suppose that an object is moving with constant accelerationos,,82xp(g,jk ru rmqkvyzq 1s z5) m(. Make a statement concerning5qk2)o8 (rus,rqxm,s ,yzpg j 1 mk(zv its motion with respect to time.

  Can an object have increasing speed while its acceleration is dec jowrxxl(, 9t :chanwi/6,qm-reasing? Support your answer with an -,hx: anwql,9i6o xtjrm c/(wexample.

  Suppose a can, after an 1otsvw ; ek kwou(4e6+aga *li,lx17jinitial kick, moves up along a smooth hill of ice. Make a statement co7gejk w;av*a1(u,li+e6olkx 41 owtsncerning its acceleration.

  Under what condition is average velocity equal zjx)a9wf2l;aj5m eu+ to the average of the object's initial an29 )uaz+aj;fx5w ljem d final velocity?

  Objects A and B both start at rest. They both accelen5k0y peiauy9 nb6 k .r(mr4a+rate at the same rate. However, object A accelerates for twice thea5 a iy(9knk mpur 6+br04y.ne 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. Thko- p *;yuz6r/ha(m z1coa6rdey both accelerate at the same rate. However, object A accelerates for twice the time as object B. What is the ( azy *z6khr;o6 d/a-urmop1cdistance traveled by object A compared to that of object B?

  When an object is released from fxxb vc+yau+n-b2q4 9 e* a0ntrest and falls in the absence of friction, which of the following is y +x9au* 0q 2nb4ct +efanxb-vtrue concerning its motion?

  When an object is released from rest and falls inh 9 q1fdp,f1+ucme)ab49p:joghfzfq-+ f f 0x the absence of friction, which of the following is m fz9 4ocfqqf-e0h pf1x)jfg1,d:paf++ 9 hbutrue concerning its motion?

  Suppose a ball is thw4 04 hbeo+ui(z wx3hcrown straight up. Make a statement about the velocity and the acceleration when the ball reaches the highest poi(zh+ wxie o4w4u30bch nt.

  Suppose a ball is thrown straigs /bk,-hry k1dbckv /.ht up. What is its acceleration just before it re dk,y/b k1b.-krs c/vhaches its highest point?

  Suppose a ball is thrown straight up, reaches a maximum height, then falls gcg7qr0iiu- * to its initial height. Make a statement about the direction of the velocity and acceleration as the ba*c0iqu- ig7 grll is going up.

  A ball is thrown straight up, reaches a maximum height, then falls to i(h22 c.f * bczimkcgw4ts initial height. Make a statement about the direction offkgcb(m 22 wci4c* zh. the velocity and acceleration as the ball is coming down.

  Suppose a ball is thrown downward in the absence of air r f/cj)d(sdb6b esistance. Make a statement concerning its accele dc) (6bbfjds/ration.

  Suppose a skydiver jumps from a high-flying plane. What is her ac+bbtot:n3 5l;m e u) c3yxqqu)celeration when she3 t:xbenu+35qq ycl m;to))ub she reaches terminal velocity?

  A ball is thrown vertically upward with a speed v. A s3dlpiw9xt9cg2/e6ch rk q4 )n 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 first balcclt2 9h3pkw4)6/9xei sqrg d l?)

  Ball A is dropped from the top of a building. One se ldjiv;1 yi/a ,g qw.;91-khhgt2 tiugcond later, ball B is dropped from the same building. As time progresses, 1i ;qdu,v2 g1h;/ktat hyiwli- jgg9. the distance between them

  Ball A is dropped froq9 1ro8jmal-gm the top of a building. One second later, ball B is dropped from the same building. As time progresses, the difference in tqgml9-1o ra8j heir speeds

  Two objects are thrown from the top c *zqe/hp3jbs w1:p3 gof a tall building. One is thrown up, and the other is thrown down, both with the same init q z3cwpgb:/e13*phjsial speed. What are their speeds when they hit the street?

  A brick is dropped from the top of / ,migv.p e8rma building. A second brick is thrown straight down from the same.,mirme /g v8p 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-zla m2l3 pk7zdk.ul0y n*r/ s6iq;jv8 oero velocity in the +x axis. The position versus time graph of this ob8y 6 krj;l./q3dml27v pusnoz alk*0 iject is

  An object is moving with constant non-zero acceleration in the +x axis. The pl6savid -s*g +i;n hp0osition versus time grapha*v s;l0ipdi6-+gshn of this object is

  An object is moving with constant non-zero veloci qtk73;ceyo;fi 2-mxgty in the +x axis. The velocity versus tm-kx c2 ti7g3f eyqo;;ime graph of this object is

  An object is moving with constant non-zero accelerati6k + unq be,:g5:ltwzion in the +x axis. The velocity versus time graph of this object ieu lng:i+:5q6 kwt,z bs

  The slope of a position versus time grap 6vtn,que6 l)sh gives

  The slope of a velocity versus time graph give 3pt52jq3df yxs

  The area under a curve in an acceleration versus time graph gccw o3d 1jw775v/ufjvives

  The area under a curve in a velocity versus tpzrz 7d e ;h*fr)yc7l;ime graph gives

  If the position versus time graph of an object is a horizontal line, 0kbis k2)st5ex :kn e0the object i0x i5k0nst 2)k bse:eks

  If the position versus tj /2f egpqs c-s2s(9ekime graph of an object is a vertical line, the object iscg s (-29e 2qpkejs/sf

  If the velocity versus fu ibr+,hv 7v4time graph of an object is a horizontal line, the object rbf4v+ h7iuv,is

  If the velocity versus time graph of an objec. cho 3)kw6-m bgv4kvdt is a straight line making an angle hkdgov . 64v-)mbck3 wof 30 degrees with the time axis, the object is

  An object moves 15.0 m qwhd .ff;bk/ fnt/-q(ux7w b3north and then 11.0 m south. Find both the distance traveled and the magnitude of the displacement vectorku-dn/q/ qf;xbw fw3 t.h7b(f.

  A boat can move at 30 km/h in still water. How long will it take to move mzw0661 .iagiea ,d ntzo 7zkxj-w61 p12 km upstream in a river flowing nw 6xzaepo j.mdz,t66 -a1g0k 17i zwi6.0 km/h?

  55 mi/h is how many m/s? (1 mi = 1609 m)9+/hxqd4g5am3 frui r vqu 2l hz818lq

  What must be your averav t7/(0;i nvk 0vexifdge speed in order to travel 350 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 km) in 2 hours:wbs;c- f l7d7w 8 c4wpdye3fa and 57 min. What is the average 8: ;e47padslywc3c bfw7 fdw-speed of the runner in m/s?

  A car travels 90 km/h. How long does it take for it to travel 40-aja 6cbde(t/ol+h* u0 km?

  A ly (light year) is the distance that light travt; h o08ycf djgu-58ucels in one year. The speed of liggd05c ctouyjh 8fu -8;ht 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 lotfr aaxo i+xdg 2. hy.,m11g9nok to the side for 4.0 s, how far do you travel during this inattenxiat gyf ..n,1oamgh2r + 1xd9tive period?

  If you run a complete loop around an outdoor t6z9jft (:h bcsw tzr.+rack (400 m), in 100 s, your average velocityz : src9+tzfb t.jhw(6 is

  A polar bear starts at the North Pole. It travels 1.0 km south 6wt8 +3mnx+pd;ud3ti0asq tx, then 1.0 km east, then 1.0 km north, then 1.0 km west to return to its starting poimid3a6+uwsp 38x0t + t;dnqxt nt. 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 1g+fsabm8kq(44 fgs0 j .0 km east, then 1.0 km north, then 1.0 km west to reg 8sg fka q(4bsm+4fj0turn to its starting point. This trip takes 45 min. What was the bear's average velocity?

  You are driving home on a weekend from schof5 kt;rc))o naol at 55 mi/h for 110 miles. It then starts to snowafnkt o5c) )r; and you slow to 35 mi/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 at 100 km/h. rfyut-eno t 8eq; -*p- What is the average speed of-*rt;-eqnf o uptye8- the 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 a 1qf0,lew lt:/c 7b 8hn v-sbz1)ewolwverage speed for the tr l1/0,w be clh-7fe)z1l:sw qntb ow8vip?

  An airplane travels at 300 mi/h south for 2.00 h and then at 250 mi/h north tz ag3judv.8e.zw5;ufor 750 miles. What is the avez5a.jwe.8 gtu u z;d3vrage speed for the trip?

  In a 400-m relay race the anchorman (the person who runs the last 100 m) for tea 5aqb:by0 x4c:c/kqcim A can run 100 m in 9.8 s. His rival, the anch k5 c4ay0/xc:i:qqcbborman 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 af l+q -y8flkx(mter 12 s. The car's average velocity during deceleration was 43 km/h. What was the car'sf 8lkmxl+ (yq- deceleration while slowing down?

  An airplane increases its speed from 100 m/s to 16)s0coq t9byn 70 m/s, at the average rate of oby7)tn 90csq$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h ac(b twfttt0v(ajl7 -n 0celerates 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 at0kv7if77q ob8gl6 ljm $4.0 \; m/s^2$ 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 bqio2g5 c2lg9up with a constant accelerationcbq52go 9li2g of $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial veliqvloaqtd / bmcaqb9 ;6x61-6ocity of 7.4 m/s experiences a constant acceleration of qat ; lbvd-i6qmbx /oqa661c9 $2.3 \; m/s^2$. What is the cart's displacement during the first 5.1 s of its motion?

  A bullet moving horizonbck2+q am 2+od*cb .prtally to the right (+x direction) with a speed of 343 m/s strikes a sandbag and penetrates a distance of 41.91 cm. What is the average ap.r 2 cqb++obk ad2c*mcceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launch zrg2vb;jb ba9tmmc(r3+ 7-m b6bv pv5ed from a catapult on an aircraft carrier. It reaches a speed of 42 m/s at the end of the catapult,mr 2brm+jv-tz6bv59g bca (b bvp73;m 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 constps9qvbp9gpn) l36 cxin.te 0.ant 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 otcv*/ s4jq5x(5wpvm;q grj 5i f 200 m. What is its average acjs xcg*5 j/pv5q 4tqvwr;(5i mceleration?

  An object starts from rest and undergoes uniform acceler9ijtpu8t t*969 dvf yration. During the first second it travels 5.4 trduftjy *tiv9 89p96 m. How far will it travel during the third second?

  An object is moving in a straight line with constant y62fo4 8 e xvqnu).hbwacceleration. Initially it is traveling at 16 m/s. Three seconds later it i2 6vh ey).fuwxq8 b4ons traveling at 10 m/s. How far does it move during this time?

  A car starts from rest and accelerates un45 w dkx5kcvi)iformly 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 decsiyq0/yf -dr/ elerate 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, a0 bcvq43rw ,nk+(+sla;0brv orgizg* car that has been waiting at the intersectio+ 0b0 g,*(o4lb3s rcqn;vr +zavwrigkn 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 upwardvy1vln3hqvg1 )f3vysj)8 1 cp with a speed of 12 m/s on the surface of planet X where the acceleration d 31y8 fq) nl1y3cv 1v)gvphvjsue 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 su;m5l5*o o zhkhrface of planet X where the acceleration due to;om* 5lhzhk5o 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 surface o 7(thy;vdhy2 pf planet X where the acceleration due to grav h7(dy2vpyh;tity 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 wit+;p0rq0jxg5n:xwt f eoy)-iqofre ;sjb n 2+9h a speed of 14 m/s on the surface of planet X wheren0o)q5pj; s-b+ye 0 r j +2nfxoget;:f wrxqi9 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.j:f4:l6hrssoemu z1 610 s. If your friend holds a ruler between your fingers and releases it without warning, how far can you expect the ruler toej:fsu6z6r1 4mos hl : fall before you catch it?

  A ball is thrown upward at a vel:*q lj .rsduh7ocity of 19.6 m/s. What is its velocity after 3.00quh: . ljr*7sd s?

  A bullet shot straight up returns to its startingli* jymase+wy+* * n6d2z )wugin;;i k point in 18 s. What is the initial se2 ;i);6i+s**wud*n gmznw jy yik+lapeed of the bullet?

  A ball is thrown straight up with a speed qc.yygpy .myxgu5 -,6of 36.0 m/s. How long does it take to return to its start.y ,y yucyg6.5pmxg- qing point?

  A ball is thrown downward from the top of a building with an initial speed of v86eg*xja2u .x-y aia18 m/s. It strikes the ground after 2.7 s. How high is the - xvuagxja e*6i. 8ay2building?

  A ball is thrown straight yd1j8g,h*/lgj 7gj jm up with a speed of 30 m/s. (only fill in numerical value i md7g8yj*j/gl,hgj 1jn 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 speed of5xoopr(lu/ d6. cq 9fi 45.8 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 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 m3be; go(7gulg** gedis the velocity at t = 1.0 s?

  In Fig. below, what is the (w2c7 dh jhg9gt3us6c velocity at t = 2.5 s?

  In Fig. below, what is the velocityc,oju; e:wdnpgz077 9kd o/ :mz*kxsrae s,k9 at t = 4.0 s?

  In Fig. below, what is the velocg.,k*3jx h z:b+h ppnjity at t = 5.5 s?

  In Fig. below, what is the average velocity f pp37 ycp50nrpic4gzl*k p5( orom 0 to 4.0 s?

  In Fig. below, what is the averat3 ;uc,vxor8 9,mcjeaal rsuv8 :0vm)ge velocity from 0 to 6.0 s?

  In Fig. below, what is the acceleration at 1.02 uct9dxj5a d) s?

  In Fig. below, what is the accgjgvi l 6/hrr:4 *w. /sp2*uu8vpuzgf)j1 zjreleration at 3.0 s?

  In Fig. below, what is the average acceleration fromm2vwch/ag i2iz: t14x 0 to 5.0 s?

  In Fig. below, what is the average a d*2qox8;f*ocd9 rsekcceleration from 0 to 8.0 s?

  In Fig. below, what is the displacement from 0 hlarq-ldq;;7to 8.0 s?

Does a car speedometer measure speed, velocity? {speed|vi(i l.ivkz9+u 8tgoi +elocity}

  An object can have a varying s7 m1,llgbhsj -6bu ts0i lh1.uv/dj; ypeed if its velocity is constant.

  The velocity of an object can be 0n: *bzfgae8anr/egn2( fn,pu-r t di5 kt,q1negative when its acceleration is positive.

  If one object has a greater speed than a second zhqudc e 4m0 o6:j*9hcobject, the first must have a great9 jq 4zu06oc:hh cem*der acceleration.

  Two cars emerge side by side from a tunnel. Car A is tanzh9h6zosxlro,: .( raveling 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 decrezw qd0ij1jd s)5wl5l;cy 3j0 tases.

  A baseball player hits a foul ball straight up into the air. It leaves the bat:/iuu5ye l ngxf.ch/ 3;cpdz1*x f;ed with a e ./ if3x hc;gndpel*1:f;d 5c/yuxzu 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 happening3mdcwz: lbjkk(r0 0+ k7rsd 7o to its acceleration, how does it change if air fricti0r dd7 0k(rk:jzl+7 kombwc3son is ignored?

  As a freely falling object speeds up, w4 bxpo+ih3l;,0u.cavtr c6odhat is happening to its acceleration, how does it change c4b 3 xadhrp6cvli;o.o,u0 +tif air friction CAN NOT be ignored?

  An object that is thr9tw4wt) y,w7uvs d y5iown vertically upward will return to its original position with the same speed as it had initially if air resistance is negligible. sy wtw4vyw,5td7iu 9) If air resistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzero accelerationuva xe/frndqhku ueu(3 78f*/ 0b5n*zcj3u7 a at the same time.

  An object can have nonzero velocity and zero acceleration at hpwdz1 a 12c2jthe same time.

  An elevator moving from the second flooe4l e.z * ;ks9bj0jk/nap s6rhr to the fifth floor making no stops along the way has zero acceleration all the r jj4sz9ke0*e/ pnlb.6;hkastime.

  A rolling ball moves fr k.tvpe1+ eo1hom $x_1=2.3 \mathrm{~cm}$ to $x_2=-5.8 \mathrm{~cm}$ during the time from $t_1=2.7 \mathrm{~s}$ to $t_2=5.1 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-4.1 \mathrm{~s}$ is at $x_1=3.2 \mathrm{~cm}$ and at $t_2=3.3 \mathrm{~s}$ is at $x_2=8.2 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight coq3h2b6at 10vzwlt//-* lu.djh-lu y7c gqwpm mplete laps around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 11.5 min. Calculate (a) the average speed  (数值)  $m/s$ and (b) the average velocity    $m/s$

  A horse canters away from its trainer ik17cxzspyy 104b ry5jn a straight line, moving 90 m away in 10.4 s. It th4yz1ky51cyx0 j7s rpb en turns abruptly and gallops halfway back in 4.7 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 fr13cm r p4l,l:y-t puabom $12 \; m/s$ to $25 \; m/s$ in 5.0 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 frod z;d se6n:t1f2d4u:h hv) arsgjxs53m $22 \; m/s$ to rest in a distance of 83 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a spoyen i h(m v,1q.k*di-eed of $28 \; m/s$ 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 the blocks to essential5-ojgnba f) -5c a+wokly top speed abouta ocn+ f-ab)g- k5wjo5 $10.7 \; m/s$ in the first 11.1 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 speed oqpgyo*k ,0 o1df $18 \; m/s$ to rest in 5.83 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves skidmw c7bo m+a8h+85 gzgm marks 92 m long on the highway. Assuming a decelergh w b8++mmom 5g7azc8ation of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck goin-7dku f 1hy/llg $25 \; m/s$ 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 co+o5 v2tus+;zq cfvs (xmplete the 10,000-m run in less than 30.0 min. After exactly 27.0 min, there are still 1100 m to go. Thetq+s vcxs 2ofuz5+;v( runner must then accelerate at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$