Suppose that an object travels from one point in space to aneq(ez 5+lu-nf other. Make a comparisnue5efqlz-( +on between the displacement and the distance traveled.

  When is the average velocity of an object equab,jzw.4zge nyil8u +k 3;+fugl to the instantaneous velocity?

  A new car manufacturer advertises that their car vj5teh6k *h,qung09ci7 2 ifvx2cm7x can go "from zero to sixty in 8 s". This is a descrit2e,vf7hcj6 5 0ivqh7xngc m9x*ki 2uption of

  An object moving in the +x axis experiences an accelera ff84ca cf :8 ej3u()dltj+sittion of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x direction) begins to s 8p wp -yz6rij+g;p8gulow down as it approaches a traffic light. Make a statement cogp+ - rupy wzi8;p8g6jncerning its acceleration.

  Suppose that a car traveling to the West (-x direction) beg- ky,nq:zs c ak,99bj -/bumlsp: rv+jamzh9 5ins to slow down as it approaches a trafficbup yas /lbrk mm:-qzzv-s 9jc h+9,,k:an5j9 light. Make a statement concerning its acceleration.

  Suppose that an obje5bqf6jgw8jja*: f1eact is moving with a constant velocity. Make a statement concerning its acce :*1a6wjgfqjb faj e58leration.

  If the velocity of an object is zero, does it mean that the acceler6,fkfps 4l0o7nn2dun j e/t2yation is zero? Support your answer with af6/0sj24lu2 ydt e,pon nnf7kn example.

  Can an object's velocity 5hk4allpjs++ 7y 3vow change direction when its acceleration is constant? Su+hwlok+374ajvls5 p y pport your answer with an example.

  Suppose that an object i2 ls/*. imfxvn)+hxfo8e+j jms moving with constant acceleration. Make a statement concerning its motion l/vf+j.mfxo h8* mnx ei2) s+jwith respect to time.

  Can an object have increasing speed while its acceleratihmmf,v0 2smtih:4 hvj j31b/yon is decreasing? Support your ans3iyj0,hvf21hs: mjtb/m m 4hv wer with an example.

  Suppose a can, after an initial kick, moves up along a smooth hill ofgcufd0ba5 5+ gs/swccilcmz1( * 2oh- ice. Make a statement concerning its*fc1 /g 0hagwu cli sc52cdomz5+ (b-s acceleration.

  Under what condition is average velo ruwfd bkj82g1)+z,ii city equal to the average of the object's initiai2fi k1rud)8 +g,zw bjl and final velocity?

  Objects A and B both start at reo i fu/k8o8/shst. They both accelerate at the same rate. However, object A accelerates for twice the time as object B. What iu8oi8/o/shf k s the final speed of object A compared to that of object B?

  Objects A and B bothz 36uaj olxw30 start from rest. They both accelerate at the same rate. However, object6 3z3a xuowjl0 A accelerates 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 from rest and falls in the absence of friction,l2tkgl+2ka : bb8n pfvi,2, fx which of the following it+ akb l2,f,2b:k8 xln2vgfpis true concerning its motion?

  When an object is released from rest and fooxv)b/ y8 ( rh*slgd:alls in the absence of friction, which of the following is true concerv*x8 (grody/o)lsh:bning its motion?

  Suppose a ball is thrown straight up. Make a staxa xed8v0a1 yi//jied*lt t:8tement about the velocity and the a*i:08a/81tejvxtx edayl di / cceleration when the ball reaches the highest point.

  Suppose a ball is thrown straight up. What is its acceleration just befofpyg 8qro.io9+; is l3re it reaches its highesi3pgi8yqf.s9+ r ;o olt point?

  Suppose a ball is thrown sayr84sh 7n1kctraight up, reaches a maximum height, then falls to its initial height. Make a statemr8s7n4kh1a ycent about the direction of the velocity and acceleration as the ball is going up.

  A ball is thrown strm6 u7r0 zsj5 6hksr6o.khvk7iaight up, reaches a maximum height, then falls to its initial height. Make a statement about the direction of the velocity arh70 u7ms5k sv joh6.k ki6r6znd acceleration as the ball is coming down.

  Suppose a ball is thrown downward r,vdkk9:f4j fin the absence of air resistance. Make a statement concfj:9rf d4k,k verning its acceleration.

  Suppose a skydiver jumps from a hrx7vct ;oz0e7 igh-flying plane. What is her acceleration whevxr7; zc0t7o en she she reaches terminal velocity?

  A ball is thrown vertically upward with a speed v. An izh( lzsi aicb341vq.5 dentical second ball is thrown upward with a speed 2v (twice as fast). What is the ratio of the maximum height of the .ha(l3 vzcisi 1b4qz5second 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 laterjeox7n(j eq --, ball B is dropped fjx e joe(n-7q-rom the same building. As time progresses, the distance between them

  Ball A is dropped from the top of a building. One second later, bv,91qy phq/ j5,tlfvs8lhn s)all B is dropped from the same building. As time progresse,h5hyj ll vtqq)f8n /sp s19v,s, the difference in their speeds

  Two objects are thrown from the top of ibv/d h kx8-l2a tall building. One is thrown up, and the other is thrown l8/-hdbkix v2 down, both with the same initial speed. What are their speeds when they hit the street?

  A brick is dropped from the top of a building. A second brick is thrown straa8tsua6y,scz0 3w+0i no vm:d ight down from the same building. They are released at the same time.z06s,cdt:wa n8+ysv30a muio Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with constant non-zero velocity in the +x ekq94 sd/m q;mi.3vh z7afku(axis. The position versus time graph of this obqvsmm47aq.( zd i/h kk ufe9;3ject is

  An object is moving with constant non-zero acceleratiiyqj)q.p w0 6ton in the +x axis. The position v.0)6iqpqytj wersus time graph of this object is

  An object is moving wip+kvny zf.d (tx6:ap9th constant non-zero velocity in the +x axis. The velocity versus time nt:6+zv9pd.ka xyp f(graph of this object is

  An object is moving with constant non-zero acceleration in the +x axis. The9 u n+;7qi4beg.wj+iv7ey hm b velocity versus time graph of t4 n7 9bmi7jg i;hbqy.wv++eue his object is

  The slope of a position versz;( e /*ykpygsi4mqg+us time graph gives

  The slope of a velocity versus time graph giv ;.m(wum,3rxvlekj/dq8xu 0-fp3dp5oec- j des

  The area under a curve in an acceleration versus time o88aelv *xl u*,4sxa5v :t tvivaea+ 4graph gives

  The area under a curve in a velocity ver pnj1g7g9*bzifo 9xp/x )p)t csus time graph gives

  If the position versus 3 makx6k +aniv/ur/ u2rx2(ng time graph of an object is a horizontal line, the object 2rx n m(3uk/rvuk/aai+2x6 g nis

  If the position versus time graph of al0* imrvam y4+uto mcvn/x s-3z8v9c.n object is a vertical line, the object is+avzt.n4cvm9l-*3mic y 0 8/oxvrmsu

  If the velocity versus time graph of an objec1ldv/ 2y8thpu 3.unvjt is a horizontal line, the object is3v2 .y1/ tnuuh vlp8dj

  If the velocity versus time graph o:pz 6u pm46nlof an object is a straight line making an angle of 30 z 4pl m6uo:p6ndegrees with the time axis, the object is

  An object moves 15.0 m north and then 11.0 s )n2tbgu1y3s(x k9zu m south. Find both the distance traveln1g(sbz2kt)u yu9s 3 xed and the magnitude of the displacement vector.

  A boat can move at 30 kmocn(;puk v gd4j7b;:n/h in still water. How long will it take to move 12 km upstream in av7;:nn;b dokg j4 cpu( river flowing 6.0 km/h?

  55 mi/h is how many m/s? (1 mi = 1609 mv5k2zj 3x 6sa *38 rufi eaj-v5 gn7o*ul5ymvk)

  What must be your average speed in order to trav 1x4gr;)(dv0zyj/jtdv ki r5t el 350 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 km) in 2 hours and 56n go6nt(j (9ufr d0mh3(b i( ktbp*ns7 min. What is the average speed of the runnergmj p 630d*ktu(f6i(h r(bno(sbnn9 t in m/s?

  A car travels 90 km/h. How long (hm-mgj9r/u , o,kpwcdoes it take for it to travel 400 km?

  A ly (light year) is the distance that light travels in one year. The speed o r 3ju 9 zard m.5c5iyye:1d.isu6pln/(jdvp/f ljuajyuliic nrp evy65 d53.s/9 pdr z1dm./:(ight 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 a.o 1 a1f/5yhbhi 127)pe kgemaz0f ijxlong a straight road and you look to the side for 4.0 s, how far15e h.0x1o f1febaj y hkmi7ag )z/2pi do you travel during this inattentive period?

  If you run a complete loop around an outdoor track (400 m), in 100 s, your sko jpzoj36-(on: f ,baverage velocity iobk poo6f3:(-,jz jns s

  A polar bear starts at the North Pole. bnu9g6gz(bi ; It travels 1.0 km south, then 1.0 km east, then 1.0 km north, then 1.0 km west to return to i9b6 bigzgn;(uts starting point. This trip takes 45 min. What was the bear's average speed?

  A polar bear starts aty85b 1bn4e4yr-1muzn j mai6f the North Pole. It travels 1.0 km south, then 1.0 km east, then 1.0 km n bi6my benf841jrnaz-14 5u ymorth, 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 school at 55 mi/h for 110 miles. It t8s1 ql4wa-al then starts to snow and you slow to 35 mi/h. You arrive home after driving 4 hours and 15 minutes. How far is you8ls lat4qa- w1r hometown from school?

  A motorist travels 160 km at 80 km/h and 160 r -llx5/ri0 .qal93qruf2 mdxkm at 100 km/h. What is the average speed of the motor2fl- darmxl3q 0.xu9r/5lr qiist for this trip?

  A motorist travels for 3.0 h at 80 km/h and 2.9e; e9ittrr4 e0 h at 100 km/h. What is her average speed for the tr9e; 4eettrir9 ip?

  An airplane travels at 300 mi/h south for lv9vw(/rb.6fln4jpbn a g:cts0 cz0(2.00 h and then at 250 mi/h north for 750 mileljr vn0f6g4w cb(n .l9atv/bs(p:zc0s. What is the average speed for the trip?

  In a 400-m relay race the anchad, ab u.i9,3rl4b0. udqls) 1 wyrmkgorman (the person 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 leg of the race, in ,u bm,ya0dral4 1 kql)3 .sbi9 .udgwrorder that the team A runner not lose the race?

  A car decelerates uniformly and comes to a stop after 13 s. The car'sklh *dfee26-s9b km;i d:w mwb.l.b8r average velocity during deceleration was 33 km/h. dk.- lb.h f ew8*6ersb;i:mlb 9wdkm2 What was the car's deceleration while slowing down?

  An airplane increases its speed f8*h( r, r vzgw6s9yejtrom 100 m/s to 160 m/s, at the average rate of rwhy,8jts (gz*r96ev$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h a ,*.caqii0rz accelerates 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 r37pnoqh(i z (gest 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 thena xiy)9h(o): mjiv7vle 2g:dm speeds up with a constant acceleratioi:7mdjiogel mh9vy:va( )2 x )n of $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial veloc (ysdc4. i,9f u z/msmn+dw c3o(zxaj:ity of 2.9 m/s experiences a constant acceleration of s f(ziw,nos3j(admcx m :/c94u z.+dy$3.1 \; m/s^2$. What is the cart's displacement during the first 4.2 s of its motion?

  A bullet moving horizontally to the right jeg:s8y;8wn au,e3 yq (+x direction) with a speed of 357 m/s strikes a sandbag and penetrates a disguw,e3j 8q:a e;ysn8ytance of 34.28 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on an airc 7 j:a 5)fe0dump;1oy5x tzlelraft carrier. It reaches a sp 5ypxet f j o:1l5al)mzde70;ueed 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 of the catapult?

  A car starting from rest moves with kf5qv9b) dmv6constant 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 7nypc l.bh/h 3m. What is its average accelh/n cy l.phb73eration?

  An object starts from rest and undergoes uniform acceleration. Dxj)4ig(aq1 au8(9: cq fsvad ij2t8z5(icag auring the first second it travels 4cg (((q8adxf tg9ij i caa:u siq4ja8zav2)15.9 m. How far will it travel during the third second?

  An object is moving in a straight line with constant acceleration. Initially jb5 foatvnn7pr4 (d4/ it is traveling at 16 m/s. Three seconds later it is traveling at 10 ab(vf445 jrnd7 /tn pom/s. How far does it move during this time?

  A car starts from rex8rfq;l )nti8q3 i*j fst and accelerates 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 at about 5 syape.68tjw$5.0 \; m/s^2$ 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 turnsat o-;hhhgp) m;/4wq;s i1 qgs green, a car that has been waiting at the intersection starts ahead with a constant acceleration oft;p/a whh;s)g;h s om4 g-1iqq $2.00 \; m/s^2$. 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 qq 5lq:+wd ;lga speed of 12 m/s on the surface of planet X where the acceleration due to gravity is q:;g5qqldwl +$1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown upward with a speedu(j)y:pt.i6h x wxls 0zv7 n3v of 12 m/s on the surface of planet X where the acce.:h 3 pxvui)6yn w0xjlvz7(stleration 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/s5y+ d)q4j;ssrn 3xzr y on the surface of planet X wherdr; j+)r4 qyy3xzsn s5e the acceleration 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 speed of 14 m/s on the surface of wsx1b:+ky th8 planet X where the acceleration due to gravity ikx+hw1:b sy 8ts $3.5 \; m/s^2$. What is the speed of the object after 8.0 s?

  Human reaction time is usually greater than 0.10 s. If your friendyom+tt5wh ( m* holds a ruler between your fingers and releases it without warning, how far can you expect the ruler tmtmh w(t5+y*oo fall before you catch it?

  A ball is thrown upward at a velocity oua:5p br)bmqw lvf*3 (6c;d bay(uc5ff 19.6 m/s. What is its velocity after 3.0u;dm y6*w3b5pa ab ((uffr5bqc c):vl 0 s?

  A bullet shot straight up returns to its startino9ozjw kw0 (il; ip7ah:k:sb7 g point in 4 s. What is the initpol7ok:i7(a9 ;w 0iz :bskwjhial speed of the bullet?

  A ball is thrown straight up with a speed of 36.0 m/s. How lon+. 0zhx 5mwawmg does it take to return to its starw mx.ma0 w5+zhting point?

  A ball is thrown downward from the top of a building with an initial speed o7 ptbsman 9t:5f 9 m/s. It strikes the grounds5mptn ba97t : after 7.3 s. How high is the building?

  A ball is thrown strg7x.y/w l 5nkhaight up with a speed of 30 m/s. (only fill in numerical value in h lgx7y/knw.5 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 :4z .o )zi dmtowoooau5*i+7f a speed of 38.2 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 9 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 9.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is f98c( itu,bs,3jger a the velocity at t = 1.0 s?

  In Fig. below, what iry.b+q uo.it 0s the velocity at t = 2.5 s?

  In Fig. below, what is the velocity at t = 4.0 s?p;0ychd, 47jj5hck j k

  In Fig. below, what is t9qozw80l)gv bor3 qb, akwa ,:he velocity at t = 5.5 s?

  In Fig. below, what is the average veloim-;2 fgifvevr1d7uin0o a66city from 0 to 4.0 s?

  In Fig. below, what is the averboxv.jf0wq oiv f2 ),s (e3k:rage velocity from 0 to 6.0 s?

  In Fig. below, what is the acceleration a 8uno3n d(a c/n7fwcd tj(25lst 1.0 s?

  In Fig. below, what is the accex)0bt 16zed d5n9ygwdleration at 3.0 s?

  In Fig. below, what is the average acceleration from 0 to 5k8szayx8)f2pr oo+ cx*1.qo k.0 s?

  In Fig. below, what is the average acceleration from 0 to 8.0 sa:q0oxp 0)7 sptrm:ay t;sbcx4)bx 5y?

  In Fig. below, what is the displacemlo; ;i,.w pxcvent from 0 to 8.0 s?

Does a car speedometer measure speed, velo7, ( pqzkyzg,o1pkx, gm,y xt/city? {speed|velocity}

  An object can have a varying speed if its velocity is co :kvxw8j cxr+di 3.:banstant.

  The velocity of an object can be negative when its accel1 9oqk(ikn k3d)bsg4ieration is positive.

  If one object has a greater speed than a second object, the first must tv+c5o a zvngf1u ajapvj;.: uo;:02q have a grvqo2;ja tp10an .j ;za5v: +:vcufg oueater acceleration.

  Two cars emerge side by kggz1z6 + )w(lralr5u side from a tunnel. 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 l5v; nedf,sjb(m9 zo* 0qm6hj speed as its acceleration decreases.

  A baseball player hits a foul ball straight,bzhn,bq: o6/cx uxz69l e 6iv up into the air. It leaves the bat with a speeuzhbo/c6 v9 i e,l6xb,q:xz6nd 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 objects00 / yws +gyb npk*k o1eam);ysy(rn( speeds up, what is happening to its acceleration, how does it change if air friction is ignoredgo0bp*ry;y)1e(skk+ n as y( smy0/wn?

  As a freely falling object speeds up, what is happening to its acceleration,hm 4t(1d*dlofdqfl (:;kwjz+ d 0il1k how do4fdwtlmf hi(1l1(d kk *jdq0;o + z:dles it change if air friction CAN NOT be ignored?

  An object that is thrown vertat1t:2jxrrnz1 2ji e r wdu*e:rj )/6eically upward will return to its original position with the same speed as it had ini 12i r :e*ntx1j/wajue )erj 2z:6rtrdtially if air resistance is negligible. If air resistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzero acceleration at6dr8e 8xd eh;n the same time.

  An object can have nonzero velocity and5td 2q-3 ccp ahlv(bi8 zero acceleration at the same time.

  An elevator moving from the second floor to the fifth floor making no stw;./+bn o sz -jaby)7lmozs/pjt 9 ejaf1.wd7ops along the way has zero accy;7jbbm )7ezzww /aso-sj.pl9 +o fatn /j1d.eleration all the time.

  A rolling ball moves m6- akdj (z:8cn,6n3u 2ucm fvxxnkz7from $x_1=2.8 \mathrm{~cm}$ to $x_2=-6.5 \mathrm{~cm}$ during the time from $t_1=2.2 \mathrm{~s}$ 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 $t_1=-2.4 \mathrm{~s}$ is at $x_1=3.3 \mathrm{~cm}$ and at $t_2=3.3 \mathrm{~s}$ is at $x_2=7.4 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps7 . h+hzs zkgady5f;+m around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 9.4 min. Calculate (a) the average speed  (数值)  $m/s$ and (b) the average velocity    $m/s$

  A horse canters away fromiah/nndaw 0rx71d f88 its trainer in a straight line, moving 90 m away in 12.7 s. It then turns abruptly and gallops halfway back in 4.6 s. Calculate (a) its aver8fdn i0naaxrd h w/187age 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 fro/ 3jnmkw/ul7sn dw)t1 m $12 \; m/s$ to $25 \; m/s$ in 4.1 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 frouzalb 8h .(ye:m $20 \; m/s$ to rest in a distance of 59 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a t1tf+*q9y q tbspeed of $32 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.3 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of the blocks to +s).jb bqbp v-essentially top speed about b b)psb. j-+qv$10.9 \; m/s$ in the first 12.3 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 fromdet i9f5+z zjt.8ezr5 a speed of $16 \; m/s$ to rest in 5.66 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves skid marks 92coeh zzbk()0 z l9ul2w6c5xq7 m long on the highway. Assuming a dezox6(k 2cwbzh e0c )z9ll5 7quceleration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck goia2e. s;f9kf3fkcrg 3mng $25 \; m/s$ 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-m run in less than 30.0 min. z3b6 + cfhju.e6q2mnpefpy)tdh+) w)*h ba w; After exactly 27.0 min, there are still 1100 m to go. The runner must then accelerate+ate2 z;w3e qh)dchm6)f*f)w6 bbjpyp u+ .nh at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$