Suppose that an object travels from one pointjjqx j1e4 2h5uf ;sg5a in space to another. Make a comparisuga he5 x j;js241fjq5on between the displacement and the distance traveled.

  When is the average velocity of an object equal to the instann mixmvy:8l2 -z -)qgetaneous velocity?

  A new car manufacturer advertises that their car can go "from zero to sixty in 8 k5ot+(kscbei 0:r/nv s". Thv0nt5k+ /:ie scb(rokis is a description of

  An object moving in the +x axis expewamp( .n4b qlk7b p8h3riences an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to j0qgrcy+8d9heqw* +pthe East (+x direction) begins to slow down as it approa0q 9+w8c*qe gh j+ydrpches a traffic light. Make a statement concerning its acceleration.

  Suppose that a car traveling h ht;tm1f2jqb(mf /)oto the West (-x direction) begins to slow down as it approaches a traffic light. Makeho1;f h2 ttb jm/qf()m a statement concerning its acceleration.

  Suppose that an object is moving wit.zzekos fo j3b .iteiu1/2b). )r8nluh a constant velocity. Make a statement concernubf b1) s3jk/e.)le ui .oz82otizrn.ing its acceleration.

  If the velocity of an object is zero, dlgkh8n ,b* n(*ds-;yb2 l(hvq um+zwf oes it mean that the acceleration is zero? Support your a, -2gvb(m;dw uqn+hsbl*hnzk (ylf*8nswer with an example.

  Can an object's velocity change direction whe(a tt(8 mvxwq:ic+y*lu-rb/hn its acceleration is constant? Support your answer w ixt*q /h(u:+-wyarlcbt v8m(ith an example.

  Suppose that an object is moving with constant acb;ihv u6:-s usceleration. Make a statement concerning its motion with respect to timei6:b;s uhsu- v.

  Can an object have increasii /an),piyya+f, )qtsi-fn pb 021dwgng speed while its acceleration is decreasing? Support your answe2i)igd- f+ i tq/,an abfny0s)pwpy1,r with an example.

  Suppose a can, after an initial kickkkv277/ qlihp6t (zsq, moves up along a smooth hill of ice. Make a statement concerning its a6qsqtlvkp k 2h7i7 z/(cceleration.

  Under what condition is average velocity equal to the7f8 g(t(c kmvahctgefy9p 1cn q595b0 average of the object's initial (p9cffcbtq c1et k9v5 gga(7m 80n5yh and final velocity?

  Objects A and B both start at rest. They both accelerate at the wf6ari74bb fpjl;,;lpru0a//lvip 4 same rate. However, object A accelerates for twice the time as object B. What is the final speed of object A compared to that of obj,6aw 4/fip7lrab p4;jblvf/pu 0rli ;ect B?

  Objects A and B both start from rest. They both accel 6uzoktrhrguja7r;*4ilv:cpc-, gks 4-bu(1 erate at the same rate. However,6 :g *kzu4(t1;our j hva,p-ic7urlkb-cs4rg object 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 relea3*t+dgdgh*kx, d3 fmv gb-h*(ln ni1used from rest and falls in the absence of friction, which of the following xm*lh3 *3 f* nndugihd-vt1 ,bk+dgg( is true concerning its motion?

  When an object is released from rest and falls in the absence okkuk4do+g( yzxfgi :3b-l/ c4f friction, which of the followcko ydik:4k/b+ xu g4(f l3z-ging is true concerning its motion?

  Suppose a ball is thrown straight up. Mu 6zayi8guj4-( b- dtvake a statement about the velocity and the acceleration vd zug-(ib8j-6t 4uya when the ball reaches the highest point.

  Suppose a ball is thrown straight up. What is its acceleration just before it gyk. r r,p/z;freachefrg ;k/,pry. zs its highest point?

  Suppose a ball is thrown straight uyh5*u blr(d tk;+y 5wwp, reaches a maximum height, then falls to its initial height. Make a statement about the direction of the v 5; +ruhl y5*(btkwydwelocity and acceleration as the ball is going up.

  A ball is thrown straight up, reaches a maxid y(*k*juyfu0nt vx1sy 8ysr( w7 qv3wn9,c/lmum height, then falls to its initial height. Make a statement about the dire qctyw90(, k y*uj*/fnvs73(srwlyvy dn81xuction of the velocity and acceleration as the ball is coming down.

  Suppose a ball is thrown downward in the absence of air resistance. Make a di6povfm+l4lt 4 :qe. kg)wr3 statement colg4i)3ft ple. wvkqmo4:+6drncerning its acceleration.

  Suppose a skydiver jumps from a high-flying plane. 6i- kwb 0yyi.cWhat is her acceleration when she she0yicbi.y6 -k w reaches terminal velocity?

  A ball is thrown vertically upward wit ln2// *rty bn:1diiavw5nm h0*+zjelh a speed v. An identical second ball is thrown upward with a speen b/:+l*d5v2irnalw 0* imj/z 1ehytnd 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 ball?)

  Ball A is dropped from the top of a building. One second latqi5cfh1w/*f ter, ball B is dropped from the same building. As time pfwt* q h/1fi5crogresses, the distance between them

  Ball A is dropped from the top of a building. One second later,:h4fbrpq 0d6 t ball B is dropped from the same building. As time prp:rf4b60h td qogresses, the difference in their speeds

  Two objects are thrown from the top of a tall building. One lriid c+ ,o:g0*5rk vna x*zixij:1f /is thrown up, and the other is thrown down, both with the same ini: /ki+ x *cln5dzi:ijrv i,o*g1x0r aftial speed. What are their speeds when they hit the street?

  A brick is dropped from the top of a building. A second brick is thro,hzt ku9p. sydh2*ib2ps s) y:wn straight down from tb zi ).ss2hh:, 2*tkspuyy p9dhe 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-z22e1v ke k9mpkero velocity in the +x axis. The position versus time 2v 2ek mek19kpgraph of this object is

  An object is moving with constant non-zerol:9l,q7k2il s. hl xh4xjt un8 acceleration in the +x axis. The position versus time grapujsh 9tq l7lll2i:x,8 4xh .knh of this object is

  An object is moving wi- 5mdn3u,9v lly z0wbiu.n uq.th constant non-zero velocity in the +x axis. The velocity versus time graph o. l-b nq05.viu9d z3ulnu,wy mf this object is

  An object is moving with constant non-zero acceleration in the +x axis. The vel0qb f wc3pz56locity versus time graph of tcw5 6q3pz0 fblhis object is

  The slope of a position versus time grastb0 34x,wabluh0x 07fnzj9y s ,*lmwph gives

  The slope of a velocity versusa0+v.5m6b*p nddswb 4alu l,m time graph gives

  The area under a curve in an acceleration versus time graph gil7a8 y1jqo4 jf b.s/y(3fozlxves

  The area under a curve in a velocbed bdrcm 4mhg) k+cj96y:,0k9f3tn z ity versus time graph gives

  If the position versus time graph of an object is a horizontwe w. v320aqwwal line, the object e0wvww3 wq.a2is

  If the position versus time graph of an object is a vertical linp 3 ub.oydb)w(66y nw mb)crs*e, the object iswocbs d (b))m6y3nrby p. *6wu

  If the velocity versus time graph of an object is a horizontal line, th:s ccff:g/:(8 yssvq he object i (:s/qh8vfyfs: c :cgss

  If the velocity versus time gr-3 vgo p(6 bm)ch+2hdthzxw3iaph of an object is a straight line making an angle of 30 degrees with the time axis, the object i) +thvm3bg d3o(hwh c x6i2zp-s

  An object moves 15.0 m north and then 11.0 m south. Find both the distanvdbepx*,hjp69tkmr (m ix** -ce traveled and the magnitude of the *mer-i 9x, jhvk*tpdbm*6(x pdisplacement vector.

  A boat can move at 30 km/h in still water. How lo8fq7-/ yzc mh1idqs a;ng will it take to move 12 km upstream in a river flowing qcf8-qz hsd ;7m/a 1yi6.0 km/h?

  55 mi/h is how many m/p(0o yev ;3div6g*hxe s? (1 mi = 1609 m)

  What must be your average speed ysjv 3j5 ;q4mhin order to travel 350 km in 5.15 h?

  A runner ran the marathon (approximatelz e**ytl2b xpiho.h )9+nul,gy 42.0 km) in 2 hours and 57 min. What is + zgoh.y*heuli9n pbxl, 2t *)the average speed of the runner in m/s?

  A car travels 90 km/h. Hoyp 5goz v(dw2g5w1 ;dqw long does it take for it to travel 400 km?

  A ly (light year) is the distance that lk 6,nbxq d opd+62:exbdbw 3k2ight travels in one year. The speed of light i,ebq6b6b:wd xn2dko+p2dxk3 s $3.00 \times 10^8 \; m/s$. 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 ugexw0 91g5un and you look to the side for 4.0 s, how far do you travel during this inattentiv90 15uwnugx gee period?

  If you run a complete loop around an outdoor track (7nob. guzb8zbxp-v 3 aq/cc 23400 m), in 100 s, your average vc 3qz.ba/ob-n8bpc2 gx7zu3velocity is

  A polar bear starts at the North Pole.*4v*:rlvz fcg It travels 1.0 km south, then 1.0 km east, then 1.0 km north, then 1g*lrvvf:c 4 *z.0 km west to return to its starting point. This trip takes 45 min. What was the bear's average speed?

  A polar bear starts at the North Pole. It traveo z2*i5 k3zza4(t wqahcp :j)zls 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 take:*acah z2zp3qw)kt 4 z(izj5 os 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.up5uasx);ycn(; j8jm It then starts to snow and you slow to 35 mi/h. You arrive home after driving 4 hours and 15 minutes. How far is 8(yp c usnaj;jx )u5m;your hometown from school?

  A motorist travels 160 km at 82tfn ;p1sude.0 km/h and 160 km at 100 km/h. What is the average speed of the motorist for tep f2nt.s1du;his trip?

  A motorist travels for 3.0 h at 80 km/h and td qtict2 pja 3u498e(2.0 h at 100 km/h. What is her average speed for theqitd 2ucpja8et9(4 3t trip?

  An airplane travels at 300 mi/h south f ec+dh*.az9/ily n1wi w/z;it+ ojf*ror 2.00 h and then at 250 mi/h north for 750 miles. What is the average speed for the trip*;i.yz/ d+j+ifrzlw9n/hao c1w i *te?

  In a 400-m relay race the anchorman ( 11oq(wju6kkashu ha( 2+i2datcjxbx )*oz+9 the person who runs the last 100 m) for team A can run 100 m in 9.8 s. His rival, the anchuq c1b ji1 sd9o j (h+(kxz6*+oawk2ut ah2a)xorman 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 k*++75s9 q,ynps4 odtyals-lsp- n6 nof4a wdto a stop after 10 s. The car's average velocity during deceleration was 41 km/h. What was th-lys nn,46p9wdan*y 5fs to-7kso4l qdap+s +e car's deceleration while slowing down?

  An airplane increases its speed from 100 m/s to 160 m/s, at the average rate qpjz5(:k y2;tws adw7of kd5qst 7: y(jp;zwwa2$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/hr 5awg+1 n),(oora ktk 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 rest and accel)u(7tsbj6ad del3fmk z1 8a4h3lgl q6erates 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 upz(jfpvh5k0d 8/ hu2 rj with a constant acceleration of hzk2rjf8p( hdj5 v0u/ $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 2.8 m/s experiences a constant accelerh1+ mqv lg/g5lsiy3d i,ge6y, ation of ,hm5dl+,6 ys1lyqig /i3ggve$2.1 \; m/s^2$. What is the cart's displacement during the first 8.6 s of its motion?

  A bullet moving horizontally to ie-sx;i.vhe-nu 13w*hl,v n fthe right (+x direction) with a speed of 404 m/s strikes a sandbag and penetrates a distance o .eiv lhx;h1w vsnu *,ef3-in-f 61.24 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched xiur7 s f2j+d8* a2shqfrom 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 acceleration is constant, what is the length of theji82+f27s adu hq*s rx catapult?

  A car starting from rest moves with constant accel,nw4mjbp vofy,k0b . whss ,( -ki: h*4qzgk1xeration 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. Wj ai -tpts(y .g6x6tj0hat is its average acceleratij6igap0 ty(j-sx 6. tton?

  An object starts from rest and undergoes uniform acceleration2k 7jwpks9im 2. During the first second it travels 1.6 m. How far will m2k7jw kis2p9 it travel during the third second?

  An object is moving in a straighjqvmm */v; ai(7 b.ex fbi5b)ht line with constant acceleration. Initially it is trav;h xb.v/m*5qafb)7i(jmb vie eling 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 aor:/.x z /tm .cyx0 3;bhxqepqccelerates 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 athqg l6.9g5t+yh v o)ve 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 ca8yi8;tl2lh. ;loes onr that has been waiting at the intersection starts ahead with a cons i82n l y;o;hl.toles8tant 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 wm*;/jfy/* hr4 p itrvon the surface of planet X where the accele; t//h*rw v*myj 4fpriration 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 surface o.+go3kj vsu b0;3 chzh2do/t4ir3pwr f planet X where tj4 23. psr;ithcgvdow h3uro kb+z0 3/he 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 k;n( ct9as j*xx0mi1q15 m/s on the surface of planet X where the acceleration due to it9a0skjqm *1xc n(x;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 speer oc,nvc6a,oky 9/ kg(d of 14 m/s on the surface of planet X where the9,(ck/o co,ravk6ngy 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 gdug2eqd,o:j u h;* b1than 0.10 s. If your friend holds a ruler between your fingers and releases it without warning, how far can you expect the ruler to fall before,ehd:jdgug*u 2 1b qo; you catch it?

  A ball is thrown upward at a velocity :cftw;5mi y8fz*hhr,+ (waj ttws x9, of 19.6 m/s. What is its velocity after 3.00 +rfcft5m* i,; hahy9sww : t txj(wz8,s?

  A bullet shot straight up returns to its sxfi( 7cjdbzil88-a 0j3jw v-v tarting point in 8 s. What is the iniiajwv-- 8f 0bdc jl8i3v j7(xztial speed of the bullet?

  A ball is thrown straigh(9xkj( z5qgv;dpj xc3t up with a speed of 36.0 m/s. How long does it take to return to izc x;gj (xpd(3kjv 59qts starting point?

  A ball is thrown downward from the top of a building with anw 0qkx b.zgz38 initial speed of 12 m/sbw 8z3gqk0.z x. It strikes the ground after 5.9 s. How high is the building?

  A ball is thrown straight up with a speed of 30 m/s. (only fill in numerical:srt.1.j -rxcblap, 5z 1 ydm8wqjur 3 val, 85u :j3 1cm.q lw -drsypb1xj.rraztue in 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 witm /3y1ey,-zyid bu s5xh a speed of 30.7 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 y44bh9p x 1lh k-j(jvbis the velocity at t = 1.0 s?

  In Fig. below, what is the veloci kop (1-e5lzycty at t = 2.5 s?

  In Fig. below, what is the- y04c ay915wb.p,yp kcatxtpqb8ze 6 velocity at t = 4.0 s?

  In Fig. below, what is tpcb2jpx/+ :m.s1j4c ruwq p,lhe velocity at t = 5.5 s?

  In Fig. below, what is the average velocity from 0 to 4 6is9)wo rt b0rg53grz.0 s?

  In Fig. below, what is the average veg pq/i+*m1,mfe a jv.jlocity from 0 to 6.0 s?

  In Fig. below, what is the acceleration at 1.0 qgzg65ce 6svo w1c 47(n-q n6mavh8kjs?

  In Fig. below, what is* 1*0ldp2h ko5t zjt)pm,pnid the acceleration at 3.0 s?

  In Fig. below, what is the average a sg utb5dfpzp;txtp / z-;jvf -t:.u82cceleration from 0 to 5.0 s?

  In Fig. below, what is the average acceluzlb)xz 3gkf;9p)qd8eration from 0 to 8.0 s?

  In Fig. below, what is the displacement froon9gl u,+t6l: emj3e; j lci7um 0 to 8.0 s?

Does a car speedometer measure speed, ve 8rjw-w a2bhdc1fk 8+ilocity? {speed|velocity}

  An object can have a varying speed if its velocity is consh2eq6g i,mv lsfzy8((9dpd/ , qba) astant.

  The velocity of an object can be negative when:x97x(56n yp uea wvo5t g evknk*:lz4 its acceleration is positive.

  If one object has a greater speed xj02ra y s5b4cx5)znq than a second object, the first must have a greater acceleratajncx r0 2byx55) sq4zion.

  Two cars emerge side by side from a tunnel. Car A is travelj t-qv1h .rjk-ing 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 h-cd( tb x-ed2j*,vvqn.xs6y in speed as its acceleration decreases.

  A baseball player hits a foul ball straight up into the air. gr )pl:;cr52od3b ysz It leaves the bat with a speed of ycl sr2)b d3rz5o:p;g $120 \; km/h$. 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*og7w 7l l-nq( up4tei speeds up, what is happening to its acceleration, how does it changeeplq * go4-w7l(uint 7 if air friction is ignored?

  As a freely falling object speeds up, what is hz)hse sl:j )lcft 66x(appening to its acceleration, how does it hl )):lesx6z s6ft(cjchange if air friction CAN NOT be ignored?

  An object that is thrown vertically upward will return40l8rm c0ppk5lmki 6d to its original position with the same speed as it had initially if air resistance is negligible. If air resistance is a mpl0l468k05dk cripmppreciable, how will this result be altered?

  An object can have zero velocity yqph,yyl /cdm(h8a:dp8v 5p 5and nonzero acceleration at the same time.

  An object can have nonzero velocity and zero acceleration arm 2uq wm3 o:l;jfcg7fgq(7h8 t the same time.

  An elevator moving from the se)jm ff1)r06mqo*jnh 4g gv)f* d1tre jcond floor to the fifth floor making no stops along the way has zero6drfogjm11g* h))vme rj*) fftjn40q acceleration all the time.

  A rolling ball moves from4xpg mwphlrd5g8(gt5y1 y)5k $x_1=2.4 \mathrm{~cm}$ to $x_2=-7.3 \mathrm{~cm}$ during the time from $t_1=1.9 \mathrm{~s}$ 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 $t_1=-4.9 \mathrm{~s}$ is at $x_1=2.6 \mathrm{~cm}$ and at $t_2=3.8 \mathrm{~s}$ is at $x_2=7.9 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight comp2qht0 ( epm:dzlete laps around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 10.3 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 104 m away aji.o j;8un /pin 13.2 s. It then turns abruptly and gallops halfway back in 4.8 s. Calculate (a) itsjnai /up;j. 8o 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 fro 1khg-hof-li+b(ad /6irw2 8esdx6q a m $10 \; m/s$ to $23 \; m/s$ in 4.5 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 fro0n2o lfe0 rm9zm $17 \; m/s$ to rest in a distance of 66 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach oku/;y;-b a wma speed of $29 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.1 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of the ( lrp0 alrp6/cblocks to essentially top speed aboupalrp0/( l 6crt $10.4 \; m/s$ 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 .b2jmc jk+ *v-gcw3 zl2mzu0aspeed of $20 \; m/s$ to rest in 4.38 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 ,qc yd : xy-tf+zx6h7tthe highway. Assuming a decect:+y hy6fxx7q zt,d-leration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a trg znbg*:0v) exvyy/w*he;( ppuck 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).    $m$

  A runner hopes to complete the 10,000-m run in less than 30.0 min. A y x d. r,yx90sb7sln4be1nb3qfter exactly 27.0 min, there are still 1100 m to go. The runner must then acce3bexbn0 yy l417xqd.r9 ssn,b lerate at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$