Suppose that an object travels from one point in space l39be -h3ymxk to another. Make a comparison between the displacem9-b h3ky3le xment and the distance traveled.

  When is the average velocity of an object equal to the instantaneous ve(es( + b71w 4mhtdswyfk90euelocity?

  A new car manufacturer advertises that their car can go "from zero to sixt0 dour+k 0enw-y in 8 s". Thi+uwern0 k0 o-ds is a description of

  An object moving in thecwm;knvc(m (, (e8rbo +x axis experiences an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x direction) beg*98zt9ujh vj a2mml2 zins to slow down as it approaches a traffic light9mvjuz29am2 h8jl tz *. Make a statement concerning its acceleration.

  Suppose that a car traveling to thc mi 3x1vru:5de West (-x direction) begins to slow down as it approaches a traffic light. Make a si3dv5cu: r 1mxtatement concerning its acceleration.

  Suppose that an object is moving with a constant 6jvtz,5le +wi i7ubd 26bb;xbvelocity. Make a statement concerning its acceleration.tibje2+b lvx56,6wbudiz ;7 b

  If the velocity of an object is zero, does it mean that the accelchqi o,k:p(;c0h(q 8em(upm ;b fg*lderation is zero? Support your answer with ,upq0 kl8 p h(imm( f:oc(gqed;c;*bh an example.

  Can an object's velocity change direction whe 6p;si ,y:fe6g pszs,dn its acceleration is constant? Suppo:ypg;izf,6es, s6 dp srt your answer with an example.

  Suppose that an object:pj wcs2ewtl ;:e )k)+pwfzf 2 is moving with constant acceleration. Make a statement concerning its motiplf2j )w;wt: z2 )p +ce:kfeswon with respect to time.

  Can an object have ik wbx7( egh 9:.bwy7cc() xhf6vvs, qqncreasing speed while its acceleration is decreasing? Support your answe (,y wcx7x)e(h9vq.hwbvgc6f7 :bqsk r with an example.

  Suppose a can, after an initial kick, moves up along a smooth hill of ice. Ma3 ofzm(+q 2+8ewcxkkuke a statemen(+zwq+e c3fmxko 8uk2t concerning its acceleration.

  Under what condition is average velocity equad5jm n hb9zbmr0n;3 ,wl to the average of the object's initia59h,mz0b n;bndrw 3j ml and final velocity?

  Objects A and B both start atl dqy )yr1q4,jefh3 )l rest. They both accelerate at the same rate. However, object A accelerates for twice the time as object B. What is the final speed of ) 1rjqh 4yl,e df)yq3lobject A compared to that of object B?

  Objects A and B both start fr8r tfthbl ,iq;fx ew-8gdk5*nm/ b5 .som rest. They both accelerate at the same rate. However, object A accelerates for twicm-nr; 8ftbq85.s ebt5 lik x dh*w/gf,e 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 absenc( dcm2ra c1qwjbwqjt yl1+ ,;5e of friction, which of the follow,w2qj +wdb t1c;( lcj5arm1y qing is true concerning its motion?

  When an object is released from rest a jl9tqsf 2so7zj3.z v3nd falls in the absence of friction, which of the folvj9zsoz .ts 3j l23qf7lowing is true concerning its motion?

  Suppose a ball is thrown straight n;2 we,t v6(mt(eywy hqckp -sg 6jx5(up. Make a statement about the velocity and the acceleration when the ball reachesc (;hmw5((6tt6p2y, jwke-e xgq yv ns the highest point.

  Suppose a ball is thrown straight up. What is its acceleration jur-fs 4v6w8 zsf6h ,a/scy8 2gqc mhlg1st before it reaches ia zgh6 h8 l6sc,1fm2cyw-s f rv/8s4qgts highest point?

  Suppose a ball is thsrr0pg9- i b(vrown straight up, reaches a maximum height, then falls to its initial height. Make a statement about the direction of the velocity and acceleratr -(9v b0psrgiion as the ball is going up.

  A ball is thrown straight up, reaches a maximum height, then falls to its s4re; fqm k68f w7ydb81k ac(uinitial height. Make a statement about the direction of the velocity and acceleration as the ball is coming down.fk fr7 b uwk8a8sd4m( c1ye;6q

  Suppose a ball is thrown downward in keq8*oo h8hp0 ,) asw/ cqric+the absence of air resistance. Make a statement c e8 h8qi)cwoar+ k*s0cph,/q ooncerning its acceleration.

  Suppose a skydiver jumps from a high-flying plane. What is her acceleration wh+mma.rll5 prj 6yz)pm: pr+ ;men she she reaches terj+5)prr;pm .+l rmp6a:zlmymminal velocity?

  A ball is thrown verticalliz63 y oyiuk.k pk(zdo5+g- :gy upward with a speed v. An identical second ball is thrown upward with a s.3+-o(kpgyk:6i zdu zi 5 ygokpeed 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 ifl8 8phb4nt e8)8hmathe top of a building. One second later, ball B is dropped from the same bui88ft nlhpbhme4a)i88 lding. As time progresses, the distance between them

  Ball A is dropped from the top of a building. One second lateiq,et:i umr r,; fis1e6n;k/gr, ball B is dropped from the same building. As time progresses, the difference in thmgi/;:e 1kr;fi,nqe rs ut 6i,eir speeds

  Two objects are thrown from the top of a tall building. One is tj -tupjw 1+s4;y.wi ovhrown up, and the other is thrown down, both with the same initial speed. What are their speeds wh-jjiy1po +u.;4v w twsen they hit the street?

  A brick is dropped from the top of a building. A secjf7jud:y;; va ond brick is thrown straight down from the same buifujv:7j a;;y dlding. 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 velocc/urj68 rw2h aity in the +x axis. The position verh6j28 a/r ruwcsus time graph of this object is

  An object is moving with constant non-zl u5 ;l zlq1-hf0bi0taero acceleration in the +x axis. The position versus time graph of this o 0ul;fha1qib5z-0tllbject is

  An object is moving w9h5hw 9obi+r9ds: 8 strg5rxxith constant non-zero velocity in the +x axis. The velocity versus time graph of this obj5+shd5gs899bxr oir t:9xr whect is

  An object is moving with cons6uw dy 7dk /vjo*r/om(tant non-zero acceleration in the +x axis. The velocity versus time graph of this object is(rujkyo/w/od *d m67 v

  The slope of a position versug 1wejn3d */ymruve6 * 5-al 6med)yfrs time graph gives

  The slope of a velocity versus w g-n 7oq-ktp1o-mm: ktime graph gives

  The area under a curve in an acceleration versus timerviyxrsq /el r/3.- y69 2ajev graph gives

  The area under a curve in a velocity versus time grpp) c ,b01m7uv.se8ou ugp8fgaph gives

  If the position versus time graph of an object is a horizontal liyr 4wvm k5i(8bne, the object by rmk5wv8 4i(is

  If the position versus7l9/rs:ibz h mjsa 9y)g(-w gc time graph of an object is a vertical line, the object is)bz 9ggilah c/9s s7jr-w: (my

  If the velocity versus time graph of anlcb itm6jyb h)tj/54/ object is a horizontal line, the object is 6bi/bc4l jmjt/)5ty h

  If the velocity versus time graph of an b05/05 (axdzw8ay mb fj j/xehobject is a straight line making an angle of 30 degrees with the time axisb5/a0j 50 hfxy 8d(b a/xwjezm, the object is

  An object moves 15.0 m north and then 11.0 m south. Find both sx*x+jnuqhg 4u* w5y- the distance traveled and hwxjux*+u*- nsy g4 q5the magnitude of the displacement vector.

  A boat can move at 30 km/h in still m;ivnqly+ n tr1/)f g:water. How long will it take to move 12 km upsqn1i r+/l:tf)v; gnm ytream in a river flowing 6.0 km/h?

  55 mi/h is how many m/s? (1 mi = c 6mh,++3hxmdvw3fg z 1609 m)

  What must be your average speed in order to travel 35080be;h8g du hz km in 5.15 h?

  A runner ran the marathon (approximately 42.0 km) in 2 hours and 57 min. Whan14zf jc jr36tt is the average speed of the runner i63 jfc1tjnz r4n m/s?

  A car travels 90 km/h. How longk0c0 i n(8 y,n j,jds(on:mapy does it take for it to travel 400 km?

  A ly (light year) is the distance that light travels in qj/*fbxxcl*vr9 4of / one year. The speed of light lq* */xxrbf /f49ojvcis $3.00 \times 10^8 \; m/s$. How many miles are there in a light year? (1 mi = 1609 m, 1 yr = 365 d.)

  If you are driving 72 km/h alf*aa ,vh pdd)s o:0etm,ik w(.ong a straight road and you look to the side for 4.0 s, how far do you travel duringa):d,* ik ,(fe. pvdsha mwo0t this inattentive period?

  If you run a complete loop around an outdoor track (400 m), s;k/k9bo wrb -/pf+oy in 100 s, your average velocity y skf/ +/- ;borwkpbo9is

  A polar bear starts at the North Pole. It travels 1.0 km soz8mto)c; ap idhqr4*xc( 6no 9uth, then 1.0 km east, then 1.0 km north, then 1.0 km west to return to n;qzhapcx ( t4co)8ir9 d*m6oits starting point. 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 souco+awz2fz/ .hr s /tl7th, 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 saf.7r cwo2t/lh/z+ zmin. What was the bear's average velocity?

  You are driving home on a weekend from school at 55 mc ocym f*y2r..*m4 oo.ay2 iyqi/h for 110 miles. It then starts to snow and you slow to 35 mi/h. You arrive home after driving 4 hours and 15 minutes. a.m*coyr*o q 4mo. cy2yfy2.i How far is your hometown from school?

  A motorist travels 160 km at 80 k, n wfqw1)eb::moj8ddp4.dpe m/h and 160 km at 100 km/h. What is the average sp4d):ew jopb.fdnpqed8 wm1,:eed of the motorist for this trip?

  A motorist travels for 3.0 h at 80 km/ho ncy1ax5t.qs7uawz5teodu .5 7 e 5/9jczym2 and 2.0 h at 100 km/h. What is her averageo asc77 5tn9u /wx zeq c55yydtam.e.jo2u51z speed for the trip?

  An airplane travels at 300 mi/h southx7nn 0 :4f;cegca3g hd for 2.00 h and then at 250 mi/h north for 750 miles. What is the averag 3fcex0g4cn7gn; :dah e speed for the trip?

  In a 400-m relay race the y8hu*s9;mr,xs c uqb;gve 61lanchorman (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 thl 9h6*u8ub,yg;s1qs ; xmvrec e final leg of the race, in order that the team A runner not lose the race?

  A car decelerates uniforml v96ce(hlfj- fy and comes to a stop after 8 s. The car's average velocity during deceleratio elhcfv9 (-jf6n was 57 km/h. What was the car's deceleration while slowing down?

  An airplane increases its speed from 100 m/s to 160 m/s, at the average ra.6j q1l ,yz 9nay5okoste of 5o q ano.lk1,ysyz9 6j$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h acce+9ih +;whof.gft4f fblerates 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 renxpd;bi o69t k+4z0w 0kk5oyjst 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 then speeds up with a constant accelerat xfg xeomk6+5y6)ms q 1*,0afdqluy(hion of f+yyouq*gm0,6q1ax k6f (d hlx5es )m$2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity 3w rp30/hpz sbof 1.7 m/s experiences a constant acceleration ofs3 rbwhzpp0/ 3 $3.4 \; m/s^2$. What is the cart's displacement during the first 8.2 s of its motion?

  A bullet moving horizontally to the right (+x direction) with aw unx+4ufe 3+h speed of 244 m/s strikes a sandbag and penetrates a distance of 17.68huunfw+x 4+3e cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on an aircraft carrier. It rec;.5q cepk axps: ;3iyaches a speed of 42 m/s at the end of the catapult, and this c yex.pkcas5iq 3 p;:;requires 2.0 s. Assuming the acceleration is constant, what is the length of the catapult?

  A car starting from rest moves wipitif tgz3njpt+94i m02dx, 6 ;q(gzqth constant 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 o vddv(o yk60 ::s0jo68eb imdof 200 m. What is its average accelerationo600jvibmdyosv:d 8k(:o6e d ?

  An object starts from rest and undez lwxhd*8 bl:.rgoes uniform acceleration. During the first second it travels 9.8 m. How far wiw.l:l bzd8 *hxll it travel during the third second?

  An object is moving in a straight line with constant acceleration. If c8ln+c +u.r/e(xqnj)u3ih vi(b8kh nitially it is traveling at 16 m/s. Three seconds later it is traveling at 10 m/s. How far does it move durk(bnfn u/+ xqi ch. 8ie)jv8+ 3l(crhuing this time?

  A car starts from rest and accelerateonk9 g/ypx3; os 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 eegv wz8d4xyf/+ nf8 1+0hyonroad 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 light turns grko7fuvo7zfjy:, f 2 c1een, a car that has been waiting at the intersection starts ahead with a constant acj fvfoky7o:21cuz, f7 celeration 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 th03v 6wk xrvo wws00,dze surface of planet X where the acceleratioww0d0x0skwvv 36 rz o,n 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 bc a)yw176s50q:bav: etubt :o ud-eqon the surface of planet X where sqb tave w:e-6 b:1o)t0b7u5qy:dau cthe 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 surface of planet X;ut us ms59l k+51 yveij.6bwc where t +jwe .9m;uvc15k5ltsbu6s i yhe 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 wity8uwq.kep t0i:3- cxi h a speed of 14 m/s on the surface of planet X where the accyi ptkix.q-:3w0u c8eeleration 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 0.10 s. If your friend bxs(z+hwg;48rg o4z pholds a ruler between your fingers and rzhx;4+zo8wgp b( 4gs releases it without 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 is its velwzvx:ih;tb s46 sg )f(ocity after 3zgvsf:x6i ;4h )sbw( t.00 s?

  A bullet shot straight up returns to its sta l6d f: mg9((flz5vuntrting point in 10 s. What is the initial speed of the b dtf:96m(5un fl(zglvullet?

  A ball is thrown straight up with a speed of 36.0 m/s. How long do4bnw/b ve 0ek3es it take to return to its e/nbe 0 w43kvbstarting point?

  A ball is thrown downward from the topz hmq.fd(*w i9 y-/6pxzr4uk ;rh ou9h of a building with an initial speed of 27 m/s. It stri;muzqx .dpih*r z(/fkh 6rywuh-94o9 kes the ground after 7.1 s. How high is the building?

  A ball is thrown straight up with a speed ofx a2 tbz( k,y xvgiluv:),;ze.b:uuu3 30 m/s. (only fill in numerical value in the blan:zu:i( v,zbv;y g,)u3tau2b ul. xk exks)
(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 wu bf.;cfhn9v u,w,og 3ith a speed of 48.2 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 1 seconds later.  (数值)  $m/s$
(e.) Determine the time at which the ball pass a point 6 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 6.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is the velocf)azka g9+k32l/o th:lsm+ mwity at t = 1.0 s?

  In Fig. below, what im msu37*rbu7 :kbok6t s the velocity at t = 2.5 s?

  In Fig. below, what is the velocity at t = 4.0 02jwem;86 bdsms 2 t k z;8ck5nl:dioms?

  In Fig. below, what isvxhf/s7 r:4gb the velocity at t = 5.5 s?

  In Fig. below, what is the average velocity from 0 to 4.05ttgnvn 9vmv /:h3l w,eyjr8- s?

  In Fig. below, what is the average velocity fro,n+u+sz; cu2 e tyeg3cm 0 to 6.0 s?

  In Fig. below, what is the acceleration at 1.0 ;sz +, t/pdu3j ne;qtvs?

  In Fig. below, what is the acceleration t zli-pg c(b4ek/.eba 5ww1nli6ob1(at 3.0 s?

  In Fig. below, what is the average acceleration from 0 to 5.0 s(pf,wb -0r ant?

  In Fig. below, what is the average acc lwfq;s7. hy0deleration from 0 to 8.0 s?

  In Fig. below, what is the displacement frota b g/k)wqrc ry(z-)1m 0 to 8.0 s?

Does a car speedomete99nu/cze 7ol17.q pd ynokd1nz(q hw:r measure speed, velocity? {speed|velocity}

  An object can have a varyinht36fcu0ai 7gd1jai k )f3p f:g speed if its velocity is constant.

  The velocity of an object can be negative when its acceleration ivt 22opcu6s 7ms positive.

  If one object has a g3 j,c01g 6op y1e /ghvkhnbv5qcflb/(jnys+0 reater speed than a second object, the first must have a greater acce5j6/b 3+hf nh01n1 o(vgb jygpyc/sqvc,k el0leration.

  Two cars emerge side by side from a tunntp)thpx a:l5cr9) yojq l 4 u,hgpg2:/el. 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 speoy/v9. 14 7:fitwkvd bf6jqezed as its acceleration decreases.

  A baseball player hits a foul ball straight up into the air. It leaves ; p6lx(m6au,b 9tcc *dw)bypy3 ot8dbthe bat with a*bym696b;8poxp l(dut,)dc yc t 3awb 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 sdad2eh z),zqxzd1r.ae b(r:01 6 ez rmpeeds up, what is happening to its acceleration, how does it change if air friction is ignored?02 :11xdzr)b zqz eedmdrz,a.6eh(ra

  As a freely falling object speeds w6wui. g0d8sie.g kg1up, what is happening to its acceleration, how does it change if air friction CAN NOT be ig gu0e. ggiw.d8ks 1wi6nored?

  An object that is thrown vertically upwa5q duhv5ggbl+1l9*i j rd will return to its original position ilj+ gb h5qv5gl91u*d with the same speed as it had initially if air resistance is negligible. If air resistance is appreciable, how will this result be altered?

  An object can have zero vdvm -p5.mq8lm7e r;fhelocity and nonzero acceleration at the same time.

  An object can have nonzero velociwe v5 k2yqsg0fs488zvty and zero acceleration at the same time.

  An elevator moving from tmwryy (61msd8u fhz*pg5w6: 3ok /g hwhe second floor to the fifth floor making no stops along the way has zero acceleration all the tim(w/fw m5sho6zd: hmg68 ruyyk1g w3p* e.

  A rolling ball moves from hn :uj*zvj o8aa52wkh(q.ij -$x_1=1.8 \mathrm{~cm}$ to $x_2=-8.5 \mathrm{~cm}$ during the time from $t_1=2.7 \mathrm{~s}$ to $t_2=5.6 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-2.1 \mathrm{~s}$ is at $x_1=3.3 \mathrm{~cm}$ and at $t_2=3.2 \mathrm{~s}$ is at $x_2=8.1 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps arzlpgxu euk 0 /*b:v9ciagc74j3 :o;onfvl9d.ound a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 12.3 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 90 m a4oyaf/q 2i5zq1j xb k8way in 12.6 s. It then4oqbifk/zj 8qxy a251 turns abruptly and gallops halfway back in 4.8 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 from +np,w mf hiu c;yq2m10$11 \; m/s$ to $22 \; m/s$ in 4.7 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 frockj6 3-b(voc4 gqiy5 s zc:sg+m $18 \; m/s$ to rest in a distance of 69 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reachhl iu +qf5wavqu :qd83/ q59a/lro f,c a speed of $28 \; m/s$ 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 ess qo4auymks.x x +2c11jentially top speed about .a 1u+x2qocy4mj 1ksx $11.1 \; m/s$ in the first 13.7 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 unif ad v1b0be,5xzormly from a speed of $20 \; m/s$ to rest in 4.61 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves skid mame2dcsj,:1ym (9+o 8i dgwgzorks 92 m long on the highway. Assuming a deceleratis ,1 9ocg ym2ezw:g+j(8moiddon of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck: o jgyn.z.6mt 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).    $m$