Suppose that an object travels from on( ucqb*/5xtd re point in space to another. Make a comparison between the displacement an qr 5xdbu(c/*td the distance traveled.

  When is the average velocity of an object equal to thhn+ 16-lbt2 zxn; tolwufn.:he instantaneous velocity?

  A new car manufacturer advertises that their car can go ieb;qq5 +q+gfm , xpan6qegi) wi,7v o(..o yq"from zero to sixty in 8 s". This is a description . ,+gb)qg7qi,ew(y+ xaqoe.fp5;voimq qni 6of

  An object moving in the +x axis experiences an acceleri - fv/8egbb y-pz6x0*y 5ap0gfov b,tation of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the Ea ecjuas:4i;2 lst (+x direction) begins to slow down as it approaches a traffic light. Make a statement concerning its accelerae;jl2 iu:cas4tion.

  Suppose that a car travelivognvwqv8 wi18 l:1d fr *:nd/ng to the West (-x direction) begins to slow down as it approaches a traffic lodl vv q1g wi: :/8dvf1*n8nrwight. Make a statement concerning its acceleration.

  Suppose that an object is moving with a constant velobe-fffdv28* oknmles;-qs 9 ,city. Make a statement concnf-vdbfos*me92s kl ,e;q 8f- erning its acceleration.

  If the velocity of an object is zero, does it mean that the acceleratiohra(yj *ufo:8e f8q l;rm;e yow2; uk3)ri sl)n is zero? Support your answeroy:3 )h28;r ;o;laqerfwyj(sek *m8ulir)u f with an example.

  Can an object's velocity change direction when its acceleration is con+k, jhlyv8o.m s ew+f*stant? Support your ans,.+lk+*vyj eo8mfhsw wer with an example.

  Suppose that an object is moving with constant acceleration. Make a stf. 7mju ws*b8 w4h*ucxatement concerning its motion with rj 4s78* fux*whumbw.c espect to time.

  Can an object have increasing speed while its acceleratiznqc )n+ e*l a w4r8j3*ar9bwcws55jnon is decreasing? Support your answer wits58 w ncz ewclq9w5anb+r* ) 3j4*rjnah an example.

  Suppose a can, after a:q-nzo.pw7 xvcpzi+6u2b e 9dn initial kick, moves up along a smooth hill of ice. Make a statement conc7vuqc deno pi6+-:2x p.z9 wzberning its acceleration.

  Under what condition is average velocity equal to the average of the xbli9q49j*+)figrjf7 irn h9 object's initial and final i4n if)g9rj+* j x7b9lqrfih 9velocity?

  Objects A and B both start at rest. They bot-(2 4h fv8khtoj2twnih accelerate at the same rate. However, object A accelerates for twice the time as object B. What is the final speed of object A compared to that ofto 2hntkv2f(w i -h84j object B?

  Objects A and B both start from rest. They both accelerate at the same rate.w7uu* )e-e idz However, object A accelerates for twice the time as object B. What is the distance u-*ued ie w7)ztraveled by object A compared to that of object B?

  When an object is released from rest and falls in the absence of fr t. jh;i4: gus;ygve6jiction, which of the following is u 4 ;ivhseg gj:jy.t;6true concerning its motion?

  When an object is rell;pli,jahr 6d-e +hp ;eased from rest and falls in the absence of friction, which of the following is true c+d l ;i;pehr6l,jh-a poncerning its motion?

  Suppose a ball is thrown straight up. Make a statement about tg0yjop76cj 3the velocity and the acceleration when the ball reaches the highe3ojpt 6g0y c7jst point.

  Suppose a ball is thrown straight up. What is f wcr. 3ivvjqrur+s43b+2 8nd its acceleration just before it reachesc+wvs+nfvi 3u8243.q jrd rrb its highest point?

  Suppose a ball is thrown straight up, kjgvewz p,f449a+(oqreaches a maximum height, then falls to it 4k4(ef+wajq,z gvpo9 s initial height. Make a statement about the direction of the velocity and acceleration as the ball is going up.

  A ball is thrown straigh+n6 a3:xdmgq qt up, reaches a maximum height, then falls to its initial he3qangd+:xqm 6ight. Make a statement about the direction of the velocity and acceleration as the ball is coming down.

  Suppose a ball is thrown downward in ty,m h*dqjt8d5(x ve8she absence of air resistance. Make a statement concee8j*(y 85tddxm hq vs,rning its acceleration.

  Suppose a skydiver jumps from a high-fly hhxw7ai ;(kux.pe 93jing plane. What is her acceleration when she she reaches terminaaepxw.kh(7 x3u9; ji hl velocity?

  A ball is thrown vertically upward with a speed v. . a-r(m jl2cstAn identical second ball is thrown upward with a speed 2v (twice as fast). What is the ratio of the mj2arm-l .ct (saximum 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 later, balb )(3mk 1yku rwnpdw-fq.vj.5j2r, zml B is dropped from the same building. As 1m.r k)f-,(jv qz3ukm r.ny pdjb 2ww5time progresses, the distance between them

  Ball A is dropped from the top of a building. One8 j 6o97s+ vb4ayrrs4:boifg s second later, ball B is dropped from the same building. A4b :a4rsjv+86 9iobryf7 osgs s time progresses, the difference in their speeds

  Two objects are thrown from the top of a tall building. One is thrown up, and b aj 42soego35the other is tgsob432 o5aej hrown 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 k *(h1i*m yjf5vd yv0his thrown straight down from the same building. They are rel* hv10 m*hd yj(5kvfiyeased at the same time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with constanz*d9 :ed17ol szqp1nn t non-zero velocity in the +x axis. The position versun71 1zq*olze9s npdd:s time graph of this object is

  An object is moving with constangt:nfwq2+) j m6pvr8 ht non-zero acceleration in the +x axis. The posinr2)gt vwhp6 q: 8jfm+tion versus time graph of this object is

  An object is moving with constant non-zero velocity in the +x 5b4 eh ;di /43jimgomzaxis. The velocity versus time grajm 4mg hz4ei; odbi/53ph of this object is

  An object is moving with conwb 65)vvn/ws)bwb ih :3zhxw)j : n/xdstant non-zero acceleration in the +x axis. The velocity versus time graph of )3njswdbzhvnwx i:)b x ) 6hw/5b:v/wthis object is

  The slope of a position versus time graph give4+ dzpaj2s f el1(vsa.z o kv8f6e3az:xt): ves

  The slope of a velocity versus time ;x733g cwfm0 i n- sl2efpv9mqgraph gives

  The area under a curve in an acceleration versus nlpg8g to;j41time graph gives

  The area under a curve in a velocity v3cbwn c t;,x/bxo;oi,ersus time graph gives

  If the position versus time graph of an object is a horizontal line, the objec zt9uwkc0he3* t 0c3 k zw9*tuheis

  If the position versus tidai vbvvh,edp.1b5 j 0 h:uccd0vb34-me graph of an object is a vertical line, the object isvvpb:v icc3hjd duahbd0 eb,01. -54 v

  If the velocity versus time graph of an object is a horizontal li58xqxom3ye 6m95olfx ne, the object is6m8x 5qex9lxy 3fo m5o

  If the velocity versus time graph of an object is a straight linkeqsff4yiatp/s 62k, )(v t*ge making an angl p/iq g*fy(atte,k 642kfvs )se of 30 degrees with the time axis, the object is

  An object moves 15.0 m north and then 11.0 m south. Fimz( 3ioyg :4 dlzb7y0end both the distance traveled and the magni7bg (z :imod0lyezy43tude of the displacement vector.

  A boat can move at 30 km/h in still water. How long will it take to move 12+u7l uzpf w/5p53.svuwv 7 wbj km upst/ f753v vpw+u buwp uwz.j57lsream in a river flowing 6.0 km/h?

  55 mi/h is how many m/s? (1 mi = 16xn(j u u8)3aey09 m)

  What must be your average speed in order to ho (8qvvw otc94kqo- mqs8n* :travel 350 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 km) in 2 hours and 57 mxy/ 7 p6jwse/7:lypfdin. What is the average speed of the r7jsxdyf76p/p/e: w lyunner in m/s?

  A car travels 90 km/h. How long does it take for ufptvn7i 6da/5g.dk 1it to travel 400 km?

  A ly (light year) is the distance that light travels in one year. p szv4+3y wjgiba065c The speed of light pwac v4jy5s +zgi b306is $3.00 \times 10^8 \; m/s$. 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 look to t20b,ai7x+oevizrs 8a6 3rddche side for 4.0 s, how far do you travel during ti r8a0ddc 62aie,s+ ozx37vrbhis inattentive period?

  If you run a complete loop around an outdoor track (400 m), io,7 m/k6l. halysj*pwn 100 s, your averagal.pl6,koyh/m sj*7 we velocity is

  A polar bear starts at the North Pole. It travels 1.0 km south, then 13-n1xwr+gx wwf mr8e 1.0 km east, then 1.0 km north, then 1.0 km west g x+e-w 1wwrmfxr381n 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 travels 1.0 km south, then 1.0 kqkzrxp* bgj89+wcv) g4ub (1bm east, then 1.0 k bqxbv1j (uz9g * 4c+kbr)g8wpm north, 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 weekenduv-r unx:+x6lrc t4v 7 from school at 55 mi/h for 110 miles. It then starts to snow and you slow to 35 74x-v6lnxrc:u rt uv +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. W:za,6 qi7q iuwhat is the average speed of the motorist for thisii7:au wq6z ,q trip?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h. What is h7sipbhu- n )zmtl zx9kgy-:5j h9 9ep4er average si)kx t:ep 94m-b9-yl npsj5zg 79hhzupeed for the trip?

  An airplane travels at 300 mi/h south for 2.00 h and then at 250 miwdt -crug( a+7/h north for 750 miles. What is the average speed for tcrwdt+-( ga 7uhe trip?

  In a 400-m relay race the anchorman (the person who ru5 y 6hyn2c/zwnk0o 9(*vlst uqns 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 ru w*oq t6un0cn 2y5khs9l/(v zynner 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 10 s. Th /lxnn1 ku/4zae car's average velocity during deceleration was 61 km/h. What wa4/1zn nkxu al/s the car's deceleration while slowing down?

  An airplane increases its speed from 100 m/s to 160 m1(iqjyubwpz * d;/g6 p/s, at the average rate of */ w61;uybp(digjq pz$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerj 9,r8toskq e-ates 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 k o5s+eh-.emi-kjezo7 7)3 5kjhxd ei 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 pt; hga/ 4ycnq,sf8oqqc6-y4 speeds up with a constant acceleration qya g/t6;q,p o84cy4 qfhcs-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 velocity of 1.4 m/s experiences a constant acceleration za/gf1+uimk3 o1mgz3+iaf /ku f $1.8 \; m/s^2$. What is the cart's displacement during the first 4.5 s of its motion?

  A bullet moving horizontally to the right (+x dir+mkp6um p7 /yqection) with a speed of 424 m/s strikes a sandbag and penetrates a distance of 93.96 cm. What is the avm py6+qkmu/7p erage acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on , tf2*m/hwodh an aircraft carrier. It reaches a speed of 42 m/s at the end of t2hhof td,*/mwhe 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 wio mkq,.omk*hg-6u+r3n mr z0 lth 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 of 200 m. What ir:ely. b :w.w co-2bets its average acceow-ebr.b. :2wt: l cyeleration?

  An object starts from rest and undergoes unifor(a v0ks8ilxnqn6 4sx *m acceleration. During the first second it travels 9.3 m0q (vxl k 4ns8sanxi*6. How far will it travel during the third second?

  An object is moving in a straight line witrw(p0c ofwo/h+uk/f3y1bg,gkqzy: ga : i) - yh constant acceleration. Initially it is traveling at 16 m/s. Three seconds later it is traveling at 10 m/s. How far does it move dur bgh y / ugqy) k( fz/a+:wofi0ocr-1g3pkyw,:ing this time?

  A car starts from rest and ar ,hjcm ggyv)k9;;+p 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 a,o(4atqvvj 1age kd-. bout $5.0 \; m/s^2$ 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 tha by )7k7czzio-f .dkfi jtvz 6wh400q6t has been waiting at the intersection starts ahead with a constanq64h-dk bi )fzvftizjwk6.z0 7c70 yot 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 7nq5 6-(ynefdy.ws-q wzw5t gsurface of planet X where the acceleration due to gravity isqyeg t.fw s 567n-(n5dyw z-wq $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown upward with a speed of 12 m/s on the surq:rke pik8xm9: sc79txo04ylface of planet X where the acceler ye4t 98s0pl qox:r7kkxm :ci9ation 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 plad3pyy()w lsj 54i +yj)rq,grznet X where the acceleration due dz) ig5y,p y+ rj(qyl3wj4)sr 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 surf 9r0mo l9 5z)e x*dillahl*p)cace of planet X where the acceleration due to gra x mrle)zd5alpl9c*9*)i0h olvity is $3.5 \; m/s^2$. What is the speed of the object after 8.0 s?

  Human reaction time is usually greater n9cf 5 ab+wbhgnju,vd +ju4*5than 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 befo +,h5gfjjad+bwvuunn59c4 * bre you catch it?

  A ball is thrown upward at a velocity of 19.6s eqd-r3 eqc8( m/s. What is its velocity after 3. 83ceq(qrse-d 00 s?

  A bullet shot straight up returns to its starting point in 15 s. What is the in4pnn;ip.*q)ike*sx b s ,sgj 4itial speed of the b s.j b ;pqnnsi4*xg4p,ke)i* sullet?

  A ball is thrown straight up with a speed of 36.0 m/s. How lxn dxpk/f cd1u*53hy9ong does it take to return to its starting poinfdxx / dn51h9py* uk3ct?

  A ball is thrown downward from the s0h .):*stfrhqd nua3fuo7tg ort2 b 8obp/+:top of a building with an initial speed of 13 m/s. It strikes h hb g*f+3tus.uo8 odt0rr2ontq afps ) /7:b:the ground after 4.6 s. How high is the building?

  A ball is thrown straight up with a speed of 30 m/s. (only fill in numerical valqn4 w2:gr)qfyue in the bla)ng2rq4 q y:wfnks)
(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 wit -a6*-9ot2xqb siclw*1xkn rfxm l t..h a speed of 47.3 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 15 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 15.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what -:m40k+kdgr5h3vl -cjvmvd yis the velocity at t = 1.0 s?

  In Fig. below, what is the velocity ar1y(cu9x1 xo ,,zhaxdt t = 2.5 s?

  In Fig. below, what is the velocity.b5yzxey((cac ck y-4 2 bw7zx at t = 4.0 s?

  In Fig. below, what is the velocity at d5yj*;nreq+ -yjejde*ki p ++t = 5.5 s?

  In Fig. below, what is the average v ot8e1.yqox 5velocity from 0 to 4.0 s?

  In Fig. below, what is the aver4z-pe:z h avs.age velocity from 0 to 6.0 s?

  In Fig. below, what is the accd5k x9hrwvfr0vakse9b:)/c8bc u1* teleration at 1.0 s?

  In Fig. below, what is the az;p ,rn7t:2d -,j ;d hfoydpqpcceleration at 3.0 s?

  In Fig. below, what irlvd* qa-jd* 0s the average acceleration from 0 to 5.0 s?

  In Fig. below, what is the average acceleration from 0 **9b ki/maiopekt n68to 8.0 s?

  In Fig. below, what is the displacement from 0 to 8.0 ecrhmpnd7 ;t0g (7nr+opm xm0,d93i as?

Does a car speedometer measure speed, velocity? {speedrgmzw +g;/wy;xixg ifi -::;t 4b8zp d|velocity}

  An object can have a varying speenpbrjz. t1, +xaz4 9a3 d*cfgjd if its velocity is constant.

  The velocity of an object can be negative when go7d;8q )xvz2i2)nv : dtpnb oits acceleration is positive.

  If one object has a gread 4ue0yw4d)t9( acn0koe z j*oter speed than a second object, the first must have a greater ac*uoz(e e0 tjy4co)ndk4w0 da 9celeration.

  Two cars emerge side by side from a tunnelk*p r/sp3)do gcbo+0 p(w/g 4 2qw of;:ammdho. 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 as its acceleratio e8:t/u i/zipti2ew wc11el f5n decreases.

  A baseball player hits a foul ball s6.x +;dfcvy 6sj hnyh5traight up into the air. It leaves the bat with a 6xd+ hn. f;s6hyc5jyvspeed 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 o5jm q k05y5xwpjeufno -k 4r+b-)xy q8bject speeds up, what is happening to its acceleration, how does it change if amjy-8 4 w rjekfqukxq n5y)pb0+-5o5xir friction is ignored?

  As a freely falling object speeds up, 0 ids8b3v0b 1z*vtam ewhat is happening to its acceleration, how does it change if air frm1 3ta bi*svev d00bz8iction CAN NOT be ignored?

  An object that is thrown vertically upward will return to its original posit7fe+lz k*j ptdlx3hbt-l1y 5s3)ie ;zion with the same speed pe7;dtl t1ixhy3ez*s3-b lzjfl +k 5)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 velocity anf 5udv(phr;6 8j-gi ,djh7l zud nonzero acceleration at the same time.

  An object can have nonzero velocitk 5/,njsvywe y86 jo(qy and zero acceleration at the same time.

  An elevator moving from the second floor to the fifth floor ma u2p ;bt3 pn q9cbvnc9il5)ozc8 3nv3cking no stops along the way has zero acceleration allbcvbp;nuqic c)59238 c3v no zp3tn9l the time.

  A rolling ball moves fs aqvh s)9-( t*y7gofwrom $x_1=3.3 \mathrm{~cm}$ to $x_2=-8.6 \mathrm{~cm}$ during the time from $t_1=2.8 \mathrm{~s}$ to $t_2=5.5 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-3.7 \mathrm{~s}$ is at $x_1=3.4 \mathrm{~cm}$ and at $t_2=3.2 \mathrm{~s}$ is at $x_2=8.4 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight comple4hosan 0 +ny-palk7c 9te laps around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 7.5 min. Calculate (a) the average speed  (数值)  $m/s$ and (b) the average velocity    $m/s$

  A horse canters away from its trainer in a straight line, mon.zh/d h 6qb(hyk;w4b ving 105 m away in 8.2 s. It then turns abruptly and gallops halfway back in 4.8 s. Calculate (a) its /hnh6bh .k4 d;bq(ywzaverage 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 ff s2p88x*r bplqy1t4m $11 \; m/s$ to $23 \; m/s$ in 5.4 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 from5fqh4f4x9 fgp10px w;wwdj* g42qgqx $21 \; m/s$ to rest in a distance of 67 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a ; fg3:o5p9k dkm kqpm;speed of $26 \; m/s$ 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 blocks to essentially top spexyd tr-, vzjd ..3zh2ded about rz2v3d y .-hzd d,j.tx$10.6 \; m/s$ in the first 12.7 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) s2w3lyp ybn cto6m5/ormly from a speed of $19 \; m/s$ to rest in 4.90 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves skid mar g((/nfdxk8 lkzd)k* bks 92 m long on the highway. Assuming a deceleration ofxb k*d fz(k(d /gn)8lk $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck ed59g :vt tnuo1)vcl9 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 min3 cvser3r tb:ibw2+ n7. After exactly 27. trv2c3 wsn+r7 :3bieb0 min, there are still 1100 m to go. The runner must then accelerate at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$