Suppose that an object travels from one point in space to another.6m7 vbazk2a zty9 or .2hsdj*- Make a comparis6khz*2r-ydso t az abm2v.7j9on between the displacement and the distance traveled.

  When is the average velocity of an object equal to the instantaneous vetj 6z3y.quf akk.5oi ol5r4 ae2v/yv. locity?

  A new car manufacturer advertises that theia4(;e ifdz:j+xav 8gtr car can go "from zero to sixty in 8 s". This is a descript v:ge+;4zt(8ijadax fion of

  An object moving in the +x axis exper2d0mf3h6 l /otib seb5iences an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x direction)v ibx*)lc(c 1s q .etdnp+x-*r begins to slow down as it approaches a traffic * lrpn.t+*x -i1q bs exv)dcc(light. Make a statement concerning its acceleration.

  Suppose that a car travelinm5;0yq azm*m *f jq)pcg to the West (-x direction) begins to slow down as it approaches a traffic light. Make a statemenjfm c 0)*q*mmy ;aqp5zt concerning its acceleration.

  Suppose that an object is qua6-q ,kg)bwc +kbnr9e*/czmoving with a constant velocity. Make a statement conc eg 9nzrqca b/,kqwk6-c+b) *uerning its acceleration.

  If the velocity of an object is zero, does it mean that the acceleration is da4 0 ; aac2g eumox,jbje6x;0zero? Support your;2 cxm0egd,bjeaa; 64o j0xau answer with an example.

  Can an object's velocity change direce*:x/r+l)ksnkeg o3r;s3fgvuk/r+ ction when its acceleration is constant? Support your answkcr *k3roer :; v)sl+fe/uxsg /k+3 gner with an example.

  Suppose that an object is moving with constant acceleratvol gq30 5mu2gion. Make a statement concqgv5g2 0lu o3merning its motion with respect to time.

  Can an object have increasing tcqx )5yq;rxt9-emp9 j ;cy :wspeed while its acceleration is decreasing? Support your answer with an e; e:yq9t jc 5p- mywxr;)x9qtcxample.

  Suppose a can, after an z0gh.c 0l5m xuj8c6g hcf;n4zinitial kick, moves up along a smooth hill of ice. Make a statement concerning its accelerationm.z0nxlhg cu48 065;gch jc zf.

  Under what condition is average velocity equal to the average of the object's k8cqhjg 1d9.k.1.de;r g,as2 qrvssginitial .d hsrg 2 agj.esdqk.1rcvqs8gk1;9 ,and final velocity?

  Objects A and B both start at rest. They both acc qlppro*j hk3a6 +u)w)elerate at the same rate. However, object A accelerate 6)ak+whr po q*)ljpu3s for twice the 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 3*zb 13nx0t1wmk w0h hbkase 6yn1 y)jrest. They both accelerate at the same rate. However, object A accelerates for twice the time as object B. What is the distance traveled by ob30 k*thny)xb1 n0ez6hkw abj y13m1ws ject A compared to that of object B?

  When an object is released from rest and falls in the aw 3-fpiz z:sofr;g2* ebsence of friction, which of the following is t*s-rf goz;2efzpi3w :rue concerning its motion?

  When an object is released fro,rw3q psw4kzas23:d0 wk5c)y defu x-m rest and falls in the absence of friction, which of the following is true concerning its dad kspzwy-)e2w,qr3 4cs3:5 x0ufwkmotion?

  Suppose a ball is thrown straight up. Make a statement about the velocity and ppgf3,r-(*pa j z9ese the acceleration when the ball reachzrg ,p(fp9-s3e*pea j es the highest point.

  Suppose a ball is thrown s50*lgcn ipo d4traight up. What is its acceleration just before it rip40lndc*o 5geaches its highest point?

  Suppose a ball is thrown straight up, reaches a maxim-ytin v7fub 1(hav2+lum height, then falls to its initial height. Make a statement about the direction of the velocity and acceleration as n712lh +-vi(ut yavfb the ball is going up.

  A ball is thrown straie8f, prq;1c yyght up, reaches a maximum height, then falls to its initial height. Make a statement about the direction of the velocity and acceleration as the ball is coming doceq 8yyr f1p;,wn.

  Suppose a ball is thrown downward in the absence of air resistan gu+qd otd06m8oiwk3, ce. Make a statement concerning its accew0d3ko8 ,gq tu6o+ dimleration.

  Suppose a skydiver juuqu5m 1q+oc m5mps from a high-flying plane. What is her acceleration when s+1m5mcqqu5 ouhe she reaches terminal velocity?

  A ball is thrown vertically upward with a speed v. An idan,im8kx. 9h fentical 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 thhx9fnmki 8 ,a.e second ball go than the first ball?)

  Ball A is dropped from the top of a building. One second later, ball B ,qgg5eqededdago-;fmk .*, t 5es 7v7 is dropped from the same building. As time progre57tg ,eeodadskeg ;.,gme 7d*q-5 fqvsses, the distance between them

  Ball A is dropped from the top of a building. One second later, h4s ac8wdw 9b98g.xw pball B is dropped from the same building. As time prhw.dww889 sg49c b axpogresses, the difference in their speeds

  Two objects are thrown from the top of a tall building. One0eiw6068 x vbutap o-k is thrown up, and the other is thrown down, both with the same initial speed. Whaeb0aok6-8 i twuxpv60t are their speeds when they hit the street?

  A brick is dropped from thw2 fxti :qh(9.zqqp4j e top of a building. A second brick is thrown straight down from the same building. They are released pf. i(:zj4q2tw9qh xqat the same time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with constant non-zero vel6ivc3u* rdyht du+1ldu-a c4* ocity in the +x axis. The position verd*a*d6-4chcuy+d1 vrl 3u uitsus time graph of this object is

  An object is moving with constant non-zero acszt n5y39 ctz*celeration in the +x axis. The posit*t5y szc 9nt3zion versus time graph of this object is

  An object is moving with constant non-zero velocity in the +x axis. The velocit(e )::azfy8y nbcia1g yfaa) n1:(cbz:ei y8gy versus time graph of this object is

  An object is moving with constant non-zero acceleration in the +x axis. Thex4brjd*:r)z r velocity versus time graph of this orj*d:z ) xrb4rbject is

  The slope of a positi jl zoi6kad9/ z.7x*tkon versus time graph gives

  The slope of a velocity vfp+ (fu v:l/exersus time graph gives

  The area under a curve in an apfp3eavb3ke)2 uiry:bl-d )pkyn6x7 :lv1 b6 cceleration versus time graph gives

  The area under a curve c-xpss1bj,3 t in a velocity versus time graph gives

  If the position versus time graph of an object is a horizontal line, the object ol0h7kcnn ben06dp/py3klwi :b09 t+wp0+thonb 3/p : 96dck 0kilbnn0y7elis

  If the position versus time graph ool f v yda+*k*n,i*p2ef an object is a vertical line, the object isnio,vea*lp k+f2*y*d

  If the velocity versus time graph of an object2fl l v6zk/bgztszfdt82sbu03o9ya y04k (( c is a horizontal line, the object i szl c9vkfyabtoy z8(3kgz22l(btd /0 04fus6s

  If the velocity versus time graph of an object is a straight line makin )mrhoge:-kg u7q2 9tzg an angle of 30 degrees with the time axis, t-u)h:2q9o7ket gg mr zhe object is

  An object moves 15.0 m north and then 11.0 m south. xd vzs6d7gui-;ih 24fkyu 5(gFind both the distance traveled a7zifx;dy5v- 4ksdggu uh6(2i nd the magnitude of the displacement vector.

  A boat can move at 30 km/h in still water. Howamq,p)n(hmov6 y rt46 long will it take to move 12 km upstream in a river q rvn4tahy()mo6p,m6flowing 6.0 km/h?

  55 mi/h is how many m/s? e)qn+ft+ccx8 *lfbo:(1 mi = 1609 m)

  What must be your average speed in 8zsrka*sw5b01x8yhx 0a gt y2order to travel 350 km in 5.15 h?

  A runner ran the marathon (approxim4jcxlf; 27 s ,uv4as36sdg ry/:uivsqately 42.0 km) in 2 hours and 57 min. What is the average speed 2yvif4r3/dv;s :js 4sausclu76,qgx of the runner in m/s?

  A car travels 90 km/h. How long do:kt*1 4w/pkmwp( 5 an; dmqnrqes it take for it to travel 400 km?

  A ly (light year) is the distance vmh ofdrlb.;i/z-;-o that light travels in one year. The speed of lighi.md/ o hb;- ro-lfzv;t 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+fz +ez*h:s yolong a straight road and you look to the side for 4.0 s, how far do you travel during this inattentive peri sey oz*+:hf+zod?

  If you run a complete loop a.ich (b .h4y/kjcyeyt89o3fzround an outdoor track (400 m), in 100 s, your average velocity iyfk3e (h/tcbi.. 9zo yyhj8 c4s

  A polar bear starts at the North Pole. It travels 1.0 km south, the3r;e-a mjzb2 +ycac(f8)tz dg n 1.0 km east, then 1.0 km nort3)2mgcarayz+;bd8t-fe c (jzh, then 1.0 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 trdzt/ 6y.wber*fe0k(w avels 1.0 km south, then 1.0 km east, then 1.0 km north, then 1.0 km west to r6 kdt*rf/e .ew zwb(0yeturn to its starting point. This trip takes 45 min. What was the bear's average velocity?

  You are driving home on a weeken3;geja m m 2.xk)cl7qgd from school at 55 mi/h for 110 miles. It then s.jc;a2kxe7 3lgmq)mg tarts to snow 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.g:h1nh5)v4w lpio b8d What is the average speed of thhbgd v8w)n: l5i pho41e motorist for this trip?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h a qi2i z vh.yhi):qqw 7z bai-q8lv5p70t 100 km/h. What is her average speed for t zi. bqw vvhlhiz qyqp:i7q-0)ia8527he trip?

  An airplane travels at 300 mi/h south for 2.00 h and then ix +6/ct7z vklat 250 mi/h north for 750 miles. What is t/7kvli+ x6 zcthe average speed for the trip?

  In a 400-m relay racd:n rwl xr0r7/e the anchorman (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 orde r ndr/70:wrxlr that the team A runner not lose the race?

  A car decelerates uniformly and comes to a s)b+svjtb(p),c6 3fg)z eu ofqtop after 10 s. The car's average velocity during deceleration was 69 km/h. What was the car's decelerasb3b(j6p) z )tec fgqv)+o,uf tion while slowing down?

  An airplane increases its speed from 100 m/s to 160 m/s, at the averageye t) 8te060ab ewc+fv rate of a0b t0e )e6tfwc+8vye$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerates at the b5)9lmbm7v m4r: wv ysj72e p)xp 6qlsrate 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 an idhms8 6wp,y9x08g x28ehyfnd 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 consd(6 rt/zns*fb 1)hwbatant acceleratio1(/d)sbnaf6t zw b *hrn 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 2.1 m/s experience q+)n/;y,a ondup 8 xvx4rb2efs a constant acceleration of n 4uy a/evbnxpof+x,) d;8q r2$1.3 \; m/s^2$. What is the cart's displacement during the first 10.0 s of its motion?

  A bullet moving horizontally to the right (+x direction) with a speii zjz7m c/k yr474py4xla +m/ed of 467 m/s strikes a sandbag and penetrates a distance of 76.87 cm. What is the a i 4ri4ml7/y az74zx+mckj/pyverage acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on an aircraft carrier.oj*t7:wstnbg;5 cws ) 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 the catapults7wn);:j *gb 5otwc ts?

  A car starting from rest moves with cotp lt. 9oun6(fnstant 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/s3: 2)/d hzu0n qao gb)dsn42 xrmvdc2d to 80 m/s in a distance of 200 m. What is its average acceleraz3/ d02nch)nsvag2qu4dr m2d boxd):tion?

  An object starts from rest and underg:ggudrazd 7a a*l8n8;oes uniform acceleration. During the first second it travels 4.6 m. How far will it travel durin*zaga7dd rg lu8:n8 a;g the third second?

  An object is moving in a straight line with constant accel:nnbltelb3: +m8*k w4budjs9ni.2 oceration. Initially it is traveling at 16 m/s. Three seconds later it is travelin2nste9l:3wn4l b idbj:8*uo.+ck mnbg at 10 m/s. How far does it move during this time?

  A car starts from rest and accelk5s fuc:+8y;be) . zdokkw-zb erates 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 dra 3qanl5+/ax iy road 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 green, a car that has ;hxf6buy2 68/,ag w x9iems1wfz ,lnfbeen waiting at the i6,6nyx1b fhl8f wu aswx 9;/e ,f2migzntersection 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 upward with a speed of 12 m/s olr-kmtkwiw qi q.3ooog*;5lt * -6f:hn the surface of planet X where the accehiog-ko3rt *;i56ot l .m q*w:lqfk -wleration due to gravity is $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown upward witnm 9pgjt203 uwh a speed of 12 m/s on the surface of planet X where the acceleration due to gravwm9pnu t2 0j3gity is $1.5 \; m/s^2$. How long does it take for the object to reach the maximum height?

  An object is thrown + bc.f k 7,b:gsukm cslr/0+xa);waqsupward with a speed of 15 m/s on the surface of planet X where the acceleration dueb );r.:scquw7fa mckk+,x ssg+ la /b0 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 k(xn1vx ev5g3m/s on the surface of planet X where the accel5x3gx k(n vve1eration 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 f8jhka1 p4 283.sartyvamc-kuriend holds a ruler between your fingers and releases it without warning, how far can you exp8apyj2h34mk 1sa-vu8 t ck. arect the ruler to fall before you catch it?

  A ball is thrown upwa9i2q6my,q qvwhp 1 jd;rd at a velocity of 19.6 m/s. What is its velocity after 3.00 iqq6w,vmdq p1y92;hj s?

  A bullet shot straighri joza(9;s,fj d0 i3rt up returns to its starting point in 7 s. What is the initia0d(i;orr izj9 s,3fjal speed of the bullet?

  A ball is thrown straight up with a speed of 36.0 m/s. Howd*ex fb3 qwh( dy7gh1l8 qhuq(ku+.bj 3*. ena long does it take to ret(b dhhx3 u g7jb.hqn yw31e8e u*(a+. fkqqd*lurn to its starting point?

  A ball is thrown downward from the top of a building with an initial speedig* yx k;ukr(2 of 14 m/s. It strikes tu *k (rygx2k;ihe ground after 2.8 s. How high is the building?

  A ball is thrown straight up with a speed of 30 m/s. (only fill in numericalctulo0fc :fjii ,;*n - value ifi0untc;-i:*o cfj, l n 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 of 27t8ozvjd5r7n 7 .0 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 7 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 7.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is 3 u2)gp8k (fhtoyqt-pthe velocity at t = 1.0 s?

  In Fig. below, what is the velocity at t = 2.z; pajcjyha3 b+yl6- *5 s?

  In Fig. below, what is thvx1l+o +)z phue velocity at t = 4.0 s?

  In Fig. below, what is the velocity at t = 5.5 te( ghz 6af-4js?

  In Fig. below, what is the average veloc gqalgwot*s u3/:*;g rity from 0 to 4.0 s?

  In Fig. below, what is the average velo;;cu y jka47tzqmgcz4als /1/city from 0 to 6.0 s?

  In Fig. below, what is the acceleration at 1.+pltkvq9d;i / r/l iv/,p 3quc0 s?

  In Fig. below, what is jjs54)d3w bx8k8o5mdc/pzr i the acceleration at 3.0 s?

  In Fig. below, what is the average accelyrhfxfi6zb5:5 :r;li eration from 0 to 5.0 s?

  In Fig. below, what is the average acceleration from 0 toxhx+0jzevnw35o -:bj5*li vb f/ imb( 8.0 s?

  In Fig. below, what is the dqir.p9.7 q4bqb 6nd,a);s ctoq u5vmuisplacement from 0 to 8.0 s?

Does a car speedometer measure 8n( g 3iju(/xxbp)h ngspeed, velocity? {speed|velocity}

  An object can have a varying speed if its velocity is z8dbq 4npka 8 ;t jmo,*zjd,3econstant.

  The velocity of an object can be negative when its accele j-7ahe rqj+:j(7vjcdration is positive.

  If one object has a greater speed than a8,l2kt2rux2ezcec +xxi- u ,z second object, the first must have a greater accelerationzxcu22t x ,2e8z,i k+rcx ul-e.

  Two cars emerge side bpjhc y 9 2+rz+gjj1g/vy 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 spey2p bzwi mk9/m,3pvr /ni(e4wed as its acceleration decreases.

  A baseball player hits a foul ball straight up into the a2zppc 5j3vl 6zir. It leaves the bat w25jp 36c zpvlzith a 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 sep )i8o 4/lwgkpeeds up, what is happening to its acceleration, how does it change if air friction is ign4 lei )/wgop8kored?

  As a freely falling object speeds up, what is happening tgxxl/ fx37wj/ri9 4m sou v,e-o its acceleration, how does it change if air frictionfr /-w 47xl3oxxvg 9j,se/umi CAN NOT be ignored?

  An object that is thrown vertically upward will return to its originaln4 ube 5au 2o4+d-aqfl position with the same speed as it had initially if air resistance is negligible. If air resistanc+ade-q u2 4bonu5 a4fle is appreciable, how will this result be altered?

  An object can have zero velocity and nonz0wf0s d5colb.f q1bp0 ero acceleration at the same time.

  An object can have nonzero velocity and zero acceleration at the same tifhf st)d1.+3/j dxzztme.

  An elevator moving frqu4me :exk v46 jiq82nk(cm/ hom the second floor to the fifth floor making no stops along the way has zero auxm(6 hmv4:/eqkc 8e2j4i knq cceleration all the time.

  A rolling ball moves fr k,m08cianch e,5j7s nom $x_1=2.0 \mathrm{~cm}$ to $x_2=-7.9 \mathrm{~cm}$ during the time from $t_1=2.0 \mathrm{~s}$ 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 $t_1=-2.8 \mathrm{~s}$ is at $x_1=2.2 \mathrm{~cm}$ and at $t_2=3.2 \mathrm{~s}$ is at $x_2=7.8 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete lapsgi .8 qrkk3vp6 around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 10.6 min. Calculate (a) the average speed  (数值)  $m/s$ and (b) the average velocity    $m/s$

  A horse canters away gp afxy/zkg02-g -r3lfrom its trainer in a straight line, moving 98 m away in 9.5 s. It then turns abruptly aggz xla3-0p/ k yfg2-rnd gallops halfway back in 4.6 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 frn8c p4*yfr*u:stujbso67ce1 g1v qqpe5 6 5 bzom $12 \; m/s$ 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 from4w01eua pwvh0 $22 \; m/s$ to rest in a distance of 62 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a speed of tolfd+9:ic9(v+. c.v )b3jtoyy mdja $27 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.7 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of tt9 l 06+ q5f3efwkzcsa 5:icpehe blocks to essentially top speed abouf 5e36ta0fwlz95 i:+ qk cscpet $10.7 \; m/s$ in the first 14.3 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 qxl i ffb 06:pw7c.)twfrom a speed of $16 \; m/s$ to rest in 4.01 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 the highway. As-4 fce; zj:)x8zmzvmxf 9y 1fvsuming 4y8xv z:ezm1x zvf;c f9mfj- )a deceleration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck going y;u4x9 8fhisc $25 \; m/s$ 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 pah.5r3vnbi. jupp xp- * 69utless than 30.0 min. After exactly 27.0 min, there are still 1100 m to gxn* u .3pp9hrj5tv.ub 6a-pipo. The runner must then accelerate at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$