Suppose that an object travels fror9wi6c5n) d 3zzmaocqa) j(x3m one point in space to another. Make a comparison between the displace 3n)zaz3)jr(mod5cc i ax9w6qment and the distance traveled.

  When is the average velocity of an object equal to tsq 9bv/of )v3+sny*wlx68;d zbk)qaiepb 2+m he instantaneous velocity?

  A new car manufacturer iyox nynw*1k.kz:+v*l w92 ouadvertises that their car can go "from zero to sixty in 8 s". This is a description *wzluo k *iv won.k912y: yn+xof

  An object moving in the +x axis experiences an accele.5 shyef*mxcb y/ ,s;eration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x direction) begins to slow dsj), ifpjka3 -own as it approaches a traffic light. Mak3akjs p- )f,jie a statement concerning its acceleration.

  Suppose that a car traveling tkp5tye5sl8g2s 1 g *omo the West (-x direction) begins to slow down as it approaches a traffic light. Make a statement concernino2 pgmlsgy*5kt85s1eg its acceleration.

  Suppose that an object is moving w5,ni84le/ n)icc qdmgc bu 48xith a constant velocity. Make a statement concerniceng/4 m)xd4n,cq58uic 8 lib ng its acceleration.

  If the velocity of an object is zero, does it mean that the accelerationvt*0wfeya)naf f 84f)v(t o3u is zero? Support your anst*fnffeuvy))fat4(oa8 v30 w wer with an example.

  Can an object's velocity change direction when its acceleration is ,sba, asy y(vu0y;s 2yconstant? Support you2( ybys va,,s0yyu ;sar answer with an example.

  Suppose that an object is moving wfb: :v r4f 4w2qzbc;tpith constant acceleration. Make a statement concerning its motion withfvcpbf r;4:: 4 2qwtzb respect to time.

  Can an object have increasing speed while its accelerationf tk80/jrwrh,aqi0 ryz-p:y0 is decreasing? Support your answer wfqzjtri0 y:r,/ky -rh8a00 p with an example.

  Suppose a can, after an initial kick, moves up along a smooth hill of ice. Mak+s 1g:ggq,2a0s9d6xqblyl m +pw n;dge a statement concerning its acc bas ;g0d +xdlygl+w91,q ps :mqn2gg6eleration.

  Under what condition is average velocity equal to the average ofnh8r +of ca sjr++:sh) the object's initial and finar+ )aoh+s 8sh:cj+rn fl velocity?

  Objects A and B both start at rest. They both accelerate at the stwamu )pe2ot3i . ei;5ame rate. However, object A accelerates for twice the time as object B. What is the final speed of object A compared t;toi).pae e 5umi23 wto that of object B?

  Objects A and B both start from r p4py-/md4/ 6m xtioehest. They both accelerate at the same rate. However, object A accelerates for twice the i pm- 6d4yexh opmt/4/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 fr6/)xa w+0z/ *kypymdc(woc xuiction, which of the following is true c xzxywa/yk / *+cucdmwp )06(ooncerning its motion?

  When an object is released from rest and falls in the absence of friction, whic3 g525m xqe1oo /tsguyh of the followioxtgey5/gu2 q 5ms1 3ong is true concerning its motion?

  Suppose a ball is thrown straight up. b g--b0, 1k5bdeexdwr Make a statement about the velocity and the acceleration when the ballerke51bwgd- dx-b 0, b reaches the highest point.

  Suppose a ball is thrown straight up. What is its 1a+*9sq eyrcar a8;xg7b, (2sd nb hkracceleration just before it reaches its hig*a1y7 +( 9csdbrbek,rh2;asrx n qg8ahest point?

  Suppose a ball is thrown straight up, reaches a maximum height,wu- p,lzd v89k then falls to its idkz,lp- w uv89nitial height. Make a statement about the direction of the velocity and acceleration as the ball is going up.

  A ball is thrown straight up, reaches a maximum height, then falls tc ea;) gkq 9z-atx 02sp txc3sj/j6wd-o its initial height. Make a statement about the direction of the velocity and acceleration as the ball is coming w ag0et2 j-sx3)/scpaqk6 -j9;xcdz tdown.

  Suppose a ball is thrown downward in the absence of a ;r(h*q*:aj bth sujwlx; 2,mnir resistance. Make a statement concerning its accele(;smt: ahw j;qr, bx2j*l*hnu ration.

  Suppose a skydiver jumps from a high-flying plane. What is her a ql9,xu- yfbq6cceleration when she she reaches teu,xby6q f9 -qlrminal velocity?

  A ball is thrown vertically upward wyg:a f8si,o8aith a speed v. An identical second ball is thrown up, sfi8aog y8a:ward 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 the second ball go than the first ball?)

  Ball A is dropped from the toq(sojd n/3qo :p of a building. One second later, ball B is dropped from the same building. As time progresses, the diqo/ js3(nod: qstance between them

  Ball A is dropped from the top of a building)*t;zixby2oqpxjj 4- -y 5c7.ujw img. One second later, ball B is dropped from the same building. As time pr2j yzb)54ojxp mig7 j txi.w;y-*uc q-ogresses, the difference in their speeds

  Two objects are thro8l, c/z5qb hm6 lw8hjtwn from the top of a tall building. One is thrown up, and the other is thrown down, both with tt5ch/ l ,8qj mh6zwl8bhe same initial speed. What are their speeds when they hit the street?

  A brick is dropped from the top of a building. Atz5o63pmyx nm (yplg3 gg4 8-f second brick is thrown straight down from the same building. They are released at the same time. Neglect air resistance. Compare the accelerations of y(gm8g3 n-o lxmpp5 ft63yg4zthe two bricks.

  An object is moving with constant non-zero velocity in t)gycuj rk9. fhqp)+ w:he +x axis. The position versus time graph of this cqhru 9)+f: y.kj)gpwobject is

  An object is moving with 8to1 *ce ,nugs ktmqg4)+ve-d9s +mkgconstant non-zero acceleration in the +x axis. The position versuv1,c tgm ugdm)+eqsk9-t+k g*8nose4 s time graph of this object is

  An object is moving with constant non-zero velocity in the +xq5 *rdzciah9fn-(a tf1u 8*oi axis. The velocity versus time graiuq-c(* 5 ohraff8 iz* 9n1tadph of this object is

  An object is moving r n+e5:3pua8tdp fu g3with constant non-zero acceleration in the +x axis. The velocity versuur3 gpa:u3 e5tpndf8+s time graph of this object is

  The slope of a position versus time graph g;f(( +ihgae:f*s (m gqk o pymrvv.4n;ives

  The slope of a velocity versus time grapf 3re:zan e22kh gives

  The area under a curve in an acceleration versus time grama 7f-4k pown0z3ugt2 ph gives

  The area under a curve in a velocity versus lt :m11o9 .i yhuf2m )fpn-zpytime graph gives

  If the position versus time graph of an object is a horizvz8l5*xcajcp6--et p1r +8t bue, gahontal line, the object isa 1t cp xe- 8a*ljgzpr 8c6h+v,5te-bu

  If the position versus time graph of an object is a vertical line, the o//v(h avengz mo m5 wmet8*7-pbject ism*p/oag57mem8nze - tvv(w h/

  If the velocity versus tim9ok *t*c 8vlwwe graph of an object is a horizontal line, the object isw* lcwv o9k8*t

  If the velocity versus time graph of atgy)rg/ 2- e aqx:ue62ndw5 nln object is a straight line making an angle of 30 degrees wit g6 : 2yxe ql2-rdn)at5/enwguh the time axis, the object is

  An object moves 15.0 m north and then 11.0 m south. Find both the dis( 6)*os/feqskyfbn) 5 vqr+ pstance traveled and the magnitude ofn (vryoesqs5 f )f*/k6b+)qps the displacement vector.

  A boat can move at 30 km/h in still water. How long will it tak jr555 bbp3tii09j9q+kr/gwvgprzp aj8,d7n e to move 12 km upstream in +iv59jwqjpb tn rg ragb7/5,0pzr pj5k3d98ia river flowing 6.0 km/h?

  55 mi/h is how many m/s? (1 :2k r n53i0xa4xadxsrmz 4j z9mi = 1609 m)

  What must be your average speed in order to trjm;)t y 6fjo.tavel 350 km in 5.15 h?

  A runner ran the marathon (8nra kv6 z3tq1approximately 42.0 km) in 2 hours and 57 min. What is thent16zr8 ka 3qv average speed of the runner in m/s?

  A car travels 90 km/h. Hoi5ark6w1 tjy(w long does it take for it to travel 400 km?

  A ly (light year) is the distance that light travels in one year. The speedhc8cmhh8g i f:)o05jy of lig0ohhfig:c8j)m h y c85ht 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 kms*ux1k, k6:t lx:l*ozcn 0d t0r)hjfx/h along a straight road and you look to the side for 4.0 s, how far do you travel during this inattentive pekt xo0zdxlk f:,cx0u 1*6* shntr):ljriod?

  If you run a complete loop around an outdoor track (400 m*hh 9 v98teafunz.x e9), in 100 s, your average velocity i*9veu e ztxh89n 9.hafs

  A polar bear starts at the North Pole. It travels 1.0 km south, then 1.0 km */pm.yt5 v5.o3 xzfrsf t(iciovwfm i,1z ;o4east, then 1.0 km north, then 1.0 km west t /zv5 .tzv* (;5t3yxfr,ffoioi1oswpm4m .ic o return to its starting point. This trip takes 45 min. What was the bear's average speed?

  A polar bear starts at the Norjc6 x+c)i -0wczfh7nxth Pole. It travels 1.0 km south, then 1.0 km east, then 1.0 km north, then 1.0 f6c0 x)i-+hc7wxj zcn 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 aez tdyck3*bq z8 p*y4-t 55 mi/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. How far is yo 4d*k3yyzpbc-t ze q*8ur hometown from school?

  A motorist travels 160 km a7na( kt+ej rc-t 80 km/h and 160 km at 100 km/h. What is the average speed of the motorist for this trip? rn t7k(aec-j+

  A motorist travels for 3.0cbs+it gkth+dl )6te, 17 j- ckc/n7ms h at 80 km/h and 2.0 h at 100 km/h. What is her average speed bcmc,-g/tl7n7t hi kdstcs+1k 6+)ej for the trip?

  An airplane travels at 300 mi/h south f:sm5iq 9k.r 92nvifd-ow p/kpor 2.00 h and then at 250 mi/h north for 750 miles. What is the average speed vn ik-m pp.9k:widr s2/of59q for the trip?

  In a 400-m relay race the anchorman 89f50io.yx.y yq zrse(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 8i9 y.zxo5q0er sy.y fof the race, in order that the team A runner not lose the race?

  A car decelerates uniformly and comes to a stop after 12 s. The car's ave+lo.2lyr3xe4 er)g b hrage velocity dur e4 ror3xg2)+l.bhyeling deceleration was 54 km/h. What was the car's deceleration while slowing down?

  An airplane increases its speecp9vf6 0fr re njb8+n,pcoz88d from 100 m/s to 160 m/s, at the average rate of 98 nr8c06eop,+ vjn8fczfrpb$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accy+q-au.3m.my . pxh vgelerates 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 acce. ,ehou1bd( tu4i4 rd7m g(a6rzd2brh dam3 9tlerates 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 accelert z/+8+)l h kdpln7sg2r kw)veation oftp+ nd8) rk 2hl/sw ev+k)lzg7 $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 7.4 ie,9sa4di yh90g od n8m/s experiences a constant acceleration of0dei9a8ns ,o4 d9 higy $1.7 \; m/s^2$. What is the cart's displacement during the first 4.9 s of its motion?

  A bullet moving horizontally to the rigmszc s,6p36 lzht (+x direction) with a speed of 382 m/s strikes a sandbag and penetrates a distance of 23.43 3ls,psc66zmz cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapultpaht,3*i opc : on an aircraft carrier. It reaches a speed of 42 m/s at the end of the catapult, and this requires 2p*p hiaoc,t: 3.0 s. Assuming the acceleration is constant, what is the length of the catapult?

  A car starting from rest moves with constant qq 7 +yh,tk2h:y, gt;xiek5uk 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 tdphcs/)5 asv+o 80 m/s in a distance of 200 m. What is its average accachpd/5s +)sveleration?

  An object starts from rest and undergoes uniform acceleration. vbg yjq s..wnud-.1m5During the first second it tr5ug.nqbs .1jwdv -.my avels 7.4 m. How far will it travel during the third second?

  An object is moving in a straikb/xb x-x y1z6ght line with constant acceleration. Initially it is traveling at 16 m/s. Three seconds/xkbx -bzxy61 later it is traveling at 10 m/s. How far does it move during this time?

  A car starts from rest ahb8+ kqq2ruovu:r24xnd 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 roa rg; f57 oq,b2zpx.uefd 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 t/qt fd56ksn9f ij.if8urns green, a car that has been waiting at the intersection starts ahead wit6k sq98fint5jif /.d fh 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 on the surface of planet 1 w,iws+b:hsg gynz. a1c+gn 6 ocr*.hX where the acceleration due to gravity i+y,s:awsb w 6+ gch1 cr.hnigz*g. on1s $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown upward with a speed of 12 m/s on the surface of planer lbpagg11s sr28a d,/t X where the acceleration due ,1br/ as1s2plag8rdgto gravity is $1.5 \; m/s^2$. How long does it take for the object to reach the maximum height?

  An object is thrown upwarg jk 3uia8vpu6j*t.-td with a speed of 15 m/s on the surface of planet X where the acceleration due to u-8* aj3 jv.kuittg6p 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 p/q kxcod./l *q6i ax7n2mym 4klanet X where tqa47x6*yclikm no qkmd// 2.xhe 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 iklf (qc (m6af7 2gi/sthan 0.10 s. If your friend holds a ruler be g q/(fcks7ifia(6 2lmtween your fingers and 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.u5ep on4 u5 y +lhp9(n)jdgiy: What is its velocity after 3.0e9+5y:h op(u5di)ynguj pnl40 s?

  A bullet shot straight up returns to its star*.n / ealmh ,xt8wolf7ting point in 16 s. What is the initial speed oet/ w, f nomxa.*lhl78f the bullet?

  A ball is thrown straight up with a speed ofpa)g3ign ;+i esz(pf6 36.0 m/s. How long does it take to return to its starting point?giz3gp6ap+ ; e)fni(s

  A ball is thrown downward from the top of a building with an xj8i+ q p/ za:qhyp* z:zz+rt*initial speed of 8 tp :+x*a8 z/zihz zjpr:*yq+q m/s. It strikes the ground after 3.0 s. How high is the building?

  A ball is thrown straight up with a speedj/z koxje9e4 ca (h9t/ of 30 m/s. (only fill in numerical value ck9ejaozt4 (hx9/ je/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 a5r*t*bn8 i jf-r bt-wwir with a speed of 25.2 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 2 seconds later.  (数值)  $m/s$
(e.) Determine the time at which the ball pass a point 13 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 13.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is the velocity ryxp /mj6tw1 )at t = 1.0 s?

  In Fig. below, what is the velocity at t = 2.5 b vcvksg+nh*linxmvu3z09 n4a -;1-ws?

  In Fig. below, what is the velocity u );0.:n gdxi) :phyvo6o )3 jwly/rjvhaad7iat t = 4.0 s?

  In Fig. below, what is the velocity at t = 5.y+0z3t m 6b9cecmjs kcx.:r uhjh63(p5 s?

  In Fig. below, what is the ave. 6 fnam561ed:8k h5egzikpo lrage velocity from 0 to 4.0 s?

  In Fig. below, what is th: icx1 mm:ak lpt6z2u/e average velocity from 0 to 6.0 s?

  In Fig. below, what is the acceleration at 1.0 bvfjz +gi3 )7k/ihw)0*c 3l*edftqu zs?

  In Fig. below, what is tn2n5 b5cb xn9*yqrxf8+d ):yko qyo1r he acceleration at 3.0 s?

  In Fig. below, what is the average acceleration from 0 to 5.0 s? 3f,q sq+y uihwzs38x*

  In Fig. below, what is the average acceleration from sq:4y- nco ;x.reka. i0 to 8.0 s?

  In Fig. below, what is the displacement from 0 t sxz5 dw;q 6togu18biada-:q8 o 8.0 s?

Does a car speedometer measure speed, veloc m-ep,ezoy( *tity? {speed|velocity}

  An object can have a varying speed if its velocity is cons+cx+.upucmw -tant.

  The velocity of an object can be negative wro d(82sebqe: hen its acceleration is positive.

  If one object has a greater speedurn2(a:sqmsmq-d ,2z +d u, tm than a second object, the first must have a greater accelerationma d+dnzqmut 2mrsq,2(-,u: s .

  Two cars emerge side by side from a tunnel. Cark 0*sl2pv8vpq *.vo-bkv/ zkw 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 increasin5 g6wut+s,2t ;fw g6jcmxy vq6g in speed as its acceleration decreases.

  A baseball player hits a fy+1hj kj(qj) k/ idk:toul ball straight up into the air. It leaves the bat w+k /) (tk:dijhj j1ykqith 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 speeds up, what is happeninx uq9ga5r2y 8kxu8z:hg to its acceleration, how does it change if air fric2ra9 kyx8 5h8ugqz:xu tion is ignored?

  As a freely falling object speeds up, what irp o4okjl:,* ys happening to its acceleration, how does it change if air friction CAN N jo4*p lr:yko,OT be ignored?

  An object that is thrown vertically upward will retj m+t/qw+3 ;,s lyeixmurn to its original position with the same speed as it had initially i mm xw jt;i/,lsy+e3q+f air resistance is negligible. If air resistance is appreciable, how will this result be altered?

  An object can have zero velocity an dy*l/2 nf301dfw.sszvv pb,s df2s;gd nonzero acceleration at the same time.

  An object can have nonzero velocity and zero acceleration at the saxv a( 8yubu**yme time.

  An elevator moving from the second floor to the fifth floor making no st(yy jhvp7tnd3d5fwynz07n 1 6 ops along the way has zero acceleration all the 7(hj16znd0dyv3w 7ntnypf y 5time.

  A rolling ball moves frogq lv2u juosk(pbo :n1w52f 3/m $x_1=3.4 \mathrm{~cm}$ to $x_2=-6.7 \mathrm{~cm}$ during the time from $t_1=1.1 \mathrm{~s}$ to $t_2=6.1 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-2.7 \mathrm{~s}$ is at $x_1=2.1 \mathrm{~cm}$ and at $t_2=3.3 \mathrm{~s}$ is at $x_2=7.9 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight com 15oyrqw7jp2 uplete laps around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 8.9 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, ih 0qy6 u )/uwspt)6 2wtz)pajmoving 115 m away in 8.9 s. It then turns abruptly and gallops halfway back in 4.7 s. Calculate (a) its iw)/hsaj6tt)q2y 0w)6uzp puaverage 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+8t qn-eymd 42p3tnqs $12 \; m/s$ to $23 \; m/s$ in 5.7 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 from w:aq(xa amx.a)a, +gs mjc ,8r$17 \; m/s$ to rest in a distance of 85 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must rz8 ;rplb9 b5ezyw: wy7each a speed of $29 \; m/s$ 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 essentiai u)i,rkx 6q6rlly top speed abou krq6ix6ir, )ut $10.3 \; m/s$ in the first 13.0 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 spee nlgb)q6cbah ;qa 2xk0p+)o/ pd of $20 \; m/s$ to rest in 4.33 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, al)imv e:7p.ttd9iwo c 2hzx;1 car leaves skid marks 92 m long on the highway. Assuming a deceleration oi;.xvwid)hpt7mlz9 :1o2ce tf $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a trudfc 9*cb7-yfqum4e v2 ck 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: ,n 6ccifwf,0q;c+s j0crcqa run in less than 30.0 min. After exactly 27.0 min, there are still 116wj, fq,ca0cccr:c0 q;si+f n00 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?    $s$