Suppose that an object trisa4flap1,o k *4t:vl avels from one point in space to another. Make a comparison between tho1 f,lia*sk:pv t4 a4le displacement and the distance traveled.

  When is the average velocity of a9vw45/fn4qhot3 cxq pn object equal to the instantaneous velocity?

  A new car manufacturer advertises that their car can go "from zero to sixty) ip*a /cbl-3qwe +csff7* nqa in 8 s". This is a desaff c*-abw/ n7 p +qqs3l)*eiccription of

  An object moving in the +x axis experiences an axyxfj *o:+o( ebe 8c5xcceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x direction) begi 5mo2:+.yc,tc qgqw4kma7 8hdec ldr 5ns to slow down as it approaches a traffic light. Make a statement conce ,r8y5 wo kqadcdgm4+cl:mtqhe .752c rning its acceleration.

  Suppose that a car traveling to ceszrf fd 3 0dy4yw:w2uk 7:z5the West (-x direction) begins to slow down as it s u:7ew2cyr f4kzzd 053:fwdyapproaches a traffic light. Make a statement concerning its acceleration.

  Suppose that an object is moving with a constant velegroddul4h7s1 6 0w4vyl e m:-ocity. Make a statement concerning its 4vrdy:40l7duso e ew -h16glmacceleration.

  If the velocity of an object is zero, does it mean that the accele4)zwke57euvo *k: f8 0; wq.ta7y 2usoumb dzsration is zero?7eov qu8 s. 4fazdykw)2m*7obueswz; :k05ut Support your answer with an example.

  Can an object's velocigxh0s(px x odub o:5/7ty change direction when its acceleration is constant? Support your answer with an u so x7x05g/o xdp(b:hexample.

  Suppose that an object is moving with constant acceleration. Make a sta(jw3nkyq01cusq5 z d* tement concerning q 5ncq*uzd0js 1(3ykw its motion with respect to time.

  Can an object have increasing speed while its acceler((kkx g;h6lnt ation is decreasing? Support your answer with an example. 6xglkn;k(th(

  Suppose a can, after an initial kick, moves up along a smooth hill of icoj.ve8ke-*l zaibt .e p(41iy e. Make a statement concernini8t4vepjb*e-ikz(. e1 .oaly g its acceleration.

  Under what condition is average velocity equal to the average of the o8ptzc 0 gkxbci1()p(x-a :bjzbject's initix:kbz pa i c(bgt-c8j(zp01x)al and final velocity?

  Objects A and B both start at rest. They both accelerate at the sam:1 il:q1 pfq*g +auibve rate. However, object A accelerates for twice the time as object B. What is :a:vi 1ip 1lubfqg *q+the final speed of object A compared to that of object B?

  Objects A and B both start from rest. They both accelerate at the same rate. ctt+ foa.p2bnja w 9+55rr)7ohqob v) However, object A r n5+7baoopvfqo r 5b)tcjtahw.9+2 )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 released from rest and falls in the absence of friction, whichi 7jtx oj7h.4oe9ahwvnba 0 (8 of the following is true concerning its motije 7hx h bvn8o(0iw.7a4ja9oton?

  When an object is released from rest and falls incvy0zb14yw q ; the absence of friction, which of the fozcw yq;41vy 0bllowing is true concerning its motion?

  Suppose a ball is thrownl gv v+0.ea-tc straight up. Make a statement about the velocity and the acceleration when the ball reaches t cvl+ t.vg-ae0he highest point.

  Suppose a ball is thrown straight up. What is its accelerationa,:aktwot + 5c just before it reaches its highesco5twa ,:+ ktat point?

  Suppose a ball is thrown straight up, reaches a maximum h e*8(vv5/4odbri/jcv6 (xi.ij5qk fy z/kus c eight, then falls to its initial height. Make a statement about the direfejjiyz(xc/* uki6/5s d4oc5( vvki.r8q /v bction of the velocity and acceleration as the ball is going up.

  A ball is thrown straight up, reaches a maximum height, then falls tst0fkv6 : s-p.oog x4eo its initial height. Make a statement about the direction of the velocity and acceleration as t.6:sg4pfkxe s 0-oot vhe ball is coming down.

  Suppose a ball is thrown downward in the absence of air resistance. Make a statj kg )dr:nl(2nnevf55ement concernin (ejf)dr25nv: nnl kg5g its acceleration.

  Suppose a skydiver jumps from a high-flying plane. What is her acceleraa( h 4l h(j sk1k;9;s+efhsmlqtion when shej(kq;(h49h sk;s el +fm1shla she reaches terminal velocity?

  A ball is thrown vertically upward with a speed v. An identical second ball ):q-dssb knw-ghz4/x is thrown upward with a speed 2v (twice as fast). What is the ratio bk dsg:-/whz s)4q xn-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 bu.pre*x ds7p 9h g0kqy:ilding. One second later, ball B is dropped from the same building. As time progresses, the distanceg 9px. 0qs hkpdy:e*7r between them

  Ball A is dropped from the top of a building. One second late 4e unj xb-s,w1z 1vjoe9d2dda:)hge8r, ball B is dropped from the same building. As time progresses, the difference inodnagw bx-j,:8191v2 dsee h)u d4ej z their speeds

  Two objects are thrown from the top of a tall building. On8 rgralee,asg6r o;; wo 1w9h8e is thrown up, and the other is thrown down, both with t r1res;al owa,r8h8; 9e g6gowhe 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 is thrc,( b: j o.eb9cf7espxown straight down from the same building. They are released at the same time. Neglect air resistance. Compare the accelerations of the two bricbx7c, (bje.sfoep9 :cks.

  An object is moving with constant non-zero velocity in the +x axis. The positii z t0 xa43 zu:mazlmq80u6a+eon versus time graphl8a+x 0mae6z4u3 zmai :0 tqzu of this object is

  An object is moving with constant non-zero acceleration in the /yndf ,t3x * wkxzd16w+x axis. The positi1fddnwz63* yk/,x wtxon versus time graph of this object is

  An object is moving wi9 ztfi z-paj;:t(dtc8 th constant non-zero velocity in the +x axis. The velocity versus time graph of this objectc(p-t;dt t 8fzi:a 9jz is

  An object is moving with constant non-zero acceleration in the +x axis.hgd6u3 jvs40i The velocity versus time graph o3gis 460hvj udf this object is

  The slope of a position versus time grs2b ob3vvbkd4(9at 4yf. 4iba0wpx 4zaph gives

  The slope of a velocity versus time graph gives 6 tnmdopj79)n

  The area under a curve in an al)0ro ua q/w w*9p8mvl+af1 dw 38kmm2eusgn-cceleration versus time graph gives

  The area under a curve in a velocity versus time graph givj v/s7bn sin3.es

  If the position versus time graph of anpvwkoi* 4lpl(m8 1,eq 1-g/thm wp7oa object is a horizontal line, the object is8(ltlo1 1 vq- pmw4ak 7poi,egh pwm*/

  If the position versus timr8jfo8 d,7dj ge graph of an object is a vertical line, the object is ,d8rfjo87d jg

  If the velocity versus time graphx4jtpoc1o s n:czq33* of an object is a horizontal line, the object xnc 3qops1o jt 4*3:czis

  If the velocity versus time graph of an object is a straight line myxqa vwu fsi g(r()*4f,whh)*aking an angle of 30 degrees with the time axis,r)sxw )u,4 *w fq(hfvya(i g*h the object is

  An object moves 15.0 m north j2 /3mij63g lweyf3nmdq :n)fand then 11.0 m south. Find both the distance traveled 3l/qe3yn) 3wn jmi2 :fdmfg6j and the magnitude of the displacement vector.

  A boat can move at 30 km/h in still water. How long will it take to mony;e r,2hfii8ve 12 km upstream in a river flowinhf2rin ;e ,i8yg 6.0 km/h?

  55 mi/h is how many m/s? (1 mi ;r3:g0ncv z b0y8tveq8 o 6ecr= 1609 m)

  What must be your average speed in order to trave dc;r-hp5:lv6zz0 6s k1imqmc l 350 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 km) in 2 hours and 57 mj:/cl7.4jq sd*h ua jmin. What is the average speed lu.qjdj7j* m/h:4cs aof the runner in m/s?

  A car travels 90 km/h. How long does it take for ikjo : +1hr4a*k a3qwqjt to travel 400 km?

  A ly (light year) is the distp 9sbj2(yqbot:qj8 )1k0 lyqgance that light travels in one year. The speed of lighkqq8b t)bj 9:oqj1yl2y0(pgs 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 al0pf,sxk duc8+fk/ awbl0 - cw6ong a straight road and you look to the side for 4.0 s, how far do you travel during this ink psw0 0lfcc8 -aud6/f+b,kwxattentive period?

  If you run a complete loop around an outdoor track (400 m), in 100 b-jnd v y.2.eus, your average..ydvu2 nje- b velocity is

  A polar bear starts at the North Pole. It n.ganujj04- o travels 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 takes 45 min. What wa-0gn.jj4 anous the bear's average speed?

  A polar bear starts at the North Pole. It travels 1.0 km soys:ox7jnh9v 8 3 qe*n(bjg-cv uth, then 1.0 km east, then 1.0 km north, then 1.0 km wes:8 nv3cbxo e9jvhn *q-7j(ygst 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 at 55 mi/h for 110 mr p(+ xr (hm80 ruapn*a98zcq4th8o rdiles. It then starts to snow and you slow to 35 mi/h. You arrive home after driving 4 hours 8*xh+8dn (ruz9a qh0rt8apr 4mrp(ocand 15 minutes. How far is your hometown from school?

  A motorist travels 160 km at 80 km/h and 160 km at 10g ykpm )*qkh,kpy 3/t90 km/h. What is the average spkp ,3p /htykk)9m q*gyeed of the motorist for this trip?

  A motorist travels for 3.0 h at 80 km/h4:+j;uuh w, yphhd6 pi and 2.0 h at 100 km/h. What is her average speyu;h :dph,+4 i 6huwjped for the trip?

  An airplane travels at 300 mi/h south for 2.00 h and then at 250 mi/h 8o et 1n,-kqqbnorth for 750 miles. What is the aveqoq-,kb18ne t rage speed for the trip?

  In a 400-m relay race the anchorman (the person who runs aqlnkh/x) dyi14spkg 8/5 e( xthe 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 lep/ dils81y)hngkxk a45/ (qxead 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 to a stop after 10 s. The car's ave(j v8veixc/u.a5+ 7jkkfz 4hwrage velocity during deceleration was 69 km/h. What was the car's dv8(/z7f5u4 +kx j.hv jkeca iweceleration while slowing down?

  An airplane increases itk r:myccuywljz-b 6 pc7f799*s speed from 100 m/s to 160 m/s, at the average rate of uc7ybry* cwm97-: l6p9zk cf j$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerates atbi ;qq,(l2wgb 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 accel3.dht-*l iz 82 bbe-eikq r-saerates 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 g8a /hc abic(h q-es,q -o8np9a constant accelerationcpq-qa8g8a/o h -9einh(sc, b 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 7.8 m/s experiences a con +z71,brr-zym jnwkyu6s0z,f stant acceleration of ,sz6kuzbfj 7 0ynr+y 1rzwm,-$4.5 \; m/s^2$. What is the cart's displacement during the first 4.7 s of its motion?

  A bullet moving horizontally to the right (+x direction) with a speed of nbb vi h5p,.y4sjh z6bg-3t5v;8 mcwu309 m/s strikes a sandbag and penetrates a distance of 65hgn4b ib.3-5cjmhu8wp ,yvtz s; bv11.37 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult.qtnut jj m3 *9es+/wd.eid* z.k8 sit on an aircraft carrier. It reaches a sddtk iew9*tse8i ju +.* ntmz..j/s3qpeed 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 catapult?

  A car starting from rest moves with constavpsn 5/,v qc*nnt 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 g9s8fd slh/tnluj:; ; 80 m/s in a distance of 200 m. What is its average accelera9shjl lgs;; /:8fndtu tion?

  An object starts from rest and undergoes uniform acceleration. During nz umz4hv bgw4)i)l2- the first second-z)m2z44i gvlu)bh nw it travels 3.1 m. How far will it travel during the third second?

  An object is moving in a straighw6 h4kvhv/k/yt line with 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 during this tim6k hvh 4/w/vyke?

  A car starts from rest and accelera1 exotg t6g -;ebn( 1tjqp/pd2tes 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 p)f5ee0z-c kjat 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 hj5spzy(c/0uc 0. ;c gcj e tg7s.wcit7as been waiting at the intersection starts ahead with a consttej cus5gz..ccpt/igycw 0j 0 s7(;c7ant 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 surfac+9 ftfs 4 3r:d-paudvf*v+mmce of planet X where the acceleration due to gravity af*rf4tvd+-mscv + 3pf9 u:md is $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown upward with a speed of 1y, cphw,5a 0pz.ai0z b2 m/s on the surface of planet X where the acceleration due to grp0apw, i.y0 5zzc,hbaavity 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 dck+cst;4+- e9kqdtu where the acceleration due to qtcte+k9uc+k4 ds-;d 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 withj6lr zi6na7*y a speed of 14 m/s on the surface of planet X where the jl *6yzna67iracceleration 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 gr s o( txffhfibwh ;ik487-/9jreater than 0.10 s. If your friend holds a ruler between your fingef7x;hf9-ii(sf4/ rb hko jt8wrs 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 vezvj(:jd/r 6 oq15 ldbqm4x3fu5y:wlzlocity of 19.6 m/s. What is its velocity after 3.00 zjyuq:/ 51l:6(bz xq34r jw fm vddol5s?

  A bullet shot straight 4ex2 o 0avqbg6(p1 qvi-2 c9dabojsfqs /+v*tup returns to its starting point in 19 s. What is the initial speed of the bullei/sq o e4b(xfavj-6p9c* d q2o2av sv+ 0bq1gtt?

  A ball is thrown straight up with a speed of 36.0 m/s. How long does i1+1e mcb u 1v+rkgjohz 8a2vx-t take to return to itsgr +1xavj1hv 1 -c8umkeb2 zo+ starting point?

  A ball is thrown downward from the top of a buigw-zg3-v zrw -cx- :ailding with an initial speed of 29 gi-v-x-w3:gracw -zz m/s. It strikes the ground after 6.7 s. How high is the building?

  A ball is thrown stra)qe ,fa+re am -y-e3ciight up with a speed of 30 m/s. (only fill in numerical value in theafymq ,a)e -ei-3rc +e 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 straicryb be;v 8-;7k(7 bqjxh+bqg4jh 7 nught up into the air with a speed of 30.8 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 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 the velocitnk q:evww 2(z3y at t = 1.0 s?

  In Fig. below, what is the velocity at t = 2.5lf:asgax,hvm.5( mu 6 s?

  In Fig. below, what is the velocitphn- j,9r/ hs8uhei5hy at t = 4.0 s?

  In Fig. below, what +wp(f (,2p cn0aaorf h.eg8dcis the velocity at t = 5.5 s?

  In Fig. below, what is the avewqcteb-*96sqjp0. s m6dane: rage velocity from 0 to 4.0 s?

  In Fig. below, what is the average velocity from 0eptjcp1t / m7v 7g9sal1b37dp to 6.0 s?

  In Fig. below, what is the accelera5mpg v.f4q:kg tion at 1.0 s?

  In Fig. below, what is the acceleration at 3.0 s?)ioy iolmn8:se8)bs8)bt/6al6 + dy k-lw ltx

  In Fig. below, what is the aver/va4+nn-qfu5 8 g a s/;whtl8bhhbd9tage acceleration from 0 to 5.0 s?

  In Fig. below, what is the average a y3b +7 e 0q) r,tpeoj9r*intq4/qghpzcceleration from 0 to 8.0 s?

  In Fig. below, what is the displacem8 p e,d5smz));y 9jw8wrmdde went from 0 to 8.0 s?

Does a car speedometer measure speed, velocity? {speed|veloel5l8j8zun/h city}

  An object can have a varying speed if its vy .b)v qpn07saelocity is constant.

  The velocity of an object can be negative when its accelerak plo9i2.gx4q to ih/6tion is positive.

  If one object has a greater speed than a second object, thpdqp .j9,caj-vtgh .(e first must have a grea vcppj,j.tg ( 9adh-.qter acceleration.

  Two cars emerge side by side from a tunnel. Car A is traveling with a s2.o j8 m 6pzrvungwe;0peed 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 d+ei p )l3-wjyacceleration decreases.

  A baseball player hits a foul ball strs*f3igh j-(a;fa xhk 2aight up into the air. It leaves the bat with;aj2 sh f(k-3ixah*gf 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 objr4zhi;n+qlduvz :+ j1ect speeds up, what is happening to its acceleration, how does it changd:hu+z zr1 qj+;v4i lne if air friction is ignored?

  As a freely falling object speeds up, c ck66pkf+1f .hnsig(,dc5nl what is happening to its acceleration, how does it change if air friction CAN NOT be ignnlgfn.5k6c(k, c6s+hd cfpi1 ored?

  An object that is thrown vertically upward will ret,xs xqm/z sya89ay 6*uurn to its original position with the same speed as it had initially if air resistance is negligible. /sysqaauz9x8y m,x *6If air resistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzero acceleration+lkl7 km9h x.a)- nisc at the same time.

  An object can have nonzero velocity and zero-z)v /eiak :zv acceleration at the same time.

  An elevator moving from the second floor to the fifth floor making no stops alon) ai0rn, ztwt6i) w0nrta,tz6 g the way has zero acceleration all the time.

  A rolling ball moves frhe8yzjvj k: 9nhr6 )b9om $x_1=1.7 \mathrm{~cm}$ to $x_2=-4.3 \mathrm{~cm}$ during the time from $t_1=1.2 \mathrm{~s}$ 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 $t_1=-4.4 \mathrm{~s}$ is at $x_1=3.1 \mathrm{~cm}$ and at $t_2=3.8 \mathrm{~s}$ is at $x_2=8.3 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps around a quarter-mile 76 kocwgsadc)khkwp-279( uhrn g *:d ($1 \; mile = 1609 \; m$) track in a total time of 10.9 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, sjah7herg18 (moving 109 m away in 11.4 s. It then turns abruptly and gal 71 g8hae(shjrlops halfway back in 4.7 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 fro mm6er8z.(trfvjz;wz8i eh zq89y -(m m $13 \; m/s$ to $23 \; m/s$ in 4.4 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 fropg:b2)mwrlae 3- o u4km $22 \; m/s$ to rest in a distance of 74 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach(p8m81xe i tr8e/xtfm a speed of $31 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.8 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of the blocks to essentialnea l/ 3l 1cvk3pro77jly top speed about enca/r33 lv1 j7 pok7l$11.5 \; m/s$ in the first 10.9 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 o7*4flgs8f uq a speed of $16 \; m/s$ to rest in 5.08 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves skid ma.;7z0lagdrxq 7xp0 ukx qcxc)+c gs0-rks 92 m long on the highway. Assuming a deceleration.l07x07q)acx-gc+g0px; ckqszrx d u of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truc;.2 jo7m hypvzk 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. Afteq:hldy*thm jnhp )g2daae3((.ro n pn.-1cs9 r exactly 27.0 min, there ar .np haqg(snton(dp3)d r .jh2:ae ly*19c- hme 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?    $s$