Suppose that an object travels from one point in spacecr27 tx b4w .)qv5 r0qtuywf(g to another. Make a comparison between the displacemtyvx.ct5 b )wfwqgu274r0 (rqent and the distance traveled.

  When is the average velocity of an object equal to the -it vjog0pt oep5 locf7ie3b9e9 0t3*instantaneous velocity?

  A new car manufacturer adve2eh1tex xs+l,ptf/ t0rtises that their car can go "from zero to sixty in 8th 1 pse,0xet/ltx2 f+ s". This is a description of

  An object moving in the +x axis experiences an acceleratij7r hhgp-ir* 5.(c hdion of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x direction) begins to slci c;v kzumj/zm.htk37,u xp9of 7.z:ow down as it approaches a traffic light. Make a statement c3okhc.:m7/t z jz9;um up.kx,7v zifconcerning its acceleration.

  Suppose that a car traveling to the West (-x direction) begins to s9f,bvo. d mfmnf ,5vf(low down as it approach nfm,fd (.v5mbffov9, es a traffic light. Make a statement concerning its acceleration.

  Suppose that an object is moving with a constant velocity. Make 6 ni9f 6-jozjia statement concerning its 6jfnz9ii6 j-o acceleration.

  If the velocity of an object is zero, does it mean that the acceq/c 21ajo1huww(rhv 1 leration is zero? Sow(2j /v arw1uh11chq upport your answer with an example.

  Can an object's velocity change direction when its accelerauen: jn4.ymq 6tion is constant? Support j mynqeun :.46your answer with an example.

  Suppose that an object is moving with cobcwd:,:w nkv: upho7 uz0gt5.nstant acceleration. Make a statement concerning its motion with w5:pgct w0 hdbuu .v:k n:zo7,respect to time.

  Can an object have increasing speed while it go/em6 6;(k rlnj8vkis acceleration is decreasing? Support your anvn oj/g6m6r (lk8k i;eswer with an example.

  Suppose a can, after an initial yf7a) u,etrk f:u5ky: kick, moves up along a smooth hill of ice. Make a statement concerning its acceleratio uryf,k7e u:ak5:ft) yn.

  Under what condition/+agg fq uw:*q is average velocity equal to the average of the object's initial angqgfa*q wu +/:d final velocity?

  Objects A and B both start at rest. They bothhanqb;;36e rf accelerate at the same rate. However, objeb r3q;an;hfe 6ct A accelerates 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 st:8b7(vm ht r bl0gb2euart from rest. They both accelerate at the same rate. However, object A accelerates for twice the : mb(b 0le2hu t78vgrbtime 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 fallsjb.nof4 0 :j,qae/ 0cmz/iv lz in the absence of friction, which of the following is tra l.: j 04eo/0cmnji,/b vzfqzue concerning its motion?

  When an object is released fromn,wgcq* j9 )yizu1h )j rest and falls in the absence of friction, which of the following is true concerning its motinqz)wh* u9ci ,gjjy1 )on?

  Suppose a ball is thrown straight up. Make a statement abou(9pfl,8ztk6 zso 1dr+biol4o t the velocity and the acceleratiolfo6 r+tz(9bpodl 1, 4o8kszin when the ball reaches the highest point.

  Suppose a ball is thrown straight up. What is its acceiqfovn/ 7srbw30l +5 mc 7b.deleration just before it reaches i .qe 7s /nv7i+r3b5 0mclbwofdts highest point?

  Suppose a ball is thrown straight u ud*6xi7 pgksj;.5wv xp, reaches a maximum height, then falls to its initial height. Make a statem i;kgwjsx*5x.p6d7vu ent about the direction of the velocity and acceleration as the ball is going up.

  A ball is thrown straight up, reaches a maximum height, 4za.u9gbs lr)d/x(m fr+uopor(f:y 3 idt ))tthen falls to its initial height. Make a statement about t3z4ao tg ((yddxp /+:)9ur)smi.t bu)o lfrrfhe direction of the velocity and acceleration as the ball is coming down.

  Suppose a ball is thrown downward in the absence of air resistance. M1 -v(kybvy0lrzol+r4 ake a statemelkr+1( lr oyvv40z-yb nt concerning its acceleration.

  Suppose a skydiver jumps from a high-flyim759 gt bsefp0ng plane. What is her acceleration when she she reaches terminal vet5pbfgse79m 0locity?

  A ball is thrown vertically2qy3sm/ o4viv6 ad5e j7p5 ydm upward with a speed v. An identical second ball is thrown upward with a speed 2v (twice as fast). What is the ratio of the maj3o v755d4sy /my2dpv6qmie aximum 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 late3nfzlyj:3kwi jbf ciu 4 r(40(r, ball B is dropped from the same building. As time progresses, the distan 3 l3(4(wyfckjn4f0 zuijbri:ce between them

  Ball A is dropped fro x9 lly3war.0nm the top of a building. One second later, ball B is dropped from the same building. As time progresses, the dnly.r9aw0x3 lifference in their speeds

  Two objects are thrown from the top ob(yo,t1 xhru+xq 6(wf f a tall building. One is thrown up, and thtx,6 fx+(qh1o (ywu bre other is thrown 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 * aw9hbqxi,9w second brick is thrown straight doxi,*ahbq ww 99wn from the same building. They are released at the same time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving wpq5u-j h-/ yctith constant non-zero velocity in the +x axis. The position versus tiq-/-pc ty huj5me graph of this object is

  An object is moving with constant non-zero acceleration in the +x axirv+mz,l9+3x lteh, yp s. The posipx hl9,r3y t ezm,++vltion versus time graph of this object is

  An object is moving with constant non-zero velocitk t9+vd/ ti py.*nzsy z.na3p-y in the +x axis. The velocity versus time graph-.ydtt.s /npiykp*9z 3a+z vn of this object is

  An object is moving with constant n yu( k/it-xht *;q.hlbon-zero acceleration in the +x axis. The velocity versus time graph of t/*bhqh tt l(y.;uk ix-his object is

  The slope of a position versus time gra n9dquf6 h g1d ;8.kvqoy3ioi(ph gives

  The slope of a velocity versus time grk/c4 w *+onla 4gjl2obaph gives

  The area under a curve in an acceleration versus time graph give+kp0,tnsl rw(dz1gn+i1sc- zs

  The area under a curve in a velocity versus time graph gi:xvsjioh *-nud.7sfu2m zb)( au uy 24ves

  If the position versus time graph of an object is a horizon+wp 1wi6bvhp.tal line, the object + wh.wvp6i 1bpis

  If the position versus tinq-5 ty r9kwa.f.a 2weme graph of an object is a vertical line, the object is2ka. w n-f9ya5retq .w

  If the velocity versus time graph of an object is a horizontal line, t*z9hvtccs0(k phvokk . z, ;4bhe object i*pk,kvoh zs9vck;c z t.b4 (h0s

  If the velocity versus time grah3 gih/kg h g-3ad18 elrs8t63slsm.gph of an object is a straight line making an angle of 30 degrees with the time axis, the objecgtli hrg3-.8le 1/ s6k3 madg3gh ssh8t is

  An object moves 15.0 m north andhd0(+9uelk g w then 11.0 m south. Find both the distance traveled and the magnitude of the dis0g( 9kldhw eu+placement vector.

  A boat can move at 30 kmf p1xbh7igxv (5py (e)trop.,k 4-mte/h in still water. How long will it take to move 12 km upstream in a rieg ,i x-hp (xf7)45ovk yp1p(.rtbemtver flowing 6.0 km/h?

  55 mi/h is how many m/s? t i8hl phz/t;xb**)vv(1 mi = 1609 m)

  What must be your average c j5o*+ kmyz2rtc/qke* l 88bospeed in order to travel 350 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 km) 5 ,c6dml4ecr9sfa ,ocy4kgv: in 2 hours and 57 min. What is the :fys4 o e6lavmdrc,k5cc 9,4gaverage speed of the runner in m/s?

  A car travels 90 km/h. How long do d9a;wknv8n 8etsk,i- ji,.mt es it take for it to travel 400 km?

  A ly (light year) is a yph./f/-bc fmnz38a the distance that light travels in one year. The speed of light is8.h/nzam/fbcpa -3 yf $3.00 \times 10^8 \; m/s$. 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 the side v -.o )ur- ortp)b*fxyfor 4.0 s, how far do you travel during this inatf-.o ytrruo b vp-))x*tentive period?

  If you run a complete lo4fy/z a o rv/r:u32hzcop around an outdoor track (400 m), in 100 s, your average velocityh yr /4:au3crzfv 2oz/ is

  A polar bear starts at the North Pole. It travels 1.0 km so..7) 3wr23a wkce m,wg.1oks ugxj cmduth, then 1.0 km east, then 1.0 km north, then 1.0 km west to return to c,7 ug32rw )dg.o1 sme k. w3wmkx.acjits 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.ox jn.lr,(f(8zc2 g9. t5+mghm nfban0 km east, then 1.0 km north, then 1.0 km west to n8cnja(g,f thgnolzmx 9.brm 5f+2(. 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 miles. Itww3d+q(sx jd-7 rk+o c then start 3kx sr -qcdw7wod(+j+s 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 fw, tl) n/q;lp +7 iv*t/pjdwhkm/h and 160 km at 100 km/h. What is the average speed of the motorist fw ,l;q+f )jlid/ /ph t*t7vnwpor this trip?

  A motorist travels for 3.0 h at 80 km/h ad 6djm0i/upg)nd 2.0 h at 100 km/h. What is her average i/m6djd)u gp0 speed for the trip?

  An airplane travels at 300 mi/h south for 2.00 h and then at;t ,bawbx(jb. 250 mi/h north for 750 miles. What is the averab w.x,;(ba tbjge speed for the trip?

  In a 400-m relay race the anchorman (the person who runs the last 1 2vybkllk 8/+2.shwu g4k+oh x00 m) for team A can hgsuh 8kok2vk.x y2+4+bl /wlrun 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 order that the team A runner not lose the race?

  A car decelerates uniformly and comesg/ya* n+ tqqrtv( d.;8twd tk. to a stop after 9 s. The car's average velocit + ..8kttr/v*a;ytdqw( dngqty during deceleration was 49 km/h. What was the car's deceleration while slowing down?

  An airplane increases its speed from 100 m/s tu *ng3/*zoeyoa:6 o6,z zyeet o 160 m/s, at the average rate of :z3zo eey*gzu,neta*6oy/6 o$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerat(e xgiz9 ju9wxzhrz*(7(-i nxes 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 anlp0aj*d fr5.gee1cc bk/+,ozd 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 acceler um-uqk 3u3ni*ation ofu3nu i 3u-mq*k $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial veloci btvy) 1vv;*bcw 9vte-ty of 7.6 m/s experiences a constant acceleration of 1-ettvc)* vyb9vvwb ;$5.0 \; m/s^2$. What is the cart's displacement during the first 9.4 s of its motion?

  A bullet moving horizontally to the right (+x direction) with a speed of 3bsaqfl fjd45m2( ub./ o5cg1o79 m/s strikes a sandbag and penetrates a distance q2odf j g5b(bfsua./1l5co m4of 59.18 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 reaf 1f )01p kokiqp ,7usi-:mb1oxw;gxpches a speed of 42 m,p1 ;o) - uwqsf:pf 71bk 0gpm1koixxi/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 cints5g06;6. +wv .c /zjqa; sijnqplconstant 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 mk-zd;p bx7m656ptg q x/s to 80 m/s in a distance of 200 m. What is its average accx zp xb5km7qtg6d -p;6eleration?

  An object starts from rest and undergoes uniform acceleras7rzz:9pg*egd2di 7 c vi r0lgutv;*(tion. During the first second it travels 3*7l0zec dtiguzd79g(g:;s* vrvr 2ip.5 m. How far will it travel during the third second?

  An object is moving in a straight liy,z.yj)7k (svpimpm ,46hfsb ne 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 time?ppm.sy)vi76 hzsmk(, fybj4,

  A car starts from rest5vxo1xoyr7+f and 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 srpl8a7znq96)rb g6y)iw5u ,m paxq 1 on a dry 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 ty+zcqezq g -3atcoyx7sj :8+.a;i5 zzurns green, a car that has been waiting at the intersectios :a ;goj qqizc8+ya+et-c . yz3x7zz5n 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 on the surfawq9zyg3- 6dhh4u6q lk ce of planet X where the acceleration due to gravity ihql4669k wyguqdh z-3s $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown upward with a speed of 12 m/s on the spng ytrrt 38ts6 ap)2*h hc.)4armz;yurface of planet X where th; 2 rzc38n4*psr6ah)p)ttra t .hmyyg e 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 mq5-+fixv-*q mnxgfnks8h yy); -z 0tu/s on the surface of planet X where the q;yq+uf0n-v kg)-mt*- n5xhz8fixys 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 with a 5/8y dwy:cwya speed of 14 m/s on the surface of planet X where the acceleration due to gryyc w8awd: /5yavity 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 yourh 0gnccg*:(gq4ph jl.ar +j, n friend holds a ruler between your fingers and releases it without (,ah g:c hp *g4j0cjrln n.+qgwarning, 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. Why/u8c6fo8e vr at is its velocity after 3.00 svor/8yue6 cf8?

  A bullet shot straight up returns to its starting point in 16 s. What is thej(8n)e8nfod n initial speed 8jod (n 8fnn)eof the bullet?

  A ball is thrown straight up with a speed of 36.0 m/s. How long does itf-x9v.cn u8hv 3b(ae f take to v.9c3(heafxbuvn8f- return to its starting point?

  A ball is thrown downward from the top of a building with u2fo tgi j-*j5 4hc5:tyvhhv)an initial speed of 21 m/s. It strikev55oj2ih*tgjh :hv c)u y4-ft s the ground after 3.8 s. How high is the building?

  A ball is thrown straightxz*0 t jqsgjf+hf(pys( e:j-9t,k6 nu up with a speed of 30 m/s. (only fill in numerical value in the bla09jfjh* y-txpq+:f,(getzkj s (ns u6nks)
(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 nv+p(itm++mlcg8ee gus,1 w9the air with a speed of 22.4 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 8 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 8.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is the velocity at t oc,x;ht:fcu 2 = 1.0 s?

  In Fig. below, what ia16ow 5hjcc,z rj)s3 zs the velocity at t = 2.5 s?

  In Fig. below, what is the velocity awas++s 1 n9veat t = 4.0 s?

  In Fig. below, what is the velocity at t = 5.d2 0kcb5c m cs l0sxs08sx a8l+84sahw5 s?

  In Fig. below, what is the averag vl 5cnum6l,n-kooi.5) g9jtce velocity from 0 to 4.0 s?

  In Fig. below, what is th16h +qlts)yhdch 00+ e.yh1s lz len:oe average velocity from 0 to 6.0 s?

  In Fig. below, what iskews4hph863k t nk78y the acceleration at 1.0 s?

  In Fig. below, what is thelm53q5crg4zgw y8tjr zx9/f- acceleration at 3.0 s?

  In Fig. below, what is the average acceleration from 03o. qf-ov d1 )wa3amew to 5.0 s?

  In Fig. below, what is the average acceleration fromqbgy 0e)b dh)54o 3osk 0 to 8.0 s?

  In Fig. below, what isjda8h*)3 gbne the displacement from 0 to 8.0 s?

Does a car speedometer measure splozaj *e5j s*w,q0,gueed, velocity? {speed|velocity}

  An object can have a varying speed if its velocity is c1e r2,hmg:f keonstant.

  The velocity of an object can be negative when its accele/pevawpgj9u* u2 nn-5qh2ho3ration is positive.

  If one object has a greater speed than a secnjn( 5(-xa) f/, u:w 9wdtdnema,bdwqond object, the first must have a greater acceleration5( w/wjeq x)fa( mnb9wa nn,d d:-tud,.

  Two cars emerge side by side froiqgpdg- .ww9jt.bn q 6c w45l)m 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 speed as its acceleration t)d*2 4hg o ljfkn4gc1decreases.

  A baseball player hits a foul esya o*2gtq80 ball straight up into the air. It leaves the bat wog sqe*2a80 tyith 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 happening to its accelerazucfx6;7:j;1wykv j ztion, how does it change if air f;jx7uf6y:vjcz 1;wkz riction is ignored?

  As a freely falling object speeds up, what is happening to its accelerationmtg0 74jv mfnhuwr5/t 07ut-m , how does it change if air 7ug-tmwj4 0v 5u/ n7fhm0rmtt friction CAN NOT be ignored?

  An object that is thrown verticaudot3cyo.7 om*h kg;8 lly upward will return to its original position with the same speed as it had initially if air resistance is negligible. If air resistance is appreciable, how will this result b k7o. y3o*d h8tou;cmge altered?

  An object can have zero velocityaq 8olgv.0,g4c dxgi v/dt +u2 and nonzero acceleration at the same time.

  An object can have nonzero velocity and zero accel ,9bxsfq( 9v,1 qcyquaa wrj7+eration at the same time.

  An elevator moving from thef2qsaz o 218,ya15rcfvdxln1 second floor to the fifth floor making no stops along the way has zero 5z aox 2q ,l8f1svycfnard112acceleration all the time.

  A rolling ball movesf chy b44bl sbc**n-l) from $x_1=2.1 \mathrm{~cm}$ to $x_2=-7.1 \mathrm{~cm}$ during the time from $t_1=2.5 \mathrm{~s}$ to $t_2=5.3 \mathrm{~s}$. 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 $x_1=2.5 \mathrm{~cm}$ and at $t_2=4.1 \mathrm{~s}$ is at $x_2=7.5 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps around a qusy.y 4)d:fnj;l;y4 hfcl/ st4p.syzwarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 11.6 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 straight6zqeubb4 ;o ;m line, moving 103 m away in 9.1 s. It then turns abb;bzem6;4qou ruptly and gallops 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 fr9r 6 iacgwch49 yo838 jtrb8svp j/5meom $13 \; m/s$ to $24 \; m/s$ in 5.1 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 from94ca*luqf.puml j h q(3+-yvm7x v/ru $19 \; m/s$ to rest in a distance of 57 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must rw.l b-dg a/8 q;l6eklc9ogx(8g-hkcpeach a speed of $27 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.9 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of the blocks to essentij9 wbs n/), kaj7pw:pmally top speed about mw9/)a,j: p b nkjp7ws$11.5 \; m/s$ in the first 13.1 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 uniformly29yd+ ier*( bty w. (nk bn:y93hoilg yui)+bj from a speed of $17 \; m/s$ to rest in 5.96 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a b4uzdl c:*n d0car leaves skid marks 92 m long on the highway. Assuming a d*b4 ulczn0:ddeceleration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck going omf vcd:lw b:889 gepr k+a(8z$25 \; m/s$ 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. After exact u3j:6 xx 4f+xww0cnbis a5f,ily 27.0 min, there are still 1100 m to go. The runner must thexca jxfibs3 4+w0uw, :inx5f 6n accelerate at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$