Suppose that an object travels from one point in space to another. Make ap/ -w /jfeqt8)a5iuit comparison betweeq-eaittu/f 5)ji/w 8pn the displacement and the distance traveled.

  When is the average velocity of an objefoqqu6wdm z951m 8lx*bs is37ct equal to the instantaneous velocity?

  A new car manufacturer advertises that their car can go "from zeroh; w0s.05-cogjoq. yf whg 8i/6dl lue to sixty in 8 s". This is a description ;./huj5lqow8o-d .ye 6 sc0l gg0ifhwof

  An object moving in the +x axis experiences an acceleration of on-sphj)-h ; zb /k/uj$2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x direction) begins uk+tu djo7o:*+b yb( vto slow down as it approaches a traffic light. Make a statement concerning yok *:bu7+( t o+djvbuits acceleration.

  Suppose that a car traveling to the Wfuc *j-x wd0rb+7u si*n hs2e)est (-x direction) begins to slow down as it approaches a traffic light. Make a wjhs2r*0uunc7i fd*s+- ex)bstatement concerning its acceleration.

  Suppose that an object is moving withho vwq1f9np45 eg/j9ohuy 22j a constant velocity. Make a statement concerning itw2j9/ey gu9h24n5pqjoh fov1 s acceleration.

  If the velocity of an object is zero, does it mean that the accele* mwd9d3 yq9fmdf-j 1pration is zero? Support your jdd-mf d y*m13fq 9wp9answer with an example.

  Can an object's velocity change directsx)xky+z+bc 1 ion when its acceleration is constant? Support your ans xxy+kbs)1+czwer with an example.

  Suppose that an object is moving with co xo)vd.bm f.4(yq tq8vnstant acceleration. Make a statement concerning its motion wi4mv.df.8yo t(vqqb x )th respect to time.

  Can an object have increasing speed while its acceleration is decc k,xybl7 za:t* 8vbgq24)k qpreasing? Support your answerp2) b :*7kcqbxvlg84z q,ky at with an example.

  Suppose a can, aftercf1q(jk lel 47 an initial kick, moves up along a smooth hill of ice. Make a statement c1flk4q lj(7e concerning its acceleration.

  Under what condition is average vel;x aq2+pl7 dlyewj p--ocity equal to the average of the object's initial andxqael yp;-j7-+ dl2pw final velocity?

  Objects A and B both stpi gkl)t 03rbd9g 9i,rart at rest. They both accelerate at the same rate. However, object A accelerates for twig rgtl 0b,)9kpi9 r3idce 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 rest. They both accelerate at thw l+q gjw ec*1s3( ji,jf.jjq(e same rate. However, object A accelerates for twice the time as object B. What is the distance traveled j+(gcfjwsje jl,w*31( qjiq. by object A compared to that of object B?

  When an object is relrl,r g( mxrn*6eased from rest and falls in the absence of friction, which of r ,mgr6r*xl n(the following is true concerning its motion?

  When an object is released from rest and falls in the absence of friction, whilz80u6pestbjb ut 2 j8q*8an. ch of the following is true concerning its moti u6e8j2.lzupbt jstb 80nqa*8on?

  Suppose a ball is thrown straight up. Ma d jnn(lm7h5s mkeu05(ke a statement about the velocity and thn 7ks5l (u(nmdem5 0jhe acceleration when the ball reaches the highest point.

  Suppose a ball is thrown straight up. Wha00g+ho qu,g xurgj/0bt is its acceleration just before it reaches its highest point h+ go qbu0jgg,u00/xr?

  Suppose a ball is thrown straight up, xo3ry1p +hbh ;reaches a maximum height, then falls to its initial height. Make a stathbop; rh3 1y+xement about the direction of the velocity and acceleration as the ball is going up.

  A ball is thrown straight up, awb6kn 8 c(zv.c)6 de8nxe ylyuf7; .areaches a maximum height, then falls to its initial height. Make a statement about the direction of the velocity and acceleration as the bayvc6af).nu7yx8n e.lb a kw6c (;z8 edll is coming down.

  Suppose a ball is thrown downward in the absence of air resistance. Make a37qi*un;m.p jzr 99u m6srvy f statement concernip.;nz6srumim7 *v 9qfu 3rjy9ng its acceleration.

  Suppose a skydiver jumps from a high-flying plane. What is her accelera)j4-oup4-b uiy. ukr fjcb b+:tion when she she reaches termioujbci4ur4y+:k.bpu -j )f-bnal velocity?

  A ball is thrown vertically upward with a speed ri5 ger-.6 bssv. An identical second ball is thrown upward with a speed 2v (twice as fast). What is the ratio of th5brsg-esi r6. e 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 from7(bcvgixe9l+42 fqjl 67f yyq the top of a building. One second later, ball B is dropped from the sa2jcey9l6 7vl+47x gyqiq f(f bme building. As time progresses, the distance between them

  Ball A is dropped from the top /j2ru 1pn8fxiof a building. One second later, ball B is dropped from the same building. As time progresses, the difference in their 81n/u f2ri xjpspeeds

  Two objects are thrown from the top of a tall building. One is thrown ci;de y0(r qc1up, and the other is thrown down, both with the same initial speed. What are tr(01 i ccdeq;yheir speeds when they hit the street?

  A brick is dropped from the top of a building. A seconn4 okfs*s. n93z vs4vtbs3/lxd brick is thrown straight down from the same n3o. nsss43 fvzt/v skl*b49 xbuilding. They are released at the same time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with constant non-zero v*4 w m6rni.dmbelocity in the +x axis. The position versus time mdw*.4 nri 6mbgraph of this object is

  An object is moving with constant non-zero acceleration in te; k5 1x g1zkoqtly7:iz92 yfa5c6xiihe +x axis. The position versus t519 k2 i157eazftokxqgyc izl;: x6iyime graph of this object is

  An object is moving with constant non-zero velocity in t5.h8wuucu e)/4 zhymche +x axis. The velocity versus time graph of this object i/)ccmu uzyue w8h54h. s

  An object is moving with constant non-zero acceleration in the +x axis. The vrq. -jkuz8 q5telocity versus time graph of this objeqq-r u.j58zk tct is

  The slope of a posittba0bh3 u g,,g*uu.s aion versus time graph gives

  The slope of a velocity verwm t*tw pi/wnv/ nt4*,8.clpasus time graph gives

  The area under a curve in an acceleratpvo-okjs.b -*l .epn.ion versus time graph gives

  The area under a curve in a velocity versus13ldn vr1; :9 xiucphk time graph gives

  If the position versus time graph of an object is a horizontal line, the objen/ikm mu+b u)/rrgu3j *tl8 6cct isumn gr)8m3/r6u+ ljbtcu i*/k

  If the position versus time graph of an object is r:b;j h6 jb6isa vertical line, the object is6ibh jr: sbj6;

  If the velocity versus time graph of an object is a horizontal lum,/msi:pk qa5my:u 3 ine, the object iaum :i/qkus: y5,3pmm s

  If the velocity versus time graph of an oy/ hkxzewn.7 ;7wt3e b1b(htqbject is a straight line making an angle of 307hnb7t /wet .whx;b3kqez (1y degrees with the time axis, the object is

  An object moves 15.0 m north and then 11.0 m s7ha tg xp6v+5gouth. Find both the distance traveled ag7 v5gt+h 6apxnd the magnitude of the displacement vector.

  A boat can move at 30 km/h in still water. Hwmd3b3qnk u; rbibwm*:fz l9lk(+,l0 ow long will it take to move 12 km upstream in a river flowing 6.0 wwf 3 z 9udll krql0(m:+,3kn;mbb* ibkm/h?

  55 mi/h is how many m/s? (1 mi vnjm5)jx5u3m = 1609 m)

  What must be your average speed in ordexdy7pqicih (5s . w+5rr to travel 350 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 km) in 2 hours and+r7p48k db5xfmztl,2 qya m7ajwj73s 57 min. What is the average speed of the runyabz7wp2q 58+ jl7djm4s k 3rfmat7, xner in m/s?

  A car travels 90 km/h. How long does it take for it to travel 408+/kz o // uibkueqi+n0 km?

  A ly (light year) is the distance that light travels in one year. The sb9etw3:ylci 3t2h6v cpeed of i3tb 3yt6hc9vw:ce l2 light 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 along a straight 1n:*h r2.ik i4quqk hzroad and you look to the side for 4.0 s, how fhi*huzriq2qk 4n:1k. ar do you travel during this inattentive period?

  If you run a complete loop around an outdoor track (400 m), in 100 s, ,f2o)gf4xx 3dt1gh+n b :qvlmyour average velocq42dfv g1,f3hxmnb+xo tg :l) ity is

  A polar bear starts at the North Pole. It travw) ,ibau6 verp00 -auzels 1.0 km south, then 1.0 km east, th,w0)zuiape 60- ra vbuen 1.0 km north, 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. Ic6j- okz7 4qvzt travels 1.0 km south, then 1.0 km east, then 1.0 km north, then 1.0 km west to ret 6cz qz4v7-kojurn to its starting point. This trip takes 45 min. What was the bear's average velocity?

  You are driving home on a weekend ;6.t lbodf.0(ydrl stfrom school at 55 mi/h for 110 miles. It then starts sd;ttfl0 r.dy6blo. (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 klc-v2rwuy;vzmqbsd ,bj;o/(+*x4a ym at 100 km/h. What is the average speed of the motorist for td ,q;/mvxv 2ob az 4l*rysw cyjb(-;+uhis trip?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h. What is her2 uf(hggo :m(3wp nes+ average speed for (ogs3pmnfw gh(u :+e 2the trip?

  An airplane travels at 300 mi/h south for 2.00 h and then at 250 mi/h noruu8+l(b 9 vl/vnccv 8ith for 750 miles. Whatvn88ulb(v9 i/cvl + uc is the average speed for the trip?

  In a 400-m relay race the anchorman (the peftg4i x0jquocj. 4wefr. ek*ia4i: 41rson 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 order that the team A t4x i .4eufe0i qi 1jw4*agoj:.rcf4krunner not lose the race?

  A car decelerates uniformly and comes to a stop after 13 s. bwv *orjpmhl tf77j:*8 dal2. The car's average velocity during deceleration was 69 km/h. What was th *d :h72m*tal vrjb8.o7 jwlpfe car's deceleration while slowing down?

  An airplane increases its2 c-8evmol-(3 bnqpol speed from 100 m/s to 160 m/s, at the average rate of 8n3(v- opco ell2-q mb$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerates 7 6lj.lra-4htom m,kvat 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*(r(ylmw wl- z 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 thenra i7m+.nwucbdx5l55;ksij unp865t speeds up with a constant acceleratio +pdic;56j tu8n.nkalwmx 5u7sr55bin 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 3.7 m/spc5jvxj wr q;kz *1 --mq23gqi experiences a constant acceleration of2q5g 3j;-kmxq j r-wzvc1q *pi $1.9 \; m/s^2$. What is the cart's displacement during the first 7.0 s of its motion?

  A bullet moving horizontally to the right (+x direction) 2m9xcpok7 j ed8e.fad1aav(.with a speed of 306 m/s strikes a sandbag and penetrates a distance of 74.00 cm. What is the average accelx1j2 8epov7c(aa9 . me.a dkfderation, in $m/s^2$, of the bullet?

  A jet fighter plane is launched fmg68(n2 potm-ph4zge4s2 gxtrom a catapult on an aircraft carrier. 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 catatng 4z2xghs( t8 m64-ope2pmg pult?

  A car starting from rest moves with constant achusc6gpo:f pcld94q)b( n; w1celeration 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,/-; y;ga 4sp 0lmcpaynih-1wig2vpx /s in a distance of 200 m. What is its average acceleration?; splag ,2;/c-g y40vy 1h-iixap mnwp

  An object starts from rest and undergoes uniform acceleration. Duriuuup b)m3d(: rs;gx,. q fqqf1d )wv0r1exd:y ng the first second it travels 5.9 m. How far will it travel during the third second? qv0rxuxs( deq yp df wbu.)::gfu1r3)m;d1,q

  An object is moving in a straight line with constant acceleration. Ini*3 hq 2y4jcyw :rumgl)tially it is traveling at 16 m/s. Three seconds later it is traveling at 10 m/s. How fy2g4ul3qj) hyw: cm*rar does it move during this time?

  A car starts from rest a/ x sbb6;t6jxhnd 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 afpxm6dazhul7 /*b)d /ubn56kt 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 thec(2hx heh32p ff*jidplb *.-at has been waiting at the intersectiof- p2hb(2e.xihef lphj* 3d*cn 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 upwarhi,yj ,61qy9q am(9gt 1 oyaftd with a speed of 12 m/s on the surface of planet X where tm,96aytyiq 1toq a,h9fy1(g jhe acceleration due to gravity is $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown up mis9 *gt1s4wnuh ,;yxward with a speed of 12 m/s on the surface of planet X where n4g ;9sywi*,musxh t1 the 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 witcqp4*r*m;w ish a speed of 15 m/s on the surface of planet X where the acceleration due tm;pqsr**cw4 i o 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 kx hvk;8lwonf)4g/6f 14 m/s on the surface of planet X where the acceleration due to gravityhk w8f/ng;k ovl46x) f is $3.5 \; m/s^2$. What is the speed of the object after 8.0 s?

  Human reaction time is usually gre m2y +bbz3+momater than 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 fallb2mbm+3moz+y before you catch it?

  A ball is thrown upward at a velocity of 19.6 m/s. What isflj 4zc q3a 65inmbzzs*9b 3l/ge(/lq its velocity after 3.00 s?/5jaifgbsn3( llz4b / qlzcz36m9 * eq

  A bullet shot straight up returns to its star2j2yizp8 7dcd ting point in 6 s. What is the initial speed y2872 dzd jpciof the bullet?

  A ball is thrown straight up with a speed of 36.0 m/s. How 9 azw6 t8ftz2elong does it take to return to its staz6fwt 2e98z tarting point?

  A ball is thrown downward from the top of a building with an initiady(a5 lslhx)4dh +*9a ;kjpial speed of 17 m/s a +a*hp;jai xls4yl9hdk(d5). It strikes the ground after 7.9 s. How high is the building?

  A ball is thrown straigj8n y uk1 +vq0*ahdsq1ht up with a speed of 30 m/s. (only fill in numerical value in the blank+ j nvy1ahk*q1uqs0d8s)
(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 48.3 x s97-+ ddo+aaflmyj 5uz/a.dm/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 5 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 5.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what isdqm qvmr*- 6;n2qui6glkz1p,16nl + 8wtp avi the velocity at t = 1.0 s?

  In Fig. below, what is the velocity at a-o- yd-op5gqqk6 q4xt = 2.5 s?

  In Fig. below, what is the ve x-1lxyh5j sdn(*dh1nlocity at t = 4.0 s?

  In Fig. below, what is the19ogyu /cddq - velocity at t = 5.5 s?

  In Fig. below, what is the avera() rwo(p a8mibxxm * zrx.-s0wge velocity from 0 to 4.0 s?

  In Fig. below, what is the average velocity from 0 t dk*3 rh jsdn*s4tc/h1o 6.0 s?

  In Fig. below, what is the acceleration at 1.k/7/m lwgk mak 2( 2k,cg)tloj0 s?

  In Fig. below, what is the acceln*jcj :nee:0 en fd7d7eration at 3.0 s?

  In Fig. below, what is the an5t+nty(lez-u5cr+tc.f ip* verage acceleration from 0 to 5.0 s?

  In Fig. below, what is the avu( x)i d,hcu-q21akurerage acceleration from 0 to 8.0 s?

  In Fig. below, what is the displacement from 0 to 7xzxoeo0an:vik372guu)a z.mg ow5 :8.0 s?

Does a car speedometer measure speed, velocity? {speq: ./my02vauh:jpuy q ed|velocity}

  An object can have a varyi;io r 1b16ft8c- rpx quoaq0y5gmz)h* ng speed if its velocity is constant.

  The velocity of an object can be negative when its ) wqgs6t+8 7zt a/etcbacceleration is positive.

  If one object has a greateo))wt .h pc1hnjog 6-kr speed than a second object, the first must have a greate)g .onj-hp)w1ok ht6cr acceleration.

  Two cars emerge side by side from a tunnel. Car A is traveling with a spw r-k z-,uqeqx6f7 o0beed 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 decrek0k c+m86 ojv7o0p1 )ix tndkjases.

  A baseball player hits a foul b+odbqmg0f u 5.all straight up into the air. It leaves the bat with a speed 0uo+m 5gb.fqd 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 ob*b;qrzj u(8k3ey1p/n+yac gjject speeds up, what is happening to its acceleration, how does it change if air fricnc yky* ap;ujqg(b813er+j z/tion is ignored?

  As a freely falling object speeds up, what is happening to its acceckwg : *2uelt3leration, how does it change if air friction CAN NO3t cge*wl:2 ukT be ignored?

  An object that is thvp 8ji.za4s 4orown vertically upward will return to its original position with the same speed as it had initially if air resistance is negligibl.84soiazv p 4je. If air resistance is appreciable, how will this result be altered?

  An object can have zer2tc23ld) cax go velocity and nonzero acceleration at the same time.

  An object can have nonzero velocity and zero accelerationitud p z l167/gmvj8b+ at the same time.

  An elevator moving from the second floor to the fifth floor making no z -wv:8k37+e zb dghcvstops along the wae g khbzz8d c-:vwv+73y has zero acceleration all the time.

  A rolling ball moves pgctam/w2l , f. 8qrw/from $x_1=3.2 \mathrm{~cm}$ to $x_2=-8.6 \mathrm{~cm}$ during the time from $t_1=2.6 \mathrm{~s}$ to $t_2=5.4 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-4.7 \mathrm{~s}$ is at $x_1=3.2 \mathrm{~cm}$ and at $t_2=4.4 \mathrm{~s}$ is at $x_2=8.3 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight compagpa 4rhwuar -2q- rc,95p2qhlete laps around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 11.9 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, moving 103 m away in k*z) 8q4drtxtka 2hjdi1r/ )yatp72o11.7 s. It thtddhy t428o)/t k iaj7*rpq2ak1r)zx en turns abruptly and gallops halfway back in 4.5 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 from)*ue odh, tm;3f9 ydu5 s+pjiy;)vvjf $11 \; m/s$ to $23 \; m/s$ in 4.8 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 je8to a bh4g412im z k oo-sab8b/w*.b$20 \; m/s$ to rest in a distance of 80 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a speedyy)l :m bisu75ga crw )qp7j 5j,t2c6w of $25 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $3.0 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out ouq5bp0c93:k- lbqyy4 w cu9krf the blocks to essentially top speed about 0 9u:3by y5cqwclrub4pq9-kk$10.8 \; m/s$ in the first 11.9 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 fr-0ayfg8 drhc: om a speed of $16 \; m/s$ to rest in 5.83 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leavesn;4c id/vry8 w2pxo, m skid marks 92 m long on the highway. Assuming ad2 /r4nop ix8;w mvcy, 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 k.3zg :+xww1wk jxwc8$25 \; m/s$ 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 exqxxdq8qyxv)x ,.wa,- ,qp.)g 2k wwp yactly 27.0 min, there are stil- w p)gqqvww ,kx.2yxd a8).p,qxy qx,l 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?    $s$

  A stone is dropped from ,1k+ompset1f the top of a cliff. It hits the ground below after $2.46 \; s$. How high is the cliff?  (数值)  $m$