Suppose that an object travels from one point in space to.gutrhdh or8s1r:p gf:ys 2r4:a 1n m1 another. Make a comparison between the displacement and the distarfh 1ha1:sg2 ru.4mo:yn rd8gpr:1 stnce traveled.

  When is the average velocity of an object equal to the instantaneous v; ;z9n9-ho8s q sexjabelocity?

  A new car manufacturer advertises that their car can go "from zero to sixty/8h e cr,hbt,e in 8 s". This is a descriptioh8, ct/rh,ebe n of

  An object moving in the +x axis e6 wdvw2b7 aut83fk :mmxperiences an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x direction) begins to slow down as i/cn*ydau1 , +bv2ndovt approaches a traffic light. Make a statement concerning its accel vdauo1bv+yn2,*/n cderation.

  Suppose that a car traveling to the West (-x direction)lf( 8/szs( hnok2lvu) begins to slow down as it approach)oun(sv8f (2 l hkl/szes a traffic light. Make a statement concerning its acceleration.

  Suppose that an object is m h7wq9lhj)m:lihm0 3doving with a constant velocity. Make a statement concerning its acceleration: 0wdlih3hl79)mh jqm.

  If the velocity of an object is zero, does it mean that the acceleratiqu*n aeq2s4xtz6n7blam 8j 6ek 4m9yw-g:4hw on is zero? Support your answer with bwme kh mqqnsj*24elax4 6uga6w4-8y7n:t9z an example.

  Can an object's velocity change direction when its accelu em,0kd-ge+ aeration is constant? Support your answer with adee0km,a+-g un example.

  Suppose that an object is moving with constant acceleration. Mx- dapp13 wa9ks rrkm9wdq7:8ake a statement concerning its motion wit 3kpq9dm9ar1kw 7w:sa-8drx ph respect to time.

  Can an object have increasing speed while its accelndwff 0y i d5/lqu +y:0;d5:fasu7gjb* qn1jgeration is decreasing? Support your answer 00 nf lf;jduyi 7:*dgs f+1abw n5/gyqjqu:d5with an example.

  Suppose a can, after an initial kick, moves up along a smooth hill of ice. Mak1ic65:i9 p:2,l8niuh kb)xigax b emxhn p 8y3e a state1iciax) 6hkx bi39 8bh:luy x5i8:pm ,e n2gpnment concerning its acceleration.

  Under what condition is average velocity equal to the average o9ch4 s96 qecy2-j zkgwf the object's initial andj cwe 9shckyqg6-9z 42 final velocity?

  Objects A and B both stawozu4pm - t2wi2-9wtfrt at rest. They both accelerate at the same rate. However, object A accelerates for twice the time as object B. What is the final speed of obje2uz wt-w9tmfp4 o2w-i ct A compared to that of object B?

  Objects A and B both start from rest /3zuzmeh g8(4oeb:uakygy +y 0rs12s . They both accelerate at the same rate. However, object A accelerates for twice the time as object B. What is the d 2gyo 34be/uhssz:+gzyuym81 ( e0rak istance traveled by object A compared to that of object B?

  When an object is releh+*ps tj* lko(ased from rest and falls in the absence of friction, which of* lk sohj*(p+t the following is true concerning its motion?

  When an object is reeqy:2*:ah+1 bt nk43rcgh )o qg vpt(zleased from rest and falls in the absence of friction, which of the following is true con3otvh4c:(zr+g t p :b 1yehk*)q qag2ncerning its motion?

  Suppose a ball is thrown straight up. Make a statement about the vel aqb fnl3kqonno9(:+gf7.ox,ocity and the acceleration when the ball reaches o gn9no(n 7f+.qxl:afbqo3,kthe highest point.

  Suppose a ball is thrown straight up. What is its acceleration just before i*v1hldh /z(sh t reaches ivhhs*hd1 z(l/ ts highest point?

  Suppose a ball is thrown straight up, reaches a maximum heigh1y+z -k ws3sz/xeh+c lt, then falls to its initial height. Make a statement about the direction of the velocity and acceleration as the bas1e wklcz/+ x+z3-syh ll is going up.

  A ball is thrown straight up, reaches a maximum height, then falls to its1d abvej1l(3ysk3k(qd4/ e k p initial height. Makeyb/3ajkd3ps1e 1(4lv( kekdq a statement about the direction of the velocity and acceleration as the ball is coming down.

  Suppose a ball is thrown downward in the absence of air resistanc e .md.qvk*4+zo *bdcee. Make a statemcoke . de*4zm.+*qdb vent concerning its acceleration.

  Suppose a skydiver jumps from a high-flying plane. What is herqx;x+ c7ob(bc acceleration when she she reaches termin;b(xbxccq 7o+ al velocity?

  A ball is thrown vertically upward with a speed v. qzcppq52 0go71wj8mw2ii p- u An identical second ball is thrown upward with a speed 5i-p qwzg 02pw 2iujmc8p1o7q 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 top of a building. One second lat-42uq.t.zfn(jqi4 x8ul dj zf er, ball B is dropped from the same building. As time progresses, the distance betweend-4 xq4z ufn(j.ftjl.i8z q2u them

  Ball A is dropped from the top of a building. One second mfykn3) vkdg0 zpwsg(3/g q4d/w 0l qxgb(t8.later, ball B is dropped from the same building. As l fkq dw/ mgnsg( p3yzb8kvg 43.(t/0g)wdx0qtime progresses, the difference in their speeds

  Two objects are thrown from the top of a tall building. One iu9h mn 1mk*:pds thrown up, and the other is thrown down, both with the same initial speenk:9 dhup m1m*d. What are their speeds when they hit the street?

  A brick is dropped from the top of a building.q5z/x7)cmn5zvro) j(+j iwb q A second brick is thrown straight down from the same building. They are released at th7c o r xiqq5w mz)5/vz(+n)jbje same time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with constant non-zero velocity in the +x axis. The po2lvc7wi qm-obd: q05gsition glcq:v2m-5 dowb 7q0iversus time graph of this object is

  An object is moving with constant th0k zal5+mm ;*i vcz3ywm0 orb00e w/non-zero acceleration in the +x axis. The position versus h3 i0m*zmlrow0t0wyckez;a v/ m +b05time graph of this object is

  An object is moving with constant non-zero velocity in the +:f:se c(1 gugyx axis. The velocity versus time graph of f gc :ye(g:us1this object is

  An object is moving with constant non-zero acceleration in the +x axis. 4kq sb4 s+3erh The velocier44+ qhk3 ssbty versus time graph of this object is

  The slope of a position vers u g/8;1ug4cskosetk5 us time graph gives

  The slope of a velocity versus time graph gives 4 ib,qpg2yhi:

  The area under a curve in an acces4nq(:u (soafud g:- mleration versus time graph gives

  The area under a curve;a4vr(( hej0ioc x2/5gn jbp i in a velocity versus time graph gives

  If the position versus time graph of an object is a horizontal linxve v:5ocj dbe ezx8;,/1mog7e, the object i e5xzv;eg,8o c/job1em 7:vdx s

  If the position versus time graph of an otz q* *8gqqujy 9u 55(gtpo(fnbject is a vertical line, the object isqpjgut85(q*(fqg u*9 5tynz o

  If the velocity versus time graph of an object is a horizontal linefxs0.;a:b 1sd wcpaq-d k4:j l, the object is 1j0kd q cl.ap;4w-:d :sfbsax

  If the velocity versus time graph of an object is a straigh cdt:wllt 4qvemi-.o0 t, q0l0t line making an angle of 30 lt,. -lvt 4c0qidol0mqw:0etdegrees with the time axis, the object is

  An object moves 15.0 rs ):p 7guotoy.fd+0a m north and then 11.0 m south. Find both the distance travel0o7y+gro ufda .pst:) ed and the magnitude of the displacement vector.

  A boat can move at 30 km/h in still water. How long will it t) )khlbcz0 rmk84yiz-ake to move 12 km upsk b0-8hmilkr4) czyz)tream in a river flowing 6.0 km/h?

  55 mi/h is how many m/s? (1 mi = 1609 m)u 5p5v 9 *(svans+bqmc-5tow o

  What must be your avf: w91zc4xsks 07kghnerage speed in order to travel 350 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 km) in 2 hours and 57 min. Whkjan+oqpy(g: py*i la/ 4l9j+ at is thenaoi+p+*9 gy (k l ap/jl4q:yj average speed of the runner in m/s?

  A car travels 90 km/h. How long does it take for it to trav/k ,u. eigapn0el 400 km?

  A ly (light year) is the distance that light travels i,::ak u7pejjjprh6ihr, f; 9mn one year. The speed of lighkm9,:r:ef6auirh7p,; jpj jh 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 along a straight roayvgq n s5v6*;h wsoz -vl/ene3v2 60rsd and you look to the side for 4.0 s, how far do you travel duringv h *qsos v/s6v03e g-yv5znew;n6r2l this inattentive period?

  If you run a complete loop around an outdoor track (400 m), in 100 s,gy)5pc4 a pxg9 your average velocityg)yc4p xa9gp5 is

  A polar bear starts at the North Pole. It travels 1.0 km south, then 1.0 km eazbq; a3 dp (1sa8pd (n-vwja(ast, then 1.0 kmq z(3d-av a 1;(n8w(abdsapjp 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. It travels 1.0 km south, then 1.0 k:1m; fs8frn yem east, then 1.0 km north, then 1.0 km west to return to its starting point. This trip takes 45 min. Wh:f r; sem1f8nyat was the bear's average velocity?

  You are driving home on a weekend from school at 55 .nzf y6h lxh-7mi/h for 110 miles. It then starts to snow and you slow to 35 mi/h. You arrive home after driving 4x6l 7zyhh- .fn hours and 15 minutes. How far is your hometown from school?

  A motorist travels 160 km at 80 km/h and 160 kbb+ 7ps6r -gwhi*+pj nm at 100 km/h. What is the average speed of the motorist for this +p*i7jwbg bns6+ - hprtrip?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h. Wotx)x 2rs*9*8je:s gtl jf 3xihat is her average speed for2x * jsr98xt xjf e3*)isolt:g the trip?

  An airplane travels at 300 mi/h sout;*ftmjs)/j ;m l2uaqp h for 2.00 h and then at 250 mi/h north for 750 miles. Whaa jt/ lp2msfqj;;)*m ut is the average speed for the trip?

  In a 400-m relay race the anchorman (the persond p5ifctm26 8uut;i5s, 6o chquuc+be)q5 p(j 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 runner not lose tct5 6p bciiuqcmo2 s5dt 6j5uu;eup+h8(fq, )he race?

  A car decelerates uniformly and comes to a stop after 11 s. The car's averai0w92x fh j,f amoy8aof7:dr) *c3isege velocity during deceleration was 65 km/h. What was the car's deceleration while slowing domoi8af 30w i*df)yh2 fec,:x 9a j7roswn?

  An airplane increases its speed from 100 m/s to 160 m/s, at the m3wutsmf05 66knpmr h4-y h9eaverage rate of 4ftknmm0 5sy-hw h6mue96r 3p$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accn4x5z-u yn hys e)nr4,elerates 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 ai 2hi*rt+bi 4dnd 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 speestq1- p 6 3qphhdfe ulo5,x)d:8oji9s ds up with a constant acceleratiof q8 1d u-6j pesop35txdo)9 :ihl,hsqn 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 2.5 m/s experiences bmgb3n*u4nu*my2q rw: kos s q4z2i0)a constant acceleration ok4*2brs :) ngmwy4oq2zm u*bn3qis 0uf $1.3 \; m/s^2$. What is the cart's displacement during the first 9.5 s of its motion?

  A bullet moving horizontally to the right (+r p yzl;f:yi;:*rhtp/ x direction) with a speed of 483 m/s strikes a sandbt: * rzri;:yy/;hfp plag and penetrates a distance of 62.74 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on ay/vit, -wob msx6 y9xq5m6ey7n aircraft carrier. It reaches a speed of 42 m/s at the end of the catapult, and this requires 2.0 s. Assuming theowyx7e6bt/s,- mm y v 95x6yqi acceleration is constant, what is the length of the catapult?

  A car starting from rest moves l z*uk wi ggv2 e4i2z90znh3r2with constant 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 80 m/s 9lhn r9 hq;,o+uv+x4 ru7dhfkwq5bg* in a distance of 200 m. What is its average accel+vx unk+9h ; d ohq4r *gflq7b5uh,r9weration?

  An object starts from rest and undergoes uni8ok ogc 26ii3bform acceleration. During the first second it traviogo 82 36bkicels 9.8 m. How far will it travel during the third second?

  An object is moving in a straight line with constant acceleration. Ini9 l tvrcn 4ytj d020efk11)yjptially it is traveling at 16 m/s. Three seconds later it is traveling at 10 m/s. How far does it move 1njk9 dtye) lj2t0v4rf1 y0cp during this time?

  A car starts from rest and acceleratese x/okq. xky+6 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 at ab8gotqvgg 2h g+p3 xv d9nhm*.2out $5.0 \; m/s^2$ 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 been waiting at g-jf6nb 8f6e2pntr z8 the inr8 bfne6zfg6n t82 jp-tersection 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 5m0 mz3pif mp 9)j8agubv83ezz 3n0gba speed of 12 m/s on the surface of planet X where the acceleration d3bgvbn3 )809 m0pi 58jgu azemzmzp3fue to gravity is $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown upward with a speed of 12 m/s on the surfacj+h:eg (3lk ,fei-mqc/ pyq0ze of planet X where the accelera:z0ke3-pfilqm(e cj , +qghy/tion 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 bm/4z fj 98 xofpn2i/vgat 3e:speed of 15 m/s on the surface of planet X where zot 4if/n8 /bpef923gx: mvjathe 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 upwardwm: fl 2t+cg o83jomp: dz0;ym ryz-88:qod hz with a speed of 14 m/s on the surface of planet X where the acceleration8y3: mo rm wqzm 2lt:h0pc 8zo8f;+zy:djdo-g 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 friend holds; ckx6wrcn zno9lr e2 )jc hf8*5w8a;a a ruler 5nc)w9zne6whrao; 2 l*8xc raj kf;c8between 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. What is its velocity ase yv/)udl6h.gd rdi+5j7s du 6py4*after 3.dey7 4ij .l+66 duuyrh)gds5*pa/ s vd00 s?

  A bullet shot straight up returns to its starting point in 13 s. Wha n aow93j98crkt is the initial speed of the bwjn r39 8ocak9ullet?

  A ball is thrown straight up with a speed of 36.0 m/s. How long does it tak7ch 3p nkoel8r w(h4l2e to return to its startinlo42w 3( pkenclhrh87 g point?

  A ball is thrown dowfiaj 98(c1qhzvbv632 kjhz9s n7 5 bmcnward from the top of a building with an initial speed of 30 m/s. It strikes the ground aft5hmk vjvz39ich(asj1z7 6q92 8fbbc ner 1.4 s. How high is the building?

  A ball is thrown straight up wip/8my3)wvvs bz2tr4 oth a speed of 30 m/s. (only fill in numerical value in the blbwrvm)8 yt4v3o2psz /anks)
(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 speedoz/ svkx oock5f*/0( ifu.;wo of 26.8 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 9 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 9.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is the velocity at t = 1.0 s vj8bvso8 w on g7*9vdbl.44owykvt (7?

  In Fig. below, what is the velocity at t = 2.5 s?8y dwm f9; gmw.d,/jxx

  In Fig. below, what is the velocity at t = 4.0cc+4z /k(wl;ha lmq1 k s?

  In Fig. below, what is the veloci t **wwqz/.oi7vafw.rty at t = 5.5 s?

  In Fig. below, what is the average velociq5mip ind.5 0kty from 0 to 4.0 s?

  In Fig. below, what is the average velocity f(lb8er7bcc.dqo m/ enuo)k2:rom 0 to 6.0 s?

  In Fig. below, what is the accelerac bha( s4qc9mm4 ,r bpgk+tu27tion at 1.0 s?

  In Fig. below, what is the acceleration at iz*1wzlxc wlv+9ab/ pc1*w d* 3.0 s?

  In Fig. below, what is the average acceleration from 0 to gc.)3-ry mnyq 5.0 s?

  In Fig. below, what is the average acceleration fruv9hmd9co.amx8a b dd1 us.7 fd +/m:fom 0 to 8.0 s?

  In Fig. below, what is the . +4f:l6ifhn8wmoqb zu fe,s5d/m *up.uym7 i displacement from 0 to 8.0 s?

Does a car speedometer measure speed, velocity? {speed|ve:7pg mh eig q7ft5l/;elocity}

  An object can have a varying speed if its velocity is cons76i8exth yz/psiuqvz/ k4j( 8 tant.

  The velocity of an object can be negative when its accc 6;t99tj lu/.vgquo 0pcu c4ueleration is positive.

  If one object has a greater speed than a sec scfj))hkomrdk.x+ zig5w2 78ond object, the first must have a greater ac.wfo7rd) )52cmhizsx 8kk gj+celeration.

  Two cars emerge side by side frt4:3gm ol/h ioom 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 accele k/ek6bdn4d f0cow72,u mz +ohas,v(kration decreases.

  A baseball player hits a foul ball stra7yip+eucfd s99/c06 g7p p spnight up into the air. It leaves the bat with a speed ocn9p60+ug s7pyp de7cp/s 9 iff $120 \; km/h$. 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*1 w qtf;fip; cg szaud,-q9z78apq1m happening to its acceleration, how does it change iz1pq18 tc9mf q*pgzs-;fq iw;7 a dua,f air friction is ignored?

  As a freely falling object speeds up, what is happening to its acfmm s.j+n6 pe/celeration, how does it change if air frictim. 6esmn+p/f jon CAN NOT be ignored?

  An object that is thrng3u.1fu ld8rh 3-hwcsh 8* wxown vertically upward will return to its original position with the sa8wns3.fwuu3xhd 8rg*-h1 c hlme speed as it had initially if air resistance is negligible. If air resistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzero accelerati 0glh-.wh/l7yht fzjh)un )w, on at the same time.

  An object can have nonzero velocity and zero accelerationcmw;(9rd3sbga 9+wztx sotm,my *5b )0f6yrq at the same time.

  An elevator moving from the second floor to the fifx9xa 8p * pbiw7ffx9(qth floor making no stops along the way x97xf(xq *8b wfa ipp9has zero acceleration all the time.

  A rolling ball movesw .edgg.l;qq. gc+.a o from $x_1=1.8 \mathrm{~cm}$ to $x_2=-7.4 \mathrm{~cm}$ during the time from $t_1=1.4 \mathrm{~s}$ 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 $t_1=-3.3 \mathrm{~s}$ is at $x_1=2.7 \mathrm{~cm}$ and at $t_2=3.6 \mathrm{~s}$ is at $x_2=7.7 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps around a quarter-mifek1dgl5/o6 kl 4fqd3v .6ryt le ($1 \; mile = 1609 \; m$) track in a total time of 10.3 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 89 m ak/ s 8inxa m6b1w+o4fsway in 9.4 s. It then turns abruptly and gallops halfway back in 4.7 s. Calculate (b +1 mni kxs486fwsa/oa) 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 fru 4u.jq. yn9pb (ulc;0ikbf4yom $11 \; m/s$ to $25 \; m/s$ 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 px hkhu1*zkfr: fv24*$21 \; m/s$ to rest in a distance of 66 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reachgcc 15inq+ 1)0f, y c4o m1nusfrflt3dn: wh(o a speed of $32 \; m/s$ 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 :*ag4s h4.o+b w* l;qvbmt zbzthe blocks to essentially top speed about4b4 ;z smqgaobzv:** bw h+l.t $10.2 \; m/s$ in the first 10.5 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 pu5a0se8glp 2ajp.g9k( w.xrom a speed of $16 \; m/s$ to rest in 4.54 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a carf5 i76y xp tzd1t+ybb8 leaves skid marks 92 m long on the highway. Assuming a deceleratio8 t z1b7iypxt6+5f bdyn of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a trucnoh:ot(6(poz k 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).    $m$