Suppose that an object travels from one point in sp9 +kobmww ,hrns* g-;yace to another. Make a comparison between the displace;bn ,k+s*owymh w9 gr-ment and the distance traveled.

  When is the average velocity of an object equal to tfo5u b7n ah zz5*jr58jhe instantaneous velocity?

  A new car manufacturer advertises that their car can go "froz2mptiz*d+0 p :t2 fetg4q nu.m zero to sixty in 8 s". This is a description op.f2+q tzt:4 nm u0tg*2 edzipf

  An object moving in the +x axis experiencesp6f:aer 0h jkvyf ,bhdn, p.(d2b x8d; an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the Etk77)**kcmnfo9 bx+ on wjisob 7odvw 23c)1nast (+x direction) begins to slow down as it approaches a traffic light. Make a s widc k)2k7x oob9 v7c)nb+nojtnw7 1sm3*o *ftatement concerning its acceleration.

  Suppose that a car traveling to the West (-x directm +t5o4z8zwybn5 c-ccb/b/ xs)f 1uscion) begins to slow down as it approaches a traffic light. Make a statement cony +8c/)c-cwts bo54 xz bsum5 fbz/cn1cerning its acceleration.

  Suppose that an object is moving with a constant vel(:vihwr(dw -o ocity. Make a statement concerning its accelera(wo-h v:id(rwtion.

  If the velocity of an object is zero, does it mean that the acceleration c1c. fdm,p7 sois zero? Support y7s,cc do 1.fpmour answer with an example.

  Can an object's velo7i mx7u: ja ail;d+z)/bfy 1gpcity change direction when its acceleration is constant? Support your answer with an example.dx +l/7 :fz7yb1ui)jgiap a;m

  Suppose that an object is moving with co 8aq4+ckd:6jmcy pog5 5.nte+ ydl2zgnstant acceleration. Make a statement concerning its motion wcd+85m o2p :g5lcaygqy.6 d +nk4jtezith respect to time.

  Can an object have increas aoff6/z+i f.qing speed while its acceleration is decreasing? Support yif/q +fao6z.four answer with an example.

  Suppose a can, after an initial k*o1pt13sszq 2vw/ sx ; h.cne2h azp0kick, moves up along a smooth hill of ice. Make a statement q/ eo0;ssa* z.h23zhnt12c vp px1skwconcerning its acceleration.

  Under what condition is average velocity equ(g frlop k;f62al to the average of the object's initial and final velocr; pfl6g2o kf(ity?

  Objects A and B both start at rest. They botis7rf+:2f 7qgpy c/q bh accelerate at the same rate. However, object A accelerates for twice the time as object B.f27rf7+:piysbqc q/ g 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 thkbuc + -/d9rlf:ic -wpe same rate. However, object A d pu fcc-w-+i :kr/bl9accelerates 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 friw iq/zzg 00m/4ki0pr qction, which of the following is true concerning its motk/p0 zqii0/mz0r 4 qwgion?

  When an object is releasek1 wq *,(aqsq*dxs llvgoebycv1( 94. d from rest and falls in the absence of friction, which of the following is true conceroxqvsk1*es d1*qlc4a qg,v9 ylw .((bning its motion?

  Suppose a ball is thrown straight up. Make a sy0 3qo5s +6/21msmooi.i a2gia6;gv c lb pxyitatement about the velocity and theiyma2gi +go.li q/ys6b;x cmvp156 0so2 ao3i acceleration when the ball reaches the highest point.

  Suppose a ball is thrown ub5bdd7uz, *hbshl)d.9kg3c straight up. What is its acceleration just before it reacld*73 9u dbg)sd.k hb5zc,ubhhes its highest point?

  Suppose a ball is thrown y8 vlrpmw4z j 5vybz458l;u3k straight up, reaches a maximum height, then falls to its injlvmz3 ;548kv 54 pr ul8ybwzyitial height. Make a statement about the direction of the velocity and acceleration as the ball is going up.

  A ball is thrown straight up, reaiy22 icoomy -b 8h2dbcj y5:z.h:7ekeches a maximum height, then falls to its initial height. Make a statement about the direction of the velocity and acceleration as the ba72 h ym e: :c2k ydco8y2-.hbie5iobzjll is coming down.

  Suppose a ball is thrown downward in the abx,dc1-,qa*b bk cs;hmsence of air resistance. Make a statemen, *1xc m,hbbas-qcd;kt concerning its acceleration.

  Suppose a skydiver jumps from a high-flying plax (*3kv smhqq9ne. What is her acceleration when she she reaches terminal v(qhs 3mkxv *9qelocity?

  A ball is thrown vertically upward q iafo(6i83 n;v mvq9lg4agc vn8u)5vwith a speed v. An identical second ball is thrown upward with a speed av9 5q3n84gc 8;nou flg6i i mv(vq)va2v (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 fro)n: fq.gc 7cr58: fv4skixw, frz /xrum the top of a building. One second later, ball B is dropped from the same building. As time 8: f/xus ,:fxni7vkcfc5g r)qr z4.wr progresses, the distance between them

  Ball A is dropped from the top ofqow6mnf: : dzk:yn -m()75e,f,lkb ollb c9di a building. One second later, ball B is dropped from the sawi5:l6e n9kl bl:z ,m)dofymc7-k:dnq f,b (ome building. As time progresses, the difference in their speeds

  Two objects are thrown from the top of a tall build1r/4e l5d wjawing. One is thrown up, and te45/jlwar1d whe 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 second brick is thrown stryk xt8p ,u+pi:aight down from the same building. They are released at the same time. px u+t,y:k8 ipNeglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with constant non-zero velocity in the +x ah2 kdwy2,o3-zg2jw4 kd9ad koxis. The position ve2o4k2jddwak h-zw y 9,2ogd3k rsus time graph of this object is

  An object is moving with constan29k svhnb4gu, t non-zero acceleration in the +x axis. The position vers2gu svk hn,9b4us time graph of this object is

  An object is moving with constanzc37z2gofz3 e bi4b*et non-zero velocity in the +x axis. The velocity verscoizeb4 3zezg b2f*3 7us time graph of this object is

  An object is moving with constant non-zero accelerm.hg1ix3vt ,) 8lc:bd fw bf.,rif g*xation in the +x axis. The velocity versus time graph of this object x .gm x1fgdfctf, h 3.:)*ilb8vbwi,r is

  The slope of a position ver 4e*99l3s qqcy+(vp8svh8ysi;of le bsus time graph gives

  The slope of a velocity versus ti0d6:h ynlt d0ume graph gives

  The area under a curve in an acceleration versus time gr1a;-;ppva bx naph gives

  The area under a curve in a i9*ghv,5a frx; kpri-nx/ck5y, zj r2velocity versus time graph gives

  If the position versus time graph of an object is a horizontal line, the object xwt5za5r2ct(v25 i 3 1reublxk4; y eeisa(v;i5yeecrb 2t154ztelu523x xr wk

  If the position versus time gr03xe mzcgqmjb:b*j27 aph of an object is a vertical line, the object is07b:j e2bcmz*3xgqj m

  If the velocity versus time graph of an object4;bshl x4:vpw is a horizontal line, the object pbhv ls4;:wx 4is

  If the velocity versusbemvv z25gt ip87i **g time graph of an object is a straight line making an angle of 30 degrees wm vei*gz g 725p8tbv*iith the time axis, the object is

  An object moves 15.0 m north and then 11.0 m south. qsn3f h zq(r)xznx7 sr8(w0:r Find both the distance traveled and the magnitude of the displacemennrnx7hz: zr(s w(rxfsq q3)8 0t vector.

  A boat can move at 30 km/h in still water. How long will it take((sn2ytvj2w mf zp04q to move 12 km upstream in a river y n2v(tfz(p4smw 0 2jqflowing 6.0 km/h?

  55 mi/h is how many m/s? (1dwc;lhfvy)of u a 9xbz6 +q0*9 mi = 1609 m)

  What must be your average speed in orderh*afiquav36 zk0) dkg i.v80n to travel 350 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 kmdn 1d5iipvv/1 ) in 2 hours and 57 min. What is the average speev1 i5 /pv1inddd of the runner in m/s?

  A car travels 90 km/h. How long does gyfrro)dsb9r4i/mg /qo ag5c 8rx 7 ;2it take for it to travel 400 km?

  A ly (light year) is the distance that light travels;l1nafc p;z+ j6cl gt5qnqj2: in one year. The speed of lightjlqa jpcq5:;+gn1fz ctn;l26 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 road and you look to the s yb4xii:u7rf6ide for 4.0 s, how far do you travelfy6r4i:x ub7 i during this inattentive period?

  If you run a complete loop around an outdooru.cfo4) ttzt. track (400 m), in 100 s, your average ve .tf .z4t)uoctlocity is

  A polar bear starts at the North Pole. It t+rb8:c ee,+ar5 wmjwqravels 1.0 km south, then 1.0 km east, then 1.0 km north, then 1.0 km west to return to its start w+ rejcm5a8wq +:,erbing point. This trip takes 45 min. What was the bear's average speed?

  A polar bear starts at tb s )u0y0ehmb mtxp;09he North Pole. It 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 was the bear's avera ;ymbtp9 )mhbu0ex00s ge velocity?

  You are driving home on ae:tq pqf :c48y weekend from school at 55 mi/h for 110 miles. It then staqp ec:f8yt :q4rts 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 k b,ucc eutfhq c..8x7)m/h and 160 km at 100 km/h. What is the average speed of the motorist fu ,e7q 8h.cxcf. )cubtor this trip?

  A motorist travels for 3.0czh,4cu*h5jg h at 80 km/h and 2.0 h at 100 km/h. What is her average chg, z5* huj4cspeed for the trip?

  An airplane travels at 300 mi/h south for 2.00 h and then at 250 m: pjx4ybvr7qf 3*7g 0.8 q6osghmgolbi/h north for 750 miles. What is the average speed for th plggbgr 8.m3o7oqv:h0s4bfq y7j*6 xe trip?

  In a 400-m relay race the anchorman (the person who)iv qfqns: t9j*yab wk0 .v4q- 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 is4jn.isv-v aqk09 *)fyqtb :wq 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 comed,aif 3.q,anh s to a stop after 9 s. The car's average velocity during deceleration was 49 km/h. What was the car's deceleration while sl,,nif.hdqaa 3owing down?

  An airplane increases its speex;rg lr)0:hpg d from 100 m/s to 160 m/s, at the average rate of r:)xpgh;rl g 0$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerat( ,-o-a .dqzy jqktb8res 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 s 9k u2dkctz6n*4*t lo:g/k.litlp -baccelerates 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/,/* c e: b 6wg,u:9gwueyywreibh9m v 10 s. It then speeds up with a constant acceleratio,:wrmiyece by guw6,:*//eug 9hvb9wn 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 1.9 m/g 14je ujun9y6s experiences a constant acceleration of 4yuu n16je9gj$2.6 \; m/s^2$. What is the cart's displacement during the first 7.6 s of its motion?

  A bullet moving horizontally to the r;a(eduu:av -d5as3ae n1 jv1l ight (+x direction) with a speed of 343 m/s strikes ae(j1vvn3ae:;a -su a1add5lu sandbag and penetrates a distance of 99.46 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on an aircr hjzm;v1i,qzw ng/t4,z3bug 4aft carrier. It reaches a speed of 42 m/s at the end of the catapult, and this requires 2ngiqtwu h ;3,,m4/zzgb4z vj1.0 s. Assuming the acceleration is constant, what is the length of the catapult?

  A car starting from rest mo ) gk+o.lc+)v3mjb7sn1(oiz2z sne nbves with 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 in a distance of 200 m. What is its average5 c).p gu+i s97el/if a:sonko acceleratkge7u/isl : cai5)+sofp.n9oion?

  An object starts from rest and undergoes unifoe0 q 4:.esttrwrm acceleration. During the first second it travels 4.2 m. How far will it trave4 eqsrw tt.0e:l during the third second?

  An object is moving in a straight line with constant acceleration. Initig pwk c**ga)4 b1i*ker4 s gkqanc(pg0k 11r;xally it is traveling at 16 m/s. Three seconds later it is traveling at 10 m/s. How far does it move during this ti11pbkw( gegka*i grcx1pk4* 4g 0;qk) s a*rcnme?

  A car starts from rest and accelerates unifovza/n5 kipn-:ex9d rq -j9b;v rmly 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 aboutm jbj l6p.x))q9z;hdk $5.0 \; m/s^2$ 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 lightca8g*a t3op3s6v kkb;25 bqjg turns green, a car that has been waiting at the intersection starts ahead with a constant acceog bkbp2s *3 ;kcgj3qt8av56aleration 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 s7e6o tzj+0txy(mu7a upeed of 12 m/s on the surface of planet X where the accelerae6ot(7yumj7+0 tx z uation due to gravity is $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown upward with ai6;la u r.vt*z speed of 12 m/s on the surface of planet X wherli6v r.*a;u tze 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 with a speed of 15 m/s on the surface ouurm24p+ckl 6f planet X where the acceleration due to grarc pml+ 6uu2k4vity 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 speeahpl- dw5uu 1pg ;0b0pd of 14 m/s on the surface of planet X where tha1pgu0b0u;pdh5 p wl- e acceleration due to gravity is $3.5 \; m/s^2$. What is the speed of the object after 8.0 s?

  Human reaction time .9gykpg6 qdm 0c:g/7nel( svxx ptu0.is usually greater than 0.10 s. If your friend holds a ruler between your fingers am9 xv07ut xl0g y/gd(p6c.qsen. gp:knd 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. Whatnauprr4; 8sgnfpv5 jaz4:-q, is its velocity after 3.00 v4r grzjspa:n 4,q5a;f-8 pu ns?

  A bullet shot straight up returns to its startb:3 tx k8wywe0xvg,6uj8df. f ing point in 11 s. What is the initial speed0vfx3w.f ,wedg 8kb6tx8 y:ju of the bullet?

  A ball is thrown straight up with a speed of 36.0 m/s. How long does it take tb;q6o.c j w5tz55lq9ghv4 ho po returb .p4q5wj6oq c9 5tg;5lvoz hhn to its starting point?

  A ball is thrown downward from sybuskbr;,6g+ ( yg9fuaz2m+the top of a building with an initial speed of 18 m/s. It strikes the ground after 6.4 s. How high is the b;9sgzbrk uyf ,ms2g6u (ba y++uilding?

  A ball is thrown straight3m drh .6 q l gr)ncve)4fpid83w.6pnv up with a speed of 30 m/s. (only fill in numerical value in the bl)g43n rvi .f6 r)n p8dwelmd.hv p6qc3anks)
(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 2bqed:t b ybvxw flwt752/k0 q1+mam8 the air with a speed of 46.5 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 3 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 velocitz0pb0oe/ h9vg y at t = 1.0 s?

  In Fig. below, what is the velocity at t nus*)p9mi3gi= 2.5 s?

  In Fig. below, what is the velocity at9m)l7hqp dd)8msp wq. t = 4.0 s?

  In Fig. below, what is the velocity at t = 5.u86 r gey9 :rk5 ha+ahpvtd03m5 s?

  In Fig. below, what is the averag+gz9qwt:or1 w s.l ig3a 0.pen 75ehcoe velocity from 0 to 4.0 s?

  In Fig. below, what is the avebxc92j +e(bg iphxk p9ckm/8,rage velocity from 0 to 6.0 s?

  In Fig. below, what is the acceleration a)u +:5aqz 7pb k6uc8nnn+owv gt 1.0 s?

  In Fig. below, what is the acrjan1:d 2islc2a crvq):/z f 5celeration at 3.0 s?

  In Fig. below, what is the average acceleration from 0 to):0pssfhg9 illgj m;8 5.0 s?

  In Fig. below, what is the avut /d)iq qsd(four2v; tiu(; 1d.w m)zerage acceleration from 0 to 8.0 s?

  In Fig. below, what is the displao*(b1j4cgv i6i0iy hecement from 0 to 8.0 s?

Does a car speedometer measure sp4gp2 vgb:hjkfv9/;39wk o ev need, velocity? {speed|velocity}

  An object can have a v4s lxkz 7hv3z) s7hwm6arying speed if its velocity is constant.

  The velocity of an object can be negativzmn . ,pown/z-e when its acceleration is positive.

  If one object has a greater speed than a second object, 5 qea/v*tujg 8 )z:hbwthe first must have a greater acce8ujev/ t*g) :bhz awq5leration.

  Two cars emerge side by side from a tunnel. h)/d1tn+mpg oCar 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 itsgu6ce9g,127bmlzh -3 uxb ptc acceleration decreases.

  A baseball player hits a foul ball straight up into ts)t fx;t v3wfo2p6* p mm4j+wthe air. It leaves the bat with a ptxtmf 4pvo6ms;+3ft*w)j w2speed 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 itsytl4uivms5ld;ngdl,, /:/ir*7 tmv m acceleration, how does it change if air frictivt /d nu/l7r; lvsd, ltmi4 ig,5m*:myon is ignored?

  As a freely falling object speeds up, what is happening to its accelerati w20ic,5xj *m31mnhf)tenk:m6 q ria ron, how does it change if air fricthmim1i: ,n f30) r*eajm 5r6w2qcxnktion CAN NOT be ignored?

  An object that is thrown vertically upward will return to its originale fjcr3 l /azr c4*3*xxf5ntd0 position with the same speed as it had initially i4 r 0*flf d5ccx/rzjna*x3et 3f air resistance is negligible. If air resistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzero accelest hd;3j0gv a g4+o6kzration at the same time.

  An object can have nonzero velocity and zero acceleration at thy*;we5 jt3*inh0r va se same time.

  An elevator moving from the second floor to the fifth floor makinhhl7hik0- x2dc) dhzw/ck30k(epd:r g no stops along the w0hrh)ik(d0hdwh3xc7 2pzdl/ k :e k-cay has zero acceleration all the time.

  A rolling ball moves fb*s24 v q:fgsfrom $x_1=3.0 \mathrm{~cm}$ to $x_2=-6.4 \mathrm{~cm}$ during the time from $t_1=1.9 \mathrm{~s}$ to $t_2=6.0 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-2.4 \mathrm{~s}$ is at $x_1=2.7 \mathrm{~cm}$ and at $t_2=3.8 \mathrm{~s}$ is at $x_2=7.8 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps around a quarter-m wj9-+ su,bgoa 8)x -dwxo6yflile ($1 \; mile = 1609 \; m$) 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 x zyp2 (fm6zx2 5zc2adin a straight line, moving 108 m away in 12.2 s. It then turns abruptly and gallops halfway back in 4.8 s. Cax(zzd2fp6m2acz5 x2y lculate (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 frog8a225yzkdg8 t-vwn /.*5zlewwpjwn m $12 \; m/s$ to $24 \; m/s$ in 5.4 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 from )3ngmi)r;t-*f+rvhd xmj v k0$17 \; m/s$ to rest in a distance of 68 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reafvd41 e)zd ,eklqx ;cy e:azc097-hiue-b md)ch a speed of $33 \; m/s$ 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 essent(u 1sy2: kvktrially top speed aboukrk:1 t2 y(vsut $10.9 \; m/s$ in the first 10.7 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 unifoejuf;tnvz -( r 5 k/hhbk,k)x)rmly from a speed of $18 \; m/s$ to rest in 5.43 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves skid marks 92 m long cl2+dm(+uceu on the highway. Assuming a deceleration ocm ul(+c de+2uf $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truckkdz gti5)iooh7 u/ 1j, 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 i)kvhut2*ru m.ozu9i h;/7 a jrn less than 30.0 min. After exactly 27.0 min, there are still 1100 m to go. The runne) mu.* rujv7rhikuhtoz92/a;r must then accelerate at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$