Suppose that an object travi2pt4;0e:l i+yk mysbels from one point in space to another. Make a comparison between the displaypi;lb m4ek2ti:+ sy0cement and the distance traveled.

  When is the average velocity of an object equal to teox .*b9qod9 che instantaneous velocity?

  A new car manufacturer adii;8m wrtnyc7 egxs.s*r*0htr1 q.4 vvertises that their car can go "from zero to sixty in 8 s". This is a descriptx7tsqw1vt r.yi 8nsr ;ireg0*c .h* 4mion of

  An object moving in the +x axis experience3d vifra 19xyl78d v:hs an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x direction) begjk c(g -zk7q/1s) .p zdytzz2k, vqfg+ins to slow down as it approa17g-2 yfzqcq, /zskt pgk d()zv .z+jkches a traffic light. Make a statement concerning its acceleration.

  Suppose that a car traveling 92w/ o bw, /czmrzu1msto the West (-x direction) begins to slow down as it approaches a trafw9 mmwcr/ u b,1o/2szzfic light. Make a statement concerning its acceleration.

  Suppose that an object is moving with a constant velocity. Make a statemen-c t0 azbxw*z)t concerning its aca* -zcxzb0t )wceleration.

  If the velocity of an object is zero, does it4f ;a7atl2r*;yojh -p2xiu8sg yh h.m mean that the acceleration is zero? Support your ans- 8u.o;24 at2;mpflyrahsjhi*xyhg7 wer with an example.

  Can an object's velocity change direction whw pz 4nih85fz/en its acceleration is constant? Suphpz8zn/4w f5 iport your answer with an example.

  Suppose that an object is moving with constant acceleration. Mak*h hf,cq,i+h5 -et4urgo, jn:y cu4h oe a statement co:cu ,c 4ufhe,ghr5io,j-4q+*nhtho yncerning its motion with respect to time.

  Can an object have increasing speed while its acceleration is decreasinualee0- kt -9ag? Support your a0-ka aut le-9enswer with an example.

  Suppose a can, after an initial kick,ibexwj11ap8p )3 o)p0ctvs 3j moves up along a smooth hill of ice. Make a statement concerning )sx8 p)pi3p0j1t1 wjv a 3cbeoits acceleration.

  Under what condition is average velocity equal to the average of the obv*.dz68y hhhs dm1( cnject's initiz* dhvh . dh(y16mscn8al and final velocity?

  Objects A and B both start at rest. They both accelerate at the same ra /:7r-h wohc7 ddi1ogo7v(5ce olqaz -c17x bqte. However, object A accelerates for twice the time as object B. What is the final spea-o 7eodil:7x7 7cghb/qv5wzoh1rq( do1c- c ed of object A compared to that of object B?

  Objects A and B both s t tsgbtg)7hv5jevk1( .vu( p9y3s* cztart from rest. They both accelerate at the same rate. However, object A accelerates for twice the time as object B. What is the distance traveled by object A compared to s 9y53zv (h(becsp.*tj1 ugkv7 tvtg) that of object B?

  When an object is re-og1nw4y a6k uwkp9q1 leased from rest and falls in the absence of friction, which of the following is true concerning its mok9uky1q4an-o g 1 wp6wtion?

  When an object is released from rest and falls in +0 fhaqjw2vdgibh-3v9 wc-, mthe absence of friction, which of the following iaid+q3jw0vmw bv,fg2c --h h9 s true concerning its motion?

  Suppose a ball is thrown straight up. Make a statement ab:r) o/pt6tdxz -g4 yqtout the velocity and the acceleration when the gptr /z-4td oy6x:tq) ball reaches the highest point.

  Suppose a ball is thrown str; v )djq09wncaeo j3)baight up. What is its acceleration just before it reaches its hi3 awob) ncdj )q0ev;9jghest point?

  Suppose a ball is thrown straight up, reaches a maximum heib;(lrpckj * 4ught, then falls to its initial he rb*;l4kp(j ucight. Make a statement about the direction of the velocity and acceleration as the ball is going up.

  A ball is thrown straight up, reaches a maximum height, then vesat14,zqs gs5ag2n4 8ta v: falls to its initial height. Make a statement about the direction of the vesv1 ga2nqte8t4 vasz sa5 :g,4locity and acceleration as the ball is coming down.

  Suppose a ball is thrown downward in the absence of wrg*3i+op 6ii air resistance. Make a statement3wioipr *i+ g6 concerning its acceleration.

  Suppose a skydiver jumps from a high-flying plane. What is her accelehswx sn;bw u:yv06;be w*hf4 9ration when she sh6h: 0;fxuse 9 s4*vwy;bhbwwn e reaches terminal velocity?

  A ball is thrown vertically upward w+5xv b7 8h (jw-aij x.fqyqo2fith a speed v. An identical second ball is thrown upward with a speed 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 t -v2f wjxxq5+8iho.afj (7bqyhe first ball?)

  Ball A is dropped from the top of a building. One second latekgor0o g qy873r, ball B is dropped from the same building. As time progresses, gygo0r78 o3kqthe distance between them

  Ball A is dropped from the top of a bu d rxwlkbpfa)i*7 ui k:;h0y,,ilding. One second later, ball B is dropped from the same building. As time ,0)ba*pkk,yr :fih7iulw ; d xprogresses, the difference in their speeds

  Two objects are thrown from the top of a tall building. One is thrown upa/c0 zcjy* +hj, and the other is thrown down, both with the same initial speed. What are their speeds whe+h jjcac/0z*yn they hit the street?

  A brick is dropped from the top of a building. A second b61pltc9 a-qz0pgvo0u rick is thrown straight down from the same building. They are released at the sa001 l gap-6ot9pvz cqume time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with constarpz)-)qppznre aa (a4i(q)* ant non-zero velocity in the +x axis. The position versus time grapqapz i-(n)4)rrpa z(a*eqp)a h of this object is

  An object is moving with constant non-zero accelp/tv0 7vu-j*gpd6 kzweration in the +x axis. The position versus time grapht pv-w*j0v6gupd /k7z of this object is

  An object is moving with constant non-zero velocity in the +x axis. The velocity0u-;)xv5 v9r b lkdmvobd;ml-vv59rxou 0 kv) versus time graph of this object is

  An object is moving with constz,8:te / 5 7ps .jdt7oycrxszbant non-zero acceleration in the +x axis. The velocity versus time5soj/x t87yrbz :p7 dts,ez c. graph of this object is

  The slope of a position versus tim)zhfmt-b 91nu1oav4 mp8hj4ze graph gives

  The slope of a velocity versus time grovwm0x 6ur/ kxax aaste7 9c20ir03a+ aph gives

  The area under a curve in an acceleration versus time stl(qzo* 56jwi:mjw, graph gives

  The area under a curve in a velocity versus time graph26r lvib v:l-q gives

  If the position versus time graph of an object is a horizontal 0l .o/ y2gyhibkch,l1rzow3i 6 v, ms;line, the object k lgs mli0wh ,;boyvz6 hociy.3/r,12is

  If the position versus time graph of an object is a vertical lz jsqhi; *7m8v-p1br qine, the object is*qshi7vr1m q8 p-;bjz

  If the velocity versus time graph of an object is a horizo r9g -k),cfbnx;u9zo hf)hp1tntal line, the object is)1z fg;9phbrtof)un hk,x9 - c

  If the velocity versus time graph of an obji)rt:.7ir bij : 6opnoect is a straight line making an angle of 30 degrees with the time axis, the objec n 67ribpt.:oijio):r t is

  An object moves 15.0 m north and then 11.0 m . wigzc ;b*blzhhovas4k4q(/ :7 -naty)2zyxsouth. Find both the distance traveled and th bach-;a s.:7y/niyxb)( l4wgoq4*zkzht 2vze magnitude of the displacement vector.

  A boat can move at 30 km/h in still water. How long will it take to movehh9 d n9z/w 7pbm62i/jtndr; h 12 km upstream inhij/b9z 9w nrt; h6d/m dhp72n a river flowing 6.0 km/h?

  55 mi/h is how many m/s? qdh122 -/m(pl x d 5ju2lmxnze(1 mi = 1609 m)

  What must be your average speed in order to trpqfa,j widon7(h;ap8 ;y 6je 2avel 350 km in 5.15 h?

  A runner ran the marathon (apvo4odwib93o zq tu g8h u(7k*(proximately 42.0 km) in 2 hours and 57 min. What is the average speed of the runner inubo34 (duz*w q7 (oivk8og9t h m/s?

  A car travels 90 km/h. How long does it take o 0hem7c6 n9nb xw1ri;k2dl +ifor it to travel 400 km?

  A ly (light year) is the disxf: gdh0ygb39 tance that light travels in one year. The speed of d 9x yg3h0fb:glight 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 side for ,1t: awlyzruby;o3i / 4.0 s, how far do you travel during this inattenaob3 1ry/ tilz;wy, :utive period?

  If you run a complete loop around an outdoor track (400 wah5wu4w, xn9m), in 100 s, your average vh ,aww u45nwx9elocity is

  A polar bear starts at the North Poa pc yd)r-i+4 b5 cdo03lg8ngkle. 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)3n yr8pia 4d0 o- kg5+lgdbcc 45 min. What was the bear's average speed?

  A polar bear starts at the North Pole. It travels 1.0 km south, tah m hbe1)cq;+rit6a)h-zd3d hen 1.0 km east, then 1.0 km north, then ;zb r) ) aid+ eh3dcmh1-q6hat1.0 km west to return to its starting point. This trip takes 45 min. What was the bear's average velocity?

  You are driving home on v cupg5t y;30ga weekend from school at 55 mi/h for 110 miles. It then gg5tu3v y;pc0 starts 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 160fhy a5svz(m4: -hxch u)guj-sd 0l37s km at 100 km/h. What is the average spdj37 5ug)uc- f h(h4ssza s-xlmy:vh0eed of the motorist for this trip?

  A motorist travels for 3.0 h at 80 km/h y6nsv*t2(d :drcu :s37 swnhgand 2.0 h at 100 km/h. What is her averahvcrw stddn:n 7u:sys (2*3g 6ge speed for the trip?

  An airplane travels at 300 mi/h south for 2.00 h andw:3ldpv,3(d()q ycdvr)tu vfr , ykd. then at 250 mi/h north for 750 miles. Wv,(w3qrydv,dcv dtpy :r) (d uf)k3. lhat is the average speed for the trip?

  In a 400-m relay race the anchorman (the pervw8q:;uu, lrason 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. Wharvlqauu,w; :8 t 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 yz7xf dl-26-u + ybmhr0f: tbes +ezi c180ygland comes to a stop after 13 s. The car's average velocity during deceleration wa2l s0fzfuc0tye- ehl bd1xg :iry+6zm7b8+-y s 45 km/h. What was the car's deceleration while slowing down?

  An airplane increases its speedtdkh5xg x qg5.mt.7: y from 100 m/s to 160 m/s, at the average rate of k57q xgh5. x: mt.dtgy$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerates at the rate o v:ak1l2:mb8y2o ow sbf $2.0 \; m/s^2$. How much time is required for the car to reach a speed of 90 km/h?

  A cart starts from rest and accelerates qewnh-rw+v62f t8jnbxh 0u) ll nbl qb879.p 3at $4.0 \; m/s^2$ 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 up7rv /1 yhm*,vcr1msoh7radfoe h/ / e/ with a constant acceleration s/ efmh/ rc7 1a 1,/h m7*d/vvrroyoheof $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 4.9 m/s experiences a constant acceleration o)fsd) x:op51 h7xmrzs4r6 w76sqe yfwf 5 s6sqpe46rsxr m1fzh)w)7x 7y: d owf$2.0 \; m/s^2$. What is the cart's displacement during the first 9.9 s of its motion?

  A bullet moving horizontally to the right (+x direction) with ox-ff4as*+ sja speed of 485 m/s strikes a sandbag and penetrates a distance of 68.05 cm. What is the average acceleration, in fo jx *a+s-f4s$m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on abap /f9np2lu s0mp)w 3n aircraft carrier. It reaches a speed of 42 m/s at the end of the catapult, and this requires 2.ln0 fp)3a mbs9/ up2wp0 s. Assuming the acceleration is constant, what is the length of the catapult?

  A car starting from rest moves witg:zu(/79n+to1 h vt ndq mdp(qjd+s y7h 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 omt3u y4-) nkke kol.6cf 200 m. What is its average acceleration3 y k)clk.nu4met-o6k?

  An object starts from rest and undergoes uniform acceleration. During th1.ndvk1y hbhpk i+d(3 e first second it tr1dibk dy phh+13 k.(nvavels 6.8 m. How far will it travel during the third second?

  An object is moving in a straight line uw-r9xdc7z a27 qa2 uwwith constant acceleration. Initially it is traveling at 16 m/s. Three seconds later it is traveling at 10 m/s. How farruu7dz2c 2 qwxaw-7 9a does it move during this time?

  A car starts from rest and accelerates uni(czfdai0(c h6 formly 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 decelera2n+21pyhasi p0- vpifte 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 turns green, a car that has been c/ b(1d uh2k7ptkjl (awaiting at the intersection star ubckthd(j/al2 p17 k(ts 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 uxji.k.b a d08surface of planet X where the acceleration due iubxda8jk 0.. 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 surface of plan+ t8qyfe b1w3awny*0)8w+e aq fqlup 6w3we9ret X where the acc8enq+3yw b +t6f)w9w*8qlep3arqe10a yuwfw eleration 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 sji8y9dwg q 7k.peed of 15 m/s on the surface of planet X where the acceleration due toq.id8jy9 k wg7 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 14 m/s on the surface of planej nwrz;4w l-+* d(rfmtt X where the acceleration (rw r+m dtw4zj ;fl-*ndue 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 holdo9jm0d z7fg2 ts a ruler between your fingers and releases it without warnigtd9mo 0f2z j7ng, how far can you expect the ruler to fall before you catch it?

  A ball is thrown upward at m6- tv g,lqwr;a velocity of 19.6 m/s. What is its velocity after 3.qvgm,-wt;r l6 00 s?

  A bullet shot straight up returns to its starting point in 14 s. What ikxb(gyowetbv/24/ 8og cv aenxg6t a59f*:z+ s the initi/kv*+yg8 5 ob v ea(b4xocznwaggtt269:e / fxal speed of the bullet?

  A ball is thrown straight ;r1 ;5z -hls8 blc y;m76leskk. if onrbl6m2uup with a speed of 36.0 m/s. How long does it take to return to its starting point?eb2s; 1nl 5cmrhm -luzbyf6;oi68.l 7kskl;r

  A ball is thrown downward from the top of a building with an initial speed o(lowdly b7uaq)ak* t//b ,5sd f 16 m/s.5a7u (/ ,k q*lyb /dlda)obtws It strikes the ground after 7.2 s. How high is the building?

  A ball is thrown straight u( 7h5ix+qf ivkp with a speed of 30 m/s. (only fill in numerical valuv 5qxkif(7 +hie in the 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 stra*r n(0xc;0 i ibin d4ysfkep:)ight up into the air with a speed of 26.2 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 velocity at t = /:e uzz3 yw * o5mec3)zx2ojfq1.0 s?

  In Fig. below, what is aww ;2v2rk be 8luy3.hthe velocity at t = 2.5 s?

  In Fig. below, what (zax*pe(l4jl*;a ws qis the velocity at t = 4.0 s?

  In Fig. below, what is theu rzb:a/ haipbkg0tzvo0u2:e* 0ei:/ velocity at t = 5.5 s?

  In Fig. below, what is the average velocity from 0 hu:7j.vvd. c rto 4.0 s?

  In Fig. below, what is the avex1shtc c+y n/ )z.pvj;rage velocity from 0 to 6.0 s?

  In Fig. below, what is the accelhdxi 4ld1ys8 -flhl5 3 6f(nnmeration at 1.0 s?

  In Fig. below, what is the acceleration at 3.0 s wp f1s5j,:tg6w7zop j?

  In Fig. below, what is the apu,k 1fiqj. -d388dqj,b)ast ax: x cbverage acceleration from 0 to 5.0 s?

  In Fig. below, what is the average accelerati7 q unkfy3ms9j: lrm9p+5lfb,on from 0 to 8.0 s?

  In Fig. below, what is the displacement from 0 to 8.0 snweap7 +j.)b :;erfpp?

Does a car speedometer measure speed, velocity? {speed|ve iq ,hid1mlh8+locity}

  An object can have a varying speed if its velocity is const a jmt1mh6i9g+t 11o k5sjm2sfant.

  The velocity of an object can be negative whe*w3z8wo 6e7zqvqml s -n its acceleration is positive.

  If one object has a greater speed than a second object, the first musem*0dc x o h*h5i-h(dqt have a greater acceleration.5 miohh*(c hx-e0*d qd

  Two cars emerge side by side from a tunnel.at- scp(,tf2p 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 snnhdj* /(5 / 0zppsnlas its acceleration decreases.

  A baseball player hits a foul ball straight up 3w5. rynr9qwhinto the air. It leaves the bat with a speyrwq 5.rnw3 9hed 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 it9rcsnwl *p6:tpcn+af of* +5 zs acceleration, how does it change if air friction+wpas n9ct: fon*f6l zr*+ cp5 is ignored?

  As a freely falling objecqii gfr4 f;:va(dmn/- d)wz0tt speeds up, what is happening to its acceleration, how does it change if wdzt:f n i/0fargm ;v(d 4-)iqair friction CAN NOT be ignored?

  An object that is throt8s,;w)bq1xc*mu;6 qab(auv t o-cfrbpn6s8 wn vertically upward will return to its original position with the same speed as it had initially if air resistance is negligible. If air res16) ;s-sb 8bq ba8(a uctfmqu* x;pworv,6 nctistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzer23gcevgr* sso gk33 )rba m:,q ezcwq9f9+c .bo acceleration at the same time.

  An object can have nonzero vej1 *5ns *ahkvbdaf7+e65xtm; + lvgnl locity and zero acceleration at the same time.

  An elevator moving from the second floor to the fifth floor making no stopa3uqoeqn ra u4-duz5rn,c5, * j80xkis along the way has zero acceleration all the timeqxkd4e *j3z5,ari ,8 rnc -uunqu0ao5.

  A rolling ball moves fro;e tf1l1mvt4rg;ijdl 6j5:uq m $x_1=2.9 \mathrm{~cm}$ to $x_2=-7.7 \mathrm{~cm}$ during the time from $t_1=1.5 \mathrm{~s}$ 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 $t_1=-2.3 \mathrm{~s}$ is at $x_1=3.3 \mathrm{~cm}$ and at $t_2=4.4 \mathrm{~s}$ is at $x_2=8.0 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complk*)udxykl(5v cwk0 d akw; yy,x.8(plete laps around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 11.2 min. Calculate (a) the average speed  (数值)  $m/s$ and (b) the average velocity    $m/s$

  A horse canters away from ib d0xlr0aj4( 5.ioiowts trainer in a straight line, moving 87 m away in 13.7 s. It then b(dwa0j i5i4 xro0l.oturns abruptly 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 from3vpn0cyp56 kb $12 \; m/s$ to $23 \; m/s$ in 4.9 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 frosj /z55uw6f vi-qysg0 m $18 \; m/s$ to rest in a distance of 59 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a sp d:zub/ 29kh pxvp2g6aeed of $28 \; m/s$ 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 oucnni07u va: 5h :cq*rbt of the blocks to essentially top speed abouti h: rqbcn:0a v7nuc*5 $11.0 \; m/s$ in the first 13.2 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 a speed tn gzuu5dso/ + z8t v:4ty)mr5of $18 \; m/s$ to rest in 5.04 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves skid mae(ep)ztkd:x6 ct 9me h*uhoo*6b0)yme q e:v8rks 92 m long on the highway. Assuming a deceleration oyeut:d eqxc zph)*8eeo mvhot6( k6*me)9b:0 f $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck goine-(dyj)jl ur;g $25 \; m/s$ 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 10,0 i k.lielb/9*/,aa n 3ox9wziohjox4;00-m run in less than 30.0 min. After exactly 27.0 min, there are still 110 9i;o/bk3n e j ihw9/oil*oza.a xx,4l0 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?    $s$