Suppose that an object travels from one pnv414 8y(zxvwhf4 ennoint in space to another. Make a comparison bhn4 xfenz4wn 148( vyvetween the displacement and the distance traveled.

  When is the average velocity of+ oovq1 )jt5je an object equal to the instantaneous velocity?

  A new car manufacture h*(v1 l ::zqb0aoyq*qjzp kb8r advertises that their car can go "from zero to sixty in 8 s". *zpoyzlk 08: :q(q bhbqv*a1jThis is a description of

  An object moving in the +x axco +;nz dj.ueyo+t1h2is experiences 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 slom2:4w grhu ak bjtx85)w down as it approaches a traffic light. Make a stbxar t54k): 8j wmghu2atement concerning its acceleration.

  Suppose that a car traveling to the 1mlh ryft)j2/ West (-x direction) begins to slow down as it approaches a traffic light. Make a stt fl) 2y1jr/mhatement concerning its acceleration.

  Suppose that an object is moving with a constanl 8w(.pdzn - j+*q7 je7so(enrox3efjt velocity. Make a statement concerning its acceleration.fejj o rqpe+3x((szn8*l7-e 7dn jw .o

  If the velocity of an object is zero, does it mean that the acceleration is +)e*6 g)3 jonlsm a(l4aierxc zero? Support your answer witl)a3( i 4s6o)egecalxn+j * rmh an example.

  Can an object's velocity change direction when its accelerat*, nb4 2 /iv u93egh6uxtcnfieion is constant? Supporiu exv3tifc n2h*4n,u9gb/6e t your answer with an example.

  Suppose that an object is moving with con gb4h2(ogud v6stant acceleration. Make a statement concerning its motion with respb4v g(og2udh6 ect to time.

  Can an object have increasing speed while its acceleratu7 lb4r+ifoncy1u;h ) ion is decreasing? Support your answer with an exam fuh;1bcy)l 7+oniu4rple.

  Suppose a can, after an initial kick, moves up along a smooth he9 ijfdvtv, 058 lq 0ox89l9kguu:pg iill of ice. Make a statement concerning its u9 e0lo9p89u t jkv05vqxgifd:8lg,i acceleration.

  Under what condition is average velocity equalg;+uzme /rugd.:mxh, to the average of the object's initial and final v,rgh em/uzxm+:;ud.gelocity?

  Objects A and B both start at rest. They both accelerate xu boh xnzocci)(w6-r* q +2*kat the same rate. However, object A accelerates forox 2cibkuco*h-+6 w (*qx) zrn twice the time as object B. What is the final speed of object A compared to that of object B?

  Objects A and B both start from jvyor66*xkd8 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 d* j866royxvk compared to that of object B?

  When an object is released from rest and falls in the absence of friction, whi vzwvh.e1 cve65t9 gvd/8ryzq+ x (nq0ch of the following is true conceyzvwq 0d9 +1vg5vtvhnx qcz(6ee/r.8 rning its motion?

  When an object is released from rest and falls in the absence of friction,8xdoboj gl04zarq .*( which of the folldo.o 8aqj x *04(rlzgbowing is true concerning its motion?

  Suppose a ball is thro7y(q.wmth dm *xy)r om9:1 mtgwn straight up. Make a statement about the velocity and the acceleration when the ball reach9mmyo.y:r(g mxwm) 1 q*td7t hes the highest point.

  Suppose a ball is thrown straight up. What i1o to*t v07ng;w:l mt(.odab is its acceleration just before it reaches its ha:tl*b 7gwi1.m tdo;on vt 0o(ighest point?

  Suppose a ball is thrown straight up, reaches a maximum heightc 0qn-knrz3d+i8f9 vt , then falls to its initial height. Make a statement about the direction of the velocity and acceleration as the ball is goingt-v r8fiz0 +kcnndq3 9 up.

  A ball is thrown straight up, reaches a maxim+nfz(i:+6n yiavoz4 5wryw.tum height, then falls to its initial height. Make a statement about th 5.otnz6viny za w:y4+rfw+i( e direction of the velocity and acceleration as the ball is coming down.

  Suppose a ball is thrown downward in the absence of air resistance. Make k9o2imvxv,a4c i,8ura statement concerning its 9akmr i vx, vcu,8o4i2acceleration.

  Suppose a skydiver jumps from a high-flying plane. What is heyp)(an)xmo7z 0nvd h6r acceleration when she she reachesav (m6n p ydzhno0)7x) terminal velocity?

  A ball is thrown vertically upward with a speed v. An idenebs /e 0.mte5ttical second ball is thrown upward with a speed 2v (twice as fast). What is the ratio of the maximum height of the secon50 .sete/me btd 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 build htqo7 h ge39lrxv 4a9.psej/7ing. One second later, ball B is dropped from the same building. As time progresses, the distance bethq794.7ps etaoeh jgrl vx39 /ween them

  Ball A is dropped from the top of a bu)fdx*iditd; 9kpa o.;iwp , r8ilding. One second later, ball B is dropped from the *xo;8fpiik9 itad )w;r.dp,dsame building. As time progresses, the difference in their speeds

  Two objects are thrown from the top of a tall building. One is thrown up, andm2-wad wn, 5tuc5if u: the other is thrown down, both wtdmi5-w:n awu,fu 25cith the same initial speed. What are their speeds when they hit the street?

  A brick is dropped from the top of a building. A g, v:7psx2 j ),b rj-kos1dpfwiyul(1second brick is thrown straight down from the same building. They pg sbsp1rxy7(l 1u fjjk- , w,:i)dov2are released at the same time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with cvkkn89 o49kx n:,ir8m kvhv 6ronstant non-zero velocity in the +x axis. The position versus time graph of thi 6rr,xv v8ov kh:mk98i94k knns object is

  An object is moving with constant non-zero acceleration in th iei/; ul gy8 p-aynskn:nl bv9*o +hzg,7d;6ue +x axis. The position versus time graph of this lgonu8ulsv9eznk*h,/n i 7 -;dbgya ;i+6: yp object is

  An object is moving with constant non-zero velocity in the +x axi 6z-bgto)3*tkao2c d ks. The velocity bgka )3-k*6 cztt2odo versus time graph of this object is

  An object is moving with constant non-zero acceleration in the +x axis. The v dc d x21c+5:k9zbjauyelocity cdjx 5c 2:a9d1kyubz+ versus time graph of this object is

  The slope of a posit9j .kw8gy 5 fusr) s3y*ralz2lion versus time graph gives

  The slope of a velocity versu;rz1re:n rsi/ gmdn.5 s time graph gives

  The area under a curve in an acceleration versus time gra7zxo e .n2;mgaph gives

  The area under a curve in a veloce*,p2 :uwvss k )mupedo)t+c6ity versus time graph gives

  If the position versuszqc hte.9:8+ fsk.y cj time graph of an object is a horizontal line, the object ijs:+zce8y.c9 q kt hf.s

  If the position versus time gte tv0if.zi5ojx*1as9 w m,8o raph of an object is a vertical line, the object is1 t0v,*at5i8j ow9 fszmx.e oi

  If the velocity versus time graph of an object is a horizontal line, n (tasjqq*87g 1z3arfthe object iq 13rs7*n(8g f tajqazs

  If the velocity versus time graph of an objeh2jk44c l4i1g u ;ipg1n7mso zct is a straight line making an angle of 30 degrees4c4 i i gzl 4g21;pumjs1kon7h with the time axis, the object is

  An object moves 15.0 m nort 3 pt( 5fyvj+rb,vqiy)h and then 11.0 m south. Find both the distance traveled and thtvjiy(bv),qy 5+ pf r3e magnitude of the displacement vector.

  A boat can move at 30 km/h in still water. Hs3uz+f;u 54r opqn,e fow long will it take to move 12 km upstream in a river flowing 6.0 ko5 ;sfunf4uq +3pze r,m/h?

  55 mi/h is how many m/sv8k hi9cb9j0 parw-toh l2/o2? (1 mi = 1609 m)

  What must be your average speed in order to travel 350kfzqlqsp t8t7k* g-s 4;v)dp8 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 km) in 2 hours and 57 min. ;yyb3ax6 re d8What is the avex 3b86ey;daryrage speed of the runner in m/s?

  A car travels 90 km/h. How long does it take for it to i(df2)4yl(b dqz 5 csetravel 400 km?

  A ly (light year) is the distm 8ox0e/w mn7uc5lcx+ance that light travels in one year. The speed of light iswn 8u/xc5m oc0exml7 + $3.00 \times 10^8 \; m/s$. 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 lx hhiz80fwwz9spj.9 (ook to the side for 4.0 s, how far do you tzfwzjp xhi99h8s0w .(ravel during this inattentive period?

  If you run a complete loop arouf.r5uo,n 2:)vio kslbnd an outdoor track (400 m), in 100 s, your average vell2 us k5.:)b onofi,vrocity is

  A polar bear starts at the North Pole. It travels 1.0 km southgz- d 9vltgv,-, then 1.0 km east,tg-, vlv- zg9d 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 average speed?

  A polar bear starts at the North Pole. Itr*2o.r gq3nj w 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 tw3 r*.2rjong qrip takes 45 min. What was the bear's average velocity?

  You are driving home o1x frr;bursw)n89 jc+n a weekend from school at 55 mi/h for 110 miles. It then starts to snow and you slow to 35 mis)r fnuw+ 9b1cr8j rx;/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 km at 100 km/h. What is the averlfb,3/hwg xyssu b ix6c4 /aapbz*)4 4age speed of the motorist h44us l*bg3spb6 y/af bc xiaz/x)w,4for this trip?

  A motorist travels for 3.0 h at 80 r dvko:cqjam;.j ) -d/w0u5wfbg/ x+jkm/h and 2.0 h at 100 km/h. What is her average spee/d) j/-rw 5 g ufvokx;qd.mcjj+0b :wad for the trip?

  An airplane travels at 300 mi/h south for 2.00 h and thenz8evp7 ;fqsh9 s) - sdmzti62xtzr.b: at 250 mi/h north for 750 milexi :-;zs 68q2vp .bsht7tfd zrzs e)m9s. What is the average speed for the trip?

  In a 400-m relay race themd ,qr36 2frd5di1c hc anchorman (the person 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 31fh,q 2cmid6 dr5dcrm in 10.1 s. What is the largest lead the team B runner can have when the team A runner starts the final leg of the race, in order that the team A runner not lose the race?

  A car decelerates uniformly and come y8c:5eei4jjbs to a stop after 8 s. The car's average velocity during deceleration:ijy485 ebjec was 30 km/h. What was the car's deceleration while slowing down?

  An airplane increases its speed from 100 m/s to 160 hx4vt)(mqtman z:g mm ( :/sz:5f6nia m/s, at the average rate of snz ::xt5mf 6m/zm :a4)((ihamvq ntg$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h acceleratem6 k/u n b+ hghxrr9xhe/n9+d ;ari4)ps 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 rqv,; /v+ rb-c(j fgayd/y2kf33y tckvest and accelerates at $4.0 \; m/s^2$ for 5.0 s, then maintain that velocity for 10 s, and then decelerates at the rate of $2.0 \; m/s^2$ for 4.0 s. What is the final speed of the car?

  A car travels at 15 m/s for 10 s. It then speeds up 2fhe)tg0s bj+ with a constant acceleration ob2+sgf)tj e h0f $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 7.3 m/s experiences a constant ncl.j/ j n2/tuacceleration ofc jnujln/2. t/ $2.8 \; m/s^2$. What is the cart's displacement during the first 9.1 s of its motion?

  A bullet moving horizontally to the right (+x direction) with a sp zmsqssu9nz*d );qoz s2c277 heed of 528 m/s strikes a sandbag and penetraz ss9u dss qzhq2)*z2monc;77 tes a distance of 71.70 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on an aircraft carrier. Itc pcwr7 u27ng) reaches a speed of 42 m/s at the end of the catapult, and this requires 2.0 s. Assuming the acceleration is constant,gc)nr c7p72uw what is the length of the catapult?

  A car starting from rest moves with n4vhfe1r 68 cubz)l 9pconstant 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 distantmzk7d00xt w7:7-f oj fwyrz7ce of 200 m. What is its average accel77z-zwk7mfxrt j: fyw0 t d70oeration?

  An object starts from rest and undergoes uniform accel 6l6rpy2 +r0f j2wml9tid6ztheration. During the first second it travels tl0r2pf9l t dizhr6y6jm + w268.3 m. How far will it travel during the third second?

  An object is moving in a straight line with constant acceleration. Initiallgs*z 88r ; ogmnt)5wip6feo+ ry it is traveling at 16 m/s.nzm ie6r+r) o8o*8g 5tgfw;sp Three seconds later it is traveling at 10 m/s. How far does it move during this time?

  A car starts from rest anyyc1k9 a5lp* wd 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 decelermu+8ligsx 9,f(nmw,u ate 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 li :)vjs gd1+outght turns green, a car that has been waiting at the intersection dju1:t)osv + gstarts 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 witnmrl ct/* tla35u(kmpi m.k/* h a speed of 12 m/s on the surface of planet X where the acceleration due to (5/ lumim.r*lmcn t/3kktap *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 surs08f4 mwv w gyr1tfv69face of planet X where the accelerafry f m9vg1tw6v480 wstion 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 upwarndz*t hkb3(f dt/v 5nl9rq d-li:r6m*sf5o, sd with a speed of 15 m/s on the surface of planet X where the accelerationzs3 h,rlbfs :vt-m 5qr9 n(6 k *fiotd*lnd/d5 due to gravity is $2.5 \; m/s^2$. How long does it take for the object to return to where it is thrown?

  An object is thrown upward with a speed of 14 m/ lclramv. iq6i./43m f2lwx n ntza79,s on the surface of planet X where the acceleration duec3.9 .lqx mar74ni lz,t/2i 6l vnmfwa 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 s8*iryd6;af ompq49ee. If your friend holds a ruler between your fingers and releases it without warning, how far can y6r8 ;a oimf ye*dp94qeou expect the ruler to fall before you catch it?

  A ball is thrown upward at a veloger88 +wdbhv)ozr: , hcity of 19.6 m/s. What is its velocity after 3 8r +hzv:owedb h8,)gr.00 s?

  A bullet shot straight up returns t v 7- j/m6nu jkusw:2npxf(v6fo its starting point in 7 s. What is the initial speed of the bu7ksf jvjf u/ :mnxu66p-vwn(2 llet?

  A ball is thrown straight up with a speed of 36.0 m/s. How lonsc wo( b7 va)9ttzxq)-j)qt3qg does it take to return to its startio7))avts)qt 3 w -tjcxqbq(z9ng point?

  A ball is thrown downward from the top of a building with an initial speed o qtuqcgsy9huahs2246 2uq- muz(u+/n uam/+ df 5 m/s. Iaqmu 4qu (th6cd+9u2/ aqu2umsnhs g y/+-zu2 t strikes the ground after 7.6 s. How high is the building?

  A ball is thrown straight up m e(r71fwa ot ,k+e(cmwith a speed of 30 m/s. (only fill in numerical value(+ tkcme mr7,foa(1e w 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 straight up into the air with a speed of 32.t73n eyqd7f.n 9 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 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 is the velocity at t = 1.0k8r)np ncggn :ka:e wf 7(8z,q1sg7jq s?

  In Fig. below, what is the velocityqsnwm7pk. d fb+ :(q)9srh1hk at t = 2.5 s?

  In Fig. below, what is tcy l88g6wmmca 43/jhm r oj 9d1-t*mzdhe velocity at t = 4.0 s?

  In Fig. below, what is the velocity at y/- vcx cf+nw*t = 5.5 s?

  In Fig. below, what is the avergf9lifb7r b 3z9uohl/-6oa0 h age velocity from 0 to 4.0 s?

  In Fig. below, what is the average velocity fromvtpwok:ss. q*db. oxkt,q:26d ,q l+n 0 to 6.0 s?

  In Fig. below, what is the acceleration at d7oa7 yz3/n+mnp1 gvn1.0 s?

  In Fig. below, what is the accelerad. s-an( ciq;e4h p:aktion at 3.0 s?

  In Fig. below, what is the avx u;c1giaw zbcq /f 6ji(cq65,erage acceleration from 0 to 5.0 s?

  In Fig. below, what is the average accel qwr5-vo 3xxuh(+l(d leration from 0 to 8.0 s?

  In Fig. below, what is the displacement from 0 twe n;l3er2 9yic;h 9xxfkc*z:o 8.0 s?

Does a car speedometer measure speed, velocity? {speed|velocey-kj -+2 rargity}

  An object can have a varying speed if its velocity isk/w g 2qbo io:.;lxf rk9a;vp3 constant.

  The velocity of an object cn dcdg .36ixpe 0gh 34-h:twjkan be negative when its acceleration is positive.

  If one object has a greater speed than a second object, the /ergcly 9gj *s;36uw)pmu 4rk first must have a grea)k mwy/6*seugl9j gu rpcr4;3ter acceleration.

  Two cars emerge side by side from a tunnel. Car A is traveling with a sl5,s-j.f 3 lfj eyi7urpeed 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 increasin32ey+r;nc y 2jij8fhzi :w )cog in speed as its acceleration decreases.

  A baseball player hits a foul ball straight up into the air. It leaves k+j* ;,-1xmrv ev hxe:/(szlbw cld:k the bat with jrvexc z1:vs b -h/le;* +(mdxk,wk l:a speed of $120 \; km/h$. In the absence of air resistance, how fast will the ball be traveling when the catcher catches it?    $km/h$ (please only fill in numerical value in the blank)

  As a freely falling object speeds up, what is happening to iup7iyr+c:rl , ts acceleration, how does it change if air friction is ignor: c,+7lp urriyed?

  As a freely falling object speeds up, what is happma90d ,z;; u r9otykosening to its acceleration, how doestm 0ua9s ookyz9;,; rd it change if air friction CAN NOT be ignored?

  An object that is thrown verti :poyw wc9k hur9, .:kk3woo)ycally upward will return to its original position with the same speed as it had initially if air resistance is negli : wrkc o9po:ywo3).w yh,k9kugible. If air resistance is appreciable, how will this result be altered?

  An object can have zero veloy *k3(q 6kqddkze /t a)(4zjon +xz8yrcity and nonzero acceleration at the same time.

  An object can have nonzero velocity and zero acceleration at the same titp0 +qt4 u4civme.

  An elevator moving from the second floor to thei x3mwx4fuv sy-lu03 / fifth floor making no stops along the ux4 xf0-3/lvsym3iwuway has zero acceleration all the time.

  A rolling ball moves f vpy vubh f8v9uxap)x4p,/t,*rom $x_1=2.2 \mathrm{~cm}$ to $x_2=-8.7 \mathrm{~cm}$ during the time from $t_1=1.3 \mathrm{~s}$ to $t_2=5.2 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-4.8 \mathrm{~s}$ is at $x_1=3.1 \mathrm{~cm}$ and at $t_2=3.0 \mathrm{~s}$ is at $x_2=8.5 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight completew).5qmqcuq hqk pr5 9yyn)0x1 laps around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 6.0 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 990k wg6l/lg rt1 m away in 13.2 s. It then turns abruptly and gallops halfway back in 4.6 s. Calculate (a) its avegk96l/ t0 wlrgrage 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 :o;e/c 5rz+c k+yfeu x ioosl7nv+f d2s182zq$12 \; m/s$ to $22 \; m/s$ in 5.1 s. What was its acceleration?  (数值)  $m/s^2$ How far did it travel in this time?  (数值)  $m$ Assume constant acceleration.

  A car slows down from tf :u,ik/) 1c4x47iatmh)k+ f yyw+xl za)kdp$19 \; m/s$ to rest in a distance of 84 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a speed )6/eh .ofchc iof $28 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.2 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of the blocks to essentsd t+x -jwlh/9ially top speed about /w-djx9+h tl s$10.7 \; m/s$ in the first 12.0 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 :3nh7izh9 9: lzg jxnlf 9ppo6speed of $21 \; m/s$ to rest in 5.69 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car l, hgmv 4-k6b g(v-k5, zkneiaeeaves skid marks 92 m long on the highway. Assuming a k-5k,h,e(bgev z ka6nv img-4deceleration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck wg * opk hy /x9h+nl*r9cush80going $25 \; m/s$ 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 thac 5b4r w 2r(dh*qe4idan 30.0 min. After exactly 27.0 min, there are still 1100 m to go. The runner must then accelbi4q2*rrew4(a hd5d cerate at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$