Suppose that an object travels from one point in space to ano ksh*gz83sd )uther. Make a comparison betwe3* uhg sdz)sk8en the displacement and the distance traveled.

  When is the average velocity of an object equal to the instantljh( r 0dc-7;h9(xjyv0ixldpaneous velocity?

  A new car manufacturer advertises that their caw3u 98p7vbk.tfi, bi;sp vev*r can go "from zero to sixty in 8 s".8fv; tu 9,kw3pevi ib7*vbp. s This is a description of

  An object moving in the +x axis experiences an accelerjg/hbau7 m1 w:ation of $2.0 \; m/s^2$. This means the object is

  Suppose that a car trakd(u vmizc 681u)/fwcveling to the East (+x direction) begins to slow down as it appc1/d (6cumvfzu8)kiwroaches a traffic light. Make a statement concerning its acceleration.

  Suppose that a car traveling to the Wepg)ug82ume g m3d)a7 wnc2k* cv1f3stst (-x direction) begins to slow down as it approaches a traffic light. Make a statement concerning its afmgg unpsa3v d 1cuk w8g)2 2t)*3mc7ecceleration.

  Suppose that an object is moving with a constant velocity. Make a s *5k velxd5au4tatement concerning iuaed* v 54lkx5ts acceleration.

  If the velocity of an object is zero, does it mean that the ac4wqmfgf)gmyirp3(vl sk1-8 pi ,b8) pf7(c yzceleration is zero? Support your answer with an exw))i8f yffgq7p pvs l( -y1gbc4mk,miz3p(r8 ample.

  Can an object's velocity change direction when its acc fsl1kg ,8pd9heleration is constant? Support your answer with an exam8 fhp9kld1s g,ple.

  Suppose that an object is moving with constant acceleration. Make a stateme9cu,n6dv) i pcr8s tr n;n07)kfz/wqpnt concerning it08 irw nfsr,cqcp) 9 zn/d)p u6vk7tn;s motion with respect to time.

  Can an object have increasing speed while its acceleration is decre/(;crasr lc;bgr -h/qasing? Support your ansrlbc- qa /;gr; hr/s(cwer with an example.

  Suppose a can, after an initial kick, moves up along a smooz0-v6iqiqwi ,th hill of ice. Make a state iiwv,6 0qz-qiment concerning its acceleration.

  Under what condition is average u0l.bn4r4 ed p*2 u0ewlomvl; i.x4yuvelocity equal to the average of the object's initial anolrn uuvw4;ll.4xue4p.e y 2 0*bdi0md final velocity?

  Objects A and B both start at rest. They both accelera5*u3y9i nc yrvh 3fie-te at the same rate. However, object A accelerates for twice the time as object B. What is the final speed of object A comenu3yi y5ih3cv9fr -*pared to that of object B?

  Objects A and B both start from q;bjco:v n9sh6,h0y srest. 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 that of obohqj,y:schs69v;n b 0ject B?

  When an object is released from rest and falls in the absz ovas 2xvh.be51*,mcfk+:7a 9owd t sence of friction, which of the2v fsbd hx7:+*eotza .5a, s9vkwmco1 following is true concerning its motion?

  When an object is relb.l;v;ei nw r*eased from rest and falls in the absence of friction, which of the foll;;i bw*rlenv. owing is true concerning its motion?

  Suppose a ball is thrown straight up. Make a statement about the v2 7gasvdt xh6e/ 3c7tlelocity and /lh26edg 37 stc a7xtvthe acceleration when the ball reaches the highest point.

  Suppose a ball is thrown straight up. What is its accela85-4w d vn0+wehu lrazfbq4 6eration just before it reaches i4846w-qh abz+ud5v w0 frl naets highest point?

  Suppose a ball is thrown straight up, reaches a/wtu0lze2bwatbg b)8q.8 v :d maximum height, then falls to its initial height. Make a statement aboutd )vlbtw wubqt 808e:2a.bz g/ the direction of the velocity and acceleration as the ball is going up.

  A ball is thrown straight u rv mx.a18 pd.*cpd9ze,,daqpp, reaches a maximum height, then falls to its initial height. Make a statement about the direction of the velocity and ac.8x,d*ae9dm,ap.p1r vq p dzcceleration as the ball is coming down.

  Suppose a ball is thrown downward in the abse -dktw7 v( w)68dhqr)fsvqg7n nce of air resistance. Make a statement concernik q vntdv6)d g-7h( 87)rfwsqwng its acceleration.

  Suppose a skydiver jumps from a high-flying plane. What is herh.wfe z,yczo/ pw 8.q*xknl5( acceleration when she she reaches te8,.q/wh5zwep nz(k .cx *o lyfrminal velocity?

  A ball is thrown vertically upward with a speed v. An identical second ball ksb:pi8y n4 92blld(uis 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 the b4n s2 ub98p(yli l:dkfirst ball?)

  Ball A is dropped from the top of a building. One see )(l9z8g gd t(t5ab gyenz60pcond later, ball B is dropped from the same building. As time progresses, the distancel8p z9tet d gy(5bng)(z 0a6eg between them

  Ball A is dropped from th toi3j1q y,w1(j il(bye top of a building. One second later, ball B is dropped from the same building. As time progresses, the difference in ol1(iwq3bjy j(y 1,it their speeds

  Two objects are thrown from the top of a tall building. One ish us7z2i 91ihw 1nv1fe thrown up, and the other is thrown down, both withezf19u vnhh 117iis2w the same initial speed. What are their speeds when they hit the street?

  A brick is dropped from thrd 1 gfx:w+t.ue top of a building. A second brick is thrown straight down from the same building. ur d:1wf.+g xtThey are released at the same time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with constant non-zero velocity in .;+ wtkgbr9eao1 sddz:y6 +az91( vmwpy7ugd the +x axis. The position versus time graph of td( +ta k pbz maoud:d;ve 6syg9.grwz91+y17whis object is

  An object is moving with constant non-zero acce/n95h./dglcg/i cpmz a7w 1m dleration in the +x axis. The position versuslw5gi.z nadp m/mg9/d h1/ cc7 time graph of this object is

  An object is moving with constant non-zero velocity in the +x axis. Theqx cqb2xe kre) i1c) x2e:oj7. velocity vxcxr )qjeq e2cx2k)o b.7e:i1ersus time graph of this object is

  An object is moving with constant non-zero accel;gtlcc,fyn 0, eration in the +x axis. The velocity versus time graph of;c,l0 yn g,ctf this object is

  The slope of a position versus time graphu w0ii(lhqr1tmte 1(6 gives

  The slope of a velocity ( i3 5cdbhr*ny5.ezqf versus time graph gives

  The area under a curve in an acceleration versus time grapfl i7e)qwu7f 0q rgn26h gives

  The area under a curve in a velocity versus time35op khkok4d 5 graph gives

  If the position versus time graph of an object is a horizontal line,jv: fme 064/9 yznnhxw the object 0j/ znm9eyw:hf4nxv6 is

  If the position versus time graph of an object is a vertical line, the; )3a*arce *vshk:p;hpn cch 2os.*x e object iss a2ho:k se.hax;* v *3ec hpcp*rc;)n

  If the velocity versus time graph of an oby t )x;/wcni:uject is a horizontal line, the object i/n:twxcy) iu ;s

  If the velocity versus time graph of an object is a straight line making mgimd f:37rjjne(v *0an angle of 3n:rmej*(vd j0ig7mf 30 degrees with the time axis, the object is

  An object moves 15.0 m north and then 11.0 m south. Find both the distance tr8s+iv0-q,n. hbk k - yl:eo8qhh udid:aveled and the magnitude of the diske0kso nh +ih.h:8il -qydv8d,-:ubqplacement vector.

  A boat can move at 30 km/h in still water. How long will it take to movx 27(w 6mbtrhj/1mgr m5 u3:pibn+tru e 12 km upstream in amp 6b 2xrht1 3twr+ bn7uj5/rm(mu:gi river flowing 6.0 km/h?

  55 mi/h is how many m/s? (1 mi = 169p zw-e3.o ih7cnbk0o09 m)

  What must be your average speed in order to travel 350 km inm npyg)7rl0z nk8e* t5/mi gdx/8g/zo 5.15 h?

  A runner ran the maratvqi gw fa)uwq 5(kq2.:hon (approximately 42.0 km) in 2 hours and 57 min. What is the average sfa5uk2w q .vq(i:wgq)peed of the runner in m/s?

  A car travels 90 km/h. How long dolro0o,g :na vrl yz6g e4j,50ti3kmz-es it take for it to travel 400 km?

  A ly (light year) is the distance that light travels ins j +gesck +v,6np6olo9xsf /: one year. The speed of light ,s:so9++o pxcel/6fkvsj gn6 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 alongx3 k63rk+wilp1ki nt * a straight road and you look to the side for 4.0 s, how far do you tii l+36tw *1rkkp3nkxravel during this inattentive period?

  If you run a complete loop around x;yn:ee ;sb nml2rsac2sc* 55 an outdoor track (400 m), in 100 s, your average veloci x;e*n;:y2sbcscas nre5l 2m5ty is

  A polar bear starts at the N8- 1qj tf*3:yhmd h, zwxi-sc;oyoj ,forth 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 beaxifzc owh,td-1sy3 :y*f;,8m oq-jhj r's average speed?

  A polar bear starts at the North:eg0hnd.x t4/gaju p: 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 average v:ag4 :eth.0nj p /uxdgelocity?

  You are driving home on a weekend from school at 55 mi/h fnm7 3lql m8/hcxm5 mn5or 110 miles. It then starts to snow and you slow to 35 mi/h. You arrive home after driving 4 hours and 15 minutes. How fa nlm /73h55mcqmml n8xr is your hometown from school?

  A motorist travels 160 km an9m -kwkqntuygy2jj * 279q)zt 80 km/h and 160 km at 100 km/h. What is the average speed of the motorist for this 2j9qtmk yw 2nzu)79 jkng yq-*trip?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h aksypf 273q l -eexlt ji7*mv59t 100 km/h. What is her average speedl25qfsjt*-y xmk i97lpe 3ve 7 for the trip?

  An airplane travels at 300 mi/h south for 2.00 h and then at 2* z7txydeo35 m50 mi/h north for 750 milodxm57z te3 *yes. What is the average speed for the trip?

  In a 400-m relay race ,u++abbpv (ii the anchorman (the person who runs the last 100 m) for team A can run i(ba p+ uv,+bi100 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 the race?

  A car decelerates uniformly and comes to a sto44adgbcvyd tg 6 :yt.ztj9vj y6f+p 2:p after 10 s. The car's average velocijcvyty 4 t4:.6 b atd2 g:+9dfpzy6gvjty during deceleration was 59 km/h. What was the car's deceleration while slowing down?

  An airplane increases its speed from 100 m/s to 160 m/s, at thau tb u7sl9)c9e average rate of 9 79) slcuubat$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerates at the rate xv5rftj 0zx1( 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 accelebv7pp-xb51rs*n:ob(f ovf2f rates 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 / v)cge:vbe 7p0)j mhsed )7qe10 s. It then speeds up with a constant acceleratio))vesv7/eh 70)qjpge : mdebcn 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 ofn gz4;2 r(6 w7trhkzpc-y7wyy 2.0 m/s experiences a constant acceleration ofzr r(ycy w-4wng7h; z62ky p7t $2.0 \; m/s^2$. 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 a speed u 7cjp cxe5co 18q/g0fof 496 m/s strikes a sandbag and penetrates a distance of 26.66 cm. What is the a5c08o xq1 jp7efgu cc/verage acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on an aircraft fd,wc 6voj43i carrier. It reaches a speed of 42 m/s at the end of the catapult, and this requires 2.0 s. Assuming the acceleration is constant, what is the6dfocvj4,iw 3 length of the catapult?

  A car starting from rest move+(cw*x/vcgejk*l p;k s 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 mvs:8cqbq y,e 8udzt hzvp : 3b5j2nbya47b*4 a/s to 80 m/s in a distance of 200 m. What is its average acceleratiota*hba25yv8dj 4bz7 bqn se:4cpy vqb :,zu38n?

  An object starts from rest and )kaa/8zflafqk aws6: 1*.sxi undergoes uniform acceleration. During the first second it travels 5.*:faf q/81. 6x )ka isakawslz3 m. How far will it travel during the third second?

  An object is moving in a straight line with constant ac /rvx aler/8)f1wf /teceleration. Initially it is traveling at 16 m/s. Three seconds v xr)fe f/w1a/l8e rt/later it is traveling at 10 m/s. How far does it move during this time?

  A car starts from rest and acceleracqte0jaf,/a7 i5q9hb,w-pqr6u8 w zjtes 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 cyr 7ctck:4 y9man decelerate 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 liva*)ud tm1i/s 2 7stmxght turns green, a car that has been waiting at the intersection starts ahead with a consm xis17sd/)tm vtau*2 tant 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 surface of p w06x zlyqm66a il,vq)lanet X where the acceleration due to gravity is )m a6q0v6qy6, wz xill$1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown upward with a speed of 12 m/s on h 5gy* .z/wfsrlip2:t the surface of planet X where the acceleration due to graviz/fr2p.wshl5: ig *yt ty is $1.5 \; m/s^2$. How long does it take for the object to reach the maximum height?

  An object is thrown upwarlr)du3zthbr-0a yyl60pr9v 4 d with a speed of 15 m/s on the surface of planet X where the acceler)rvp46r-ha tru z0ldy 90l3ybation 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 8c 3 ita8fygk-of 14 m/s on the surface of planet X where the acceleration due to gravik8gt c-aify38ty is $3.5 \; m/s^2$. What is the speed of the object after 8.0 s?

  Human reaction time is n8fj k)+ uep1.rkw h1vzvsc;.usually greater than 0.10 s. If your friend holds a ruler between yo .vwuch+jnkr1 ; )pek8zfs1.vur 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. z(4i)iecr:muWhat is its velocity after 3ri)( c:ez m4ui.00 s?

  A bullet shot straight up returns to its starting point1cqk/ivx7ya ( in 18 s. What is the initial speed of the bulleqxac/iv 1 7(ykt?

  A ball is thrown straight up with a speed of 3bc qi* 1uw;vlcc 3-)bog3,mwt 9v*rws6.0 m/s. How long does it take to return to ilvtrw;vqsw b*13wbmc 3) *cg ,cou9-its starting point?

  A ball is thrown downward from the top of g cr bp.kd:4hbby;yl o7a+c v,z/9eol3 )vc0ba building with an initial speed of 17 m/s.ya4 vocb; cdpe 3,:r) /bhkog09 b+yv zlcbl.7 It strikes the ground after 3.0 s. How high is the building?

  A ball is thrown straight up with a speed of 30 m/s. (only fill in numbzr xk,oxtntp . ,5:5werical value in tn5 .kptr w,,:zoxx5bthe 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 34.09ssa1a9n xj;bujw +vp -9a v8g 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 velocity at bpw 9rt4fzh/o rt:f+yj 6t*r0 t = 1.0 s?

  In Fig. below, what is the velocity ato+w4- my *rvr; fk*gce t = 2.5 s?

  In Fig. below, what is the velocuo3nmn61pj tz .rchand( nf: 8/dz7d.7; detkity at t = 4.0 s?

  In Fig. below, what is the velocity at t = 5.5 s ia4jj.2g d.z(umfhs- ?

  In Fig. below, what is the average veloccyx(xyw. 5n6l/:go g ,lqx )b0n-xxq qity from 0 to 4.0 s?

  In Fig. below, what is the av h wp(el;7fxrzgwq+2k. 3icb *erage velocity from 0 to 6.0 s?

  In Fig. below, what is thev3i +cxehyb i36d b-bs cq(:y0 acceleration at 1.0 s?

  In Fig. below, what is the accelerk35q8y-dozg5 +5a mq-kgxpu1-anx0 evu b g+kation at 3.0 s?

  In Fig. below, what is the average acceleration from 0 0oxyq 9d,. 0 bwdvjcx.to 5.0 s?

  In Fig. below, what is the average accelerak, ek8tan ;nj2tion from 0 to 8.0 s?

  In Fig. below, what is the displacso2zk)w fy 9y-dc.k43i rs2inement from 0 to 8.0 s?

Does a car speedometer measure speed, velocity? {sp,7z p.gj2k((+qr8-bn3n az mj,c psjnyuwbz5eed|velocity}

  An object can have a varying speed if its velocity is c pur;xxk4w(l(d*c j.1q fsp: yonstant.

  The velocity of an object can be negative when its acceleration is positivbd*vl3ys 4pk4a/tb8 a+z/ee qe.

  If one object has a greater speed than a second object, the f:nt;t)f nz mniz e5a*6irst must have a greater an 5 t)6 f:mz;nite*nzacceleration.

  Two cars emerge side by side from a tunnel.tc3b2 hqbsyk/ 4b1wl- 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 incr5q2h 08)oer3it( xpp-rb0r r4f4 ys8hftoj mbeasing in speed as its acceleration decreases.

  A baseball player hits a foul ball straig,u2x t zvh pgs8a,.na:ht up into the air. It leaves the bat with a speetag s,8 v2: ,un.xhzpad 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 -;pgj zol ky 4s/9a33+fv4wb qcfz/ dcjztr;;its acceleration, how does it change if air friction ilkr3wg y4 o;ztq ;zazpjj/sbf;/39c4 c+ fvd- s ignored?

  As a freely falling object speeds up, what is happening to its acceleration, ky6 f j9khvny+y9:c(ihow does it change if air friction CAN NOT be ignored6 9c( fvk:yhyji +y9kn?

  An object that is thrown vertically upward will return to its original ps66(2n p v3tphywe*dv osition with the same speed as it hay edh 6vt 3ps6v*nwp(2d initially if air resistance is negligible. If air resistance is appreciable, how will this result be altered?

  An object can have zero velocity and noncwo6: pr7fmj7 zero acceleration at the same time.

  An object can have nonzero velocity and j ijw ihzoa.gec.y+np8q) .j*+, esu+zero acceleration at the same time.

  An elevator moving from the secon, w 4qt)exl7gbtrms30 d nw7)zd floor to the fifth floor making no stops along the way has zero accelm)3er wd gzt7bntlqx) 7 ws4,0eration all the time.

  A rolling ball moves frj1e6 kh6 b g rhuh-*rki,9e-tfom $x_1=1.7 \mathrm{~cm}$ to $x_2=-8.5 \mathrm{~cm}$ during the time from $t_1=1.1 \mathrm{~s}$ to $t_2=5.4 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-3.1 \mathrm{~s}$ is at $x_1=2.9 \mathrm{~cm}$ and at $t_2=4.4 \mathrm{~s}$ is at $x_2=7.2 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight completegzw ar)f,fo44 yo*iu, laps around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 7.9 min. Calculate (a) the average speed  (数值)  $m/s$ and (b) the average velocity    $m/s$

  A horse canters away from its trainer in a straight line, mr)nr uth,7cw iuptv 3pp692v8oving 110 m away in 9.1 s. It then turns abruptly and gallops halfway back in 4.7 s. Calculate (a) its average spe7c6twp u)2rp vrphu 8tvn9i3,ed  (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 frbv h b3thj.ax4 k8b21zom $13 \; m/s$ to $22 \; m/s$ in 5.3 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 pn i2p*;./a)a h gmkqw$20 \; m/s$ to rest in a distance of 77 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a speed 9v-t 7oflju ljud;;+b of $29 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.7 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can b6n(sl*4 w6nwdhbe:m/ zw,uchurst out of the blocks to essentially top speed abou(:6 wn / cuwhwmhb ds,nz6l4*et $11.3 \; m/s$ in the first 11.3 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 au+ 0*mzvveqo4 speed of $21 \; m/s$ to rest in 5.91 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 on the highway2c4qqe n zt/u(. Assuming a de4qz/n2 (qu tecceleration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a trucyjn 6v s9iek9;o(qu6 jk 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 in j)(is ekp) a:/o3 g gohg9wmato3 ;99q q1hddtless than 30.0 min. After exactly 27.0 min, there are still 1100 m to go. The runner must then ao w91 /9)t:d3 h pooqjhmkqtag3a;( )sgid9ge ccelerate at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$