Suppose that an object travels f*8g;btnzo+qv d mom 3/x9qt8 arom one point in space to another. Make a comparison between the displacq+o m9qz8/mn8do 3 t;ga*tvbx ement and the distance traveled.

  When is the average velocity of an object equal to the instantanepgz 6fbn2 yh*x*xsb.1ous velocity?

  A new car manufacturer advertises that their car can go "from zero to sixty in lyo-t/me ai *lfy4 ;e(ibanls18 u9)e8 s". This is abylefe*(a 1l-yl uim9i e; so)at 84/n description of

  An object moving in thrsa6: hg;gzt.e +x axis 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:nw0jfjs7b0 x+op/b y+tw3k p slow down as it approaches a traffic light. Make a statement conctp3kj o0wf: +j s07/yxbbw+ pnerning its acceleration.

  Suppose that a car traveling to the xsv-jr.lej2o / c5tcx9u ;mo0West (-x direction) begins to slow down as it approaches a traffic light. Make a statement concerning its acceleratxc s tx2.5oo0rc-vu9mj;/el jion.

  Suppose that an object is moving w9i+k8 m 8g14 ufi.dzt,lvp wfzith a constant velocity. Make a statement concerning its accelk4z w.mftup+g zd,f898iv il1 eration.

  If the velocity of an object is zero, does it me916ixd41oj-lx ,kclc wsatq ,an that the acceleration is zero? Support your answer with an 9ck,s1c xdjiwta-o1 l6xql 4, example.

  Can an object's velocity change direction when its accelef1r phy)5zpdepr3v3t ) *3btoration is constant? Suppo 3p d)rto31v5yfzh rptep3b)*rt your answer with an example.

  Suppose that an object is moving with constant acceleration. Make ru fy.j:nyidee1g5a5:x .zl-x u/ ,fsa statement concerning its motion with yadz xn e i,5rjf.f:-:1gluy/xsue. 5respect to time.

  Can an object have increasing sdxfu(r -)eby* qod -h:peed while its acceleration is decreasing? Support yo qdurx -b)-*:(ohefydur answer with an example.

  Suppose a can, after an initial kick, moves up along a smof6h6i2er2pja2 zt w/ twajo: ,oth hill of ice. Make a statem6zrof2 ,hp2a wwt6ae:/j 2tijent concerning its acceleration.

  Under what condition is average velocity equal to 1ax0c rteqgws yt+hr:ov0k.*x (;/ 0mj+efuz the average of the object's initial and hro*v+ujtx. wf q1a0+ ;/0rmyesek0 gz:xct( final velocity?

  Objects A and B both start at rest. They both accelerate at the same rate.x2 /1 5ieoza iya4bai2 However, objeoiy2e2b aza xi 1i/5a4ct A accelerates for 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 rest. They both accelerate at theafn/jom6 8(qtla5(u +dh)+ jeb y kk4j same rate. However, object A accelerates for twice the time as object B. What is the distance traveled by d+f4j6han(lbte jayjqo uk5)k m /+8( object A compared to that of object B?

  When an object is releus /y7nalib(dj /+/ 8nthkyl5 ased from rest and falls in the absence of friction, which of the following i(nid h75lby n//yj+k8/lauts s true concerning its motion?

  When an object is released from rest and falls in the absenc7rrbvh(ad e (fk:. 4uke of friction, which of the following is true concerning rd:r au(v7.kbh(e k4fits motion?

  Suppose a ball is thrown straw,4t2uqehu 5 pight up. Make a statement about the velocity and the acceleration when the ball reaches the highest point.5tp u,24quw eh

  Suppose a ball is thrown straight up. Whatgj 28+kuo b0efyft;m/px6q7 r is its acceleration just before it reaches its hig t8;e /bfouxf7p+2m 6qyrgkj0hest point?

  Suppose a ball is thrvwpvb)5aqe,5n 6uf d8 own straight up, reaches a maximum height, then falls to its initial height. Make a s)8b5vuenq wp fd65va, tatement about the direction of the velocity and acceleration as the ball is going up.

  A ball is thrown straight up, reaches a mayh gnzfrxb8q+0op5+7fduq mo qq511po 58 nj,ximum height, then falls to its initial height. Make a statb qm5 f8qynh qq5o8u+17o n fgj1+od0 zp,5prxement about the direction of the velocity and acceleration as the ball is coming down.

  Suppose a ball is thrown downward in the absence of air resistance. Mde9wmtd2oi h +m76,ylake a statement concerning its t+6mm,9i yd ehdo2lw7 acceleration.

  Suppose a skydiver jumps from a high-flyingw v+cs.3bxzr s1 cj sio:51wv (ot +c/hjp(s5j plane. What is her acceleration when she she reaches terminal velscbjx5jsj t1+o zs:si hvo p1wc(3w(+r.5 c/v ocity?

  A ball is thrown vertically ups17njg eh34mr e.tzp 4ward with 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 ght jzs e174rn p3e4m.ball? (How many times higher does the second ball go than the first ball?)

  Ball A is dropped from the top of a building. One second later, mnle,k-e9.y a k m3ztu*,amq 7ball B is dropped from the same building. As time progresses, the dmee.u,*nkt- qlzy, ak9 7mm 3aistance between them

  Ball A is dropped from the top of a building. One secondjovowmlj k)qv 3-6n .8 later, ball B is dropped from the same building. As time progresses, the difference invko8 jqml3) owj6.vn - their speeds

  Two objects are thrown from t (x-4o;z;g s12f rnkg(knb liyhe top of a tall building. One is thrown up, and the other is thrown down, both with the same initial speed. What are their speed2k(oln(gbk n x z rs4-gy;;1fis when they hit the street?

  A brick is dropped from the top of a building. A4 ozd;w0kvh6swq7 2 tr second brick is thrown straight down fr62;wo 47zvhwr qd0kstom the same building. They are released at the same time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with constant non-z x()lyk 1v6x2pva 8c: qi lk4;icv4jqzero velocity in the +x axis. The positionv 4a(jck1lxi : cvx)v42qiqk;p 6 ly8z versus time graph of this object is

  An object is moving with constant non-zero acceleration in the +x axis. The z.( ya0 7s:lyq7akgr mp4 e4mwposition versus tizay4a. ps e gm :w(m0477klryqme graph of this object is

  An object is moving with constant non-zero velocity in the +x axis. The veloci 9q akitz)a9a8jb0v c5ty versus time graph ofztj 8k v0)99aa qiacb5 this object is

  An object is moving with constant non-zero acceleration in the +x axis. Theg bpase0t.l3w uup 1 qsy/0jt;-,rl a8 velocity versus time graph of this objeaglesp/ aru3.t 0p-0 s8tlj;qu,wy1bct is

  The slope of a position versus time+ejjdsjsk 9b .) c*sg4 graph gives

  The slope of a velocity versus hah i78ow- wi/time graph gives

  The area under a curve in a/zu2p4bb 55wki+ q+ljhb( wwv0csnzpd*z /u,n acceleration versus time graph gives

  The area under a curve in a veloci-0:-b cdzq pqwty versus time graph gives

  If the position versus time xw e8prjg6:igthb0 ; w6j.(gm graph of an object is a horizontal line, the object p 0weigjxj;rm. g6w g(th :68bis

  If the position versus time graph of an object is ae 3 ma.hvmbx/1bdzu*ka** 3ex:qxf4a vertical line, the object is e /*bakzvu* a3e4xdxam3*b:.h1m xqf

  If the velocity versus time graph of an object itj-zg c;ubj .e +drk;3s a horizontal line, the object ;e3jk r j+;-tcbduz g.is

  If the velocity versus time graph of an object is a straight line map9avs7zfu9( x q5qq*c 8nnpxn o,)6wiking an angle of 30 degrees with (wqfnp qc7s zi* x )np9,uxao59n6v 8qthe time axis, the object is

  An object moves 15.0 m north and then 11.0 m south. Find both the distancex sw tu d-pso2x4hiou:678.dl travelxuo: 7 wpi sds.l6dh2xt4o8u -ed and the magnitude of the displacement vector.

  A boat can move at 30 km/h in still water. How long pceni( qbx+bp5q 9)r5qvu :c.will it take to move 12 km upstream in a river fvc r5cpqiq )e9 5:b.np(xub+qlowing 6.0 km/h?

  55 mi/h is how many m/s? (1 mi =919zaww g n5htc:dqr ,3 una*k 1609 m)

  What must be your average speed in order ge7n ,zukeg/tq4+ d2 up2gz9.vid pb; to travel 350 km in 5.15 h?

  A runner ran the marathon (approximately 42.0 k.4os scsmv.-/sm kltft); 3h8f*kggs m) in 2 hours and 57 min. What is the average speed of the runner in m/s)vskf;3 -ogghk4tl/c s t.m ssfm8*. s?

  A car travels 90 km/h. How long does it take for it to trzzj)c5 er+ qoei 3+0avavel 400 km?

  A ly (light year) is the distance that light travels in one*f+9 5zitxi bo year. The speed of bi* 5i+o9tz fxlight 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,yt7ye (.ls uu to the side for 4.0 s, how far do you travel during tley(su,ut7 y. his inattentive period?

  If you run a complete loop around an outdoor track (400vr-zesru1 hnaf68 um k1:qr01 m), in 100 s, your average 1rvum1 erzq8:kns1 6a frh -0uvelocity is

  A polar bear starts at the North Pole. It travels 1.0 ktn8 6j, hvzf4(0vl mzym 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 thel 64myh8z, zvfn0t vj( bear's average speed?

  A polar bear starts at the North Pole. It travels 1.0 km sou q 2j9rf*v7iemth, then 1.0 km east, then 1.0 km north, then 1.0 km west to return to its starting point. This trip takevefi9m2 *rjq7s 45 min. What was the bear's average velocity?

  You are driving home on a weekend from school at 55 mi/h adav19 4pvs5 hz3ssd+ for 110 miles. It then starts to snow and you slow to 3s4a d sh+d9 z13vps5va5 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 160 km at 100 km/h. What is the averaj/ aa/b p9 by)zrf 4vixozy*91ge speed of the motoryry 9o1afbz9*ai j)vpz4/bx/ ist for this trip?

  A motorist travels for 3.0 h at 80 km/h and 2.yuz cfw(2db9 (0 h at 100 km/h. What is her average sw9 uzcdyb(f 2(peed for the trip?

  An airplane travels at 300 mi+2u.wiik b.r g/h south for 2.00 h and then at 250 mi/h north for 750 miles2gi.i. +wkrbu . What is the average speed for the trip?

  In a 400-m relay race the anchormfzp -ir) (/j .q0*jnhsjd 8oiaan (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 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 r(h / fj8j)qo - .0nszrpjiaid*unner not lose the race?

  A car decelerates uniformly and comes to a stop after 11 u ;0-qk+o e.kovce:xms. The car's average velocity during deceleration oquk-v ;e c0m:.ex+okwas 51 km/h. What was the car's deceleration while slowing down?

  An airplane increases its speed from 100 m/s to 160 m/s, aaye3ph; opm8m jjuczpz72tu8 1m;9s+ t the average rate of seojypa 1uzp;9+c uh pz82tm; 73mjm8$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerateaze. bmd9 q 5xybbw,qvb*k62;s 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 accelerha1 qap tx2g90ates 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 with a constant om8y ci7q7dd0 accelerationm8qo77 0yi dcd of $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial loz pqf,l q/:g1gy87ovelocity of 1.3 m/s experiences a constant acceleration ogoyflq/o8pz g 1:l7,qf $4.6 \; m/s^2$. What is the cart's displacement during the first 5.4 s of its motion?

  A bullet moving horizontally to the right (+cuzpov0/;t:mv, p+ms x direction) with a speed of 223 m/s strikes a sandbag and penoc zppvm, t;/vus +:0metrates a distance of 60.45 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on an ahw5) vm/u .x9i qp 0*vx8vxgqaircraft carrier. It reaches a speed of 42 m/s a8 wqahv xp)/ qv *ix50.gvxu9mt the end of the catapult, and this requires 2.0 s. Assuming the acceleration is constant, what is the length of the catapult?

  A car starting from rest moves with constospwss36s o+)t px+2iih9 z2jant 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 6qfs--n; 3n wjwjhp+dv( fnx /in a distance of 200 m. What is its average accel6jdhf+-fx;s / p(j vw-qwnn3neration?

  An object starts from rest anfx i9 (lotjq60es+ tv5d undergoes uniform acceleration. During the first second it travels tjev6to(+5lsx f i 9q01.5 m. How far will it travel during the third second?

  An object is moving in a straight line with constant acceleram9rko u4fimfri6a*e) y, 70z ytion. Initially it is traveling at 16 m/s. Three seconds later it is travelmfr a*f9 46i oyz,iy)u0kerm7 ing at 10 m/s. How far does it move during this time?

  A car starts from rest ja)pxl(;tw0s9 g)18 jxl wvy1vqlkyuu7. n0hand 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 tire;x; y8,ibn9x .ammsfqzpxc lpi 5);9ms on a dry road can 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 light turns green, a car tfntwewlh()sj -p8y: u 8, -azphat has been waiting at the intersection starts ahead with aphuejy l,)z ft:(88wpw ans-- 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/3kt 1e imu e,xg )x;y(d,*4 9po+e3ekkkjya hks on the surface of planet X where the acceleration due to 4uyp xx3 3,kh;ktmdeoe+k*,igeyj 9k1 aek)( gravity is $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown upward with a speedxtnz df6duwx67 dw3 *-pc*vp, of 12 m/s on the surface of planet X whernxdp pzd-u76**x v6c,w twd3fe 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:ojvgya0gj+djif2 f 1xw/ 1 u1 speed of 15 m/s on the surface of planet X where the acceleragjf:0uw1 21aivox1yjjd/f g +tion 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 spepf8z49: y z,pz vzl) .xk4arwdssju.5 ed of 14 m/s on the surface of planet X where the acceleration due to grazx :p4)a9,sv.uz4p jy.lszzr5 w8dk fvity 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) +)6 moy)snumgdyez + s. If your friend holds a ruler between your fingers and releases it without warning, how far can you expect the ruler to fall before you catch itysg+umo) zed + ym6)n)?

  A ball is thrown upward at a velocity of 19.6 m/s. What is its velowgmxn0uv;b w7sy5 w b.c4a+ 1scity after 3.00bu5c w;v. xyasww0m71+ b ng4s s?

  A bullet shot straight up returns to its starting point in 8 s. What itb7qs* h x81zgs the initial speed of t* xb7hqzs 18tghe bullet?

  A ball is thrown straight up with a speed of 36.0 m/mqz-pill. +ol s) 2r:es. How long does it take to rel -):2qe slr.o+ip lzmturn to its starting point?

  A ball is thrown downward from thd4fu*n 0pzmm64dz 4qhe top of a building with an initial speed of 8 m/s. It strikes the grouqzm4*m 4zuhd64 fp 0dnnd after 7.5 s. How high is the building?

  A ball is thrown straight up with a speed of 30 pwm+ekk0m8)m 3e c k7tm/s. (only fill in numerical value in the bl m)m3k et+wkkpc7 80meanks)
(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 ayg(o dab2aloxb 9/ a14bzgmab28 88ls ir with a speed of 44.4 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 2 seconds later.  (数值)  $m/s$
(e.) Determine the time at which the ball pass a point 15 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 15.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is t:p rsw 6j8i9o6-zs swdhe velocity at t = 1.0 s?

  In Fig. below, what is the velocity au4yaa (hl-tm,r9b.fa t t = 2.5 s?

  In Fig. below, what is the velocity at, n, y tuli3ubz(62joc t = 4.0 s?

  In Fig. below, what is the velocity at t = 5nuhx 2)vbfql g,61cx6djl/4o; ,jlfk .5 s?

  In Fig. below, what is the average velocity fw eb ia kd qb-oz:1p d+of77:ux.6h7cvxz6bx*rom 0 to 4.0 s?

  In Fig. below, what is the average ve*p3z hf p (cdd7:ry.qddn-vv*locity from 0 to 6.0 s?

  In Fig. below, what is the acceleration at suk k4o52( wor1.0 s?

  In Fig. below, what is the accel4)d.gp pi- tf9nackzx:ilc51k6b ve)usx 0e5 eration at 3.0 s?

  In Fig. below, what u7,:ojgt q-dc gr0ph-is the average acceleration from 0 to 5.0 s?

  In Fig. below, what - p 4oy.,,qd(fsfyqnhis the average acceleration from 0 to 8.0 s?

  In Fig. below, what is the zdz5e) 9je+)n,xzn irdisplacement from 0 to 8.0 s?

Does a car speedometer measure speed, velocity?3rhi62y r* ,5 ust-5h smnygwv {speed|velocity}

  An object can have a varying speed if its i5adzqa,7/ n c/-jj bb038s7cv qiyuu velocity is constant.

  The velocity of an object can be negative when n wkd- 12w(z2mha 1dvd evf18eits acceleration is positive.

  If one object has a greater speed than a second object, the f ml8nj0itj2vy6 j*5oqc+t v ,x t.uk/zirst must have a greater accelemv +jnc8. klvjtzy5 062* qt/,ouxijtration.

  Two cars emerge side by side from a tunnel. Car A is travel1yrlyhxp6w )xq ( oe)4d thx(0+y 7udring with a speed of $60 \; km/h$ and has an acceleration of $40 \; km/h/min$ Car B has a speed of $40 \; km/h$ and has an acceleration of $60 \; km/h/min$ . Can A will pass car B at the instant they come out of the tunnel.

  An object can be increasing in speed as its sgsii9 h/ x9n74uzhl2 (hs-d5yvb6v x 7guvv3acceleration decreases.

  A baseball player hits a foul ball straight up into thea* 3cg -q,i*ikcx.npg air. It leaves the bat win x ac*g,i.q*-kpgc3ith 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 f):4ymjw, zloup, what is happening to its acceleration, how doeojl 4 mzf:),wys it change if air friction is ignored?

  As a freely falling object speeds up, what is happening to its acceleration, ho5m. kom w5*vrkw does it change if air friction CAN NOT be i5wvk 5m*o.kmrgnored?

  An object that is thrown vertically upward will return to it 7kx5ey8kxr)5jrq;hjs original position with the same speed as it had initially if air resistance is yj8 ; rk5xkher)5jqx7negligible. If air resistance is appreciable, how will this result be altered?

  An object can have zer6a0d)d-)t eb/ezd xo qo velocity and nonzero acceleration at the same time.

  An object can have nonzero velocity and zero accij7p2 m+.-v- cuicy9 x4.zfh wwq(ad yeleration at the same time.

  An elevator moving from the second floor to the fifth kgzl5 o3+y8 :g;c b f29qdyvpwfloor making no stops along the way v9g2: gd q byc8zowfpk;3y5+l has zero acceleration all the time.

  A rolling ball moves r:z;/m7zsnc,edv1m i22 scmffrom $x_1=2.9 \mathrm{~cm}$ to $x_2=-4.7 \mathrm{~cm}$ during the time from $t_1=1.2 \mathrm{~s}$ to $t_2=5.0 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-2.6 \mathrm{~s}$ is at $x_1=3.2 \mathrm{~cm}$ and at $t_2=3.3 \mathrm{~s}$ is at $x_2=7.9 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps around a quarter-mile :tgdrsym1 4 2a(q(4jiy .noyq($1 \; mile = 1609 \; m$) track in a total time of 10.0 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 112 m away in v0j ec p3kc2 f.r7a;vp1q.tfm 8.1 s. It then turns abruptly and gallops halfway back in 4.7 s. Calculate (a) it.fpc 7jf p3mc.erv 2a 1ktqv;0s 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 fro0li5ua4krnq*b -3si sm $11 \; m/s$ to $22 \; m/s$ in 4.0 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 frowr8aexsuo osd iet08n6+rs :r ;*nf3 .m $19 \; m/s$ to rest in a distance of 71 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a sp3840 nua wcpnkeed 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 burst outaj4kk b7yh(bfbkbf 0wi35:zh p 5im*; of the blocks to essentially top speed about wz 450i(kb k:3k ;p5*fybhbbhji7maf$10.5 \; m/s$ in the first 13.5 m of the race. What is the average acceleration of this sprinter?  (数值)  $m/s^2$ and how long does it take her to reach that speed?  (数值)  $s$

  A car slows down uniformly from a spee65qela (8vdccd of $17 \; m/s$ to rest in 5.66 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves skid tvh,o05igpqf-3vxo k) r4 ;:9a eersomarks 92 m long on the highway. Assuming a decelerath;gotir54 v9 p0vq ar,ee3oo:k)f s-xion of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck goqe*uqg 1h6f8 pvzuk- ;ing $25 \; m/s$ 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).    $m$