Suppose that an object travels from one point in space to another. Make iyjk;q1mo*) fa comparison between the displacement and th* qkjm)f1iyo ;e distance traveled.

  When is the average velocity of an object equal to t3q;kqxs+-l y.q1urf the instantaneous velocity?

  A new car manufacturelmu0 rlgx x:0/r advertises that their car can go "from zero to sixty in 8 s". This is allx g0u /rx:m0 description of

  An object moving in the +x axis experienc2e d0kxc8 f51 gggw-r8ze ,fcyes an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x direction) begins touo(rhxm49/cf ,7w jn j slow down as it approaches a traffic light. Make a statement concerning its a w, cfh(x 7noj49/ujrmcceleration.

  Suppose that a car traveling to the Wesmet)s /ts( 6ra72 rhw1)uldkat (-x direction) begins to slow down as it approaches a traffic light. Make a statement concerning its accesld6 /teraw)a17mrt(hk )s2 uleration.

  Suppose that an object is moving with a constanl a0e8x;q)9yg5kf 5e rx je/wbt velocity. Make a statement concerning its ac5eqlabr kgxj9)f 8yw5 /0xe;e celeration.

  If the velocity of an object is zero, does it mean that the accel+2-zzvaw h ak5eration is zero? Support your answer with an exam+ ah2-k 5vzwzaple.

  Can an object's velocity change direction when its accela9iyec(t.v x1ak )4,fq-xbvo eration is constant? Support your answer witq,cf49 -tv k y.1xaieo(vxab) h an example.

  Suppose that an objectz .( lmb5pip 0(,tsiz 2w)kdxo is moving with constant acceleration. Make a statement concerning its motion with respect zlip 2i5pmt, s0z (xwb.(d)okto time.

  Can an object have increasing speed while i02(l kg olp9bpl/xii1ts acceleration is decreasing? Support youri bp9o(g/0ll p2 xl1ki answer with an example.

  Suppose a can, after an initial kick, moves up along a smooth hill of i ekrp: ed(vs0; hqgd8:ce. Make a statement concerning its acceleratq: ;0 grvs(ekdhdep: 8ion.

  Under what condition is average velocit2zy t ,b3mg zd;i zf7o+fmiupe4 u-4c3y equal to the average of the object's initial and fi4 ub ;2 g cdmf3, izp7zuzo4y3ietm+f-nal velocity?

  Objects A and B both start at rest. They both accelerate at om0e :yg; eq8 bc7fbw6the same rate. However, object A accelerates for t8;6 q7goeywem0 cb:fb wice 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 the same rate7e*,0xrbn1 5 -ungxl fz0yrmj . However, object A accelerates for twice the time as object B. What is the distance traveled by object A cox5e7u ybn1ml-fn*r 0g j0r,zxmpared to that of object B?

  When an object is released from rest and falls in the absence of*wivl 7ohe yx k, t4jsc2wp-5/zy5x:x friction, which of the following is true co5 72/ol :hyywev x,s4-5pxi ct* xjwkzncerning its motion?

  When an object is released from rest and falls in t*7a3awqaax) j he absence of friction, which of wq*a a)jx3a 7athe following is true concerning its motion?

  Suppose a ball is thrown straight up. Make a statement about the velocity and00mk;jr hh42y /wbadr the acceleration when the b a004w;bhrmjdryk/ h2all reaches the highest point.

  Suppose a ball is thrown straight up. What is its ajcd)tun,3ak 4cceleration just before it reaches i k)na ,3j4cutdts highest point?

  Suppose a ball is thrown straight u 9ccu+5k/s)5c sjwz cips;e(g4)zeulp, reaches a maximum height, then falls to its initial height. Make a statement about the direction of the velocity and accelerationkl)5szccsue(uj)+w9zcsi 4c g /e5;p as the ball is going up.

  A ball is thrown straight up, reaches a maximum height, then f*ggh3 wq mu/-jalls to its initial height. Make a statement -wm3hgjq ug/*about the direction of the velocity and acceleration as the ball is coming down.

  Suppose a ball is thrown yhabxec,*jtmjx*7 r5r b3r ;5downward in the absence of air resistance. Make a statemejcam5y b5 jr,3e bx7;rh *tr*xnt concerning its acceleration.

  Suppose a skydiver jumps from a high-flying zqs /x6 okyv(zo4j6 zbzn5vh 296*eyi plane. What is her acceleration when she she reachesjozb z9zz4hxyo66 6v*n25s(qey/ vki terminal velocity?

  A ball is thrown vertically 50:)h gs lrcr(bf/porupward with a speed v. An identical second ball is thrown upward with a speed 2v (twice as ( hg5rp/0lrsf )br:ocfast). What is the ratio of the maximum height of the second ball to that of the first ball? (How many times higher does the second ball go than the first ball?)

  Ball A is dropped from the top of iq1vqavtc b/-z b(9z 2a building. One second later, ball B is dropped from the same building. As time progresses,q c( / -zqtzbiv1ab9v2 the distance between them

  Ball A is dropped from the top of a building. One second lz8t4g qt04iq5oxz n6qater, ball B is dropped from the same building. As time progresses, the difference in their speedsnq6 4zqt4gzt58 0qxoi

  Two objects are thrown from the top of a tall building. One is thrown up,nmo/ lb(w,yq7 and the other is thrown down, both with the same initial speed.oq,m w(b7y ln/ What are their speeds when they hit the street?

  A brick is dropped from the top of a building. A second brick is thr( 1e9n ,urde/w, ,gvxbevy-lfown straight down from the same building. They arelf/-e r vew dgb,1, ,vxyu(e9n released at the same time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with constant non-zero vsp c9wo+y3p -bd/iue6nkuj4) ( 7bsx9z2ovly elocity in the +x axis. The position versus time graph of this object ibl7 iope(2- 39psuzox6wbs ncdj/+y9yku 4)vs

  An object is moving with constant non-zero aj i x0vvmhi/e0u7 t:q ,gjco;6cceleration in the +x axis. The position versus time graph of this 0cgxh; 6mvi uo,j:jei/0qt7v object is

  An object is moving wi*j/o 3h.v)4 hyo7d zyeu2xchxth constant non-zero velocity in the +x axis. The velocity versus th 7423/ yuzcd hhox jev*y)xo.ime graph of this object is

  An object is moving with constant non-zero acceleration in the +-zj:ufdv+6zt ( *if x8hh nxm.+ofe4nx axis. The velocity versus time graph of this 8 ozfi(ff+h uj-x+vndmnte:x6.* zh4 object is

  The slope of a position versus timepb/8o q)7f2r nb9vcv) xqz zz6;wfu2 y graph gives

  The slope of a velocity vooq ajo5u, csyqn53w5 ,c a1k2 ;u(jspersus time graph gives

  The area under a curve in an acceleration versus time gab589fj:qa )l,jx.j(jjsw- loc wfx9raph gives

  The area under a curve in vd+d,o2fndq( mp0x3n r;x 8iza velocity versus time graph gives

  If the position versus time graph of an object i guccjg(4q -a-lwi )(3s4ttmjs a horizontal line, the object ilc-jt)gmq 44 (s -jt(wi3gucas

  If the position versus t.eaa5qok7 *-vrgu lx1ime graph of an object is a vertical line, the object is7q real51g.*ua ov-kx

  If the velocity versus time graph of an object is a horizontal line, the object i f*mtx/i:l hz 8,gmj1igzim1hm i:/tx j*,lf8s

  If the velocity versus time graph of an object is a straight line making an*,ho 57l(wljq tlrq7adnn:5nh ( k .le angle of 30 degrees with the time axis, thekw nhr *n5(l75 ,ledaqh7nl(l :to.qj object is

  An object moves 15.0 m north and thenk wmqhfy gj vpqi q-,6t;hf3k0/wk6./ 11.0 m south. Find both the distance traveled and the magnitude of gvk.ityqkw3/6j/-h;,fqk wmq06 p f hthe displacement vector.

  A boat can move at 30 km/h in still water. How long will it take to move 12 km (r ne.gin3l7*tj0 sk yupstream in a. kg7t(i* jlys3n ner0 river flowing 6.0 km/h?

  55 mi/h is how many m/s? (1 m:nl;nakan6a h rd .t3j;u9/dvi = 1609 m)

  What must be your average va ec0hhvy08*/goh6 wspeed in order to travel 350 km in 5.15 h?

  A runner ran the marathon (ap, ody+3r 0fn ydm.*yczproximately 42.0 km) in 2 hours and 57 min. What is the average speed of the rufd0cy ,rzn+.3 *ymod ynner in m/s?

  A car travels 90 km/h. 2j cl6s)ju75knoyjthy335m xHow long does it take for it to travel 400 km?

  A ly (light year) is the distance that light travels in one year. The l9fygcy0v ydzo. l.g28 fzyn2 k(w:u;speed of li ou8:9f.ly.0l;z(gvzd 2 yyng 2ck yfwght 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 kmqpajzfr- :+l 4/h along a straight road and you look to the side for 4.0 s, how far do you travel d 4-lp+ aqfjrz:uring this inattentive period?

  If you run a complete loop around an cii drcqyz2/y(a.ik ;2k qdta8m. c7; outdoor track (400 m), in 100 s, your average velo (7addz2 ;r2k8i m.acc; q y.kqtic/iycity is

  A polar bear starts at the North Pole. It travels 1.0 km south, then 1.0 kmkahe-v4,c9k elmfb2- east, then 1.0 km north,kfev9c2-m- lh ba4,ek 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.zn z,/0 ea6uz:y m,ov0g xq6wej)yk 4k It travels 1.0 km south, then 1.0 km east, then 1.0 km northzkv myzg0x:qjy4e/6 ez06)ako, nu, w, then 1.0 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 a weekend from school at 55 mi/h o 3f5v kx5rn -74cdaoaa e+9/wy1)ashdw8y rm for 110 miles. It then starts to snow and you slow to 35 mi/h. You arrive home after driving 4 hourr)a 9v/wk cs eodaw8+hayx5f -4od17nm3yra 5 s and 15 minutes. How far is your hometown from school?

  A motorist travels 160 km at a 7bi.+st;iio 80 km/h and 160 km at 100 km/h. What is the average speed of +.b7i stiia; othe motorist for this trip?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h. What isiv4l7dk4 2wx d.a k4prq/z6- az ggsy8 her average speed for the t47q8rkg4 dl 2 vpiz yk-xs 6g4wzd/a.arip?

  An airplane travels at 300 mi/h south for 2.00 h and then at 250 mi/h north ctyy(ia:25qz for 750 miles. What is the average speed f zyc5:2iy(aqt or the trip?

  In a 400-m relay race the anchorman (the perpkn94cdgca,y+6 f(l k son 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 4,g cn96+ (dkylpcf akteam A runner not lose the race?

  A car decelerates uniformly and comes to a stop after 11 s. y0zym7k 55nm +-c smcer2pz7a The car's average velocity during deceleration w mym27cp5rm0+cae n 5zs7ky-zas 63 km/h. What was the car's deceleration while slowing down?

  An airplane increases it-rqs4q1ig* ji3wbe / cs speed from 100 m/s to 160 m/s, at the average rate of 4i1r- b*gwqcjs e/3qi$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerates ath-asrvild / ) c3qc yol5:)js) 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 acceleraz,p57cit3ni ates 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 ; cel7o*m 6ryos. It then speeds up with a constant acceleration y c7;*morlo e6of $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velo ner v ik:som/dvvt;6l jiqd525v.- 4mcity of 3.7 m/s experiences a constant acceleration ofj4 io rmv.d n t5vk:q2elvm/ivsd-;56 $2.4 \; m/s^2$. What is the cart's displacement during the first 4.6 s of its motion?

  A bullet moving horizonn+m wuls; xpdry-k+p5 u ,v)(xtally to the right (+x direction) with a speed of 280 m/s strikes a sandbag and penetrates a distance of 5+puy(x )x ; lv+nmk,p- rw5sud5.31 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from ar:otk 3 je9a7v catapult on an aircraft carrier. It reaches a speed of 42 m/s at ot 3ev:7r ajk9the 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 constant acceleration:+w-oat+6 dnk bj3qi j -4gaza of $2.0 \; m/s^2$ for 10 s, then travels with constant speed for another 10 s, and then finally slows to a stop with constant acceleration of
-$2.0 \; m/s^2$. How far does it travel?

  A car goes from 40 m/s to 80 m/s in a distance of 200 mcui g . s)jx.*)4vwdpali2gmyj. a sf,6 h;;ly. What is its average accesjm6 .4j.ylg, lava)hyfi2sp w;x .igd) cu;*leration?

  An object starts from rest and undergoes un/h*s/uygv-q 6w vr(mgl okxf i42:ln. iform acceleration. During the first second it travels 7.6 m. How farm4lr2ufxo6gl/q(sv n k:-g h ivw* /y. will it travel during the third second?

  An object is moving in a str 7,f pttsvr72o h.+pc/ yvwhlhl0lb+, aight line with constant acceleration. Initially it is traveling at 16 m/s. Three seconds lay+,2sv lcl7.+,h 7 l phb/rtf wthpv0oter it is traveling at 10 m/s. How far does it move during this time?

  A car starts from rest and m o;*tfx0o4y ;tenqu;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 i4j+ev x3 wk6xpnqq ,0xmz.9eroad 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 lismj3w/ -wb 9rbte 56to 2:aawkght turns green, a car that has been waiting at the intersect9j sbwroab/2kw m36: -wet5ation starts 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 nv: 2k.-nt r xmwx7mp2a speed of 12 m/s on the surface of planet X where the accntxm:k p7x2 v-mn2rw.eleration due to gravity is $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown upward wit id4t kwpkn*n3 ia)jgw(c:6e6 . )eazjh a speed of 12 m/s on the surface of planet X where the acceleration )keijgja6)wt zp:a3.ndwci4 n * ke(6 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 upwa1)5f rjsvhmri- rck9do5c1c8g w 3hv 2rd with a speed of 15 m/s on the surface of planet X where the acceleraw82s5)rvccmdvo 19grhi1r kc 3jh5 f-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 upwar mkr4er3nor4tn i 19a(d with a speed of 14 m/s on the surface of planet X where the acceleration due to gkreirr (m n9oa n31t44ravity 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 holds a rule 6;cm tqdol9..tzyg(qr between your f (t cq.;d.tlm6 z9oygqingers and releases it without warning, how far can you expect the ruler to fall before you catch it?

  A ball is thrown upward ah, o4((h35 vymrn czmet a velocity of 19.6 m/s. What is its velocity after 3.0( h r4vym oe(5z3ncmh,0 s?

  A bullet shot straight up repxlt+e *shop;du/s 67turns to its starting point in 6 s. What is the ini6lx t;peh7 uso/p*ds+tial speed of the bullet?

  A ball is thrown straight up with a speed of 36.0 m/s.xh*p1hg: a9ow 9v)m+ vdaq-wf How long does it take to return to its sta+ faa)1mvo x g9p:hwdw*v9q-hrting point?

  A ball is thrown downward from the top of a bui+umqru2cr *gtl g 90z0lding with an initial speed of 14 m/s. It strikes the ground after 7.5 s. How high is the building?0 uu90 c*rgzlqtrg+m2

  A ball is thrown straight up pdvb7d4dak f.cn/ 7n8with a speed of 30 m/s. (only fill in numerical value 4fb dnpv 7dd7n.ka/c8in 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 ool:x*f3jdp/k5f n1y 4-hilx39.2 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 2 seconds later.  (数值)  $m/s$
(e.) Determine the time at which the ball pass a point 13 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 13.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is the m78c5hr6 x ckgvelocity at t = 1.0 s?

  In Fig. below, what is the velocnmn2ch*lu* o,xu v+i :ity at t = 2.5 s?

  In Fig. below, what is the velocity at t = 4.0 x a/imc:tzll -.3-i; nvzss5os?

  In Fig. below, what is the velocity a*hnd-e.e r)m/ o r wz/)qpmb:ut t = 5.5 s?

  In Fig. below, what is the average velocity from 0 to 4.0 ycq fe3)0rhz c0 v6.vmg95ak +enqm6ts?

  In Fig. below, what ism81 ,btx c 1dg.rlzwihy/q+7l the average velocity from 0 to 6.0 s?

  In Fig. below, what is the acceleraz62r1l-r rjbption at 1.0 s?

  In Fig. below, what is the acceleration at q-2:bd6y5kjdc zup7 t3.0 s?

  In Fig. below, what nii3j9zek 5 w v*jmasjh00)/d, 2g0rocv8 mxdis the average acceleration from 0 to 5.0 s?

  In Fig. below, what is the avera*vqgq 8be71r xzz;8.ske) 9nrmpq ;ia0 jos3age acceleration from 0 to 8.0 s?

  In Fig. below, what is the displacement from o68 ps)uv*dombu :)gg0 to 8.0 s?

Does a car speedometer measure speed, velo 0d/d0a,z sbtrjanar17hz/ d) city? {speed|velocity}

  An object can have a varying s. d8ljwaj;y5upeed if its velocity is constant.

  The velocity of an object can be negative wf8v3d(fx/aiyao b71 ihen its acceleration is positive.

  If one object has a greater speed than a second object;gzx(m aew7 +t, the first must have a greater accemzwt(g ;+ax 7eleration.

  Two cars emerge side by side from a tunnel.zrac- 7sz 7-rv 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 increasingw;wly zc+nu y vz54+s6 in speed as its acceleration decreases.

  A baseball player hits a foul ball straight up into the bxjc62zo98fp air. It leaves the bat with axof2cb zp689 j 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 obj fp , 3r8f3 st8,,m;yjwsmrazpect speeds up, what is happening to its acceleration, how does it change if air,s88mwm zp y ,;f3r3p fsjt,ra friction is ignored?

  As a freely falling object speeds t+m x7ve.* ksx.wm4bt,9c ae kup, what is happening to its acceleration, howekc t. mtae*,mx9bs7k4w .vx+ does it change if air friction CAN NOT be ignored?

  An object that is thrown vertically upward will return to its origi/ ps 6vq7bb/nmnal position with the same speed as it had initially if air resistance is negligible. If air resistance is appreciable, how will this result be altbv/7/ qbsn m6pered?

  An object can have zero velocity a ,j(vkbjm- y3.ggar7 *yz;bc vnd nonzero acceleration at the same time.

  An object can have nonzero velocity and zero acceleration at the s:ojtk5 ddhzs7c8 1km 1ame time.

  An elevator moving from the second floor to the fifth floor itpq;03wpjx/ making no stops along the way has zero acceleration all the titipj ; 3qx/0wpme.

  A rolling ball moves:oqg 2ky 0aw,p from $x_1=3.2 \mathrm{~cm}$ to $x_2=-8.6 \mathrm{~cm}$ during the time from $t_1=2.8 \mathrm{~s}$ to $t_2=6.0 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-4.0 \mathrm{~s}$ is at $x_1=2.8 \mathrm{~cm}$ and at $t_2=3.6 \mathrm{~s}$ is at $x_2=7.6 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete law+l:d. yloqub pv a*2kn2t5;wps around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 11.3 min. Calculate (a) the average speed  (数值)  $m/s$ and (b) the average velocity    $m/s$

  A horse canters away from it-/qgxi. /() znlktsa;v*m qtvs trainer in a straight line, moving 101 m away in 13.5 s. It then turns abruptly and gallops halfway back in 4.7 s. Calculatinvxt *va. /;z()sg /qkq- tlme (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 frvm k eq16v6i,eom $13 \; m/s$ to $24 \; m/s$ in 4.8 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 u2zdek(:v 3iey3s* yta k+k+q$23 \; m/s$ to rest in a distance of 73 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a speed o)v(cfq0z o*g*plm l u6f $32 \; m/s$ 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 out of the blo3et3amnrnkk uq*--0s cks to essentially top speed aboutktq-m- 3 r*usnn 3eka0 $10.2 \; m/s$ in the first 11.5 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 /2 qs /aghlon0from a speed of $16 \; m/s$ to rest in 4.78 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves skid markumt3;1z1ul qts 92 m long on the highway. Assuming a deceleration ofzm t13;q1ult u $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truc3 qjr voi+bna/1l226 pl:nnbkk 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 completw ryvyd(-) qx*gtx*0m e the 10,000-m run in less than 30.0 min. After exactly 27.0 min, there are still 1100 m to go. The runner must th*)dxqtwgxym*-y r0 (ven accelerate at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$