Suppose that an object travels from one point in space to another. Make a comn *b0kkox:gay2 s5py(parison between the displacement and the bp*x( 5sk2yna ko:y g0distance traveled.

  When is the average velocity of an object equal to the instantaneous 0liznn7s,v s1hvv3r0 wr82eo:fdf v4velocity?

  A new car manufacturer advertises that their car can go "fro0ojhyq 6* cgblwy5gro0 mf+*z*c 3z1gm zero to sixty in 8 s". Thism yg*zbogwzq3gc0y0f lhjo*c * 1+5 6r is a description of

  An object moving in the +x axis experiences an acceleruho9ftzq*nyju:r( 4m4 he (+tation of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to t: /jp-tjc1ohj he East (+x direction) begins to slow down as it approaches a traffic light. Make a statement concerning itst :oj h1/cp-jj acceleration.

  Suppose that a car traveling to the West (-x 4xmrye(xej9; cfb/ 6ndirection) begins to slow down as it approaches a traffic light. m/ cf9x4 r nb6y(;jexeMake a statement concerning its acceleration.

  Suppose that an object is moving with a constant velocity. Make a statement dg k* /hy0 gw/ycn3cush9; 1owconcerning its acceler9*/cwon d; ksw gygc0h31uh/ yation.

  If the velocity of an object is zero, does it mean that them ge2kj *vco3h: v6/zs acceleration is zero? Support your answer with an exampl*cv:j 3vzhm/eso2 6gk e.

  Can an object's velocity change direction when its l4. 3b:ty4o) igbcanif6n5r ax2rv*s acceleration is constant? Sup4gnr xlvb*yoc4i rt526bsi faa.)n: 3port your answer with an example.

  Suppose that an object is moving with constant acceleration. Make a statew.uf ai fx8f h/ls(48tment concerning its motion with respect to timultix8(hf8./4 fsw af e.

  Can an object have increasing speed while its acceleration is decreasgut4 *m7et :kw*f5eic ing? Support yourwu7:4m*efte ctk *i5g answer with an example.

  Suppose a can, after an initial kick, moves up alonl.s .pq .nm)uav yh(v9g a smooth hill of ice. Make q (ulhvn.v .y asp.)9ma statement concerning its acceleration.

  Under what condition is average velocit,/a.erqzmw5-ms -tx ,zj. gzpy.k* i5nzi1gfy equal to the average of the object's initial an,gs ef -iy.m-aqmzz5k .rw1jngzx. z5t*i p/,d final velocity?

  Objects A and B both start at rest. They both accelerate at the same rate. q ; t5r5 hj;lzfvanc-; However, object A accelerates for twice the timr; hzlt;5a5q;c-vj fne 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 botwdg5 gf-mni-7;+sqoi s1qk ( kh accelerate at the same rate. However, object A accelerates for twice the time as object B. What is the distance traveled by object A comparmdknw-f si5q1kg qg7o si+-;( ed to that of object B?

  When an object is released fromgf a0m8:j.vx t33pg ubhh))v ubm-0mb rest and falls in the absence of friction, which of the follotgm bv0-vbg 0u:af.3p) m)3uhjb m8xhwing is true concerning its motion?

  When an object is released from rest aao n+di .3n-z l 4f6ehk7yjss:nd falls in the absence of friction, which of the following is true concerning its motion? l njhf+a4s k73 n6iz:deyo-s.

  Suppose a ball is thrown straight up. Make a statement a/cdlc5 r4vtg 2t,op3cbout the velocity and the acceleration when g 4 pdorcct3/,5c t2lvthe ball reaches the highest point.

  Suppose a ball is thrown straight up. radrzg( :l2r3 What is its acceleration just before it reaches its highest pointlr2da3g:z(r r ?

  Suppose a ball is thrown straight up, reaches a maximum hfoq8c13z ;n j o)/,ce2 toclx0kp-hh leight, then falls to its initial height. Make a statement about the di1nfoxlp 2jkoc/le,ct c-o)q 8h3h0; zrection of the velocity and acceleration as the ball is going up.

  A ball is thrown straight up, reaches a maximum heig7 hi4cl)(lmf2xtrd0eht, then falls to its initial height. Make a statement about the direction of the velocity and acceleration fxmhd t7(rl 4)2cli0e as the ball is coming down.

  Suppose a ball is thrown downward in the abse f, 5 e25wjprwur:xv2bnce of air resistance. Make a statement concerning its accr2x w:wb5v5 ,puf2ejreleration.

  Suppose a skydiver jumpla (09 :cevpiis from a high-flying plane. What is her acceleration when she she reaches terminec a0pi:li(v9al velocity?

  A ball is thrown vertically upward with a speed v. Ani,74uhvc (8unreto9a identical second ball is thrown upward with a speed 2v (twice as fast). What is the ratio of the maximum height of the second ball to that of the first ball? (How many times highen,tvecauou h7 (r984i r does the second ball go than the first ball?)

  Ball A is dropped from the top of a building. Onfydrxiow 44y6hg)k7; e second later, ball B is dropped from the same;47fxi4yy wd hrg6 )ko building. As time progresses, the distance between them

  Ball A is dropped from the top of a building. One sek7 xl qm+-ym3l4tag a)cond later, ball B is dropped from the same ba-lg3qxym7a t )4l+kmuilding. As time progresses, the difference in their speeds

  Two objects are thrown from the top of a tall building.0ha6krx *a/) ypysxj- One is thrown up, and the other is thrown down, both with the same initial speed. What are their speeds wheny0k/ypxr6) -ahx jsa* they hit the street?

  A brick is dropped from the top of a building. A second brick is thrown0keru0l9w8ae a;7 x nnk75;srnak y vmo: ;uz) straight down from the same building. They are rzo7: r y;kkmu8n knxe7 suv;5a9 w;00nlrae)aeleased at the same time. Neglect air resistance. Compare the accelerations of the two bricks.

  An object is moving with constant non-zero velocity in the +(7vm5ei q d+*tcy tv1-c 8wrsgx axis. The position versus time graph of t*rvd51 wevg cci+8ttq(7ys- m his object is

  An object is moving with conxe rg2.v d7 jsef(,-yestant non-zero acceleration in the +x axis. The position e.d,2-fygj rve( xs7eversus time graph of this object is

  An object is moving with constant9i(1 c odl7;x2vmnbio non-zero velocity in the +x axis. The velocity versus time graph of th1oxi9 d;b lov2m(nc 7iis object is

  An object is moving with constant non-zero acceleration in the +f(2 81l 3fwswbevs7k 7wsrij6x axis. The velocity versus time graph os7es2fiw 6 r7 3bjw sf(w1lv8kf this object is

  The slope of a position versus time graph a d.vz*n o ;9hn3gce)zgives

  The slope of a velocity v o y rijr2l-c714bjk9cersus time graph gives

  The area under a curve in an acceleration versus timex71m sd w 2pf+qy2f5zdo( rc99in1tij graph gives

  The area under a curve ing-l;j g zw;4e+lf aq4p a velocity versus time graph gives

  If the position versus time graph of an object is a horizontal lineh2nf1,rs/ pbac17ly.z fkk - l, the object isl lpfb1k12 h-zcr7af /, .kyns

  If the position versus time graph of an object is a vertical line, the object p::dqkbd.xdlt9lphwj( 0b/./b k. pq is0qbdp wpdbtl9:.q /k ..bh (:l/xjpkd

  If the velocity versus rs+01 b jfwgl(time graph of an object is a horizontal line, the object is0fjl+1 r( bgws

  If the velocity versus time graph of an object is a straight li( l eyh3-1b8zjba7xw tne making an angle of 30 degrees with the time axis, thewx8bz-7b e1l(y3 jath object is

  An object moves 15.0 m north and then 11.0bx (korc*3 7ouy:3 (y-+iuayb8thx txg w7+w l m south. Find both the distance traveled and the magnitude of the displacement vector.c8otyww7-obr+ +x x7 (u *t l33iyxay: gub(hk

  A boat can move at 30 km/h in still water. How long will it take to 6g k int0a)yndz7: c2vmove 12 km upstream in adnznc7a y t:k 26vgi)0 river flowing 6.0 km/h?

  55 mi/h is how many m/s? (1 mihslhy(0e ;vw - = 1609 m)

  What must be your averb0 i-ekgytb/zmcd 9/*age speed in order to travel 350 km in 5.15 h?

  A runner ran the marathonwx4z n. to)-st (approximately 42.0 km) in 2 hours and 57 min. What is the average s sw nx-ztot)4.peed of the runner in m/s?

  A car travels 90 km/h. How lonpao(hi h+m- 2,t+lcp lg does it take for it to travel 400 km?

  A ly (light year) is the dib;1: tz55v gfhqp .tjmstance that light travels in one year. The speed of lig;:.5fptv 1j 5zb gqhmtht is $3.00 \times 10^8 \; m/s$. How many miles are there in a light year? (1 mi = 1609 m, 1 yr = 365 d.)

  If you are driving 72 km/h along a straight road and you look to the side fon2qwu(j4 :aior 4.0 s, how fajuqnio 2a4w (:r do you travel during this inattentive period?

  If you run a complete loop around an outdoor track (400 m), in 100m jm;dx3 +tw5e s, your average dme5j3 tw ;xm+velocity is

  A polar bear starts at the North Pole. It travels 1.0 km h,h2 ;usht qgrsd( /-2b4jxbjsouth, then 1.0 km east, then 1.0 km north, then 1.0 km west to return to its star( q2h;dbssju j ,24rghhbt/x-ting point. This trip takes 45 min. What was the bear's average speed?

  A polar bear starts at the North Pole. It travels 1.0 /0f)ngz+v-cgm0 rres+ mmkr7km 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 r+sm/gr0g0+- vr m fzeckm7)naverage velocity?

  You are driving home on a weekend from school at 55 mi/h for 110 miles.p; ap048nv awk *7qwd l ,ab1mbj(v59rtw cs.m It then starts to snow and you slow to 35 mi/h. You arrive home after driving 4 hours and 15 minutes. How far is yr b8 wpmcwda.* ,15vjkatmqvn9;0sa ( lp74bwour hometown from school?

  A motorist travels 160 km at 80 km/h and 160 km at 100 km/h. What is tvs/mtx(52ydok b , s.yhe average speed.y,d( tbs/k5xo vms2y of the motorist for this trip?

  A motorist travels for 3.0 h ao*y 4+ioar*juyo(w8/urkk p1 yt i g8x.4+ks it 80 km/h and 2.0 h at 100 km/h. What is her average ykto(ksg+*8j r4+yui.14 oi ourak pw8* /xi yspeed for the trip?

  An airplane travels at 300 mi/h south for 2.i )k q:emh,u-5o:qkin00 h and then at 250 mi/h north for 750 mile:qqkoe5m hik-):,nu is. What is the average speed for the trip?

  In a 400-m relay race the anchorman (the person who rutc1. g5;ktcx r kd4v(oau( xnod5l(a 9ns the last 100 m) for team A a.t1(kcdl95 4x 5ogvodnr (au(ct x;kcan 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 runner not lose the race?

  A car decelerates uniformly and comes to a stop after 10 s. The car'sbz)m6mikbf: 8 p 1.cyu average velocity during deceleration was 45 km/h. What w )mzcb8:u6km1 fyib.p as the car's deceleration while slowing down?

  An airplane increases its speed from 100 m/s to 160 m/s, at the average r2x*k n kuz;n .rg:2mu73 l)wbf1k zc9c jepn+mate of umg:k 9xzl n)ckzpf37m; kn 1*ben.cju rw22+$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerates at t -i,xkro shk5; p3jcix*fw3ul7y2ao,he 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 acceleratn.u b+ mq(yfv1es 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 accelerasa83m 4vnolt kq44n7 ljt3o r1tion of 4qtvklrtlj 3nns 48m1oa437o $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 5.7 m/s experib yo:5wr2xzreo :l,ku( z qq skn,1t,*ences a constant acceleration of (ku,q5 s,:1nz rlw,q2*oxkoz ty: ber$3.4 \; m/s^2$. What is the cart's displacement during the first 8.6 s of its motion?

  A bullet moving horizontally to the righc+ j(arnvu8t9 o6 sc+vt (+x direction) with a speed of 391 m/s strikes a sandbag and penetrates a distance of 14.ocnvt 9 r( s8+6v+jauc33 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched fttt3r)io zt boy+(q+/ rom a catapult on an aircraft carrier. It reaches a speed of 42 m/s at the end of the catapult,(yb /qtri3t+to oz+t) 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 . a c8c07sioj 0,kenh.+bkiulconstant acceleration of $2.0 \; m/s^2$ for 10 s, then travels with constant speed for another 10 s, and then finally slows to a stop with constant acceleration of
-$2.0 \; m/s^2$. How far does it travel?

  A car goes from 40 m/s to 80 m/s in a distance of 200 m. Whataj(/bmb d-t *+evfgs7 is its average acceleratios v-a/ (et*mbb gd+j7fn?

  An object starts from rest and undergoes unifur i dk+c35bsh-+9xk iw 7z28hv6ftg worm acceleration. During the first second it travels 5.6 m. How far will f bgrti xws3whdz-k i2++cvh7 k5u896it travel during the third second?

  An object is moving in a straight line with constant acceleration. In gfg9+oed:hhx()30wfytefx 1itially it is traveling at 16 m/s. Three seconds later it is traveling at 10 m/s. How far does it move dur w0:fx +x hetgygd1 f9o)(ehf3ing this time?

  A car starts from rest and accelerates univ4lze5 p*c4rkformly 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 decelerate at abou :rlyyd-h i6+ft $5.0 \; m/s^2$ 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 l4;hfiiu 91qwie m06xi ight turns green, a car that has been waiting at the intf xiwmieh;16 49u0 iqiersection 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 a speed of 12 m/s on theqs we3o,0qq)f surface of planet X where the accelera)oeq3qs wq, f0tion due to gravity is $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown upward with a spevr ffajz4 .),ied of 12 m/s on the surface of planet X where the accelaf r,fzv)ji.4eration 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 skr m 9end8oxxo.*0ih7peed of 15 m/s on the surface of planet X where the acceleration due to gravity 7i90n.k8oox x*med hris $2.5 \; m/s^2$. How long does it take for the object to return to where it is thrown?

  An object is thrown upwoc)0:6 qhxzyg0 2jhj hard with a speed of 14 m/s on the surface of planet X where the acceleration due hjjzc:x0g 0 oq6 2hhy)to gravity is $3.5 \; m/s^2$. What is the speed of the object after 8.0 s?

  Human reaction time is usually grea+/f jbo7oz vrwbk0aie:04 ii/ter than 0.10 s. If your friend holds a ruler between your fingers and releases it without warnife/ zvb:4 aioi k/7ijo+rwb0 0ng, 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. What is its velocimob*u-9u:c tynh+ 1;tqdxg9 -x1rt aety after 3.00 sutoq*ytx 9bc+xn; eh1 -d -r9mau:g1t?

  A bullet shot straight up returns to its starting point in 19 s. What is wvp.r*j ( ud7mthe initial sm w(ru. 7d*jpvpeed of the bullet?

  A ball is thrown straight up with a spe4p:wr6sks2w) qdg c1jwmv9b 4ed of 36.0 m/s. How long does it take tom q) 2p wwdg9 c4s4bkjw61vrs: return to its starting point?

  A ball is thrown downward from the top of a building with an initial speed of utat(yuh1+yryrj--( 17 m/s. It strikes the ground auay-(jr- yy 1t(t+ruhfter 2.9 s. How high is the building?

  A ball is thrown str0h.-my+w t: s6 iqskgc6bbc d3aight up with a speed of 30 m/s. (only fill in numerical value in thwdb-s . hi6s kg3b0cy+:qtc6m e 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 straightc rnwuq(5 ahv.:a 1m+t up into the air with a speed of 21.0 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 6 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 6.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is the velocitybto f6t5s )/xpd)2go y at t = 1.0 s?

  In Fig. below, what ismr v xzwl:ffwa6r*5f j,;i1 8a the velocity at t = 2.5 s?

  In Fig. below, what is the velocity at t sh5e(l:q ( fz tq.m :j-ivjowpk )1lg,= 4.0 s?

  In Fig. below, what w6yp, d+xesixv: , :ssis the velocity at t = 5.5 s?

  In Fig. below, what is the average velocity from 0 tr2(rqyj*clzq5i: 5 n qo 4.0 s?

  In Fig. below, what is the x4*2;mfv jrk te8jtu 5average velocity from 0 to 6.0 s?

  In Fig. below, what is the acceleration s5r h rlit v2ku4lou7(nr /8h1at 1.0 s?

  In Fig. below, what is the acceleration at 3.0 srrmwi 9xe3iut. e.-k-?

  In Fig. below, what is the average acd.m l;oz xiw00celeration from 0 to 5.0 s?

  In Fig. below, what is the average accelerationqp(1y)zo z0ce from 0 to 8.0 s?

  In Fig. below, what is the displacement from 0 to 8.0 s?8sl qb9ts t, *0ekb7jl1pq9fw

Does a car speedometer measure speed, velocity? {speed|velocity}wg-uv/0 eydy- kor6t4

  An object can have a varying speed if its velocity is ra-*4yr;xk gsconstant.

  The velocity of an object can be negative when itn/ex.j im h+6w8p :yvc6 o-nfvkr+onvi*n6 a (s acceleration is positive.

  If one object has a greater speed than a second object, the first must 6qknel3:l e:ho0kv d4have a greater acceleration.3edlo kkl nhe04:v: 6q

  Two cars emerge side by sid bfv2lx5; ym5xe from a tunnel. Car A is traveling with a speed of $60 \; km/h$ and has an acceleration of $40 \; km/h/min$ Car B has a speed of $40 \; km/h$ and has an acceleration of $60 \; km/h/min$ . Can A will pass car B at the instant they come out of the tunnel.

  An object can be increasing in speed as its acceleration decreasyk/0 y o)432vaoxle7i.llxh/n.b cp tes.

  A baseball player hits a foul ball w6w g *2m:nt4hfp0 i3zd(dnke straight up into the air. It leaves the bat with a spep 0d4whf*i :endnz w3g(kt 2m6ed 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 tlf1r;kx 3i+ nde2/pcis happening to its acceleration, how does it change if air friction is ignore3d+t rx 1;2 enkifc/pld?

  As a freely falling objey6cp ;2 7pjopy wug,xk*/e(kect speeds up, what is happening to its acceleration, how dp67e/gywxcp y kk2*p(,j; ueooes it change if air friction CAN NOT be ignored?

  An object that is thrown verticalll bjb:18cgeg 5y upward will return to its original position w g: lb5e1bg8cjith the same speed as it had initially if air resistance is negligible. If air resistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzero acceleration at thep,mpuu 3j4 y5v same time.

  An object can have nonzero velocity and zero accelerl /mhi ht( ,,q7lupdq,ation at the same time.

  An elevator moving from the second floor to the fifth floor makida )*fi6 kmhm;kg(y*bng no stops along the way has zero acceleration all the tyh mkb m* dkg;)a*6fi(ime.

  A rolling ball moves from nsf*e: emy.,rq n 31dn$x_1=2.0 \mathrm{~cm}$ to $x_2=-6.8 \mathrm{~cm}$ during the time from $t_1=1.2 \mathrm{~s}$ to $t_2=5.5 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-4.7 \mathrm{~s}$ is at $x_1=2.5 \mathrm{~cm}$ and at $t_2=3.0 \mathrm{~s}$ is at $x_2=7.7 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps around a quarte0oukatt 4+b+cn/wl;l r-mile ($1 \; mile = 1609 \; m$) track in a total time of 12.5 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 straig nk,u48xrsfu 8ht line, moving 88 m away in 9.5 s. It then turns abruptly and gallops halfway back 88fs,unu4x rk in 4.7 s. Calculate (a) its average speed  (数值)  $m/s$ and (b) its average velocity  (数值)  $m/s$ for the entire trip, using “away from the trainer” as the positive direction.

  A car accelerates fromh xc+ -.ri-yct;an- xs $11 \; m/s$ to $25 \; m/s$ in 5.6 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 mgk- ,3*pgalg$20 \; m/s$ to rest in a distance of 80 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach aq-nw2hnv9yx lk.n6w . speed of $27 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.5 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of pfs-k30g o73*lqf ywk the blocks to essentially top speed abouskl03 7-g*qwoffp3y k t $11.4 \; m/s$ in the first 13.0 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 unifor9ho optjg c2ts;+i ke8q2n).ut 7w y,hmly from a speed of $16 \; m/s$ to rest in 4.39 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves skid marks 92 m ws:vzxuhx); u:u m 9d5uy;wy2 long on the highway. Assuming a deceleration )x ww:;uhd yy5xzs:uv u2mu;9of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a trl5shx+ h46gs l5si, mguck 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 is k/ z5. 7hlbb9nb4n(ycp8uwrun in less than 30.0 min. After exactly 27.0 min, there are still 1100 m to go. The runner must thsb 9n b7pcb4kw i/8l nz.(5uyhen accelerate at $0.20 \; m/s^2$ for how many seconds in order to achieve the desired time?    $s$