Suppose that an object travels from one point in space to an. vm* -l6gmdjoother. Make a comparison between the d mvog m-dj.6*lisplacement and the distance traveled.

  When is the average velocity of an object equal to thnfcq.:vw)-n u e instantaneous velocity?

  A new car manufacturer advertises that their car canhz 5 qrokp8lr;jp82:7cy+vg l go "from zero to sixty in 8 s". This is a descriptiycj 8lrg 2ppk8ozv:l;h5q r +7on of

  An object moving in the +x axis ex,d jm ja5o50hrperiences an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x direction) begin0d9hop7-/zvo3 m f9xi *afkz ps to slow down as it approaches a traffic ligh oxafdpiph/mf 3 9 -v*70oz9kzt. Make a statement concerning its acceleration.

  Suppose that a car tra1qumsdw)nt.3u(:b w e veling to the West (-x direction) begins to slow down as it approaches a tuwnqwt (m3 eb) 1.s:udraffic light. Make a statement concerning its acceleration.

  Suppose that an object is moving with a constant velocity. Make a statementgwsqh oo2h48 j8uu7.h conceu2 hhw 7o.gjqsuh8 84orning its acceleration.

  If the velocity of an object is zero, does it mean thaqsbu:4 j(n*84c,d ij.c jdw hqt the acceleration is zero? Support 48in*4 ,h(d du.j qjc:qwbcsj your answer with an example.

  Can an object's velocity change direction when its acceleration ied 8pd :j t0 dx* jqh;)vzjj5.x4u2hyds constant? Support your ans jvjq*8dd0d .d4y t jpz;:5)juxehhx2wer with an example.

  Suppose that an object is moving with const2gd5u)max 7s sant acceleration. Make a statement conces 7dasu 5x2gm)rning its motion with respect to time.

  Can an object have increasing speed while its aczlz gl zr143k,- choi6celeration is decreasing? Support your answer czzr,lg3ki h- ol641 zwith an example.

  Suppose a can, after an initial kick, moves;( bfzijo:hby.i1u 8h*p4agx up along a smooth hill of ice. Make a spii b oagbz :*xf.(h8j;41yu htatement concerning its acceleration.

  Under what condition is average velocity eqwj) pm+ r34kqbm gqel4m69p 9eual to the average of the object's initial and final vjp +4eq9mbe43)wmr69kp mql gelocity?

  Objects A and B both start at rest. They both accelerate at the same rate. f.;c7l2+yv h1ihwzo su6 jhl, However, object A accelerates for twice the time as object B. What is t hjls+12hh.7o,;6w vi lcufzyhe 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 r)/e tdjnl4qrsk; 2 9rbate. However, object A accelerates for twice the time asenr9d2kjqr )l/ s4; bt object B. What is the distance traveled by object A compared to that of object B?

  When an object is released from rest and falls in the absence of friction, w:zbex8stvre p( e:8o5hich of the following is true concerning its motion?8ep(r 8zt5bxvso e:: e

  When an object is releasef 6 qc( )q,gttl)trwym:el.7 ad from rest and falls in the absence of friction, which of the following is true concerning its motion?l(q:wt )7 lqfmce t.ga y)t,r6

  Suppose a ball is thrown strais5 isfp(6at7dnt)k;x/s 8 f wwght up. Make a statement about the velocity and the acceleration when the ball reaches the highes tf n)67i ;58/s sfa(tpxwdskwt point.

  Suppose a ball is thrown straight up. What is its acceleration just befb0b e/v(g qj1mxws 7p:i1vq; bore it r1 qjwv: ieg(qb1b; 0mbs7v xp/eaches its highest point?

  Suppose a ball is thrown straight up, reaches a maximum height, then awrc9 1aut: ;s1 ( vhe)b2cpdefalls to its initial height. Make a statement about the direction of the velocity and acceleration as the b;2tc1sph:9 )a ce1ebda( wvur all is going up.

  A ball is thrown straight up, reaches h 5vlm;sg3i1 ar. kw 89yj5dozs9y4d sa maximum height, then falls to its initial height. Make a statement about the direction of the velocity and acceleration as the ball is co5ksmdr ; hy53 18sjd9. wza9lsvy4og iming down.

  Suppose a ball is thrown downward in70xvdd 5a,mpm1yf5sqnb wl8: the absence of air resistance. Make a statement concerning its accelerationa,8sd71 d:v5 px wbl0qy5m mnf.

  Suppose a skydiver jumps from a high-flying plane. What is her accelerap(d4, knhmkn 3tion when hpmk,3kn4d (n she she reaches terminal velocity?

  A ball is thrown ver irvt0 7ebqwjv,5r*h. tically upward 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 ball? (How many times *i qhtvr,7bervw5j0 .higher does the second ball go than the first ball?)

  Ball A is dropped from the top of ad*kyw *9ydq3 a building. One second later, ball B is dropped froya dqdk 3*y*9wm the same building. As time progresses, the distance between them

  Ball A is dropped from the top of a building. One second later, bay ot(+7oi+l d-vhlo :g .gqy4ill B is dropped from the same building. As time progresses, the difference in their s-l7 iqot.gg:oo4lid+y (vh+ypeeds

  Two objects are thrown from the top of a tall building. One is h)vzwzec/an2y dvb 6j *e (-q0thrown up, and the other is thrown down, both with the same initial spee6(a0 ve h*wz vq/2jd-ycn)zebd. What are their speeds when they hit the street?

  A brick is dropped from the top of a builx*ed*w)z4tkm+gr rnb 7.ng6qding. A second brick is thrown straight down from the sameqm.+* xz*rrntn)6 dg7w 4bkge 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-zero velocity in the +x a l:2wfqnj1xp m 3krlfvnq(93fa ci4 .+xis. The position vers31+n fan4rkv3 qmjl (f:i9fp xq.cwl2us time graph of this object is

  An object is moving with constant no d);. kru;8zfvsx ;gxln-zero acceleration in the +x axis. The position versus time graph of thiskx )xr 8gdul.;s ;vf;z object is

  An object is moving with constant non-zero velocity in the +x axxek4.lrork h j e0.)szi-qqp 11zn+ 2uis. The velocity versus time graph of thuqerjkrsn.x+qpohzz0.l4 11-ik e2) is object is

  An object is moving with constant non-zero acceleration in the +x axis. Thep5* filbro+ dt4s6v q 7kaok:: velocity versus time graph of this object isvrq dib6 45op*k:lta:+7ok sf

  The slope of a position versusrpc3c5oul*4 v1ge ;rd time graph gives

  The slope of a velocitko6m zn+ odz.)t0cyz+qf pd((y versus time graph gives

  The area under a curve in ay x h/*(0hr bd78hsxrmn acceleration versus time graph gives

  The area under a curve in a velocity vers-gu k *dq9uxhdvdso76o.w )p *us time graph gives

  If the position versus n itw,1clmonz jdsb7k(t:k*t+(n ) t/time graph of an object is a horizontal line, the object j zt(nt/ k+idttc ,*nw1(7 )s bl:onkmis

  If the position versus time graph of an object is a vertical lyyr+:q 7yw p:j aabd,2ine, the object isy a7:+,bwap:qd jr2yy

  If the velocity versus time graph of an object is a horizonta3mf8st3l nl*crz::) fzdj+ dll line, the object isn8s 3d)z*rt3 jdm+l :flzc:lf

  If the velocity versus time graph of an object is a straight line makiiydy;a:kd*6ynq; dy(ng an angle of 30 degrees with; yy a;qn:ddy*k(yd6i the time axis, the object is

  An object moves 15.0 m north and then 11.0 m south. Find both the distance jl;hs7pzrd y9y i.)w 1lf40tgfvi:9 r traveled and the mag i.zrg jpf9yh)4if0ld;r tv:ys9w71 lnitude of the displacement vector.

  A boat can move at 3p*ft fv1qm0p g, t-yf/0 km/h in still water. How long will it take to move 12 km upstream i/t0qpvp g1-ff t,*m yfn a river flowing 6.0 km/h?

  55 mi/h is how many giqp goq1mm voy),s)(;q .gf+m/s? (1 mi = 1609 m)

  What must be your average speed in order to trav3l+l.nka8 xjd el 350 km in 5.15 h?

  A runner ran the marathon (approximfs9)maqa9 oafx.+-6a 6rto uhately 42.0 km) in 2 hours and 57 min. What is the avom.ar6) aof- q9 us9+xfa6ahterage speed of the runner in m/s?

  A car travels 90 km/h. How long does it take fv+y*(a6f bv lxor it to travel 400 km?

  A ly (light year) is the distance th:3 )wp id5zh*al.es fqat light travels in one year. The speed of ligafeq:i5sp wz d)*3.hl ht 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 ttb.wqv9 mvm*o02yv 0d1pqq ) road and you look to the side for 4.0 s, how far db)*q 29vp1modm0. 0tyvq tv qwo you travel during this inattentive period?

  If you run a complete loop around an outdoor track (400 m), n /9yqzm6t g;yin 100 s, your average velo 6yzg/ q9ym;ntcity is

  A polar bear starts at the North iu0as/h)te/ nPole. It travels 1.0 km south, then 1.0 km east, then 1.0 km north, then 1.0 km west hu na)/i/0testo return to its starting point. This trip takes 45 min. What was the bear's average speed?

  A polar bear starts ad1b kn7fegs8 ifck,k9h53:h xt the North Pole. It travels 1.0 km south, then 1.0 km east, then 1.0 km north, then 1.8bkhk eh7f :s3 xfki g5n9d1c,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 wdx5 stn71e mp f8xmcg ,w9i6t5eekend from school at 55 mi/h for 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 far is your ht1w6f ecxs9tp mx55d,i n7m8gometown from school?

  A motorist travels 160 km at1g+f w6w )xxwt 80 km/h and 160 km at 100 km/h. What is the average speed of the motorist fwf 1+g6w)xwx tor this trip?

  A motorist travels for:yww divil7 845.zw gv*gvn2)tixdgwm6 h3z; 3.0 h at 80 km/h and 2.0 h at 100 km/h. What is her average w;hwmi4lzg w vt5gdv 8xw*g 7z2vi)6yid n3.:speed for the trip?

  An airplane travels at 300 mi/h south 0i ,nv 32ifanzfor 2.00 h and then at 250 mi/h north for 750 miles. What is the average svifn 03in2, zapeed for the trip?

  In a 400-m relay race the anchorman (the person wh i 0*oxc3yuyq 0-lusl;o 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 i*xyll0y uc-os0qu 3;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 s)8:k rv 4msaudmw 5nn,top after 10 s. The car's average velocity durin :4kn)uasmw,m d 8vrn5g deceleration was 55 km/h. What was the car's deceleration while slowing down?

  An airplane increases its speed from 100 m/s to 160 m/s,jt,d*)a8 d s.mt vgk9r at the average rate of .) sgj r t8mk9*tdavd,$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h accelerates at th hh:wx (z1iji3e 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 accelerates atkzgf9 (z,ap*ted73 ov $4.0 \; m/s^2$ 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 constan b)0ylh3bvaudb + 6/qvdn3,cnt acceleration ofb0al hv bqvddn6ny/+,3)cub 3 $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 6. pxpi/, weh qrovw9*/9kubetts2914w6 m/s experiences a constant acceleration o9vwwu1o/rpe4swq , bept*2 x9thi 9/kf $2.7 \; m/s^2$. What is the cart's displacement during the first 7.0 s of its motion?

  A bullet moving horizontally to the right (+x direction) with a speed of 455 o( q +f2jj/twzm/s strikes a sandbag and penetrates a distanz2jfot(/+wj q ce of 44.34 cm. What is the average acceleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult tvj.;ge9b p(x5 gn0ji on an aircraft carrier. It reaches a speed of 42 mgg j;9bjv5.nxeti 0(p /s at 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 3f)1 a:a7:ouhn6v-deypl*bj h w2qhzwith 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 m/s to 80 m/s in a distance owb-3eo r )+ 4tdkf*qzmf 200 m. What is its average accelera*-tw) 3+qke4bmd froz tion?

  An object starts from rest and undergoes uniform acc9 wntv:ju7v 6aap-,bx eleration. During the first second it travels 2.9 m. How far will it travel during the7:6jaa btvx,w-pn9 uv third second?

  An object is moving in a straight line with constant acceleration. Initially gm3,u9)2 fgjk.lej gfit is traveling at 16 m/s. Three seconds later it is traveling at 1fk g.euf)2m9ljg,3 gj0 m/s. How far does it move during this time?

  A car starts from rest and accel3.paj6 v 9 g4+jcsb(zyj-l bhwerates 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 r9sbb fku3 8;ron 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 that hkx 0oyto 6w r;8-k1emracmo70as been waiting at the intersection starts ahead with a constan 8m; kxm0-ort6coroa ew0k71 yt 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 onkcqnk:: 8 tk :1p.xqtk the surface of planet X where the acceleration due to grav8c pkk :q.nx t:k1:ktqity is $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown upward with a speed of 1cemcq4.p6d j. wqyu 912 m/s on the surface of planet X where the acceleration due to gram 41jqq.dceu c 9y.6pwvity 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 speed of 15 m/s on the s((pfqvnd6 6qb9* e rvcurface of planet X where the acr(96e*qpbv dv(6 nfcqceleration 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 upwa.t iylx-tt nk 9pmf+-)rd with a speed of 14 m/s on the surface of planet X wherepl 9-+i.n y -tftmtxk) the acceleration due to gravity is $3.5 \; m/s^2$. What is the speed of the object after 8.0 s?

  Human reaction time is usually *bfc/o *g 9/;nn-bhb5vxqs gzgreater than 0.10 s. If your friend holds a ruler between your fingers h/ ;oq5b sn *9xzvbngg-b/f*c 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. What is its velo1sjd+rbz+bn* hd *cp1city after 3.00 s? nhpd s*1rdjb1+ c+*zb

  A bullet shot straight up:/ (cdjwcb -cmt n5o6h returns to its starting point in 18 s. What is the initial speem( cct-/n b oh56:wcdjd of the bullet?

  A ball is thrown straight up with a speed of 36.0 m/s. How long doe n,v82q jvz(q)4zbx wmcz+k5 2p1gfr ns it take to return tr2nzfz4wq gj2zc8mv5 )qn+ v(xp 1k b,o its starting point?

  A ball is thrown downward from the top of a building with an initial speedh a96;dlt4oln of 12 m/s. It strikes the ground after;9to6 anldh 4l 7.0 s. How high is the building?

  A ball is thrown straight up with a speed of hnuq hzp: 5c8+ cjw1c)30 m/s. (only fill in numerical value in :z 1c5uncqhjh+wc8)p 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 36.7 m/t wv*e / a+qttpn8//jis. (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 10 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 10.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is the velocitywx*,lp;4g fvc rn6:h z (6uycg at t = 1.0 s?

  In Fig. below, what is the velocity at t = 2u izvx 7068,f7-fhrvaw 5wk tg.5 s?

  In Fig. below, what is t:3 gyupof4lc+8yxt/sq cn -g9he velocity at t = 4.0 s?

  In Fig. below, what is the velocity at t: s u:jdjpa)6h xm47c:h.s jdr = 5.5 s?

  In Fig. below, what is/z 1tpe.) hf(.y koeol the average velocity from 0 to 4.0 s?

  In Fig. below, what is th)j wxe4pwr l9;/ erpt)e average velocity from 0 to 6.0 s?

  In Fig. below, what is the *dv0tybkuox,7ul; k+ai58 rkacceleration at 1.0 s?

  In Fig. below, what is t zky93ajhvhr19-5ww yhe acceleration at 3.0 s?

  In Fig. below, what is the average acceleration from 0 to 5.0 r l-om)0mrzn 6s?

  In Fig. below, what is the average acceleration fac8 ymfj7bpbz 8p25 3hrom 0 to 8.0 s?

  In Fig. below, what ismtufyc)qlgk+hi)bz oj ux:e-0 9,y 59 the displacement from 0 to 8.0 s?

Does a car speedometer measure speed, velocity? {speed|vedu+ ir* 6a ur(qz:(dn-ng kdc:locity}

  An object can have a varying speed if.q vsco h;nwi2rc05 w( its velocity is constant.

  The velocity of an object can 4+tfmqdd c11gbe negative when its acceleration is positive.

  If one object has a greater speed than a np mp-d,mb5 p)py+b0 usecond object, the first must have a greater m ,0y)pbp5+p u-d pbnmacceleration.

  Two cars emerge side by side from a tunnel. Car A is traveling witgmn l6d*61 ajbh 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 ac) 33(vuk3mdg;t8 ur sxam3ggh celeration decreases.

  A baseball player hits a )vv fq o+:+7liif.x7hdt sb/mfoul ball straight up into the air. It leaves the bat withi7b:o.s7vx+v lm+f dtihqf /) a speed of $120 \; km/h$. In the absence of air resistance, how fast will the ball be traveling when the catcher catches it?    $km/h$ (please only fill in numerical value in the blank)

  As a freely falling object speeds up, what is happening yq)vp/a r3sx)*jd. c9y)7mvm6evbao to its acceleration, how does it chansm/q)yr9ja p 3a*.b)y7cmv vo6ed) xvge if air friction is ignored?

  As a freely falling object speeds up, what is happema,fjign0xryjf) 3m 1mv ng4s(63b) ening to its acceleration, how does itfmr 6a,iv0g3j4fsnj(ex bnm m)1y )g3 change if air friction CAN NOT be ignored?

  An object that is thrown vertically upwardu)c jdthr7ij- .5b0:uk gpa y-fkr,6e will return to its original position with the same speed as irf-.pgkd, i0k -r5yjjh c7:6)aetuu b t had initially if air resistance is negligible. If air resistance is appreciable, how will this result be altered?

  An object can have zero velc2bpdc 9;k4 v8omlo) qocity and nonzero acceleration at the same time.

  An object can have nonzero velocity and zero accel ncpqsl- qaazecn .nh5 15v2-1eration at the same time.

  An elevator moving from the second flld lp,q, 6js*toor to the fifth floor making no stops along the way l , j*tq6sp,dlhas zero acceleration all the time.

  A rolling ball moves c. m7nk(q k hdp8i68di-drt ,ufrom $x_1=2.1 \mathrm{~cm}$ to $x_2=-7.6 \mathrm{~cm}$ during the time from $t_1=2.0 \mathrm{~s}$ to $t_2=5.8 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-4.2 \mathrm{~s}$ is at $x_1=2.1 \mathrm{~cm}$ and at $t_2=4.0 \mathrm{~s}$ is at $x_2=7.4 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight c v u2-ms 0-b.x(f6sgpzxcia4a omplete laps around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 11.4 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 ag)a6 95ovk8jn4i rpkh straight line, moving 98 m away in 8.0 s. It then turns abruptly and gallops halfa kk)4povn 5ri jh86g9way back in 4.8 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 fro.kbsrf x0hp 13m $10 \; m/s$ to $24 \; m/s$ in 5.5 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 fromn3djt kp:m- j6s2u v+r $21 \; m/s$ to rest in a distance of 69 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reach a spe0 hgi n3cahe(/ed of $26 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.1 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst ja re,/a.ik7l(z g vw). x1klzout of the blocks to essentially top speed about zrgk j.. /a()akiwe xvl,7z1 l$10.6 \; m/s$ in the first 13.6 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 ahr2q18. l o zu4s8pxhj speed of $19 \; m/s$ to rest in 4.66 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves zic + lyb9y4 uya1c8b7skid marks 92 m long on the highway. Assuming a decz+ybc 7 i914 uybalyc8eleration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truekcyaa37bzv(tepy ( a3 51 2tzck 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).    $m$