Suppose that an object travels from one point in space to+*g.s7*2u oarssi fv: g2 fjxi another. Make a comparison xi7+f*o *g.agusr2:fv sij2 sbetween the displacement and the distance traveled.

  When is the average velocity of an object v0u3z . )et8+icxx cvoequal to the instantaneous velocity?

  A new car manufacturer advertises that their car can go "from zero to sixtyg.2k:vetys rvqt1 -aa.;yzxcq8h 7 s0 in 8 s". This is a desc aq;arhy-q0ce.vvx 8: 7sttgk1yz2 s.ription of

  An object moving in the +x axis experiehunfqp: p l. 5a.o.80qkcm s3inces an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x direction) begins tk76lqfvhb 9 +eo slow down as it approaches a traffic light. Make a statemeq h97 ekl6fv+bnt concerning its acceleration.

  Suppose that a car traveling to /q,hlrg 6f.7a:lwdpb the West (-x direction) begins to slow down as it approaches a traffic light. Make a statement concerning its accel 6hard7wgf: l/p,bq.l eration.

  Suppose that an object is fdosc a/bl; vds v8vd+,*mo 7 -sp/l-amoving with a constant velocity. Make a statement concerning its acceleratd* d+m;-sloa/s-8cbds /fv , vpl7a ovion.

  If the velocity of an object is zero, does it mean that the acceleration is j3rgni x569i)bv wr1rzero? Support yjrrv36n1wi 5rg ib)x 9our answer with an example.

  Can an object's velocity change direction when its acceleration is constant3rn,+0fv p sks? Support your answer with an ep+03 r ,ksvnfsxample.

  Suppose that an object is moving wlj:m rxmkw5f.o-k) ym:6qls5 ith constant acceleration. Make a statement concerning its motion with respect to tmj 6 rw5x.kfqko)sm : l-lm5:yime.

  Can an object have in0.e(rx *c;vkom9dg8aq b9o lpk ;db*;bjs .v dcreasing speed while its acceleration is decreasing? Support d*;vmk*e(99oaxd cqkj borl8;0b .b;gp v.s d your answer with an example.

  Suppose a can, after an initial kick, moves up alo g f6jnvv75l;nng a smooth hill of ice. Make a statement concerning its accelfn;7gnjvl65 veration.

  Under what condition is average velocity equal to the averagevv +pqgv-n+q1 of the object's initial and final veloc -+vnvqq+ pg1vity?

  Objects A and B both start at rest. They bothnstb-(13qv h*y:tq0 h t6pdxo accelerate at the same rate. However, object A accelerates for twice the time as object B. What is the final speed of ot :x10 oqh tnpb 63ysh*vqdt(-bject A compared to that of object B?

  Objects A and B both start from rest. They both j+p72xnsv. 03q :lzeoofcb p 2accelerate at the same rate. However, object A accelerates for twice the time as ob ps2. o2z7lpn0e cxjoq +bf3:vject B. What is the distance traveled by object A compared to that of object B?

  When an object is rel7- psc21fhcjmi qm6za6,be *qeased from rest and falls in the absence of friction, which of the followin 6z67 qmspe1 acimch*,-bqj f2g is true concerning its motion?

  When an object is released from rest and falls in the absence ofbfk db2v11nyl v5:9 ,gzz:,3lwmn ozs friction, which of the followin gz:5mnd3oz:f1vbw1s29l ,v nbyzl,kg is true concerning its motion?

  Suppose a ball is thrown ,q.p*hs9c ,cqwo,pi ingi6p - straight up. Make a statement about the velocity and the acceleration when the ball reaches the csi, ppg.niq-,q,* w9cioph6 highest point.

  Suppose a ball is thrown straight up. What is its accelerateu8s 5(t5awd iion just before it reaches its highest puw5aie58dt s (oint?

  Suppose a ball is thrown strai.ox x4d6/g qv 1e tn vr:n2jrv,q4fpc+ght up, reaches a maximum height, then falls to its initial height. Make a statement about the direction of the velocity and acceleration as the balrnx,ptvc nj 124vg6:rq q+ /vo f4.dxel is going up.

  A ball is thrown straight up, reaches a maximum height, then falls 4k.p9zrd 8l e5bi lt2oto its initial height. Make a statement about the direction o92o8 5k ldebz i4trlp.f the velocity and acceleration as the ball is coming down.

  Suppose a ball is thrown downward in the absence of air resie; ci.mm k;ygp9n6h1 m 1ylao8stance. Make a statement concerning its a9eymkgi1yhn lm8c;6 ; .mpo1acceleration.

  Suppose a skydiver jumps from a high-flying plane. What isymqye u3l+ *:b her acceleration when she she reach*ylyq e3b+: umes terminal velocity?

  A ball is thrown vertically upward with a speed v. An identical second ball isrwgk 3 0:p njep8z6(oe thrown upward with a speed 2v (twice as o rpk6j8z0e(gp e3n:wfast). 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 t95b6 vqpvy*ma qcy6 ls a/lw:.op of a building. One second later, ball B is dropped f 6:la vmqwa5p/*yy9l sq.cb 6vrom the same building. As time progresses, the distance between them

  Ball A is dropped from the top of a b.e2* h srki:kox on):ruilding. One second later, ball B is dropped k)skr *:.irooxh:e 2nfrom the same building. As time progresses, the difference in their speeds

  Two objects are thrown from the top of a tall buildumyw9+flzwdq827r 9 bing. One is thrown up, and the other is thrown down, both withqf9wdr7 +yl29zm wb8 u the same initial speed. What are their speeds when they hit the street?

  A brick is dropped from the top of a building. A second brick is thrown straigh8vxv sdi.,e(t t down from the same building. They are released at the same time. Neglect air resistance. Compare the accelerations of the two brick e,v8.tsd(v xis.

  An object is moving with constant non-zel50/ cw ufaii1adyz6g-o*g8o c2o6itro velocity in the +x axis. The position versus time graph of thiwio 6d2ao/g86zl -iui10go5c*a y cfts object is

  An object is moving with constant non-zero acceleration in the(ip*w*4i)sqb,*p *xn k g ryei +x axis. The position versus time graph ofw,nsi** *ppk4)bi (r ey*gxqi this object is

  An object is moving with constant non-zero r +li 8f/gl4s rd;i,nivelocity in the +x axis. The velocity versus time graph of this object isl4s in;8r/l di +,firg

  An object is moving with constant non-zero acceleration in the +x axis. The vellin 2)ci+ixa c)t w13zocity versuz)iwcx 2ict nli+a1)3s time graph of this object is

  The slope of a position versus time gr a6 prs5y/4-wwxvye: eaph gives

  The slope of a velocity versuxw7.y ei1 8qkrs time graph gives

  The area under a curve in an acceleration versus tim (mgc8;x (nmcb 8il:fze graph gives

  The area under a curve in a velocity versusns llwuq/bye+ce544( time graph gives

  If the position versus time gra.kkw4puxarb1f h( ;v -ph of an object is a horizontal line, the object is4;fk-hp rw uvx1 ab(.k

  If the position versus time graph of an object is a vertical line, the 2h70 toirezv)3+ ovd4/hv/qpnuhrb3object is4+ 0r r/nuzv t/bv3od2e hh)3oviq7ph

  If the velocity versus time graph.i8.m.eih +e uf hw hjtp6n0i/o9rz+ jan,;lh of an object is a horizontal line, the object isj ,fhunpw8 j/tzh.io .e r. +0m+lh;i9n6aieh

  If the velocity versus time graph of an object iau qf8 b dt9dxgib:;k;5qg0 z0s a straight line making an angle ;aq0b0 ukgbdtx8 f5gzq;9:di of 30 degrees with the time axis, the object is

  An object moves 15.0 m j9gq2dr)p-as3x 5iub ed 0r(ynorth and then 11.0 m south. Find both the distance traveled and the magnitude of the displacem dedrbq -59ja02yxurig3p()sent vector.

  A boat can move at 30 km/h in still water. How long will it take to m (pdqae mj;8m:ove 12 km upstread8:;( jqmm epam in a river flowing 6.0 km/h?

  55 mi/h is how many m/s? (uedmx i 66e(c.s: 5u+9iqmksmf3r 2bb1 mi = 1609 m)

  What must be your average speed in order to travel 350 km in 5.15 ac4zx sg )6*we.z) rlgkgai/) h?

  A runner ran the marathon ;8sn qlc8ef+v*d0- xr wa x)id(approximately 42.0 km) in 2 hours and 57 min. What is8fadd e*rin ;- v+)xclswq08x the average speed of the runner in m/s?

  A car travels 90 km/h. How long does i q u7cju ;5.s ool+b;knuqo88lt take for it to travel 400 km?

  A ly (light year) is the distance that light travels in one yc(xf+g.ecu+d;cjqkxt 7dpsx9t/ m c33 kz,i0ear. The speed of light kdxqxzx 37tjt (m,fd +9cc3+ ;ck.cs/epg0iuis $3.00 \times 10^8 \; m/s$. 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 fxd gihm .woy*ti)/ jhw; n sv(*v;2q:ior 4.0wvig h2* ; :qywinm.xt;/*dh j )soiv( s, how far do you travel during this inattentive period?

  If you run a completrwh2 mmo6z4. dbxa 05:qure5o e loop around an outdoor track (400 m), in 100 s, your averagee0.4m zarwu5 d:5hbxmr6q oo2 velocity is

  A polar bear starts at the North Pole. It travels 1.0 km south, then 1.0 km eqhg 4u/ o9yod z1z-5xoast, 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 speed?5oz -qzyx/dgh 1o4u9 o

  A polar bear starts at the North P1:7z sbiz przmz a4.kn6gz9 )h*-ykenole. It travels 1.0 km south, then 1.0 km east, then 1.0 km a.- g)hmky z:zbrs4 pn71* kne6 9zizznorth, 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 schosw k .bib)6nw2ol at 55 mi/h for 110 miles. It then starts to snow and you slow to 35 mi/h. You arrive home after drivings6i2wk.nw bb) 4 hours and 15 minutes. How far is your hometown from school?

  A motorist travels 160t6t wqio pz0 g5e)k8 3loq((re km at 80 km/h and 160 km at 100 km/h. What is the average speed of the motorist for8 pq6tq 3ke(e5 ri0wzto()l go this trip?

  A motorist travels f z a12+gbmdhmv5:f+buor 3.0 h at 80 km/h and 2.0 h at 100 km/h. What is her average spee:uvbm+z1+a h fmg25 bdd for the trip?

  An airplane travels at 300 mi/h south for 2.00 h and then atbj6jx+ s h 3dohklj445i1nn.w 250 mi/h north for 750 miles. What is the average speed fohoid bx6lwn.k15n sjhj43j+ 4r the trip?

  In a 400-m relay race the anchorman (the person who runs the,ygifxj ps9 *, 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 xj*y,p9sig f ,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 uncxw8hae ib, d6w(i3 qj3x. 6xjiformly and comes to a stop after 13 s. The car's average velocity during deceleration was 66 km/h. What ij.w(3w66,jeqi xa8x xdh 3b cwas the car's deceleration while slowing down?

  An airplane increases its speed ,* ylah vlap 0/w-ipjt06yz5tfrom 100 m/s to 160 m/s, at the average rate of tapi/l- atwjyzv y5 ,6hl00p*$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h acceler- kg:hfu 34xquates 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 accelerat, w)smxw (s/bv0hki( 9log53; ny fxxdes 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. lc7y47:p(m bmwm lv,xyz:a,iutr9 m for 10 s. It then speeds up with a constant acceleration mya u(,xb :l w t7.zyrmi 7m,vcpm:4l9of $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 3.2 m/s experiences a constant acceleratr y-5r jlz6zp0ion of r5r6p0- jylz z$3.6 \; m/s^2$. What is the cart's displacement during the first 8.5 s of its motion?

  A bullet moving horizontally to the rtsml5 y i12yo-ight (+x direction) with a speed of 229 m/s strikes a sandbag and penetrates a distance of 94.46 cm. What is the average acce5loms yi12y -tleration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on an ry9lw +5a/nic aircraft 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, whawiry+5 nc a/l9t is the length of the catapult?

  A car starting from rest moves with constcjoab97 mk 50fv k6iql w.z)+jant 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. What is its average a:ui.dc4 uxi e6cceleration?4uiidxceu:6 .

  An object starts from resr5z 8yr/w zi504gsnclt and undergoes uniform acceleration. During the first second it travels 7.3 m. How far will it travel during the third second 0 /wnrrz85g ciszy54l?

  An object is moving in j0a(u insh+y/ a straight line with constant acceleration. Initially it is traveling at 16 m/s. Three seconds later it is traveling at 10 m/s. How far does it move duriyjs(+0/ hn auing this time?

  A car starts from rest and accelera9:kyk vb+ x2yttes 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 can decelerate at abo9:ydtd7c -)r euyj-lfut $5.0 \; m/s^2$ 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 cn pwyrl.ioi.* :;up;w /a wo.turns green, a car that has been waiting at the intersection stapaiwy p. .iro; lwc*:u/.ow ;nrts 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 w,va.dujd(. h a speed of 12 m/s on the surface of planet X where the acceleration due to gravity isa d,j(ud. .hwv $1.5 \; m/s^2$. What is the maximum height reached by the object?

  An object is thrown upward with a speed of 12 m/s opdghfq4:b1m 03w30 6t lve8tnf vwd:y n the surface of planet X where the acceleration due todnp em3yd:0lw:61 ttv3fg 4 w8b0fqvh 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 speed of 15 m/s on the surfa,q hu.- l lnm02fk(gnoce of planet X where the acceleration due to gravity nl-nmk.lg2uh(,0 o fqis $2.5 \; m/s^2$. How long does it take for the object to return to where it is thrown?

  An object is thrown upward wirnyof/us4yfcr93q -5 6 n 3keeth a speed of 14 m/s on the surface of planet X where the acceleration d cn3/ufe3e-n 5 q94royfys6krue to gravity 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. Ifc7+f8bw gjpt iyml ekl 9cmy+4+;h5- p your friend holds a ruler between your fingers and releases it without warning, ll9jctf 5h+;-mpp+mybywgkec4 7 8 i+how far can you expect the ruler to fall before you catch it?

  A ball is thrown upward 7 ye7anltx0:8z ynxc-at a velocity of 19.6 m/s. What is its velocity after 3.00 s?ycnzye8-nl7xxa:t70

  A bullet shot straight up returns to its starting point in 9 s. v5j)z +iqnqe z::aqahg j/zul r3. 7z,x)*fqn What is the iniv/euix nf gqj)7,5 zr +:ljazh q.:zaq)*qnz3tial speed of the bullet?

  A ball is thrown straight up with a speed of 36.0 m/ a+ hqkhip6jw,i 820oys. How long does it take to return to its starting poiy8o jpi kwhq62i+a0h ,nt?

  A ball is thrown downward from of og) zttgje9-8a. dgioyc)72o8en)aj1p:hthe top of a building with an initial speed of 20 m/s. It strikes the ground after 3.jy8 ) e)g:gao.1zf7 ojn titgp2-a98 odcoe)h 6 s. How high is the building?

  A ball is thrown straight up with a speed of 30 m/s. (only fi5ir.p-;* gy3 rthzmst ll in numerical val*;t -zr m ph5tiys.r3gue in 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 au 96iruaebeh10 .5xtk ir with a speed of 26.0 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 2 seconds later.  (数值)  $m/s$
(e.) Determine the time at which the ball pass a point 7 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 7.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is 0sr 35 0 ..vgomvaf3hfc8ye tdunh6+hthe velocity at t = 1.0 s?

  In Fig. below, what is the velo63bm qot ,dt4pcity at t = 2.5 s?

  In Fig. below, what is the velocity at t = 4.0 s?bsilf,6i7 ljw731 sqg

  In Fig. below, what is the velocity at t = 5.5 *v,x 5mxa7,py*2nyyfaezii 7 s?

  In Fig. below, what i8k obv2mpt(rsfu6 +7u gt(5mms the average velocity from 0 to 4.0 s?

  In Fig. below, what is the average velocity qb, d*cqfo3 s1/a ;tdsfrom 0 to 6.0 s?

  In Fig. below, what -tvm; dvfqth y,jj37c)3 w)pwis the acceleration at 1.0 s?

  In Fig. below, what is the acceleration fgb 1da7n.//n 5gqxscu5 p4wxat 3.0 s?

  In Fig. below, what is the average acceleration from 0 to 5.0 s?b*2 epbbdth,8gg of/9

  In Fig. below, what is the average acc.e9 j 3ui*miyyqjiuf)m1.e+s eleration from 0 to 8.0 s?

  In Fig. below, what isbg oe5duu4 jro,(i9n kv:yb/ ) the displacement from 0 to 8.0 s?

Does a car speedometer me /khol uhin(h zv5o576asure speed, velocity? {speed|velocity}

  An object can have a varying speed if it k;ornxl78h zdv:b+ 8xs velocity is constant.

  The velocity of an object can be negative wh-dhq7ifl q 0b(en its acceleration is positive.

  If one object has a greate+ -imtwoh csux0zt(fal)y3 :* r speed than a second object, the first must have a grz-x(utf3 ay) who0*+lti:smceater acceleration.

  Two cars emerge side by side from a tunnel.u+ c,csr/hnj+ orz94.+9agclvct )fn 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 r; q4n c1iok)-ah* ayain speed as its acceleration decreases.

  A baseball player hits a,n(cnti6 apv e3zh+m* foul ball straight up into the air. It leaves the bat with a spe+z(3ah,eit*c 6vnn p med 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 its accelerati,k2l210 b gctzxvjd a0on, how does it change if ai 12kg 0xb l,ajdz0tvc2r friction is ignored?

  As a freely falling object speeds up, what isa k3s6cqvku1r/i /,s u happening to its acceleration, how does iras61v ,k3uiq/ s u/ckt change if air friction CAN NOT be ignored?

  An object that is thrown vertically upward will return to it/wwy(/ih(z jc0t6c pb tiw) 2ms original position with the same speed as it had initially if air resistance is negligiblewcb(w(20/hp/ji )tm w6t zci y. If air resistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzero acceleration 5geflg p+,g 3g 7ve6dhat the same time.

  An object can have nonzkb:4hz8oqrqim 612h w*p- cm-p6rfyyero velocity and zero acceleration at the same time.

  An elevator moving from tbu7t ln mh:7v/he second floor to the fifth floor making no stops along the way has zero accelerab/ :7mluhtvn7tion all the time.

  A rolling ball moves fromqa4h( or*g4 t7hy rkq- $x_1=1.9 \mathrm{~cm}$ to $x_2=-7.7 \mathrm{~cm}$ during the time from $t_1=2.4 \mathrm{~s}$ to $t_2=5.2 \mathrm{~s}$. What is its average velocity?  (数值)  $cm/s$ (only fill in numerical value please)

  A particle at $t_1=-4.6 \mathrm{~s}$ is at $x_1=2.9 \mathrm{~cm}$ and at $t_2=4.3 \mathrm{~s}$ is at $x_2=8.0 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complet 9d)9 g*ly+vsjn9qxy oe laps around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 11.5 min. Calculate (a) the average speed  (数值)  $m/s$ and (b) the average velocity    $m/s$

  A horse canters awayqzmrs. y)4sj 6 from its trainer in a straight line, moving 88 m away in 11.3 s. It then turz r)sy4. jq6smns abruptly and gallops halfway back in 4.6 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 e9ul5 ovq7hd8lti sme6c07+4 jj gn(om $11 \; m/s$ to $24 \; m/s$ in 5.9 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 xi a8stv.dll903 bs g)$17 \; m/s$ to rest in a distance of 69 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must reac6km( dhud()ccv6 2 nbkh a speed 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 out of the bl ptv *ar(+xe,vocks to essentially top speed about t x(re+va p*v,$10.0 \; m/s$ in the first 14.2 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 unifor f l(kv8co:m)j +dkpi84rnri) l9pc0y mly from a speed of $20 \; m/s$ to rest in 5.23 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 hl-z o 0xj39vr0a jno;highway. Assuming a h or-vjnlx0zoj093; a deceleration of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$

  A car is behind a truck g 3 voklwtsc3e timk(yf, 1c*4jrg-90zoing $25 \; m/s$ 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).    $m$