Suppose that an objeco rj8v9:0ir xst travels from one point in space to another. Make a comparison betwev8o js0:rrix 9en the displacement and the distance traveled.

  When is the average velocityv..(vy 3drd-qek, - (tsd puai of an object equal to the instantaneous velocity?

  A new car manufacturer z0i ij 7d9 lkig/o/01 n0spiptadvertises that their car can go "from zero to sixty in 8 s". This is a descrig0zt7 1ndkjso/i9i00 lip p/iption of

  An object moving in the +x :p..h/vt8ajjlb 4ys xsf 6n+raxis experiences an acceleration of $2.0 \; m/s^2$. This means the object is

  Suppose that a car traveling to the East (+x dire1c v;c wr* tw(m(np0fqabc*3oi(ld5u ction) begins to slow down as it approaches a traffic light. Make a statlf((waunq;wco0vr3bm1t p 5d i**c c( ement concerning its acceleration.

  Suppose that a car traveling to the West (-x direction) begins to sug16e.s*fr7k4: qt, nu pgbp ulow down as it approaches a traffic light. Make a statement concerning its acceleration.:47ug*6p nu.,stqgrkfp 1eu b

  Suppose that an object is s8h oj.zgm05 zmoving with a constant velocity. Make a statement conoz5gzsh8m.0j cerning its acceleration.

  If the velocity of an object is zero, dn-2 cybg.+ ttcoes it mean that the acceleration is zero? Support your answer with an examplegy-ttc2b+. cn.

  Can an object's velocity change direction when its acce6,c3qp)h ue rsleration is constant? Suppoq,p hr ecs)36urt your answer with an example.

  Suppose that an object is moving witdg--xj 48ad hgh constant acceleration. Make a statement concerning its motion with respect to tid -- jdgaxgh48me.

  Can an object have increasing speed wh e-j0f,0emennpx - 1rnile its acceleration is decreasing? Support your jfx,epr0 m-e-n1 n n0eanswer with an example.

  Suppose a can, after an initial kick, moves up along a smootoomtu:/ q rbplo:jxtp 82350th hill of ice. Make a bq38:po lu:2o motptr/0tx5 jstatement concerning its acceleration.

  Under what condition;nta*naaq8o)0 cv *xe is average velocity equal to the average of the object's initial and final velociovx;aa*e )0nca*8n t qty?

  Objects A and B both start at rest. They both accelerate ar)nyt0(i+x,lqy3k x:l t 3ntl2b k9wdt the same rate. However, object A accelerates for twice the time as object B. What is the final speed of object A compared to that of ob: itdtbqx xt3ny)0k,l +nr(3 29wlyklject B?

  Objects A and B both star h r9lovyns p5kq:)3f/t from rest. They both accelerate at the same rate. However, object A acceleofny:shk/q pl v395)r rates for twice the time as object B. What is the distance traveled by object A compared to that of object B?

  When an object is rel1q 4xfvjvgfmf6 .0 c:o3y 7fgheased from rest and falls in the absence of friction, which of1ghq 3offx 0g7v:j. yvcf6fm4 the following is true concerning its motion?

  When an object is released from rest and fallpayrc1i. eb, ,s in the absence of friction, which of the follo pyb.1,eac, riwing is true concerning its motion?

  Suppose a ball is thrown straight up. Make a sta 3p.wq, pbm(cs/qo5sg r+ d-mn6se:zd tement about the velocity and the acceleradz./rpm:bs d mn36 gss5+,pwq( -eq cotion when the ball reaches the highest point.

  Suppose a ball is thrown straight (qxhf1j,bn6e aov2gbo,xjq +b h.4.wup. What is its acceleration just before it renb,. qj .qa6jv,hobho (f2b x4ew1+ gxaches its highest point?

  Suppose a ball is thrown straight gn2x9:c jdgg ds3kj2; up, reaches a maximum height, then falls to its initial height. Make a statement about the direct;ddjnsg k29g2xg3j:c ion of the velocity and acceleration as the ball is going up.

  A ball is thrown straight up, reaches a maximum height, then falls to fs/z ngj y5 :b.vh(/sxits initial height. Make a statement about the directionz.y5(xvb/s s/nf:j gh of the velocity and acceleration as the ball is coming down.

  Suppose a ball is thrown downwibg n).b88i5m d3qjf eard in the absence of air resistance. Make a statement co8qfd3 )g b58nmije. bincerning its acceleration.

  Suppose a skydiver jumps from a high-flying plane. What is her acceler )h3 -ck+jxd+pfwdkuf-v ;cy0 ation when she she reaches terminal jdw+-fhx3c p+k0c ;)vfdk-yu velocity?

  A ball is thrown vertically upward with a speed v.da4 e puv,62iabh px7wim53u5 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 tivd 5bxwhmu6u,5 p4 32aia7 pehe first 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, ball B is dropn f:uhrp,8uu,ped from the same building. As time progresses, thn,uf:urpu ,8 he distance between them

  Ball A is dropped from the top of a buildingy4df4q3 eo iu0r+. icg. One second later, ball B is dropped from the same buildiyci q4g+u4.03oref idng. As time progresses, the difference in their speeds

  Two objects are thrown from the top of a tall bu* 08p7xtgodg yilding. One is thrown up, and the other is thrown down, both with th g 0t7oy8pxdg*e 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 tlx3f gkig6:9zopq).o hrown straight down from the same building. They are released at the same time. Neglect air resistance. Compare the acceki9. 3xol q6g oz:p)fglerations of the two bricks.

  An object is moving with constant non-zero velocity in the +x axis. Thezs4dgp -(hfj . position versus time graph of this obj4.g f(d j-pshzect is

  An object is moving with constant non-zero ac;lta d/n8)vj eceleration in the +x axis. The positil v;a t8en)/djon versus time graph of this object is

  An object is moving with constant non-zero velocity in the +x axis. The veloch4n9+zsbb6rwrdj fy/d,f.u4y; jy* s ity versus time graph of this object i j f+wh4/ysyrd;bzj * .d64,u rybf9sns

  An object is moving with constant non-zero acceleration in the +x axis. cc) d z4c ce,r/:7uzg59cftsw The velocity versus time graph of this object cecc4tzsdw:z r597),gfc c/uis

  The slope of a position vh we) rl+vm*61nleq1p 3,wqhdersus time graph gives

  The slope of a velocity versus time grau;a k:j x1*)dgeyx1taph gives

  The area under a curve in an acceleration versus time gwx m bhk4 7n 78;gcbkpe:mt-xowp9/u 3raph gives

  The area under a curve in a velocity versus)dfvf0g r hja5.41:swsi :wcs:yzat6 time graph gives

  If the position versvwf08f v;rcn2kis2 k5us time graph of an object is a horizontal line, the object v05 ns2f rw8kvk2i;fc is

  If the position versus time graph of an object is a vertical linecmw63 45tt3j6nxfozyh1 r y1e, the object iso6 tx w1t63cjre34yh 1zy nf5m

  If the velocity versus time graph of an object is a horizontal line, thembs/o k; y2mrlzcaa3q)j; v 95 object i m3jlr;q59zocv/ b ;ks)ym2aa s

  If the velocity versus time graph of an object is a straight line making aer0gu6hx4.z 6xaf:pu n angle of 30 degrees with the time axis, the objectx6u6 x.ea4 fr gup0zh: is

  An object moves 15.0 m north and then 11.0 m south. Find both th853 zx +1ui8nh i c6mcyech.qae distance trav ci5xh8c1u 3a8.qchz6 i+yn meeled and the magnitude of the displacement vector.

  A boat can move at 30 km/h in still water. How long will it take to move vc .kn:c+vb*u 12 km upstream in a river flowi:cn. vub*+c vkng 6.0 km/h?

  55 mi/h is how many m/s? (1 mi =(7*/q h 4m sleppb02exssq xo3wwc .;l 1609 m)

  What must be your av,( .a1w hycf4t ougjy*erage speed in order to travel 350 km in 5.15 h?

  A runner ran the marathon (approximateldn-e0:y+ i5n nxi:b hm8* rnzqy 42.0 km) in 2 hours and 57 min. What is the average 0zb:x y5+:mr- nnienidn hq8* speed of the runner in m/s?

  A car travels 90 km/h. How long fbc fvx0h/ r8gc k87cpl60h,pdoes it take for it to travel 400 km?

  A ly (light year) is the distance that li 169.+yq*/x 1i etrdsufpxpygght travels in one year. The speed of l1xepg96 i1 +syfy u.xt/dp *rqight 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 al4e f nyfjeb4na;x8 4su/:jx(fong a straight road and you look to the side for 4.0 s, how far do you travel during this inattenti 8 ffu4(:xjnsn xae4 /j;b4eyfve period?

  If you run a complete loop around an outdoor track (42)f, i.a3ibe0lz m pyi00 m), in 100 s, your average velocity 0 bl3if y).eiizma p2,is

  A polar bear starts at the North Pole. 1*jq*(rlfn w aIt travels 1.0 km 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. Whanl 1q(a* j*wrft was the bear's average speed?

  A polar bear starts at the North Pole. It tr:kr2f:js7i ox avels 1.0 km south, then 1.0 km east, then 1.0 km north, then 1.0 km west to return to itsfo7 2r: ixj:ks starting point. This trip takes 45 min. What was the bear's average velocity?

  You are driving home on a weekend from school 25-i wz5kcaff0sn1g eat 55 mi/h for 110 miles. It then starts to snow and you slow to 35 mi/h. 50gef az- 2fnwsk ic15 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 kmoprk:n j15jxx-u5d 8g at 100 km/h. What is the average speed of the motorist for this txu5-kd p:gjnr5o x1j8rip?

  A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h.2 nk.n93t+daipl0as ib d7r) q What is her average speed for the tr7d.dt +bs032i al9r pnq)inakip?

  An airplane travels at 300 m1wyob2p zik/fvifq su73iy4( ii6 d* /i/h south for 2.00 h and then at 250 mi/h north for 750 miles. Whatiyp /ywo61 skz 32q7i *ufi ii(/4fbdv is the average speed for the trip?

  In a 400-m relay race the anchorm))wps b,y5s suw8kpld:09po fan (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 finasl) dy9sw: pu5bs o8p kf0)wp,l leg of the race, in order that the team A runner not lose the race?

  A car decelerates uniformly and cp2v hs1io;j ;dl )i+qjg.ww,bomes to a stop after 12 s. The car's average velocity during deceleration was 60 km/h. What wvpi b;w.s1 d;,hl jo)2+qg jiwas the car's deceleration while slowing down?

  An airplane increases its speed from 100 m/s to 160 m/s, at the averag- c:d 1tinnhk4e rate of d1 t4: icnn-hk$15 \; m/s^2$. How much time does it take for the complete increase in speed?

  A car traveling 60 km/h acceler0jfu. r* gxg hu0a6yt3ates 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 r(za+uihx8by*0 3 t)h9y jvng oest and accelerates 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 s;gkzz8h2/ib e peeds up with a constant accelerationgzbi/ze ;kh28 of $2.0 \; m/s^2$ for 15 s. At the end of this time, what is its velocity?

  A cart with an initial velocity of 3.7 m/s experiences a co6/n -vh8hs9 .hjin bqlnstant acceleration o/8nibqhj .6lvnhs h- 9f $3.3 \; m/s^2$. What is the cart's displacement during the first 8.5 s of its motion?

  A bullet moving horizontally to the right (+x directerdeh( .9da 3 *xib7gnion) with a speed of 581 m/s strikes a sandbag and penetrates a distance of 81.53 cm. What is the average acceleadh g7.*b xe93(dn ireration, in $m/s^2$, of the bullet?

  A jet fighter plane is launched from a catapult on an aircraft carrier. I n, q3ydnmhd ()2w 9pqva8.kokrlpb(.t reaches a speed of 42 m/s at the end of the catapult, and this requires 2.0 s. Assuw) 9q3,h2 bn8 d. k.nomrdvq(p( kalpyming the acceleration is constant, what is the length of the catapult?

  A car starting from rest m8ic yy .ec,os1oves with 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 of 200 m. What is i.wkiklrd 0k46p7; ciits average acceleratio4ki0k 76 ;lcirw.kdpi n?

  An object starts from rest af9,(s1tba2hw : hw6 oay2dvuand undergoes uniform acceleration. During the first second it travels s,h :ht 2 bya a(fo1ua2ww9vd62.3 m. How far will it travel during the third second?

  An object is moving in a s pw*w1mbf x6etbet1,zq06muzh) :t 4ytraight line with constant acceleration. Initially it is traveling at 16 m/s. Three seconds later it is traveling at 10 u0wm 6b,e*1zbp1e6)xt ztymtf qh4 w:m/s. How far does it move during this time?

  A car starts from rest and accelerates uniformly dmk o(n.oet6rjw:)cewd02 /d 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 iax37 y6c.1vv zhc3 tuabout $5.0 \; m/s^2$ 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 4zva 7 (djtqgvz0k f(iv1j70wthat has been waiting at the intersection st qi(jv7j0vzvga4z ktf ( 0w17darts 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 the s6)5y1lkrah fhg sr0+uak8 4u ;zz*wjrurface of planet X whe* grzhuk+ s46 1hrf508;)yl azrkuwaj re the acceleration 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 speed oo.* t 6ih-hirhg aeiu6i.yr08 f 12 m/s on the surface of planet X where the accelehti 6hhuor.* 8igir.6ea 0y -iration 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 speed of 15 m/s on the surface of planet z)x2vb8no)ull 3;dzl, * qhd0x0a68o lzaeizX where the acceleration due to gravity l8*dzxlu)6z a80 d0,2xo lzhl b;)zo 3qeinavis $2.5 \; m/s^2$. How long does it take for the object to return to where it is thrown?

  An object is thrown upward with a speed of 14 m/s on the surface bb6:y(yz 1 pwlkrd65f.s7 affof planet X where the acceleration due to gravity.7spfwakdb1l z5 6r(:y6yfbf 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 fri.vagv+f85o3hkkey8 f end holds a ruler between your fingers and releases he5ok+3v.agk8v8 yff 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 velocity after ws 8 fr(6m735lhy girz3.00 ss gfiwy3hrz 685ml (r7?

  A bullet shot straight up returns to its stavm */ 2p*u5d ,ruuvgysrting point in 17 s. What is the ini /2ym*ugs,u 5vprv*udtial speed of the bullet?

  A ball is thrown straight j+ o+0d mrpwku1ju03v up with a speed of 36.0 m/s. How long does it take to return to its +dr+3jm1ujw0oupk0v starting point?

  A ball is thrown downward from the top of a building with an initial speed tq f;8ce:w 2qfof 19 m/s. It strikes the g q; 2eftw:c8qfround after 1.3 s. How high is the building?

  A ball is thrown straight up with azoaz.uh m d,o6 sm45 ul;sca42 speed of 30 m/s. (only fill in numerical vald5z u 4olsm azs;moh .642cua,ue 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 air with a speeea yd578xf 6rdd of 22.5 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 12 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 12.0 m above the point of contact a second time.  (数值)  $s$

  In Fig. below, what is the velocity apsqwkvaz2n6 uxge/; 22jd+o nig(h(:t t = 1.0 s?

  In Fig. below, what is the velocitqlf4fd8;w*o(3x 67ill lmydqy at t = 2.5 s?

  In Fig. below, what is the velocity at t =ahors gt*c * :kw1ck3 f f.84soznym*0 4.0 s?

  In Fig. below, what ismne 7;, 6glq)3jwi hlj the velocity at t = 5.5 s?

  In Fig. below, what is the averageyf0jthz6 4v0oxp o(d/ velocity from 0 to 4.0 s?

  In Fig. below, what is the average velost:cw -xs.h6 6xe 2sljcity from 0 to 6.0 s?

  In Fig. below, what is the acceleratio-iu3*h pnp t vyo4eai6:q2(z nn at 1.0 s?

  In Fig. below, what is the acceleration at 3.0 si.se45yy0cip2v a4 aq2a ;d jx?

  In Fig. below, what is the averaei+8sb x8)dk.an fp,s ge acceleration from 0 to 5.0 s?

  In Fig. below, what is the average acceir ;(isgjk0 pvu:, m3n9;zyhpj 8cma :leration from 0 to 8.0 s?

  In Fig. below, what is the displacem 4 hw yumfc)u)xh:-9lgent from 0 to 8.0 s?

Does a car speedometer measure speed, velocig 40 v*er8bqw7,cb: zqbhx4(dc(maeoty? {speed|velocity}

  An object can have a varying speed if3c5 h4q1tvduqo+. f ys its velocity is constant.

  The velocity of an object can be negative when its acceleratikh7-quc 8ko g (;hcfqn3c2ga* on is positive.

  If one object has a greater speed than a second object, j+s 8dmme6z8jthe first must have a grd8+msjze m8j6 eater acceleration.

  Two cars emerge side bqmg p0xy(7+dw (g;igty side 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 spw mqh eu2wu-5u owc2(u1 .cmm(eed as its acceleration decreases.

  A baseball player hits a foul ball straight up into the air. It leavesr6iey8d 6az6 :m e2y)1 sihszx the bat with ad)1xa26yz :6r8 6zms iyei hse 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 o mv zv0tey2.u1*hyzw-bject speeds up, what is happening to its acceleration, how does i0m hy 1.y2*v-tzvweu zt change if air friction is ignored?

  As a freely falling object speeds up, w(nsdj4.sent-l , ujd9hat is happening to its acceleration, how does it change if air friction CAN Ndtn-lj.sd(,4 en j9suOT be ignored?

  An object that is thrown vertically upward will return to its f6ympi v(a*2kpt ,b9p original position with the same speed as it had initially if air respmi t2pvb* yp6 f,9ka(istance is negligible. If air resistance is appreciable, how will this result be altered?

  An object can have zero velocity and nonzero acceleratio4 v-8jt7hco zx4bas(y n at the same time.

  An object can have nonzero velocity aco )spnm1 :c-esul(h9o3fx 1b2l ctt/nd zero acceleration at the same time.

  An elevator moving from the second floor to the fifth floor making n ceyd ugl1p 5faq+ gjzrz3x)p8aje 87( grq);-o stops along the way has zero acceleration alxa 8d p;)q81aguf-pr+ 7 gej )qy zgcezjl5r(3l the time.

  A rolling ball moves v do;k 8am-ys;i:0yab from $x_1=2.1 \mathrm{~cm}$ to $x_2=-6.5 \mathrm{~cm}$ during the time from $t_1=1.8 \mathrm{~s}$ 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 $t_1=-4.2 \mathrm{~s}$ is at $x_1=2.9 \mathrm{~cm}$ and at $t_2=3.5 \mathrm{~s}$ is at $x_2=8.2 \mathrm{~cm}$. What is its average velocity?  (数值)  $cm/s$

  A person jogs eight complete laps tkk(; p,ve5kx around a quarter-mile ($1 \; mile = 1609 \; m$) track in a total time of 10.8 min. Calculate (a) the average speed  (数值)  $m/s$ and (b) the average velocity    $m/s$

  A horse canters away fr;1n5g(biw1 nlltarm c(b) dc4nm w+w6om its trainer in a straight line, moving 106 m away in 12.2 s. It then turns abruptly and gallops halfway back in 4.6 s. Calculate (a) its avbtr dg5 c(nc46awnw)w+n(lm mbl 11i; erage 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 fromu3fxvor0* x a89;b n.vhhx*qz $10 \; m/s$ to $22 \; m/s$ in 4.2 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 b a z4).z-dtmu$20 \; m/s$ to rest in a distance of 59 m. What was its acceleration, assumed constant?  (数值)  $m/s^2$

  A light plane must re87my)7ws9pqk +nt1l2h p gjfmach a speed of $26 \; m/s$ for takeoff. How long a runway is needed if the (constant) acceleration is $2.8 \; m/s^2$ ?  (数值)  $m$

  A world-class sprinter can burst out of the blocks to essenqk nla*3 wmt+ wp71d-ftially top speed abou lk7wa1p+wqn3dfm- * tt $11.0 \; m/s$ in the first 10.7 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 ft;sy vpma22 9orom a speed of $17 \; m/s$ to rest in 4.56 s. How far did it travel in that time?  (数值)  $m$

  In coming to a stop, a car leaves skid marks 927tp5f)iu fuwjm (:l 3j m long on the highway. Assuming a deceleratitp3wf:5)jl7 (uufmi jon of $7.00 \; m/s^2$, estimate the speed of the car just before braking.    $m/s$