Which of Newton's laws best explains why motorists should buckle-up0n7dazf)5s zd x.x :rm?

  When you sit on a chair, the resultant force pv/6h1y mzbn(q9) x/yndr7f//f phmr on you is

  In the absence of an external force, a moving object wilubu9 1lay/ l*j yt jhd.fy2/r0l

  When the rocket enginessihd8fuw8n)n 0 -l s ya+aw62o on the starship NO-PAIN-NO-GAIN are suddenly turned off, while traveling in empty space, tha8 fhoi)8 y+ndlus w-02nas6w e starship will

  A rocket moves through empty space in a straight d3r6* h o0 4) qkmw/(wb/hqjk;lyi u2qlr-lts line with constant speed. It is far from the gravitationa)oqk3 ;/ u4jir2rlmw/ q6(0 *s- wbl hhdkyltql effect of any star or planet. Under these conditions, the force that must be applied to the rocket in order to sustain its motion is

  You are standing in a movin6 miefr k7z7bx,f2zj* :tqfg) g bus, facing forward, and you suddenly fall forward. You can imply from this that t t:bezx7f zfj7 r)2g im*6kfq,he bus's

  You are standing in a moving bus, facing forward, and you suddenly fa 6uaz x*:pme(k,k gw .zzm(j2xll forward as the bus comes to an immediate stop. What force caused you to f (z2xej6kmx(w :,a.kz p*u mgzall forward?

  A constant net force acts on an object. Desc ibj4mmg6z z)2ribe the motion of the object.

  The acceleration of an object is inversely proport)zfexx; u y;e;u o-b.wional to

  A net force F accelerates a mass m with an acceleratio.wcn jai4t.hm +yf;v+ n a. If the same net forc.+mwjivn+4hct.fya ; e is applied to mass 2m, then the acceleration will be

  A net force F acts on a mass m and produceei3ldllzx)p5 c) .i71fxr8pk s an acceleration a. What acceleration results if a net for)lxlpz) .pilf 58erxc3d7i1kce 2F acts on mass 4m?

  If you blow up a balloon, and then relea5. 7y sro6gvndse it, the balloon will fly away. This is an illuodsr6y7 vng 5.stration of

  Two cars collide head-onr* z(l +e+jskt. At every moment during the collision, the magnitude of the force the first car exerts on the second is exactly equal to the magnitude of the force the second car exerts on the first. This is +ksze *r ltj+(an example of

  If you exert a force F on an object, the force which thec5up wu3zkr0 2)matd, object exerts on you wit3cpadmr 05u w),kuz2 ll

  Action-reaction forcew27ul.o -8k;iwe26tx r qfnvcs

  Action-reaction forces szefp bnx07 rl;lc /tk8pnr i9,,;s+oare

  A 20-ton truck collides with a 1500-lb car and causes a lot of damage to the ca oeqxteeyo/d 68();zu r. Since a louy ot6zeq ;o8/)( eexdt of damage is done on the car

  An object of mass m sits on a flat tablw,,m+zjf.zt kkt 9mr;5 jdd2cr8: ojde. The Earth pulls on this object with force mg, which we will call the action force. What dzkt9,,jf8k ;:r2jomcrm. tj+d z5w dis the reaction force?

  A child's toy is suspended from the ceiling by means of a string. Thkl1xr twfolh)2gk71; e Earth pulls downward on the toy with its weight force ofh r7wf;lt)gxk1k 12ol 8.0 N. If this is the "action force," what is the "reaction force"?

  Your bat hits the ball pitched to you with a 1500-N i4*j2 /nflml-p sc ,bxgnstantaneous force. The ball hits the bat with an instantaneous force, whose 2xps*-gl b /,mln4 fcjmagnitude is

State Newton's three l./ptokng)8mlr + s 6kkaws.

  Mass and weight

  The acceleration due to gravity is lower on ta5 diq cw k1tn8gnvs)69r,0sq he Moon than on Earth. Which of the following is true about the mass and weight of an asiwvks g0qt) an9qd58r,1c n s6tronaut on the Moon's surface, compared to Earth?

  An example of a force which aa kui 0 (yf72i+*t vw.bncg(alcts at a distance is

  Who has a greater weight to mass ratio, a person weighing 400 N or a person o9e7r/*hhv+f u:;xiqud v fx4 weigh7/fxu he *d+ux:9 4or;vfqvihing 600 N?

  A stone is thrown straight up. At the top of its pat;v,g2 k2va aweh, the net force acting on i;g22,wvvak eat is

  A 20-N weight and a 5.0-N weight are dropped simultaneously from the same heig)zjt*k n6mae 27x8 akiht. Ignore air resistance. Compare )ik*ae a2 n8kz76mxjttheir accelerations.

  A brick and a feather fall to the earth at the ,4qpb o ewte7hz+s1*pk,1p gyir respective terminal velocities. Which object experiences the greater y7e zb14q+ e*p ph1opg,kw, stforce of air friction?

  An object of mass m is hanging by5 cj:3itzu i+pilw+ag+b cb/+ kkh44z a string from the ceiling of an elevator. The elevator is moving up at constant sc/icb+k iah+li5z4uzt p:j3g4+ kwb+peed. What is the tension in the string?

  An object of mass m is hanging by a string from ft htiez-cd2 gfv+1bo+9v * u(g 8mnt(the ceiling of an elevator. The elevator is moving upward, but slowing down. 8fi*hduv 1 2mzt t-bvge+(ocf(ng+9tWhat is the tension in the string?

  The force that keeps you from sliding on an icy sm 8 f37 wy4xgxqw.3pfnhfsf3 6idewalk is

  It's more difficult to steaxp92+e re8 oart moving a heavy carton from rest than it is to keep pushing r9a eeo8+ 2expit with constant velocity, because

  A horizontal force accelerates a box from rest across a:7nznd n-x p6d horizontal surface (friction is present) at a constant rate. The experiment is repeated, and all conditions remain the same with the exception that the hori:zn xpn-ddn76zontal force is doubled. What happens to the box's acceleration?

  A packing crate slides down an in12qr 0 s6;k7s07ldepvm-hpdbo rlh8v clined ramp at constant velocity. Thus we can deduce that h16ldr 8 rl7vems0 h0pbqk7d s-ovp2;

  A block of mass M slides down a frictionless plank.pb+e(vf7s i,8c:rytne v)ke inclined at an angle q with the hof :vt+8e)p.i vsk crb,7k nye(rizontal. The normal reaction force exerted by the plane on the block is

  A block of mass M slides down a frictiovkc 9 pq k8o5fz-*mni)m0sfz. nless plane inclined at an angle q with the horizontal. The no vm0cf)5q.kpo mfzs*k inz 98-rmal reaction force exerted by the plane on the block is directed

  A block of mass M slides down a fricti*0 f:yz x:v4:q6 uag f3e1f*uxfzxfpwonless plane inclined at an angle q with the horizontal. The gravitationf:xf3* x16wpufxz:z q e*ug4f:yfa 0val force is directed

  Two toy cars (16 kg and 2.0 kg)by .ysscjg8sqp2. irj4 ng ia1e8; v8: are released simultaneously on an inclined plane that makes ag2gvcs ;e1y8abirn.syjiq.ps8j8 : 4n angle of 30e with the horizontal. Make a statement which best describes their acceleration after being released.

  An object sits on a frictionless surface. A 16-N for m*h*v54 bkddkce is applied to the object, and it acd*m*hdv 54k kbcelerates at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can j(jg mae -mzas4aw7*7accelerate from rest to 27 m/s in 7.0 s. What is g 7sjmmawz-7 (jaae4 *the average forward force on the car?

  Starting from rest, khq*zk ms0hyo;+6:r7 b( 6hxdp2ovhpa 4.0-kg body reaches a speed of 8.0 m/s in 2.0 s. What is the net force acting on the bo(y dp sqk+h hvh b0h mpz2*ok6o;x:6r7dy?

  An antitank weapon fires a 3.00-kg rocket which /8y, a+/iw 4jbtmdkyc acquires a speed of 50.0 m/s after travelingtmckb/4+ w i8a yd,y/j
90.0 cm down a launching tube. Assuming the rocket was accelerated uniformly, what is the average force acted on it?

  If you push a 4.0-kg mass with the same forc 5c9).k u l4g-h:vke1oaf vjlge that you push a 10-kg mass from restho ll)4j.ukf9g- a v kv5ce:1g,

  What is the mass of a person who weighs 110 lb?cn -ft4o ic611ixn8ee5pr2 gn

  What is the mass of an object that weighs 250 N on the surface of the Eart+up 4,a,sjuowu( ai, ph where the acceleration usaui4 (jw+p o,,ap,u due to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. What is the mass of the object o 0w4czkl+kd*fzmev 5m; 65eujn the surface of the Moon where the acceleration fw0c4 euv +6;ekzlmjdm*k5 z5 due to gravity is only 1/6 of that on the Earth?

  Object A weighs 40 N on Earth, and;eqjyq 0u, ja07hwp1b object B weighs 40 N on the Moon. The Moon's gravity is one sixth of Earth's. Compare the masses of the objects.;710wqjy ub ,0hqjeap

  Sue and Sean are having a tug-of-war by lav l;254 oslig.ym7pt,db5npulling on opposite ends of a 5.0-kg rope. Sue pulls with a 15-N force. What is Sean's force if the rope accelerates toward Sueam4,gdvst ib yn.l;ol7l 2p5 5 at $2.0 \; m/s^2$?

  A stack of books rests on a level frws 8(8lptarxa63n-aq 2 :f cimictionless surface. A force F acts on the stack, and it accelerates w fxl68(mi3 ar2-nsct8a:qp a at $3.0 \; m/s^2$. A 1.0 kg book is then added to the stack. The same force is applied, and now the stack accelerates at $2.0 \; m/s^2$. What was the mass of the original stack?

  A person of weight 480 N stands on a arrrz7,u::i hscale in an elevator. What will the scale be reading when the elevator is accela::ru, hr7zirerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. z5mqng .v)f7y If the mass of the person is 60.0 kg and the elevator accelerates downwar.mzyv)qn5 7g fd with an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale rides in an elevator. Ifjp* jq3x45xsn the mass of the person is 60.0 kg anq5jp*43sn jx xd the elevator accelerates upward with an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal forces act on a 5.0-kg mqvko tg*vbxm452n-d chm2 obv h1592iass. One force has a magnitude of 8.0 N and is directed due north. The second force toward the easth2i knvd* t v5159m xbbgoh4 mvo2cq2- has a magnitude of 6.0 N. What is the acceleration of the mass?

  An object of mass 6000 kg rests on the flatbed/pt dvjc)wh +7 of a truck. It is held in place by metal brackets that can exert a maximum horizontal forchjt7d)w/+pv ce of 9000 N. When the truck is traveling 15 m/s, what is the minimum stopping distance if the load is not to slide forward into the cab?

  An object of mass 6000 kg rests on the flatbed of a trwyvcx*7t a5:guck. It is held in place by metal brackets that can exert a maximum horizontal force of 9000 N. When the truck is traveling 15 m/s, what is the minimum stt wg*c5xv:y7a opping time if the load is not to slide forward into the cab?

  In the Atwood machine shown in Fig. 1+xd;pfcfm;sc / .mbv 4-1, if M = 0.60 kg and m = 0.40 kg, what is the magnitude of the acceleration of the system? (Ignore friction and the mass of the fmc m;x/.pcdf; 1vb+ spulley.)

  In the Atwood machine shown in Fig. 4-1, /aoyywrm k2lh v3.+n)if M = 0.60 kg and m = 0.40 kg, what is the tension in the string? (Ignore friction and tol +yrwkhm v).yna32/ he mass of the pulley.)

  A student pulls a box of bo s7lipix0( l1eoks on a smooth horizontal floor with a force of 100 N in a diii7lex0 (1p lsrection of $37^{\circ}$ above the horizontal. If the mass of the box and the books is 40.0 kg, what is the acceleration of the box?

  A student pulls a box of boovj*dq (kd )jhv53vkg9 ks on a smooth horizontal floor with a force of 100 N in ad3*kv v9h(5jjv qk)dg direction of 37.0e above the horizontal. If the mass of the box and the books is 40.0 kg, what is the normal force on the box?

  A traffic light of weizpl-d);lb xp l.g24)fhq7 q vcght 100 N is supported by two ropes as shown in Fig. 4-2. Whaf;x gqv7 4hb2)p clqlpld. z-)t are the tensions in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is the mass of the trafb e)hf y/:37qucvow- ffic lightqc oy:3f / -uvwb7)ehf?

  Two boxes of masses m and 2m are in contact with each o40z xwoxze):s rdnb;:ther on a frictionless surface. (See Fig. 4-3.) Wh obzdz ; 4:xe:ws0n)xrat is the acceleration of the more massive box?

  Two boxes of masses m and 2m are3wo bung d6psp u0(1o5 in contact with each other on a frictionless surface. (See Fig. 4-3.) What is the net force on the more massive uppuo3o1 d bs(n5 06gwbox?

  Two boxes of masses m and 2m are connectev*auc agau7 ct;(k:7cd by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the tension i g7tuvu; ac:cc*a7( kan the connecting rope?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4-4.) If the 3xeb 0ef:ix3b forward force on the more meb f0xe3:i3bxassive box is F, what is the acceleration of the less massive box?

Two boxes are connected by a cord runnin :m5vje1b 8ommg over a pulley as shown in Fig. 4-5. Box I of oemmj:vm581b mass
8.0 kg rest on the top of the table; the coefficient of kinetic friction between box I and the table is 0.10. Box II has a mass of 15.0 kg.
(a) Draw the free-body diagrams for the two boxes, identifying all of the forces acting on each of the masses.
(b) Calculate the acceleration of the system.
(c) Calculate the tension in the cord.

  The coefficient of static and kinetic frictions between a 3.0-kg box and a ; 9dbj0gu wgazo 6u,ws29hg20aco rm+/ ,uimudesk are 0.40 and 0.30, respectively. What is the net force 2 w,r0az0oumu,i2ua9g gos9wgd/h+6cjm u;b on the box when a 15 N horizontal force is applied to the box?

  The coefficients of static and kinetic frictions for plastic on wood a8tmj;a : cl4wxre 0.50 and 08t:;l4xacj w m.40,
respectively. How much horizontal force would you need to apply to a 3.0 N plastic calculator to start it moving from rest?

  An object slides on a level surface in c7c-j0w j lyy0;7 usxvthe +x direction. It slows and comes to a stop with a constant acceleration oc l07j0w-xu7ycyvjs;f -$2.45 \; m/s^2$. What is the coefficient of kinetic friction between the object and the floor?

  A 10-kg box sitting on a horizontal surfaa 1he4mhryh g*k 27l8c6vl7kkce is pulled by a 5.0-N force. A 3.0-N friction force retards the motion. What is the acceleration k4kl gc r h7kmy8a17*hl2hv6eof the object?

  A horizontal force of 5.0 N accelerates a1gw(.r-az m kcq:u lbv;sj:s5 4.0-kg mass, from rest, at a rate of $0.50 \; m/s^2$ in the positive direction. What friction force acts on the mass?

  During a hockey game, a puck is given an initiasys+h /)c:qqoft 25 hsl speed of 10 m/s. It slides 50 m on thqfqt2s:s5 scoh+y )/he ice before it stops. What is the coefficient of kinetic friction between the puck and the ice?

  During the investigation of a traffic accident, po tf( aqn0nuuk7*1 .mdhr2-m pxlice find skid marks 90.0 m long. They determine thx qnr2ahk d unpu7tf1.-(0*mm e coefficient of friction between the car's tires and the roadway to be 0.500 for the prevailing conditions. Estimate the speed of the car when the brakes were applied.

  Two boxes of masses m and 3m are stacked. (See Fig. 4-b j 5 (rr.hw59 cfiol*b9z jh(,itflq86.) The surface between the more massif.5i (br qh ,l hblowicf(*zrt 98j59jve box and the horizontal surface is smooth and the surface between the boxes is rough. If the less massive box does not slide on the more massive box, what is the static friction force on the less massive box?

  Two boxes of masses p p t6yxtx0xwfp)ez )+31wv5nm and 3m are stacked. (See Fig. 4-6.) The surface between the more massive box and the horizontal surface is smooth and the surface between tw xevtp n6fwpz+0x)p3x5y t) 1he boxes is rough. If the less massive box does not slide on the more massive box, what is the coefficient of static friction between the boxes?

  An object is on a frictionless inclined plane. m3 p5)mfgkk(j The plane is inclined at an angle ompkkfg)mj5 3( f $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that b2foh sr:r7se s7:e3 nwcwn m )tj,7*rmakes an angle of $10^{\circ}$ with the horizontal. If friction is negligible, what is the resultant force on the sled?

  A mass is placed on a smooth inclined plan v7h 8y:xxc:fxe with an angle of $37^{\circ}$ to the horizontal. If the inclined plane is 5.0-m long, how long does it take for the mass to reach the bottom of the inclined plane after it is released from rest?

A block lies on a smowq p1e w)c bqj,q/rb53pl1sd1oth inclined plane tilted at an angle of $35^{\circ}$ to the horizontal.
(a) Draw the free-body diagram for the block.
(b) Determine the block's acceleration as it slides down the inclined plane.
(c) If the block started from rest 8.5 m up the incline from its base, determine the block's speed when it reaches the bottom of the incline.
(d) How long did it take the block to reach the bottom of the inclined plane?

  A wooden block slides directly down an inclit g4 rnl3ceo1b2u,k/ vned plane, at a constant velocity of 6 2cro14g/ 3letv ,bkun.0 m/s.
What is the coefficient of kinetic friction, if the plane makes an angle of $25^{\circ}$ with the horizontal?

  An object with a mass m s t5lw e5azvrx xyaa f570s-h)rm/8nr /lides down a rough $37^{\circ}$ inclined plane where the coefficient of kinetic friction is 0.20. What is the acceleration of the object?

  An object with a mass m slides down a shl9+pz ycl3 r :wv-1yrough $37^{\circ}$ inclined plane where the coefficient of kinetic friction is 0.20. If the plane is 10 m long and the mass starts from rest, what will be its speed at the bottom of the plane?

  A bulldozer drags a log weighing 500 N along a rough surface. The cable a**heh bii.xgz6*-br0 r reha.ttached to ei6-*bh*0e rbz*hxh grir.a.the log makes an angle of $30.0^{\circ}$ with the ground. The coefficient of static friction between the log and the ground is 0.500. What minimum tension is required in the cable in order for the log to begin to move?

A 25.0-kg box is released from rest on a rough incl(6 /he 8f3ilqsy3 bjbnined plane tilted at an angle of (h/sn 3 eb68iyqbl fj3$33.5^{\circ}$ to the horizontal. The coefficient of kinetic friction between the box and the inclined plane is 0.200.
(a) Draw the free-body diagram for the box.
(b) Determine the force of kinetic friction acting on the box.
(c) Determine the acceleration of the box as it slides down the inclined plane.

  An object is placed on an inclined plan2 -xdkz2gbh17q 4szkbcfo oez, jwj+a+/+x x( e. The angle of incline is gradually increased until the object begins to slide. The angle at which this occurs is q. What is the coefficient of static friction between the object and the pld xx+2 k jf+ , akzz412+ojc(sgxzbbeh-ow/q 7ane?