Which of Newton's laws best explaind:i6f b mw.qx)r4f61jqiu6yys why motorists should buckle-up?

  When you sit on a chair, the resultant force on you7s lj40zv 5t8nbn l 6y05ynz(zmie 7qq is

  In the absence of an external force, a mov0s )kebuabe5)4l 6ju )m;v afuwy t44ding object will

  When the rocket engines on the m 2v6jzmsnwt-(17szt starship NO-PAIN-NO-GAIN are suddenly turned off, while traveling in e t7-(m zm 2jws6vtsz1nmpty space, the starship will

  A rocket moves through empty space in a straight line with constanl6g8oukfs 6-q t speed. It is far from the gravitational effect of any star u8 k6o6lfsqg- 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 moving b /d+q6cp 3gr+v9,xot6/wfuj8m zw hkp us, facing forward, and you suddenly fall forward. You can imply from this that thw w opkd8/,xu mpz3j+ r 9tg6/fcq+v6he bus's

  You are standing in a moving bus, facing forward, and you suddenly fall forward 7dqky l2 z.)u zq:gr;fye1ma. as the bus comes to an immediat:le yzuq2gm ya1)f qd7r;k.. ze stop. What force caused you to fall forward?

  A constant net force actd:iojm )h ,i5ep4c7q ls on an object. Describe the motion of the object.

  The acceleration of an object is inversely pk:m zz ea0r;h7z++ziproportional to

  A net force F accelerates a mass m wi, 2i*ymj cx9( kur(nty;i3gea th an acceleration a. If the same net force is applied to mass 2m, then the (a etiyxn(*;gir 9y2uckm3j, acceleration will be

  A net force F acts on a mass m and produces an acceleration a. What acc*e0* 8ejfft)gn svnw;;j cuo5eleration result5sjfngj0;)f ote ;ncue8w *v*s if a net force 2F acts on mass 4m?

  If you blow up a balloon, and then release it, a;2 gph* mvhm4the balloon will fly away. This i;m4*ma2 gpvh hs an illustration of

  Two cars collide head-on. At every moment during the collision, the magn5 j .aadou ajzpi:.17ql3k7vnitude of the force the first car exerts on the second is exacalvkp.jaqd a:z.j 77u n31i5otly equal to the magnitude of the force the second car exerts on the first. This is an example of

  If you exert a force F on an object, the force which the objeclrhz6 ;b))sl j)k ,obqt exerts on you wi)k, b)r q)j6lh lobz;sll

  Action-reaction force;din w4,)evx os

  Action-reaction forces are+u 9 ) cq(guzefr+r0ww

  A 20-ton truck collides with )wv wc grm) *yms39z,pa 1500-lb car and causes a lot of damage to the car. )c*,3rw pms9vm gyw)zSince a lot of damage is done on the car

  An object of mass m sits on a flat table,zyb;* ot3doo h) g8vz. The Earth pulls on this object with force mg,bgoy hz*8to o)v; ,dz3 which we will call the action force. What is the reaction force?

  A child's toy is suspended from the ceiling by means of a string. Thghrxaliqp) :/q n 2,7he Earth pulls downward on the toy with its weight force of 8.0 N. If this is the "actio),h:qqghar7/2p l inxn force," what is the "reaction force"?

  Your bat hits the ball pitched to you with a 1500-N instantaneous force/pxj;m) lmm oznmu-39. The ball hits the bat with an instantam 9)p/mmun3lo z x;jm-neous force, whose magnitude is

State Newton's three lawe *vo .b76usigs.

  Mass and weight

  The acceleration due to gravity is lower on the Moon than on Ezx2ooi. 8r9y x ndm(4y/9 scnfarth. Which of the following is true about the mass and weis8fcxrd /ny.x42y(n 9m 9izoo ght of an astronaut on the Moon's surface, compared to Earth?

  An example of a force which acts at a distance 9am5z9 dwz -mcis

  Who has a greater weigh q4)*(v4ehu y.lp xqmwt to mass ratio, a person weighing 400 N or a person weighing 6u)qlyex 4vh*wp. q( m400 N?

  A stone is thrown straight up. At the top oyan )x;,h1m jgf its path, the net force acting on it j;yh,g1mxn) ais

  A 20-N weight and a 5.0-N weight are dropped simultaneously from the same heigyex r q )*(;ubwo e 2(lbicspd1iob.5.ht. Ignore air resistance. Compare their acceleratiox.cii1 )(l( y d5uosb wp2 be.r*q;eobns.

  A brick and a feather fall to the earth at their respective termi dijg s.li:j2i+m8dxr1 20 pbsnal velocities. Which object experiences the greater fdssp1j .b2 ir:ixl2+gdj m0i8orce of air friction?

  An object of mass m is hanging by a string from the ceiling 3w + .s*pbl 46nrluvlj/ d,kunof an elevator. The elevator is moving up at constant speed. What is the tensiob lj*k/.4l3npwr nu6 vl,su+dn in the string?

  An object of mass m is hanginj pd2e4i7u4 zeg by a string from the ceiling of an elevator. The elevator is moving upward, but slowing down. What is the tension de4 ue pz42ji7in the string?

  The force that keeps you from sliding on an icy sidewal idwnnk 3mxw9b3 o573lk is

  It's more difficult to start moving a heavy carton from rest ta ch,yy*s2/ w*;tj rfj)jgh/q han it is to keep pushing it with cons * tqhywfcjy;rs a,h/jgj*) 2/tant velocity, because

  A horizontal force accelerates a box from rest acrogblm 3j-1d+yve4edj +ss a horizontal surface (friction is present) at a constant rate. The experiment is repeated, and all conditions remain the same with the exception that the horizontalle 3jjm4edd +yvgb+ -1 force is doubled. What happens to the box's acceleration?

  A packing crate slides down an inclined ramp at constant velocity. Thus we ca 9 :3hs6nwawdzn deduce thas9: 3ah wndz6wt

  A block of mass M slides down a frictionless plane inclined at an angle qz,)ctr *rz ,kg with the horizontal. The normal reaction force exert),rg*crz, k tzed by the plane on the block is

  A block of mass M slides down a frictionless plane inclinedz8na5ghjy ( z1 at an angle q with the horizontal. The normyzz1g8a j5(nh al reaction force exerted by the plane on the block is directed

  A block of mass M slides down a 6 ;,en,cz)p6m gze5bb; ;e-hhpdclbqew tt3+frictionless plane inclined at an angle q with thqt)w ge h z 6;,5ph;6etbn3+ c-bm bdlpzc,ee;e horizontal. The gravitational force is directed

  Two toy cars (16 kg and 2.0 kg) are released simultaneouslybga )et x5m*y7gwy3 xmh;zb 25 on an inclined plane that makes an angle of 30e with the horizontal. Make ) byhg5w7my;a tbx2me35g xz* a statement which best describes their acceleration after being released.

  An object sits on a frictionless surface. A 16-N force is applied t 9i hr,h:vgilz72ilg *o the object, and it accelerate h *zriil2,:7i hvg9gls at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass ad;.,lqo2fgfv p eb/91000 kg can accelerate from rest to 27 m/s in 7.0 s. What is the average fo/fpe o9q dlf,;2 a.gbvrward force on the car?

  Starting from rest, a 4.a o3lr1yp0yzr ko v2(90-kg body reaches a speed of 8.0 m/s in 2.0 s. What is the net force acting karz92r03 lyyv (oo1 pon the body?

  An antitank weapon fires a 3.00-kg rocket which acq, 6u:h 8esu u/d*2a8z uaoljfcuires a speed of 50.0 m/s after traud2j:6f8az u8ecsa */h ul ,ouveling
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 samhir dk/e 1b+mw 7.d6zke force that you push a 10-kg mass from re i+w./kkdm7b1hr dz 6est,

  What is the mass of a person who weigh nbmnudrot0 sl,1e00o:1vl1 qk a/ k0qs 110 lb?

  What is the mass of an qh f hw+yd4r6 /bd-zcg.+1wshobject that weighs 250 N on the surface of the Earth where the acceleration due to gravityrs.4h dz cwq 6h+/bhgd-w f1+y is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. What isgrd4 n-k c2tx( the mass of the object on the surface of the Moon where the acceleration - r4cgtxk(nd2due to gravity is only 1/6 of that on the Earth?

  Object A weighs 40 N on Earthl . (s sw*hlzj.eod5l1, and object B weighs 40 N on the Moon. The Moon's gravity is one sixth of Earth's. Comparelhsd sw.le.(o5l *z1j the masses of the objects.

  Sue and Sean are having a tug-of-war by pulling on opposite ends of a 5.0-kg5lz2pfmd qlw0+)nk s , rope. Sue pulls with a 15-N force. What is Sean's force if the rope accelerates toward Sue at ,lw0fdkm)25q p z+lns $2.0 \; m/s^2$?

  A stack of books rests on a2xo kzy f z)(,s:fmmoeo3yvdk+ly )22 level frictionless surface. A force F acts on the stack, and it ao2)v ye )sd fk:y m mky(of,2ozxzl3+2ccelerates 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 scale in an elevator. What wi6tx f(xh+q x(ill the scale be reading when the elevator is accelerating downward h(x6x +ftxi(qat $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the mas;ue h dygs1hu 13y/6wmzdx f58s of the person is 60.0 kg and the elevator acc ye53uw6 1;xdh8dusym /h z1fgelerates downward 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. If the mass oa h-ry hlx75s8a/,cvzm qo;8e f the person is 60.0 kg and the elevator accelerates upward with an acceleratios85r qmaay87 o;hezxl/vch,-n of $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal forces act on a 5.0-kg mass. One force has a maf6n.ju2oob dk,yd (kc3-t 5vxgnitude of 8.0 N and is direct23otoyk( jc.fvnk ,bxddu-5 6ed due north. The second force toward the east has a magnitude of 6.0 N. What is the acceleration of the mass?

  An object of mass 6000 kg rests on the flatbed of a truck. It is hel1j lxh7n +ghl(d in place by metal brackets that can exert a maxxg ( 1hlj+lh7nimum horizontal force 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 truck. x4t:uw8k7qi)u;bbk dg-pr7i* rfw t/It is held in place by metal brackets that can exert a maximum hor;8tii/-7k 4w w)rbuu gk tf7d:*bpxqrizontal force of 9000 N. When the truck is traveling 15 m/s, what is the minimum stopping time if the load is not to slide forward into the cab?

  In the Atwood machine shown in Fiiw*,-8c qna91 adiv i e 1dgvq.ktfx9)g. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the magnitude of the acceleration of the sys )gt 9x.dqneii vk 8vdc1*-9,awa 1iqftem? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-n4 +v -jnr;hcc1, if M = 0.60 kg and m = 0.40 kg, what is the tension in the st c4nrjc+- ;hnvring? (Ignore friction and the mass of the pulley.)

  A student pulls a box of books on a smooth horizontal f8 srfqr:g6cg7tb9wy 07w7wh aloor with a force of 100 N in a direa:q9w80gw7h fcs7 g7 wtbrry6 ction 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 books on a smooth horizontal floor with a force -puiu 52p5epr of 100 N in 52pupe5 pi-ru a 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 weight 100 N is supported by two ropes +ue ggvc* +( vjf+rdk9as shown in Fig. 4-2. What are the tensionke9+ v *gj+f+r vcudg(s in the ropes?

  In Fig. 4-2, if the tensions 0 ngbo ont*( g(g0xsr.in the ropes are 50 N, what is the mass of the traffic ln oxtr*o0.0g((g nsgbight?

  Two boxes of masses m and 2m are in contact with each other on a frictionlel 9f jtznpkl)prg:f *,a 9.;usss surface. (See Fig. 4-3.) What is the acceleration of the mlsglz,: . ;p n r*ffkjpta99)uore massive box?

  Two boxes of masses m and 2m are in contact with each ) d 0c2ylw5nrrother on a frictionless surface. (See Fig. 4-3.) 2 0n)ylw rrc5dWhat is the net force on the more massive box?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 47,,k0dg wg4w eosern+ 8bw:sabk(*g k-4.) If the forward force on gk w(g:o*w7k08 sw na +s,4ree,gkdbbthe more massive box is F, what is the tension in the connecting rope?

  Two boxes of masses m and 2m are conn;7upnl y4r4kpected by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the acceleratio4pnpk7;y4r l un of the less massive box?

Two boxes are connected by a cord running over a pulley as shown in Fhb-ugjyu sg)oo v9/- 8ig. 4-5. Box I of u-- gho vy9)jbso8g/umass
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 desi z7 f)ivwfs 2nhga+ g/ppe;2/jlf0e:k are 0.40 and 0.30, respectively. What is the net force on the box when a 15 N horizontal force is : f/ fsw+7 0gpzvijeehnp;fl/a 2)2g iapplied to the box?

  The coefficients of static and kinetic frictions for v tgskrphra/mu5ogc8*z6,1 3 juz2l 0plastic on wood are 0.50 and 0*hv8r umzguzor20s p j 6t,c 1al5/3gk.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 the +x direction. It slows and co*xx vs3)btxsa.xz 85f mes to a stop with a constant acceleration o3xs.8x)t z sa*x f5bvxf -$2.45 \; m/s^2$. What is the coefficient of kinetic friction between the object and the floor?

  A 10-kg box sitting on a horizkhfxij +y76)cf70qd 8* vv teuontal surface is pulled by a 5.0-N force. A 3.0-N friction force retards the motion. What is the acceleration of x07qk*c fyj 7h+de6)ufvit8v the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg 9 x3qet40romkmass, 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.a -i6slgv 1nw given an initial speed of 10 m/s. It slides 50 m on the ice before it stops.lan-vi6 .s g1w What is the coefficient of kinetic friction between the puck and the ice?

  During the investigation7jai s -.cf nvo6 4gh0az,jme6w-a8hs of a traffic accident, police find skid marks 90.0 m long. They determine the coefficient of friction between the car's tires and the roadway to be 0.500 for th h 67cj0z.s-ha6nmgsa,aje fo w4i v8-e prevailing conditions. Estimate the speed of the car when the brakes were applied.

  Two boxes of masses mw+*4tujv2isaho 9 a+ u sa*(kh 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 the boxes is rough. If the less massive box does not slide on the more massive box, what is the static frictionuk j+ so2s(aa*ha ui*w9v+t4h force on the less massive box?

  Two boxes of masses gowar tca2i 5.c,7 -htm 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 the boxes is rough. If the less massive box does not slide on the more massive box, what is the coefficient of stat.,gaa5 whrio-c7ctt 2ic friction between the boxes?

  An object is on a frictionless inclined plane. The plane is inclined 8;t+7j i1d. bfoyf vpdqbt1 ;pv5nv2d at an angle ofvb ;do7q d vf2 b1jfpvd y5t1+8.t;pni $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down lpm3/:fsau8 ca flat hill that makes 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 smootkeeab+) /yt2w;2gtt f ,odg0v h inclined plane 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 smo 8/hq/vo i.:o kx,mq;6fwm ckboth 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 inclined plane, at a constant velocity o z, 9dk-(- lp(c2t qmoc9mmuyxf - x2y9 t(ocl-km dm,m9u(cpqz 6.0 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 slides down a txq/u8 t)6i rwrough $37^{\circ}$ 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 dzo0zwb 69 u3egown a rough $37^{\circ}$ 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 weighih1ik4e.f (b 70eupzlwgxv. s5ng 500 N along a rough surface. The cable attached to the lw1 vpuz4ikl eb(g 7xes5h. f0.og 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 inclined plane tilted at +nd yrt ae55n*an angle o5 *ae5+yn rndtf $33.5^{\circ}$ 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 plane. The angle of incline is gradually in)de,h,8dhd /jbs *vp 5 romj1fcreased until the object begins to slide. The angle*jpr ),h/1d s8vhm5j,d fb doe at which this occurs is q. What is the coefficient of static friction between the object and the plane?