Which of Newton's laws best explains why motorists -4ku lw90 nc(uld)bqpz : 6colshould buckle-up?

  When you sit on a chair, the resultant forceht g1f ;id)t7a on you is

  In the absence of an external force, b r)nk z)i5krblut-1 8a moving object will

  When the rocket engines on the star nig.y32yvmyp99. ooxzjg j)8l 1d6zoship NO-PAIN-NO-GAIN are suddenly turned off, while traveling 1nxzy .g3j. 6z98 gvoy9l2mjoy oidp )in empty space, the starship will

  A rocket moves through empty space in a straight lines8 xdl 8 yr 4xazze2yj(tp5,1i with constant speed. It is far from the gravitational effect of any star or planet. Under these conditions, the force that must be ap, 818e4azyz2y(xpl s5r dxijtplied to the rocket in order to sustain its motion is

  You are standing in a moving bus, facing forward, and you suddenly fall forwaa6 bo1ru 71ls hvu+,)fln*sjn rd. You can implyn s fl7jhr1obls)u 1 *nav6u+, from this that the bus's

  You are standing in a moving bus, facing forward, and you suddenly fall forward i/g vo/ov+fiajq;b i2ff5 3e ,n 2b4omas the bus comes to an immediate stop. What force caused you to fambvof2qo/g5 ibifjoni ;2e3fv/, +4all forward?

  A constant net force acts on an object. Describe the motion of the objecj bd/sxe2+he coi) z5hf3kf+jv7d v6 9t.

  The acceleration of an object is i7u e0lma;xheg20(s/et hfsxs/ap 94 inversely proportional to

  A net force F accelerates a mass m with an acceleration a. If the sa*0tl kcmhu 4;37rh vat3 tmbi5me net force is applied to mass 2m, th7m atmtb3cr3h lkv;h4t*ui50 en the acceleration will be

  A net force F acts on a mass m and produces an acceleration a. What accefkxk65od .b p4leration rkxof6 p4db.k5esults if a net force 2F acts on mass 4m?

  If you blow up a balloon, and then release it, the balomj-gh16sx)hf g0 mi4 loon will fly away. This is ajsi4ho h-1x6 )mg0mfgn illustration of

  Two cars collide head-on. At ever52t /en7oiv*sk1 s y)n0y wrwhy moment during the collision, the magnitude of the force the first car exerts on the second is exactly equal to the magnitude of tho 2y1vwkss/hwnn eyi* r7t5)0 e force the second car exerts on the first. This is an example of

  If you exert a force F on mnto:mnz l 1g .ywd+6mc n0:n9an object, the force which the object exerts on you wilo0mm+: gd6lm9cnzy n1n:nt .wl

  Action-reaction forcml+vbd y3p /*;vppkw5es

  Action-reaction forcerz9o i8p4b* lys are

  A 20-ton truck collides with a 1500-lb car and causes a lot of dagp g541qv gc.t34j;fw/ bt o-rmg4zlcmage to the car. Since a lot of damaggbtcgg.j 5;-/4 tlp ogw1rf4 qc3mzv4e is done on the car

  An object of mass m sits on a flat table. The Earzy z558q*jvoi th pulls on this object with force mg, which we will call the action force. What is the reaction force?qyz5v jz*o58 i

  A child's toy is suspended1s 8jj/, ckablqq9y u4 from the ceiling by means of a string. The Earth pulls downward on the toy with its weight force of 8.0 N. If this is the "action force," what is the "reaction focu jy9q8/j4al1bkqs , rce"?

  Your bat hits the ball pitched to you with a 1500-N instantaneous force. Tz5db4fwbayh 2/k2 s;tf-3rr nhe ball hits the bat with an instantaneous force, whose magnidwh-4 t yfrbn2 ;ka52/ frzs3btude is

State Newton's three 3up:;t*2dldhn;( p .jst j e 7ilcyc+qlaws.

  Mass and weight

  The acceleration due to gravity is lower on the Moon than on Earth. zi-o8cf - pw-zq-p-kwWhich of the--p-wwc8 ipqof z--kz following is true about the mass and weight of an astronaut on the Moon's surface, compared to Earth?

  An example of a force which acts at a distance isq, -w2m+9omhmdjyxp(7 b8al h

  Who has a greater weight to mass ratio, a person weighing 400 N opqxzjd 9z x/k6q;)s0 yr a person weighq 6)qxz/9zys;xdpj 0 king 600 N?

  A stone is thrown straight u4.cfu sc ste8/p. At the top of its path, the net force acting on it 8/cstfc 4u .seis

  A 20-N weight and a 5.0-,oq69ze r(z7 em3,xym4 z:t pki5xij tN weight are dropped simultaneously from the same height. Ignore air resistance. Comparx o(im5 67tz: 4, zpzm,9je iqrtxke3ye their accelerations.

  A brick and a feather fall to the earth at their respective termina6h*;hq7 d c*f iqjvgt*l velocities. Which object e;h*c*vj6dhq gq*tf 7ixperiences the greater force of air friction?

  An object of mass m is hanging by a string from b:ibhzk2by9p2(hf1 *ug k2ro8tg kx0 the ceiling of an elevator. The elevator is moving up at constant speed. What iby:9h21z0kb* g2ok fx r(t8i2uhpkbg s the tension in the string?

  An object of mass m is hanging by a string from the ceiling of sm*wxh9mm q47 9fzs;t an elevator. The elevator is movingt fsqx9mzh47*mswm;9 upward, but slowing down. What is the tension in the string?

  The force that keeps yofab3 gf9b c,,fdc hi/.u from sliding on an icy sidewalk is

  It's more difficult tokytmp8cz1jfo90,1b p,gdy sdld4* m;pa * ks . start moving a heavy carton from rest than it is to keep pushing it with constant velo18m.; cdjkyl0t dp 4ysosg9d1mp* fa pk*z,b,city, because

  A horizontal force accelerates a box from rest across a horizontal surfa ulgo;**7dcljf 0wzp) ce (friction is present) at a constant rate. The experiment is repeated, and all conditions remain the same with the exception that the horizontal force is doubled. What happens to the box's a7pz;c0 f*j )o udgllw*cceleration?

  A packing crate slides down an inclined ramp at constant velxxkmnuv(q 0gyh6/7w :ocity. Thus we can deduce /wxx:ngu0y( h7kq vm6that

  A block of mass M slides down a frictionless plane inclined at an angle q withc7nnq- ( b(vwq t v(q -bncw(qn7he horizontal. The normal reaction force exerted by the plane on the block is

  A block of mass M slides down a frictionless plane inclined at an anm6 22hd1vuaiml6rb v 9gle q with the horizontal. d6 vr luha2mi19 2bvm6The normal reaction force exerted by the plane on the block is directed

  A block of mass M slides xcs*07-zmu d*it t 8xgdown a frictionless plane inclined at an angle q with the horizontal. The gr-8 gxdc7ti smx*0* zutavitational force is directed

  Two toy cars (16 kg and 2.0 kg) are released simultaneously on an inclined pl15au z/0iykqb ane that 0u z1 5ayqkbi/makes an 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 fora6po-o 0+tbpece is applied to the object, and ip+t-p6o a ebo0t accelerates at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accelerate from rest to 27 m/sbi 6r,pw/, xpaayp n;u2lh f(: in 7.0 s. What is the average forward force on t, aabhl6;n:i w,/pp 2(yru pfxhe car?

  Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s in 2.0 s. Whatmqza*.p6h 0p b is the net force acting.h q6 0pbazpm* on the body?

  An antitank weapon fires a 3.00-kg rocket which acquire+0dj*;l3ua jrs a+) ygvxdki-z* :g xhs a speed of 50.0 m/s after*s*axx+-+h:dzdvjj 3ya0 ;r)klgg u i traveling
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 force that you push a 10-kg mass fk 4/ w2eiuyk5arom res 5wkeuki24/ayt,

  What is the mass of aj umtp8)l+g64vs m /yz person who weighs 110 lb?

  What is the mass of an object that weighnoh klpr*91 kn0q h2/vs 250 N on the surface of the Earth where the acceleration due to gravity i/r v2khnh ql 9*0opn1ks $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. augp7gw8cki z 7 ys;61What is the mass of the object on the surface of the Moon where the acceleration due to gravity ig; 6ysuki a7c7g18wp zs only 1/6 of that on the Earth?

  Object A weighs 40 N9c ( ;a5 ulzjn wley7tpk/ do0x4j75is on Earth, and object B weighs 40 N on the Moon. The Moon's gravity is one sixth jel w5 /z5xk 0t;(ujdc7sia9 py47ln oof Earth's. Compare the masses of the objects.

  Sue and Sean are having a tug-of-war by pulling on opposite end ,za ic28r nvsto;0-xds of a 5.0-kg rope. Sue pulls with a 15-N force. Whad82o c-0 sa;xtr, vnizt is Sean's force if the rope accelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books rests on a level frictionless slgu -nx .m4ja7urface. A force F acts on the stack, and it acceler4 7u.lm- xangjates 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 will the scalehvj9*7cjssi 8 be reading when the elevator is accelerating downw7sjv9*8csjh iard at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the mass of the person is )97*lx;;ox i.oppq jgipdr )e 60.0 kg and the elevator ac* g7 pro; jxlqod;xie9).)pipcelerates 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 masy (lu1 1 (8vqyiu yaxnodcd082s of the person is 60.0 kg ax1c 1u(y2oy0lq na88ydi uv (dnd 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-kgud;;2d+56l6gwmc (pz(wijkx h p ihp , mass. One force has a magnitude of 8.0 N and is directed due north. The second force toward the east has a magnitude of 6.0 N. Whath6;k(j uzw l,c pmp5whdg+;ii6xp( d2 is the acceleration of the mass?

  An object of mass 6000 kg rests on the flatbed of a truck. Ila+;-qcvptlw o9p+ f4t is held in place by metal brackets that can exert a maxcwp +l9-tp aovl;4 q+fimum 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 truj7)ivj( gaxdt r+33 vrbl0x,zck. 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, )vxb0t33j r(ziv ,g+ax 7d lrjwhat is the minimum stopping time if the load is not to slide forward into the cab?

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what iza85rh6 o 07xrx yuoh-s the magnitude of the acceleration of the system? (Ignore friction andu5o 7 oyr-hr60axx 8zh the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 k2r*wqybv n0 viwd+v+t2zx3 7eg and m = 0.40 kg, what is the tension in the string? (Ignore w q* 2vv+2xivbrwdzte703+ ynfriction and the mass of the pulley.)

  A student pulls a box of books on a smooth horizontal floor with a force of 10g c a**mwov4*g0 N in a*4cwgm *gvo*a direction 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 of 1x5jxn0,p xui0 mp 0fc) 3z(k.zib,jof00 N in a direction of 37.0e above the horizontal. If the mass of the box and the booksj3kmfc0 (, 50x boinfjxu. zix0p)zp, is 40.0 kg, what is the normal force on the box?

  A traffic light of weighj k-pk(s:- lvat 100 N is supported by two ropes as shown in Fig. 4-2. What are the tensionsk(v-s:pj -lka in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what isf.;ayb 5s b/iv the mass of the traffic lighyb;.sa/fv 5 ibt?

  Two boxes of masses m and 2m are in contact with each other q+kznibug z5 *4fx*d7 98vt dzon a frictionless surface. (See Fig. 4-3.) What is the acceleration of the more massiid8+vn*g f z 9xbz5*7dtk 4quzve box?

  Two boxes of masses m and 2m are in contact with each other on a frictionle14froyr j5k d67ihu9ess surface. (See Fig. heyi45ju6kr 1d 9f r7o4-3.) What is the net force on the more massive box?

  Two boxes of masses m and 2m are connected by a rom8e-wsu*nmat d5v*r jn 7g- d8pe. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the tension in the connectinwet-a sn*jrdd5v*gm 8m-u87 ng rope?

  Two boxes of masses m and 2m are connected by a rope. (See u :zimjnd) ,9fFig. 4-4.) If the forward force on the more massive box is F, what is the acceleration of thndj9 ifu m,z:)e less massive box?

Two boxes are connected by a cord running over a puh/lzq6 uu+mahl4+6x rlley as shown in Fig. 4-5. B+uq/lax l6+h muzrh4 6ox I of 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 an8kgp cc c. cpwt(p.i6(d kinetic frictions between a 3.0-kg box and a desk are 0.40 and 0.30, respectively. What is the net force on the box when a 15 N horizontal force isk8i6 t( pgw(.pccccp . applied to the box?

  The coefficients of static and kinetic frictions for plastic on wood are 0.50q ttacp-7jj1h*, u2 mt 70bwdz and mcbttwhj 1-j7* d2t,7qpz0 ua0.40,
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 direct3 4taj5q,vui7 enxde 3ion. It slows and comes to a stop x iuqen,d 4e5av3 7t3jwith a constant acceleration of -$2.45 \; m/s^2$. What is the coefficient of kinetic friction between the object and the floor?

  A 10-kg box sitting on a horizontal surface is pulled byj jbxhv- mr.91 a 5.0-N force. A 3.0-N friction force retards the motion. What is the jm -jx.19bvhracceleration of the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg mass, fr7u- wgo4qn7zrom 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 initial speed of 10 m/s. It s hog-7(9xykmqg5si6sjkmn15o 0d u)dlides 50 m on the ice before it stops. What is the coefficient of kinetic friction between the p1x n o9gd kdi6hq -5sgks)0m57( jmuoyuck and the ice?

  During the investigation of a traffic accident, police find skid marks 90.0 m lo-/3/3wthc0oeq-fykr9r3po7 : tezwd tr oq: zng. They determine the coefficient of friction between the car's tires and the roadway to be 0.500 for the prevailing conditions. Estimzp f3rt3qdz- e:oe9 /-o rkw7wtyqrt3: c 0ho/ate the speed of the car when the brakes were applied.

  Two boxes of masses m and 3m are stacked. (See o8ga),okj8gtrle:l6 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 t,8:la 8j)ol oeg6gkrbox does not slide on the more massive box, what is the static friction force on the less massive box?

  Two boxes of masses m and 3h,vkxd f5u2 -om are stacked. (See Fig. 4-6.) The surface between the mor2- ,okvhxd 5ufe 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 static friction between the boxes?

  An object is on a frictionless inclined plane. The plane is inclint.j2d w9yvjru5t- 8bh ed at an angl. 9bdjwth-2yrvu5 tj8e of $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that makes an angle ofeaj.w7mbq fh qp(((:u $10^{\circ}$ with the horizontal. If friction is negligible, what is the resultant force on the sled?

  A mass is placed on a smooth inclined plane with an angle o2e j5r m6cvo4gf $37^{\circ}$ 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 smooth inclined plane tilted at an angle o oy8+rppe7t h5f $35^{\circ}$ 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, ateej5a ap55h 29tfz lz( a constant velocity ofa5t5ef5e(jz9p2 hz al 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 oa slayl,0zsm 0n)c ,jp98y.lm slides 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 dopfj ktmfi; m8bxi90be5p 9j,nb -g2o. wn 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 weighing 5yfrbjm**)rx d7/p e- 9et/scw- eyd4c00 N along a rough surface. The cable attached to the log makes a*w) er7/dep-b xcmfjtey-/rdy *s c94n 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 h4t z-,l6 ztixraf -o1from rest on a rough inclined plane tilted at an angle ofh xr 1l,4ott-fiza z-6 $33.5^{\circ}$ 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 plan9re 57 a3rorv/0whzhxe. 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 planrv 75ahr03exohw r9 /ze?