Which of Newton's laws best explai j4 /yp;v;wrui9hvtc 6ns why motorists should buckle-up?

  When you sit on a chair, the resultant force :kp2v3ap/ aby on you is

  In the absence of an external force, a moving objkqez/6 fi5 v 20pyh(fg62q rhmect will

  When the rocket engines on the starship NO-PAIN-NO-GAIN are suddenly (3wbfu4 p: i. 3*g37hfdwjci8v hnfp rturned off, while trajnipdr* hu7 (.f3gb icf 84pw3w:f3vhveling in empty space, the starship will

  A rocket moves through empty space in a straight line l jwpemg) q2slaff- b,p*lo h(1-jbcc; y6+t( with constant speed. It is far from the gravitational effect of any star or planet. Under these conditions, the force that must be applied to the rocket in order to sust,l bs- yf wfcq*g26-;tja lphcep(+l)(m1ojbain its motion is

  You are standing in a moving bus, facing forwxt zi3vyzs,hy,--oitj:: 4 xs ard, and you suddenly fall forward. You can imply from this that the bus's tt s3zx z yvs-:ii:,,ojhx4y-

  You are standing in a m /ansll-:b k,eoving bus, facing forward, and you suddenly fall forward as the busbk:-ln s,l /ae comes to an immediate stop. What force caused you to fall forward?

  A constant net force acts on an object. Describe th:wz s +2vrg-eo rl5e)fe motion of the object.

  The acceleration of an object is inversely propor22u+2ccs0nlk oyb:q ytional to

  A net force F accelerates a mass m with an acceleratmm/.cj v-iy lcce7 quun76)etn d3 /t2ion a. If the same net force is applied to mass 2m, n7t/icu lu7-tymve2nmj3cq/.ec d )6then the acceleration will be

  A net force F acts on a mass m and produces x 7jp x(*(3 25rhfrcpo*jgtskan acceleration a. What acceleration resultf5 (*2gpjp*xsr7jtx rho3c(k s if a net force 2F acts on mass 4m?

  If you blow up a balloon, and then release it, the balloon mzadko 8jw6(a lcxybdo b53v -89; sn9oo,5pwwill fly away. This is an illustration o8k -zb(wy, l 659sab3mo p9 nxdd58owoaj c;ovf

  Two cars collide head-on. At every moment durivd/yuhk1y-rp1 do .4kf; awg3 ng the collision, the magnitude of the force the first car exeryro1-v/akfh. g y ud wd13p4;kts on the second is exactly 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 object exerts onx-q 1ch stv)36 r8hbmq qbu33a you willaqrhx 6- v1bst3q )8qc3bu3 mh

  Action-reaction forces-05ac uuy ol) m-mrhto;;iec 5

  Action-reaction forclewd5l( le y:0es are

  A 20-ton truck collides with a 1500-lb car and causes a lot of damage tolmfsx- n;8oqe g;;uzln- u4 n( the car. Since a lot emuno(f x8;l-n;l u ng4- sq;zof damage is done on the car

  An object of mass m sits on a fl/:bwe6pdoaa64hc8 z p7x tu,p)8vg bgat table. The Earth pulls on this object with force mg, which we will caucpteov4xg878a b,p w:dpb g/ a6hz) 6ll the action force. What is the reaction force?

  A child's toy is suspended from the ceiling byn)oo xit.,we .hp41 6ghu** jm(unbls means of a string. The Earth pulls downward on the toy with its weight force of 8.0 N. If tpsmx bg t(1j*. un*4hlueiho o)w,n6.his is the "action force," what is the "reaction force"?

  Your bat hits the ball pitched to you wihgn/sz-y/ a(bth a 1500-N instantaneous force. The ball hits the /ybhg/a z-n(s bat with an instantaneous force, whose magnitude is

State Newton's three lafv,;vma9vnh+ e0n hjr( 5v 4maws.

  Mass and weight

  The acceleration due to gravity is lower on tpn/d1w5 b; )cid9zzx uhe Moon than on Earth. Which of the following is true abou) ;w indx/bz1u z9dpc5t the mass and weight of an astronaut on the Moon's surface, compared to Earth?

  An example of a force which acts at a a(1e(i;g3zw/ kd h gnadistance is

  Who has a greater weight to mass ratio, a person weighing 400 vhkotr7s* 8oo.+6x*- zktm eyN or a person weighing 600 +k*7other8v6-*.mooz yt k sx N?

  A stone is thrown straight up. At the top of its path, the net force acting on er.k85g.9vi vywg pxzd1:rr z/2fe6 kit k.ev9 1pe6gzf/rrvizy : kg.52 8wrdxis

  A 20-N weight and a 5.0-N weight are dropp+go.izti *ig2bh0hjj ; at)i 0ed simultaneously from the same height. Ignore air resistaih2t* t;0gzha+obi ji.jg ) 0ince. Compare their accelerations.

  A brick and a feather fall to the earth at their r:rpqp0oe i ,r,oq/y2;)mz avlespective terminal velocities. Which object experiencerp,orp 2lqq0:)eyv, m/;aioz s the greater force of air friction?

  An object of mass m is hanging by a string fromi ig1ft-ae/mc/ w6;iak-+u l f the ceiling of an elevator. The elevator is movit+i /wc -i a/m61uf k-;legafing up at constant speed. What is the tension in the string?

  An object of mass m ip v h5m9qc*ih53dbvr5s hanging by a string from the ceiling of an elevator. The elevator is moving upward, but slowing down. mh9qdh3vr* v 5cp5b5iWhat is the tension in the string?

  The force that keeps x5rwjm,us9aqphl: b d/5n e0; you from sliding on an icy sidewalk is

  It's more difficult to start moving a heavy carton frzynz -0fmg8a4wnd vbw 2,p;)som rest than it is to keep pushing it with constf20a sz ,gd-v4n yb; p)zw8wnmant velocity, because

  A horizontal force accelerates a box from rest across a hori/ u0w65,(vxso) q nrv zzqgdr kg-0cg9zontal surface (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 vnrsd rqgkowu zx0)0 (6z,9c5- gq/vg the box's acceleration?

  A packing crate slides down an inclined ramp at constant y ;fdji;t3we; velocity. Thus we can deduce t3; t wje;id;yfhat

  A block of mass M slides dowi1o6 ticn)oh.+,2locf v+olon a frictionless plane inclined at an angle q with the horizontal. The normal reaction force exerted by the plane on the blocoocf,cin l+v i)2o1 l.oo6+ thk is

  A block of mass M slides down a frictionless plane inclined at an angle qh uh8uohuu5 6*gau;8a with the horizontal. The normal reaction force exerted by the plane on the block is daouhg uua uhuh5 868;*irected

  A block of mass M slides down a frictionless plane inneo yegi;aw/,bk b:(+clined at an angle q with the horizontal. The gravitate+i/bknyga :o ,w; eb(ional force is directed

  Two toy cars (16 kg and 2.0 kg) are released simultaneously on an invj*cdd:kn,90iy2 b fa bjt4q(clined plane that makes an angle of 30e with the horizontal. Mai0dand*t b:( 2vkyj,cbf9 4jqke a statement which best describes their acceleration after being released.

  An object sits on a frictionless surface. A 16-tx p1e3uzf, n gm*z*a/N force is applied to the object, and it accelerat1pfz/ e*,3m* utgxanz es 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/s in 7.04vjsj:x5qra)d x-g(pz/ p5k a s. What is ts - / xd5v:jzkjqapar4 5()pgxhe average forward force on the car?

  Starting from rest, a 4.0-kg body rapr+pc7q9 ul/xin.k -o6 imz,:q4pi yeaches a speed of 8.0 m/s in 2.0 s. What is tukm aq.6p7ixpc/ 4yn,+qp r:i zl-9iohe net force acting on the body?

  An antitank weapon fires a 3.00-kzm d f41l/o4gumnrwm0 hc 7m90g rocket which acquires a speed of 50.0 m/s after 1hf9u c/og4mm0l40nmwz 7dmr 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 sg;yul;04p1; sz)m) iue wq3-i : kds.kuwzzfs ame force that you push a 10-kg mass from rest,)0;u 3y:k.isp 4zi- u);w;wfme1qsudlzk zg s

  What is the mass of a person who we/ f2+j1wd5sc:pppt l iighs 110 lb?

  What is the mass of an object that weighs 250 N on the surface of 0 .nhvs4mb0cq* p 0rrpthe Earth where thhcrpv*n0ps0 rq0.b m4e acceleration 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 ob71whi 1cn.c zgject on the surface of the Moon where g7wnich c 1z1.the acceleration due to gravity is only 1/6 of that on the Earth?

  Object A weighs 40 N on Earth, and object B web3 rl 9d/,n7xxw,kz psd8b bl-ighs 40 N on the Moon. The Moon's gravity is one sixth ol79 x,bw d,-s3zd/pbx8 brklnf Earth's. Compare the masses of the objects.

  Sue and Sean are having a tug-of-war by pulling on op1hhw 9 h--c3itx1f9 2 bqbttbpposite ends of a 5.0-kg rope. Sue pulls with a 15-N force. What is Sean's force if the rope accelerates towatbh1b1if9wc2x hh9 3tqbp--trd Sue at $2.0 \; m/s^2$?

  A stack of books rests on a level frictionless su9x5f 8 ellgh9xk/v 1ksrface. A force F acts on the sta1/5hks lkev9l xf9 8xgck, and it accelerates 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 elev kc4*wntkp64m m:n:vaator. What will the scale be reading when thmkt:kmp:64va4cnn *w e elevator is accelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the mass of t 2hyvl,l:8 x23 x)o,brq fdxw2cb5e afhe person is 60.0 kg cx lr bh afd,258)x:ewyq 3fb2l,v2xoand the elevator accelerates 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 thhjs 7gfn,; ujpi8pyp3eo ,b kvi3.5 i+e mass of the person is 60.0 kg and the elevator a3ieys7+3phn8og. fv5b ,jk upjp;i,iccelerates upward with an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal forces act on a 5. rgr jk) osrhya/ :k*yk(th02h3j+l-l0-kg mass. One force has a magnitude of 8.0 N and is directed due north. The second force toward the east has r0ajk k/(:jygrhl2 rt + shoyk- *)hl3a magnitude of 6.0 N. What is the acceleration of the mass?

  An object of mass 6000 kg rey0gpj l90o 1hke9uk; osts on the flatbed of a truck. 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 stopping distance if the load is not to slide forwek 0ho ;kuo9p9yj0gl1ard into the cab?

  An object of mass 6000 kg rests on th -* .hqzgt2 fuvdtptzzk48 ;4he flatbed of a truck. 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 t8q4-p2u ;. h z*ghftzk4tvzd 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 kw(u2us k cm9c)g and m = 0.40 kg, what is the magnitude of thu c)2u (cmk9swe acceleration of the system? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg d; j+3jz/a s z/jatij5and m = 0.40 kg, what is the tension in the string? (Ignt+i5zsa/jdja;/ j z j3ore friction and the mass of the pulley.)

  A student pulls a box offh:g;exvvj;j8f3fk wc r d-32 books on a smooth horizontal floor with a force of 100 N in a direction h-vvx:wrje283;f; j3 dkcffg 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 bo jva;l a*w. u:rky fo.ab/-v7bg8dn3 wx of books on a smooth horizontal floor with a force of 100 N in a direction of 37.0e above the horizontal. If the mass of the box and the books i3o/w.7rvf vaw8 -*b.:k;g yabndjl ua s 40.0 kg, what is the normal force on the box?

  A traffic light of weight 100bmb4 ni0a l r7.hva709k 3cmqs N is supported by two ropes as shown in Fig. 4-2. What aremmc.nl707bsb 49ikha03a v qr the tensions in the ropes?

  In Fig. 4-2, if the tensiurz jjn7 /2/eaons in the ropes are 50 N, what is the mass of the traffic ligeznuj/j r 7/2aht?

  Two boxes of masses m and 2m are in ci0w /iqd(dc28r-an+/ dfvngf4rs rt )ontact with each other on a frictionless surface. t(0 fq2c- gfv/san4r+i) rd w/indrd8 (See Fig. 4-3.) What is the acceleration of the more massive box?

  Two boxes of masses m and 2m are in col)dvvbo jn(8divp ;3s, 49lhhntact with each other on a frictionless surface. (See Fig. 4-3.) What is the net force on the mor3hhnvd 9)lbp voi,;(8vj4l dse massive box?

  Two boxes of masses m a/;y zso*y ukix4)bk rtw z5,(bnd 2m are connected by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the tko*;zk ib 5bzxsy(y4, /r)uw tension in the connecting rope?

  Two boxes of masses m and 2m are connected by a ri+m:my :o3:9w,wk 8iaky ruqz ope. (See Fig. 4-4.) If the forward force on8m o,zi+w9qr y3wyu :ika ::mk the more massive box is F, what is the acceleration of the less massive box?

Two boxes are connected by a cord running over a pulley as shown in bzj 8*x(1i ,;pu:d9;gcvgd ceftlje6Fig. 4-5. Bg986( xc;j;jdv,febldt *ezi1 : ugpcox 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 and kinetic frictions between a 3.0-kg boyyq z65ay+)y wjh.ug8x and a desk are 0yq )w. yazhuj y56y+8g.40 and 0.30, respectively. What is the net force on the box when a 15 N horizontal force is applied to the box?

  The coefficients of statiu*ke/bbj 2-vt( gtj +fc and kinetic frictions for plastic on wood are 0.50 and 0.40 *jk bj/2vgt(e-bu+ft,
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 c* aw ( )tj,cc fux5gi9a7l- +irs9pqpiomes to a stop with a constant accel 7f5tl(ixi9uq* ac)i-g9psc ajw p,+reration 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 surface9ex,q )hj k4yu is pulled by a 5.0-N force. A 3.0-N friction force retards the motion. Whatjh ye,kqxu )49 is the acceleration of the object?

  A horizontal force of 5.0 N accelerates a 4.0-d- dhy(zi b36fkg 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 gi :s+1xia wx9fdven an initial speed of 10 m/s. It slides 50 m on the ice before it stops. What is the coefficie+ fd1xwx sa:i9nt of kinetic friction between the puck and the ice?

  During the investigation of a traffic accidentm:4r ,sd ;,kkyzl1stp(r rv,b , police find skid marks 90.0 m long. They determinervys 1( ;skzl,rtmkbr,d,4:p the 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 md4 ornl tf/r u94 y:1flzp,z8h and 3m are stacked. (See Fig. 4-6.) The surface between the more massive box and the horizontal surfar,4h9zlp/yd :8fo41 tfr ln uzce 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 m and 3m are stacked. (See F wvuh7rt y 9m2 8(9r2po;ycrztig. 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 stato9(ztt r2puy2 yc98vr;h7r wm ic friction between the boxes?

  An object is on a frictionless inclined 0xw.,c0 9kg)u cohiqs, x(mhfplane. The plane is inclined at an anglef)suc9h(ch g ix.w,,qx ok 0m0 of $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill t5rq 9m2 a8rmurhnc 2c7hat 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 smooth inclined plane with azwb9e47wi uchw87o r4/d 8ndwn 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 smooth inclined plane tilted axc- t -.u;jrxit 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 orifb;9q2rp a*1 de 9bjfi9 9efpb 2b1qr;aj *dr 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 mc q 6q87/zm*gl-m fgmg 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 d:;yuvtwon,t9 p 5/jil own 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 500ffva p*+52z( zrb ecl/ N along a rough surface. The cable attached to the log makes an fl zvbp ef+cra (z2/5*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 tiltedsj- fc7t8hg4+ rrir7t at an angle oft4+7 i8rgs- t rjr7chf $33.5^{\circ}$ 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 p wwp m4 s0j/w*gil/tbu58v3e tlane. The angle of incline is gradually increased until theswj u lpm/3 0/8w54b*wgittv e object begins to slide. The angle at which this occurs is q. What is the coefficient of static friction between the object and the plane?