Which of Newton's laws best explains whn6,jet z8*wk 6m ucuq5y motorists should buckle-up?

  When you sit on a chair, thhxlkf j lm9g.4f3,ux/e resultant force on you is

  In the absence of an external force, a moving object 5ys*/w6m s*zetapw z* will

  When the rocket engines on the starship NO-PAIN-NO-om3kgn dqd)7p ,dew ,,evf n*6GAIN are suddenly turned off, while traveling in empty spad6g,e dn)ok nm,3d7ve ,fwp*qce, the starship will

  A rocket moves through empty space in a straight line with constant speed. It ev3(eik28afutgfd. 6 is far frdue( et6. 8vi2ga3kf fom the gravitational 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 moving bus, facimb c.l*xcdb8q/k2omrt xq .28-j e 1mkng forward, and you suddenly fall forward. You can im-xl2m rk2cb8kj 8mbqo1 . *dtxc. qem/ply from this that the bus's

  You are standing in a moving bus, facing forward, and you suddenly fall forward 76lslehpus chbzqy; )* nn(42as the bus comes to an immediate stop. What force caused you to fall forward? h2e6suznlhq);b7 psc4y* n(l

  A constant net force acts on an object. k 8mpxu *kt,-aa5xa54iukq 8eDescribe the motion of the object.

  The acceleration of an object is inesdqy1h s )njd:k k; (4):ahqyversely proportional to

  A net force F accelerates cza3r 2h:q x t (tai3e jnty)6)*y8auva mass m with an acceleration a. If the same net force is applct*n3i x )eq32t u:6ht z8)v j(raayyaied to mass 2m, then the acceleration will be

  A net force F acts on a mass m an/dv*j /ph;mre48sgo.+v j*ajc a x5g sd produces an acceleration a. What acceleration resggh ajd+p*. vsae mj c*48;x /jv5ro/sults if a net force 2F acts on mass 4m?

  If you blow up a balloon, and then release it, the balloon will flyvg 0:extqexl/gj rp20.144orjej ( ,xtw/q ll away. This is anel1( q e g ,p qlv00tjrwtgx.jox:x42el4/r/j illustration of

  Two cars collide head-on. Atc)uyr;beo; o e(6wy; mwf0)ps9 oqq5w every moment during the collision, the magnitude of the force the first car exerts on the seo5rbmfoy ;) c u)ow 6p;qy( sqwewe90;cond 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 anu3xl:tmtja 2 n w57jg/ object, the force which the object exerts on you wi jmw j7 algu2:xt5/3tnll

  Action-reaction forces m7yfm)1, rujc a3g1kw

  Action-reaction forclu) by vj;2la.b4nps7 6k9kmhes are

  A 20-ton truck collides with a 1500-lb car and cauk +7a)5yo aoe4zc uc j:w 9lv,nlzt:7hses a lot of damage to the car. Since a lot of damage : y5n j:c7vwah zl7eo49z) ou+,ktacl is done on the car

  An object of mass m sits on a flat table. Thl lwf161r/ty pe Earth pulls on this object with force mg, r/1ft1 yl6l pwwhich we will call the action force. What is the reaction force?

  A child's toy is suspendrywfviv(; ; g*g,yhw9 ed from the ceiling by means of a string. The Earth pulls downward on the toy with its weight force ofygw *v;rgvh;fi ,9y(w 8.0 N. If this is the "action force," what is the "reaction force"?

  Your bat hits the ball6c+uk qci9 f otbw(.:p pitched to you with a 1500-N instantaneous force. The ball hits the bat with an instantaneous f:coc6tku q+ bpiw9.( force, whose magnitude is

State Newton's three la kpmwn)m+xd -tl/b;i(jrw: 0cws.

  Mass and weight

  The acceleration due to gravity is lower on the Moon thanfk qqzb 6)v-n+ on Earth. Which of the following is true about 6+vn zbq)-qfk the mass and weight of an astronaut on the Moon's surface, compared to Earth?

  An example of a force which acts at a dis9 gw;s4qm;khn tance is

  Who has a greater weight to mass ratio, a person weighing 400 N or a p fz n/rc1o vvnrx3..4derson weigdo fvvc1zxrn/3 . .rn4hing 600 N?

  A stone is thrown straight up. At the top ovg, t7uzy yo02f its path, the net force acting on it isyuz0ovyt2g, 7

  A 20-N weight and a 5.0-N weight arkh62,qq6uiapf8t9 u xtxp4zyi 3z7(ye dropped simultaneously from the same height. Ignore air resistance. Com86 y3 7,p uaph9z 4xyfz iq(kt2uxiq6tpare their accelerations.

  A brick and a feather fall to the earth at their respective termh(vba nfudx90ume ;z v.*4c s kr:g*i1inal velocities. Which object experiences thr( c fmz9xaendvvkgu0 14hb u;i**:.se greater force of air friction?

  An object of mass m is hanging by a string from the ceil bz1ac.fhb,xm3a0j9jxqe) 5ting of an elevator. The elevator is moving up at constant speed. What is th1 jf0) bm 5j9tb,xx3cqehza.ae tension in the string?

  An object of mass m is hangiqk(b8g-4dfx zwjaa;9 ke 5lqp- ke4. mng by a string from the ceiling of an elevator. The elevator is moving upward, but sloa j--k5emkdp .lqf;8q9xwez b4k4(ga wing down. What is the tension in the string?

  The force that keeps you from sliding on an ic,ncv:qxwu * r)b:mks 8y sidewalk is

  It's more difficult to start moving a heavy carton froi5k bde*r*rcj ;s +nzmgcjf. 1v8u.mso//h 8fm rest than it is to keep pushing it with constant5+ rs mbcck iso *rhg * j/fnze8;md/1.f.j8uv velocity, because

  A horizontal force accelerates a box fn 5y xip7ie 0mfzsw6d, 1fmo6cv9+9rhrom rest across 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 horizontaz69, xfh wno7y+9demc vri5smf106pil force is doubled. What happens to the box's acceleration?

  A packing crate slides down an inclined ramp at constant vbw;uig( t,s* nelocity. Thus we can detb wisnu(;,g* duce that

  A block of mass M sl; owa9m tjt3)xides down a frictionless plane inclined at an angle q with the horizon3)9amxwjt ;ot tal. 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 ang, s5 v26c iff7fizbaeq20qw,dc; rn2yle q with the horizontal. The normal reaction force exerted by the plane on the blocb7q,c6ecafsn f52;2id 0vqf, ziy2rw k is directed

  A block of mass M slides down a frictionless plb2wyg- fvm k9z(kws25 ane inclined at an angle q with the horizont 5-g m9 wkz2by2fvswk(al. The gravitational force is directed

  Two toy cars (16 kg and 2.0 kg) are released simultaneously on an inclined l(,a 6 hvbl )ia3s8ln4r xtbz:plane that makes an angle of 6)rl3itz ,baa l: 8nhlsbv 4x(30e with the horizontal. Make a statement which best describes their acceleration after being released.

  An object sits on a frict2ob9 oy* /:8a doaqzld25y3 z;pdwdh hionless surface. A 16-N force is applied to the object, and it acceleratespo h;b :d* l5woo/z8hzyadd2y 32qda9 at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg cal,9qpff d(k5 an accelerate from rest to 27 m/s in 7.0 s. What is( kfqdflp9,a5 the average forward force on the car?

  Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s in 2.0 s. What iyxx 0: 9syej1f1k8x0mqzp2z q8mkdk.s the net force acting on the 1yey028m8xx.k:z9kpmd1 s kx0fzqq jbody?

  An antitank weapon fires a 3.00-kg rocket which aclsmt9;*p 14 1fzm+yd i*;jigsbzv/euquires a speed of 50.0 m/s after travelinjm9e;f+ ; 4u/** si1z bygspzd mvtl1ig
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 f c(hq9ix m ;p*fb0fnk8orce that you push a 10-kg mass from rest,90f;b8(pk mh*qxicf n

  What is the mass of a person who w om3tzo p (0chd)nvn6(eighs 110 lb?

  What is the mass of an object that wegc0ft9fbw ;y,ap4 l5r ighs 250 N on the surface of the Earth where the acceleration due ;gptwa,9yl fc0 f54brto gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. What is the :s3bvchpj9yo*p y0 k)q7m aoe+(+v i imass of the object on the surface of the Moon where the acceleration due to gravity is only 1/6 ofb0vhvm79:e+) *yj3(y+caqsi opkoi p that on the Earth?

  Object A weighs 40 N on Earth, and object B weighs 40 N on tugwd-0c b748ne:2(lhsc wz f the Moon. The Moon's gravity is one sixth of Earth's. Compare the masses of the objec2c0u e7h8g4: zw tfsl-d(bw ncts.

  Sue and Sean are having a tug-of-war by pulling on opposite ends of a 5.0-kg ropo a-fs v;; ypw;(*pjjte. Sue pulls with a 15-N force. Wh; vtyj psjw;o;p a-f*(at is Sean's force if the rope accelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books rests on a level frx)x:6e.o6 ls uj8ltapictionless surface. A force F acts on the stack6ojt x)psel8au:x .l6, 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 elevator. What will.n;k43w czonhfmk6 m + the scale be z cfnw+n36k ;4om k.mhreading when the elevator is accelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If tv7a2pesdl : rs+02k vphe mass of the person is 60.0 kg and the elevator accelerates downsesp0pldva:2r72 v k +ward with an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale rides in an ele(n i+wjie9l, 5 u;ak ceg4t/lbvator. If the mass of the person is 60.0 kg and the elevator accelerates upward with an ac; + lgn(/ewk9 ,5iitaclu4bjeceleration 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 mwefz/*9btk(0j- dhz y agnitude of 8.0 N and is directed due north. The tj9/ eb-0zk wfyzh*( dsecond force toward the east has a magnitude of 6.0 N. What is the acceleration of the mass?

  An object of mass 6000 kg resw*.z f3f1 rv o()co 8hiq)kbints 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 distanck*fir 3 8(ibv qo1w ))n.zofche if the load is not to slide forward into the cab?

  An object of mass 6000 kg rests on the flatbed x5ikyzlf wkj w:9t. 5.c;9w iyof a truck. It is held in place by metal brackets that can exert a maximum horizontal force of 9000 N. When the truck is tra 5w zck 9kityw.l5fx ;9y.j:iwveling 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 Fig. 4-1, if M = 0.60 kg and;1:o:yjjscdj lq*. wv m = 0.40 kg, what is the magnicw : :ljjsv1.oy ;dqj*tude of the acceleration of the system? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1;ro y9 u6tc ab7xf;nk)h9r mb0, if M = 0.60 kg and m = 0.40 kg, what is the tension in the string? (Ignore friction and the mass of the pulleyh9bfm;r9 0o6n7ck;)tuab r yx.)

  A student pulls a box of books on ar td 9bm03dam; smooth horizontal floor with a force of 100 N in a direction o90d mab3d;rmtf $37^{\circ}$ 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*z5.9;u kl3fs05 nu lbymihuz horizontal floor with a force of 100 N in a direction of 37.0e above thu9 fl.5ui3;zly sh mbkn*5u0ze 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 as shvel8jc ioodvtf, 15.1j/ uxi9own in Fig. 4-2. What are the tensions in o 51i jufjxicv9.o d/1vel,8tthe ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is the m,pm sx7:+-4bbdgh s yy8l67zwp5nwql ass of the traffic ligh+p l- bnlhb6q5x7d7 4y8g :pwwss,zy mt?

  Two boxes of masses m and 2m are in contact with each other on a frubq()sq st6pmr5 n+-k,eik, nictionless surface. (See Fig. 4-3.) What is the acceleratio6kbuqp+s n5) m(nqert-k,,i sn of the more massive box?

  Two boxes of masses m and 2m are in co8cuar3 )kxj 9yntact with each other on a frictionless surface. (See Fig. 4-3.) What is the net force on the more massxcja 83kyu9 r)ive box?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4-4.) b8qc /f*b+h+ojb y-tf If the forward force on the more massive box is F, what is the tension in the connecting rope?o+fq fhbc* b+/tb -8jy

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4-mjbbj1m ykqp,//e (-j4.) If the forward force on the more massive box is jp/bme km,1qyjj / b-(F, what is the acceleration of the less massive box?

Two boxes are connected by a cord running ovk -ibgu8 6tz8 m9,simter a pulley as shown in Fig. 4-5. Box I o,gz 8ii 8u9b-m6skmt tf 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 f,3b gfph7 1uk-f-evbvrictions between a 3.0-kg box and a desk are 0.40 and 0.30, respectively. What is the net force fb7-1vbkghfpe vu ,-3on the box when a 15 N horizontal force is applied to the box?

  The coefficients of static and kinetic frictions for plastic on wood are 0.5i alg9 cdg50y50 and 0.40c0i gy5gld5a9 ,
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 surfacexwft( ,3pg rncs ,3p.fqk9 :ct in the +x direction. It slows and comes to a st,n93: (cgtrkpftw ,cqpf3x .s op with 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 adh h0 q4t+i2psog-3o45ttokbaq0pu c0*cp+pulled by a 5.0-N force. A 3.0-N friction force retards the motion. What is th0ah32ub0 qtpgt4+dtoq* o5oc4ks h pc- 0i +ape acceleration of the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg mass, from rest, at a rate 8-vo-ghm6px;o 7 2zakg,evbe 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 y*8b-s w6d y30jyf bsnof 10 m/s. It slides 50 m on the ice before it stops. What is the coefficient of kinetic friction between the pu-bdsyf8yj w*n s y306bck and the ice?

  During the investigation of a trkh 6dz(n.fu hu6r/wftyy79q.affic 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 the prevailing conditions. Estimate the speed of the car when the b(k nhudyyz./frwhf97.ut66 qrakes were applied.

  Two boxes of masses m and 3m:5cb d/k4qkmb are stacked. (See Fig. 4-6.) The surface between the more massive box and the horizontal surface is smooth and the surface betweekk:5b q/c4d bmn 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 Fig. 4-6.) The surf76ki f2 rma8cu )k1qnvu/nau x9( h*n8smg3 isace 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 statu7ui9nr 1h *)unnsf3x8 m(i/vgka6 mq acks28ic friction between the boxes?

  An object is on a frictionless inclined plane. The plane is inck ,cys:j;k *no0qg ;l1b ie;rplined at an angl;y l*:ck ,q ;penr0oji k;s1gbe of $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides doenxh)4 , h3ayap y r vo)n+vwebnf-9n9+1 +xfdwn a 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 smooth inclined plane with a: wa;)5nh fr)+.sz.y nzkl)d og*aete n 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 at an anz ep0, cb/0fhggle 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 velocict)9vtouu9( t ty of 6.0 m/s.u utv9o t(9)ct
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 dow 5hz ;olpcgb/ t2/ixw+n 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 pwrp95pp n b21rough $37^{\circ}$ 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 wei12d i)tluaz- qa 7,oqeghing 500 N along a rough surface. The cable attached to the log makes an angd a z,qilta)q72eu1o-le 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 )fvx5oj c. h 3cxj.p1rplane tilted at an angle jjc c3rox5x.f .hvp)1of $33.5^{\circ}$ 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 +we* uv pw*a,vincreased until the object begins to slide. The ang,ue pvww+**avle at which this occurs is q. What is the coefficient of static friction between the object and the plane?