Which of Newton's laws best explains why motorists shox*wy+q +w rfw+uld buckle-up?

  When you sit on a chair, t771iuiy n0qkphe resultant force on you is

  In the absence of an external forwg mxix 4w7ugz 1:dx)+ce, a moving object will

  When the rocket engines on the u jnf. c*i:ow.-zdz4 jstarship NO-PAIN-NO-GAIN are suddenly turned off, while traveling in empty space, the starshicu ..znj4*-f dozi:w jp will

  A rocket moves through empty space ify9u0fy-/hq f 4tokp )n a straight line with constant speed. It is far from the gravitational effect of any star orfto )04y fk9 pq/hu-fy 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, facing forward, and yos k(j9t5-oc,r8 ifbz : ekk+axu suddenly fall forward. You tkks89-fxr,zje5a + kico:(bcan imply from this that the bus's

  You are standing in a moving bus, facssi :7(lnmj7u;4s cnxwjb 04xing forward, and you suddenly fall forward as the bus comes to an immediate jc w4s74nslm7:i(s bju0 xx;nstop. What force caused you to fall forward?

  A constant net force acts on an object. Describe the motion of the object.jw11) faz:mq v

  The acceleration of an object is inversely pfdncmv586 wq;3 ;e:qjmjub k :roportional to

  A net force F accelerates a mass m with an acceleration a. Ifi bf/l1-mkd hyp(h1vu6v0i ,t the same net force is applied to mass p,udifvy/t6 hmk-b1h0vi(l 1 2m, then the acceleration will be

  A net force F acts on a mass m and produces an accgy:pr q;hy b1tue,0 h6eleration a. What acceleration results if a net force 2F act; 0pghb6:ye1q hruyt ,s on mass 4m?

  If you blow up a balloon, a8na79b x,x5ala. uxwsnd then release it, the balloon will fly away. This i5xa.xan swu978xal b, s an illustration of

  Two cars collide head-on. At every moment during the collision, the magnitud8 2e gqh19i bbsh+*wgre of the force the first car exerts on the second is exactly equal to the magnitudee9i*rgh8 1hgb ws b+q2 of the force the second car exerts on the first. This is an example of

  If you exert a force F on an objectu 1svjyj1f/mxyg63pd 2a f6,w, the force which the object exerts on you willgvj y66yawsmd3 x12/1fupf j ,

  Action-reaction forc9zmci3 yjp r ,iqo.++ges

  Action-reaction forcm pk5 adks30,4w+lcy wes are

  A 20-ton truck collides with a 1500-lb car and causes a luf 00q /tpwu(not of damage to the car. Since a lot of damage is done on the cp u0(fqtu n0w/ar

  An object of mass m sits on a flat table. The Earth pul5 )gmo t.wq,hlls on this object with force mg, whig,q. 5w)oh lmtch we will call the action force. What is the reaction force?

  A child's toy is suspenh0+ jcb.l+ yisllx1+s ded 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 "reas sy++lb0 i jh.x1l+lcction force"?

  Your bat hits the ball pitched to you with a 1500-N instanhy/7n*y5 wv vem,upb,taneous force. The ball hits the bat with p *v7/,e,nwv byy5 uhman instantaneous force, whose magnitude is

State Newton's three lak7ujb izd. rmzr0 h0/0ws.

  Mass and weight

  The acceleration due to gravity is lower on the Mofy r4kl7m cr+i7bz08ron than on Earth. Which of the following is true about the ma8fb0lr+rrmzc7y4k7i ss and weight of an astronaut on the Moon's surface, compared to Earth?

  An example of a force which gmpj+ko tzx8-tqn sg26 :c689qsf- vbacts at a distance is

  Who has a greater weight to mass ratio, a person weighing 400 N or a personjjt l+akunu30ay 0k;. weighika3 y 0k.0+unjjl; uatng 600 N?

  A stone is thrown straight up. At the top of its path, the net force actiztr t5) :c t:nkvc1j1kys8l1 zng on il: 1czt tckt5 1jy):vnsz1k8r t is

  A 20-N weight and a 5.0-N weight are dropped simultaneously from thpjlb5:whl am*pdx). , vdhs5/e same height. Ignore air resistance. Compare their accelerations,/ wld5ph5 s.alm:hx*jv d)pb.

  A brick and a feather fall to eg)h.m 6 gc9w a)fhv40k;ybtxthe earth at their respective terminal velocities. Which object experiences the greater force of air frifmtkh9g6)e c4 x 0);h baygv.wction?

  An object of mass m is hanging by a string frvprq ;t *) udy9q;7m1 jpef3qcom the ceiling of an elevator. The elevator 9cqu *rvq1pj7 y3pe;qtm);fd is moving up at constant speed. What is the tension in the string?

  An object of mass m is hanging b/8 ;jjqfna0v vy a string from the ceiling of an elevator. The elea;8jvv/q0jn f vator is moving upward, but slowing down. What is the tension in the string?

  The force that keeps you from slihln/rd+,p ft;ding on an icy sidewalk is

  It's more difficult to start moving a heavy carton from rest than itt r.32 w+spkcx is to keep pushing it with c3 c.+w2xrkptsonstant velocity, because

  A horizontal force accelerates a box from rest across a horiqz)mbtpt w e d94d;1/o0 r2mya.pw 9 am-nqaw4zontal 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 happwt4rbwqqo1m0mz )/ m d4aeapp a;92.-ty9d wnens to the box's acceleration?

  A packing crate slides down an inclined 1ya. b xz fzc2d-:.hjzramp at constant velocity. Thus we can deduce zbd yfh.jz.z-:2 x1ca that

  A block of mass M slides down a frictionless plane incli dema3:r ;qo0,agze) /0l:ba kgiju9yned at an angle q with th 3l0g,re9zqbm dok )iyj egaa/a:0u:;e 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 angle q withli7v-8ejvgz) vb0x+u* awde7 the horizontal. The normal reaction force exerted by the plane on the zx0uv8ge7 bave+i7v)jd l*w-block is directed

  A block of mass M slides z2zw 3 pp+0jdrdown a frictionless plane inclined at an angle q with the horizontal. The gravitational force is dirp+ z r3zpj20wdected

  Two toy cars (16 kg and 2.0 kg) are released 26 gla8+kgl:4guxiop simultaneously on an inclined plane that makes an angle of 30e with the horizontal. Make a sku lo24g ip:6xggl a+8tatement which best describes their acceleration after being released.

  An object sits on a frictionless surface. A 16-N force is appy eow,q0y351j xz gf7slied to the object, and it accelerat71s5z g,qf0xo j3 weyyes at $2.0m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accelerate from rest to 27 m/s in 7fai f);t sj,t3 x*g)fxa(gs- k.0 s. What is the average forwar;tgx)s( fs-ft,ija* kf) xg3a d force on the car?

  Starting from rest, a 4.0-kg body reaches a speed oetmiyle 4:4s8f 8.0 m/s in 2.0 s. What is t4 et 4ms8y:eilhe net force acting on the body?

  An antitank weapon fires a 3.00-kg rocket which acquires ,stevo t81xhv/vcwoz -z (;kl/+ 3ogya speed of 50.0 m/s after traw8(h3 /kto;l v,s xvzgt1c+yoe /vo -zveling
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 10dkv*y3/ j j7 if/)cjg69bxioo -kg mass from res og)9v3jj i 6ojy*bd7xf/ ci/kt,

  What is the mass of a person who weighs 114 q9d ki8)nf) yw/i/ljh4ldqi+2acgo0 lb?

  What is the mass of an object that weighs 250 N on the surface of the 5kiue139ru jgEarth where the acceleration due to 9iegu 31r5kujgravity is $9.80m/s^2$?

  An object has a mass of 6kcdv3v,4+e,sbgo uks 5h 9:h y0 kg on the Earth. What is the mass of the object on the surface of the Moskk, 3hv4yd:g95ho u+eb ,vc son where the acceleration due to gravity is only 1/6 of that on the Earth?

  Object A weighs 40 N on Earth, and object B weighs 4i3m lpw8332zqaxs)1k o 2dr sp0 N on the Moon. The Moon's gravity is one sixth of Earth's. Compare twxom3asz2r8 13) slkp3i 2 dpqhe masses of the objects.

  Sue and Sean are having aluk1qs9r-faci6aq 6 eth4s dd/ 6g,0n tug-of-war by pulling on opposite ends of a 5.0-kg rope. Sue pulls with a 15-N force. What is Sean's force ifsk ts4n66qu0d ,- rd1hce6 /f qa9laig the rope accelerates toward Sue at $2.0m/s^2$?

  A stack of books rests on a levelyut41 d6ntzw a4l kk:+qkv5 z: frictionless surface. A force F acts on the stack, and it accelerates at6 44d kn5aqtlut 1:y+vkz: wzk $3.0m/s^2$. A 1.0 kg book is then added to the stack. The same force is applied, and now the stack accelerates at $2.0m/s^2$. What was the mass of the original stack?

  A person of weight 480 N stands on a scale in an e cgwog8; ).f9/3 rxdbpyhjk ;plevator. What will the scale be reading when the elevah/)g3 rdyjw 8p9x; fp;cgk.b otor is accelerating downward at $4.00m/s^2$?

  A person on a scale rides in an elevator. If thrc+8npn jdn q9 i,,,yte mass of the person is 60.0 kg and the elevator a+,ctjr,nq8 dn,iy p n9ccelerates downward with an acceleration of $4.90m/s^2$, what is the reading on the scale?

  A person on a scale rides in an elevator. If the mass of the person is 60.0 .jh8n/33 njq kwv.lz(h82b.y icjropx u-a,ykg and the elevator acce c2lv,o/jr.-hpjjw8.qnyzu8xybn3h k .i(3a lerates upward with an acceleration of $4.90m/s^2$, what is the reading on the scale?

  Two horizontal forces act on a 5.0-k:qbwmbs(dzv,88w:szd x n 2k0g mass. One force has a magnitude of 8.0 N and is directed due no:dm2bqw, z( sdb8x :kvw 80nzsrth. 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 truc;dv/ic5e ty9i k. 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 e/idc;iv9ty5 the minimum stopping distance if the load is not to slide forward into the cab?

  An object of mass 6000 kg rests on the fl*m han9mplj: k il5d,.atbed of a truck. It is held in place by metal brack k d5m*9a:ij lmlpn.h,ets that can exert a maximum horizontal 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 Fig. 4-1, if M = 0.60 kg and m(wrwikecy km7*rl;4s;5 nh6 r = 0.40 kg, what is the magnitude of the acceleration of the system? (Igr7rwl4i;nh w; ryek 5k6(cm*snore friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg and m m 5yf;/ xpx;jt 6qkfp5mzj:*v= 0.40 kg, what is the tension iny q*6z 5 mvp;j;f/k5jxx:ftmp the string? (Ignore friction and the mass of the pulley.)

  A student pulls a box of books on a sax5t x+o:26g n ouhjxkt.oj-*mooth horizontal floor with a force of 100 N in a d:on *tj6axu2xj hxt+- .oog5kirection 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 booksx)go.yqrxne, gn75- k 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 is 40. xnxyq)gg5. erkn-,7o0 kg, what is the normal force on the box?

  A traffic light of weight 100 N is supported by two ropes tpioy wxm ,b5(oq5a,7as shown in Fig. 4-2. What are the qoti y5 5wpo,7x(a mb,tensions in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is the mass of the tra -bf ;idq2+sdko,t;i xcatw*+ffic lightoi -d+ sax,tcfqb k*w+ 2;d;ti?

  Two boxes of masses m and 2m are in contac xol1z/9 in*oe9wen cqu4f(m,t with each other on a frictionless surface. (See Fig. 4-3.) What is the acceleration of the mornwz 9ceo4lom* e9(/x qi,fun1e massive box?

  Two boxes of masses m and 2m are in contact wik5mit : qw1/veba5/t1yolo (oth each other on a frictionless surfac//til1tomb vo:wo5a(q 51 kyee. (See Fig. 4-3.) What is the net force on the more massive box?

  Two boxes of masses m and 2m are connected by a g 91bpgu 9-s2nj;hfpb rope. (See Fig. 4-4.) If the forward force on the more massive box is hp9nb-;g21pfb9sgj u F, what is the tension in the connecting rope?

  Two boxes of masses m and 2m are connected by a ropeydxa n9o cehxg s3,99+. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the accel,dns9 e+ hxao9 c9yxg3eration of the less massive box?

Two boxes are connected by a cord running over a pulle v3 n9r mhk2vs7-)nm9lx9cleb y as shown in Fig. 4-5. Boxlnhnmlv ) mvb7c99kx3sr9-2 e 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 box and aj 9r:p.d-vu1s i+en imys0.ua desk are 0.40 and 0.30, respectively. What is the net force on the box when a 15 N horizontal force is appli 0 :s- myisrepuu .9ni.djv+a1ed to the box?

  The coefficients of static and kinetic frictions for plau d:/7iuy5ba kstic on wood are 0.50 andk:a7b5/uiy ud 0.40,
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 levezk7gb/o+ me* dl surface in the +x direction. It slows and comes to a stop with aob7+ /emgk*dz constant acceleration of -$2.45m/s^2$. What is the coefficient of kinetic friction between the object and the floor?

  A 10-kg box sitting on a horizontal surface is pulled g,eg;t(qa ycu,x d-*nby a 5.0-N force. A 3.0-N friction force retards the motion. What is the acceleratqd g n(*a, tg,x-ecyu;ion of the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg mas9jol5oyr:5m51j ch r)(dsg zks, from rest, at a rate of $0.50m/s^2$ in the positive direction. What friction force acts on the mass?

  During a hockey game, a puck is given an initial speed of 10 mbv tt9 o4xol76/s. It slides 50 m on the ice before it sotv47 tx9lo 6btops. What is the coefficient of kinetic friction between the puck and the ice?

  During the investigation of a traffic accident, police find skid marks 900ms uv pzb::4g.0 m long. They determine the coefficient of friction between the c4 uvzs:mp g0:bar'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 :4*ybvvuq,ofgg7.f n 3m are stacked. (See Fig. 4-6.) The surface between the more massive box and the horizontal surface is smooth and the surface betweenn.qg g 4bf*y7vv :uof, 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.) o,w exu3k sp365wd-+bxn3blt 8 uyb:a The surface between the more massive box and the horizontal surface is smooth and the surface between 3, tx luab6b8x n-3pkyd5 +uwbowe s3: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 fricti,g:wv0 pr px h(j5tqo4onless inclined plane. The plane is inclined at an angle ofjgvro, w0tqhp 5 4:px( ${30}^{\circ }$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down af j m+mh/5r1 qp5ia0ks 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 anzklzjq* q9+ -yt l/xm,mtm9:v 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 smoo,c) nd /jxyvvp/3.5rnu,*j oat bd 0rtth 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 tl9)uxy vk/ cvq,,*+imetd y(plane, at a constant velocity of 6.emvyu* vxt(c/ kqd)il t9 ,+y,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 r2h km(biv cf*epm3evc1c / r24ough ${37}^{\circ }$ inclined plane where the coefficient of kinetic friction is 0.20. What is the acceleration of the object?

  An object with a mass m slii*j+t seuy(*f pewe9 2des down 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 500 N alongoxsmh.ozv *w0pm 39f 5if x.x/tgm21z a rough surface. The cable attached to the log makes an angle of f2zgmtm/z.f miv.5sxh 3op9o1 *xw0 x${30.0}^{\circ }$ 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 an cn.3 tknwp.kg:t .4kwangle .wnw4cg3k:.ktp .nktof ${33.5}^{\circ }$ 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 1dnn egndpp9-(16sas an inclined plane. The angle of incline is gradually increased until the object begins (n6n1 ppe -gn9d s1sdato slide. The angle at which this occurs is q. What is the coefficient of static friction between the object and the plane?