Which of Newton's laws best explains why enfd4 z,a2ec 4motorists should buckle-up?

  When you sit on a chair, the resultant force on oefnfp l (w8c;,v+l*4r/rnby you is

  In the absence of an s *0jv+9;ym3qfwwy ct external force, a moving object will

  When the rocket engines on the starship NO-PAINw;(/6gt p ieim9rf32axga: * ljra8ni -NO-GAIN are suddenly turned off, whila38l9i*:2i g/ awr 6a(t fmjrnx;gipee traveling in empty space, the starship will

  A rocket moves through empty space in a sv1v t:oqi6id:;tc h/d traight line 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 roc;dii d q/vt1o c:6h:tvket in order to sustain its motion is

  You are standing in a movio 8htyh 8m52bwng bus, facing forward, and you suddenly fall forward.y8bhom8 5 2htw You can imply from this that the bus's

  You are standing in a moving bus, facing forward, and you suddegamkuw6 t ql )866m7n 1)xifnhnly fall forward as the bus comes to an immediate stop. What force caus)nmmw87fh6qax6ti n1 ) 6ul gked you to fall forward?

  A constant net force acts on anh 07uu-vy9r+kkk7dej did a 64 object. Describe the motion of the object.

  The acceleration of an object is inversely prhdysp/ 7ecpsr 7z.-iv0yw8d1 oportional to

  A net force F accelerates a mass m with an acceleration a. )em5y9 r juk8ec40nu5u iqd 2y If the same net force is applied to mamd )r ye0 uku9q5nj c4i85e2uyss 2m, then the acceleration will be

  A net force F acts on a mass m and produv1c1ov-8-rurb+ .e-e/ y,c ayncnrgb ces an acceleration a. What acceleration results if a net y +avr o/nc1cn-b 8bv-eug,-ry . rec1force 2F acts on mass 4m?

  If you blow up a balloon, and thenz+8qx6s m:gyc release it, the balloon will fly away. This is an i:6x+qczgs 8my llustration of

  Two cars collide head-on. At w-jjmi.yifn* /(ltb ep2z;)st (tpg0every moment during the collision, the magnitude of j te(n tl.zf;g *i t)pwsim/(b-0j2y pthe force the first car exerts 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 tw2;x ));yg*z75pxlyx4 k9 uoqn rpmnyhe object exerts on you wiz2;ro;np7) qg5w) xnlkyp *y4uxm 9xyll

  Action-reaction forces9 l woih()c.a9wg1p cb

  Action-reaction forces arek727rkw vu 63e4eavp k

  A 20-ton truck collides with a 1500-lb car and causes 4b3vsqb 8hoofo 9 z:4fa lot of damage to the car. Since a lot of damage is done on the 443 ofb 8v9b: zhqoosfcar

  An object of mass m sits on a flat table. The Earth pu d/47;-bus8w wqtv7rpy pbx)m lls on this object with force mg, wvdw)rs8w/p p bx7ybm uq 4;-7thich 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. The Earz)hmo8jpeedjb, n 9z5b gco,3+gm6/ lth pulls downward on the toy with its we, +e/ e8,)m9j3 gmd5g zcloopnzb j6hbight force of 8.0 N. If this is the "action force," what is the "reaction force"?

  Your bat hits the ball pitched to you with a 1500-N instantaneous forc( 3f/kk+9 sjgpdrr5 rqe. The ball hits tfr/r3d9kk +rq5(jspg he bat with an instantaneous force, whose magnitude is

State Newton's three lawsk i9 ru:v(ro:;t/hxd us/l7oi.

  Mass and weight

  The acceleration due to gravity is lower on the Moon than onzq6mqv nx,3z7 Earth. Which of the following is true about the mass and weight of an astronaut on the Moon's surface, compared to Eaqv7,zz nm xq36rth?

  An example of a force whao fzp2h i8uk+o1-r; 4i uyw(rich acts at a distance is

  Who has a greater weight to mass ratio, a person weighing yf; 8wp ilen 8 y)98yl) sqqcszp dlhr;r)3-6k400 N or a person weigqpn ;rpllw3icl;y 96-dr q 8zs)fky8)8e) h yshing 600 N?

  A stone is thrown straight up. At the top of its path, the net forceb y:p0:sp cgi;il-a/ c acting on ip: 0isi:;b/pacl gy-ct is

  A 20-N weight and a 5.0-N weight are dropped simultaneously from the same 3* 88m1v lemyucrv1*z s:2hnmgd nyx,height. Ignore air resistance. Compare their acceleratin ryy2 x 3smzm dn:mc*e188*vgh l,1vuons.

  A brick and a feather fall to the earth at their respective terminal)nf8y i9g;+p kdp7oah velocities. Which object expd 7ni; y+)8pahpk9 fogeriences the greater force of air friction?

  An object of mass m is9/+6 ol o3-vkk qql*u/ qonxwc hanging by a string from the ceiling of an elevator. The elevator is moving up at constant speed. What is the tension q*q k9l 3+okvl6c/x-q/nouw o in the string?

  An object of mass m is hangsoo9.h*+ mrcsing by a string from the ceiling of an elevator. The elevator is moving upwards9s mroch o*.+, but slowing down. What is the tension in the string?

  The force that keeps y j7)fg-u8h. o(lr:f hae dpeth puan5+6t*4ddou from sliding on an icy sidewalk is

  It's more difficult to nkjgp23 fh p6/start moving a heavy carton from rest than it is to keep pushing it with constant velocity, bhf/p2kg 3p 6njecause

  A horizontal force accel b,deknb9sx (1erates a box from rest across a horizontal surface (friction is present) at a constantdb 1x 9(bse,nk 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 acceleration?

  A packing crate slides down an inclinedy. e wzlq2 u5ce+p9rd- ramp at constant velocity. Thus we can deduce thaercu l+ 9zyq 5.wd-pe2t

  A block of mass M slides down a frimnpx b)4sbv dj+ f) enqf().t -2/vymfctionless plane inclined at an angle q with the horizontex. 2btbps))) (f4+n/f mqv vfjdnm-yal. The normal reaction force exerted by the plane on the block is

  A block of mass M slides doswv; a8wfhz, (wn a frictionless plane inclined at an angle q with the horizontal. The normal reaction force exerted by the plane on the block isvha (zwsf8 ;w, directed

  A block of mass M slides down a frictionless plane it2x,)lmfan m *:zflk 5eyd8n,nclined at an angle q with the horizontal. The gravitationalf kalzx,)nn8fe:yt, ml d2m5 * force is directed

  Two toy cars (16 kg a ck ps 14ohe7b6 e4kyn01ogwr3nd 2.0 kg) are released simultaneously on an inclined plane that makes an angle of 30e with the horizontal. Make a statement which best describes their acceleration after being releases74gyn hp1oe31kkrw c0bo6 4ed.

  An object sits on a frictionless surface. A 16-N force is applied to thlc.opp+ 8ht- w) gyin2y;;jrae object, and it accelerate hyw8n2;pg)l .pa+o;-jiry ct s at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accelerat)c9h1 rd2a u5;lubpjf e from rest to 27 m/s in 7.0 s. What is the average forward force ol;c2 jahrd) p b5fuu91n the car?

  Starting from rest, a 4.0-kg body reaches a speed ; uzv10vorca.uk j;z fz6e3y:of 8.0 m/s in 2.0 s. What is the net force actinuvoc;z. f;u1eavj 3 zkyz 6:r0g on the body?

  An antitank weapon fires a 3.00-kg rocket which acquires a speed of 50.0 m/fyp- 81ysij,8tt,zcr) 8fqe4 y8xhrps after trave8st 88,18yxchr)p,yj4 zfrpqeyt if-ling
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 erjp2.ge nnwsuk,+21with the same force that you push a 10-kg mass from res2wp+grkns.j 2e1u ,ent,

  What is the mass of a person wh un1odmpuniw).6j s4 )o weighs 110 lb?

  What is the mass of an object that weighs 250 N on the surface oq-p*nzre9 v5z;ea9n1ak.x51 kzkhp o f the Earth where the acceleration du;vkae1rn za zo hnp195-.5e* z qk9kxpe to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. ,ubes-vq xj16ni ;8eu What is the mass of the object on the surface of t1uvne 6,8u jsi;x -qbehe Moon 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 40 N on the Moon. T rdy8 /q 0j 2oc8wwy(5rpk3tyyhe Moon's gravity is one sixth dqwtk3 (jcw0y 8yo5p82r y/ryof Earth's. Compare the masses of the objects.

  Sue and Sean are having a tug-of-waik/ 3w;ri4iegt4 i8 wqb2qt)e r by pulling on opposite ends of a 5.0-kg rope. Su 3qi4te) k 2itw; weqbigr84/ie pulls with a 15-N force. What 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 su./1l xtx n2.xwwu bk8lrface. A force F acts on the stack, and it accelu2.l81b wnt/xkxlxw .erates 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 s nl8q h;/lymgw9i- 6jxtands on a scale in an elevator. What will the scale be reading when the elevator is acceleranigl9xh-l q /jwm;6 y8ting downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the mass of the person is 60.0 kgddo:7 59r k 86wahk shzhsn/8g and the elevatohkw56hr8k/ 9hg87d :nsd aozsr 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 thday .*g3,;nq8 sl boc75c cqmpe mass of the person is 60.0 kg and the elevator accele*sc;gp8qbn7ca,ycq3 5 m. oldrates upward with an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal forces act on a 5jr394ezg xer;7i 8nsw.0-kg mass. One force has a magnitude of 8.0 N and is directed due north. The second force toward the easte;z8r3i g4e7w s jxn9r 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 held in pla p: gn*98s;wlff lt mtl- )80, oercuy3i.ygkice by metal brackets that can exert a maximum horizontal force of g8nu ,e)-yysk i ;fot8w0p *c lgtlmrli:f.399000 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 hz*g/qh,vl5j: )n1cvvlfrqpve*s ;( y84t ueflatbed of a truck. It is held in place by metavh l/scvue5 vhq ,p: 84q)yeg*t;jvz*r l (1nfl brackets 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 shom7e5 urp( p0p-g cpi(rwn in Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the magnitude of the acceleration of the system? (Ignor- ( eip5pp(mc7g rp0ure friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg and m la2ow+q6 bxc /= 0.40 kg, what is the tension in the string? (Ignore friction and the mass of ta +w6o /xlqb2che pulley.)

  A student pulls a box of books on a smooth horizontal floor with a)8qdfouy15i w force of 100 do iyw8)1u5 qfN in 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;m4plk,a6 wc2xeqf/xf9q fqy6.p k)r with a force of 100 N in a direction of 37.0e above t/ x,x)f4qfrpm fqylwa9pqe;66kc2k. he 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 shown in Fig. 4-2. y io-djmtny)n)ra1 4. What are the a1on j4)d ynr-t)m.y itensions in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is the mass oo8eggm svwo*67ow0 b,;f: qd t/b5 cpyf the traffic light?wevb; p0c6og5bmy /:8stqo*7g wdo ,f

  Two boxes of masses m and 2m are in contact with each9oapb5ikuih+4, 3u pn other on a frictionless surface. (See Fig. 4-3.) What is the accelerati5ik4i3ub a9np+hp u, oon of the more massive box?

  Two boxes of masses m and 2m are in contact with f, nrchrg 2s+7each other on a frictionless surface. (See Fig. 4-3.) What is the net force on the mor+ ghcfr7 n,r2se massive box?

  Two boxes of masses m and 2m are connectedtgq,t (9kkxf*wa b* .d by a rope. (See Fig. 4-4.) If the forward force 9*.kt(a w,tg*q dfkx bon the more massive box is F, what is the tension in the connecting rope?

  Two boxes of masses m an -rt( ;rijh5htr9 1jjld 2m are connected by a rope. (See Fig. 4-4.) If the forward force on the more massive boxtrr5h9hijjj 1 t-; lr( is F, what is the acceleration of the less massive box?

Two boxes are connected by a cord running over a pulle m//yu3lie hq3y as shown in Fig. 4-5. Box I of m3 3/emu/iyq lhass
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 g:h d2n2u-t / x)xhmcydesk are 0.40 and 0.30, respectively. What is the net force on the 2t xx)hygd 2nuh/:c-mbox when a 15 N horizontal force is applied to the box?

  The coefficients of spcn . uwe5a1cm858swfcm: y,7rk .; jpvnqq:ztatic and kinetic frictions for plastic on wood are 0.50 an:5uq w 1nn8rw:qckf7yj amszv p.58,e;p.cm cd 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 level surface in the +x/i mye ztnae6)9f9*. umt1cue direction. It slows and comes to a stop with a cociya9tte m)uz. neu/e 6m*1f9 nstant 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 by a 5.0-N force. Am*hrs4qekf *phn.xdjb;a /;+ 3.0-N friction force retards the motion. What is tendpfa* * m4;x /+rskhhb;.qjhe acceleration of the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg mass, from rest, at a rate ofl -m8d3imy zo6ck+y ;r $0.50 \; m/s^2$ 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 slides 50 -y1z.wy+qeru t d0s9h m on the ice before it stop.- e9q z+yt yd0w1shurs. What is the coefficient of kinetic friction between the puck and the ice?

  During the investigation /.tcmm*c 1/dspircf5of 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 0.55c imc*cpt rdf/1./ms00 for the prevailing conditions. Estimate the speed of the car when the brakes were applied.

  Two boxes of masses m and 3m are stacked. (See Fig. 4-6.) The sutb+ cxt rsn2tnrx3,ol+i:f3qi ,f* s;rface between the more massive box and the horizontal surface is smooth and the surface between the boxes is rough. If the c*s+ixf+bst:fr ti r2n3n,l;xoq3 ,tless 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 a qqqicv :tj255y.yhi 1* wh8dfre stacked. (See Fig. 4-6.) The surface between the more massive box and the horizontal surface is smooth and the sur5 qtjd:ichqhq815 iy.f yw2* vface 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 q/96 :ldwqp ht3w 5egto 4uuz;is inclined at an angle of4hp3d/u6tq ;wz elut:go 59wq $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a hw fen4;cvsgyshk +0, f-j-8l 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 an angle ofr)g* * .f8a6nv euhqvil0asv3 $37^{\circ}$ 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 inkw nb9 a.cp.3dclined 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 inclini vt z vp+5r-y5s6e4nrrhv5l(pcey(9n1x v(j ed plane, at a constant velocity of 6.0 m/lvp ( en5-1vvc4hny+x zetry65pj5ivr (9s(rs.
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 djowqp(7x)gnlq; ;1i u)73 w 9lrhive pown 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 busgfaj6)ac- v4- )ayig x*r0 slides 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 along a rough surface. The cablew0 0h.b elk+1mrx8 smb attached to the log makexbe8+mk0 0bwmsh . 1rls 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 +kwj+j8m: e bdrest on a rough inclined plane tilted at an angle djjmw+ :b ke+8of $33.5^{\circ}$ 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 plz0 +qat80gpamsdqhebr3np3al9 8d.1 ane. The angle of incline is gradually increased until the object begins to slidaqeq+0zp3t a0h19dm 3.8nlra8 gs pdbe. The angle at which this occurs is q. What is the coefficient of static friction between the object and the plane?