Which of Newton's laws best explains why motorif1sdmuzmh.o9p i 6ia h03a+.xsts should buckle-up?

  When you sit on a chair, the resultant fo , k-x4cnl/yxwrce on you is

  In the absence of an external force, a m0,nxph- yiuy:oving object will

  When the rocket enginesi+w2 ; vmu(ipcc 0rke0 on the starship NO-PAIN-NO-GAIN are suddenly turned off, while traveling iw 0e+ 0;ck(rvui pci2mn empty space, the starship will

  A rocket moves through empty space u, :0vo64b 4, jvpkt :cc,fipn :rbyvfin a straight 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 rocket in order to sustain its motion ibf pu, v:ofbyij, :4 c,vrp:64 k0vcnts

  You are standing in a moving bus, facing forward, and you suddenly fall :f6m4 tuuc./lp7r 1qkzn* utqforward. You *uzr:c7pm4k 1fntq./ul6q u tcan imply from this that the bus's

  You are standing in a moving bus, facing forward, and you sudde214/6 g3gnx)t mwr mw 3ahcpl)rt3hoknly fall forward as the bus comes to an immediate stop. What force caused you to fall forw36p)w1hx3tr/mw4l 2 m kcgt3ar)ogn hard?

  A constant net force acts on an objecvg5x 2kwl*(ym t. Describe the motion of the object.

  The acceleration of an objea+k;qip7;gqv0 slr+ fct is inversely proportional to

  A net force F accelerates a math-9ap+b0liu6 x+7 s d4z(qr:efylfbss m with an acceleration a. If the same net force is applied to mass 2mfb7 hpz l4f(+di e69 +tybua-rxl:0sq, then the acceleration will be

  A net force F acts on a mass m and produces an accelerat/ bmkbtt09l /bn/be0 6flkz 3fion a. What acceleration results if a net force 2F 0069t// knbbtbl /fz3k melfbacts on mass 4m?

  If you blow up a balloon, and then release it, the balloon will fly away. Thiihdl kye-o; )jqvkoz6dram9d/,bah7 z8x2* ;s is an illustrationho) qz xh2*ry;meoi-aa87zbv/ dd6lj ,9kd ;k of

  Two cars collide head-on. At every moment during the collis2s8(xo* xuc,z kdtv*n ion, the magnitude of the force the firkcd t8*(v*2noz ,xsuxst 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 , 1u6edt :cjirwhich the object exerts on you will1dj,e c6uit:r

  Action-reaction forces5ik z3 mupn1+o

  Action-reaction forces a m22t3h;drqaore

  A 20-ton truck collides with a, b))eistvsqceb :y2 i 6r+n3k 1500-lb car and causes a lot of damage to the car. Since a lot of damage is done on nr)b2ts3 c b)ve6 +s:,iyiqe kthe car

  An object of mass m sits on a flat table. The Earth pulls on this objg +t(+dr k)gloect with force mg, which wegk ot+ld)gr( + will call the action force. What is the reaction force?

  A child's toy is suspenbq ges:x8e/h -ded from the ceiling by means of a string. The Earth pulls downward on the toy with its weight force of 8.0 N. bh-e sg: x8eq/ If this is the "action force," what is the "reaction force"?

  Your bat hits the ball pitched to you with a 1500-Nm3wv19 vx) ng(* uznfs q2ra2u instantaneous force. The ball hits the bat with an instantufrn 2q3*amvnusw( 1g9 z2xv) aneous force, whose magnitude is

State Newton's three ly*sm5q kd-b)vejf4.+qlvhv ) aws.

  Mass and weight

  The acceleration due to gravity i pses* e,/b3ots lower on the Moon than on Earth. Which of the following is true about the mass and weight of an astronaut on the Moon's surface, compare ts*3/e bop,esd to Earth?

  An example of a force which acts at a distance i8kuet p aq(ft )x o0go1la3f/:s

  Who has a greater weight to mass ratio, a perso*xvn :764x t+sxsmc.ianxb q3n weighing 400 N or a person weighing 3:xis n6q4cb *samtxn7x.xv+ 600 N?

  A stone is thrown straight up. At the top of its path, the net forc0: j5q/ (vgt0 n,k jk1wibloxxe acting on it i 5,qn0 g0 jjkvtix:(o/xk1blws

  A 20-N weight and a 5.0-N weight are dropped si zzvdtc *785k(cq bid( ocn2)qmultaneously from the same height. Ignore air resistanc)52(d iqczcdqn87vko *b( zcte. Compare their accelerations.

  A brick and a feather fall to the earth at t )m(2dqw3vl xb+m5zo p48djwd+pu-yg heir respective terminal velocities. Which object experiences the greater force of air friction? b dy m+d+m5pd)48xzuq3( wj-pgwolv2

  An object of mass m is hanging by a string from the ceiling of an elevator. lph y)q5,fg,c/(vvo x The elevator is moving up at constant speed. What is the tv,xl ( p5hfyvg,qc/ o)ension in the string?

  An object of mass m is hanging 3d9t,e 9d:eednkom53obm iz7by a string from the ceiling of an elevator. The elevator is moving upward, but slowing dow939dzt d,eomk e7o3d5ei n:bmn. What is the tension in the string?

  The force that keeps you from sliding on an icy sidpp /3y lnc5kg+ewalk is

  It's more difficult tq*vo3x3k iv:l; :i6jkkoq ox3 o start moving a heavy carton from rest than it is to keep pushing it with constant ve3 ox;klj3o6i* vk vki::xq3oqlocity, because

  A horizontal force acceleraten0qn,r. v x+ols a box from 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 horizontal force is doubled. What happens to the box's acce .qnnl,o0 rx+vleration?

  A packing crate slides down an inclined ramp at constant velocity. Thus we can.9 bqo61s-be xx*br wq q.b*o-b 6xe1r9qbsw xdeduce that

  A block of mass M slides down a frictionless plane iw2 vf jq0:bbfg(jb6 7lnclined at an angle q with the horizontal. T:6fjlf 7gb0wb 2vq(jb he normal reaction force exerted by the plane on the block is

  A block of mass M slidhdjq ;txz,i;3+v g r1les down a frictionless plane inclined at an angle q with the horizontal. The normal reaction force exerted by the plalz t3;+i;h, q1jrdgxv ne on the block is directed

  A block of mass M slides down a frictionless plane incl4 z :)fghmjkkettz 34)ined at an angle q with the horizontal. The gravitational) tzzgfk:he3 m)k4jt4 force is directed

  Two toy cars (16 kg and 2.0 kg) are released simultaneously on an incli*k1 v9ns rjh,x /ma1caned plane thsr1hxaanmc1*j/ ,kv 9 at makes an angle of 30e with the horizontal. Make a statement which best describes their acceleration after being released.

  An object sits on a frictb.5 sf0n e2oyzionless surface. A 16-N force is applied to the object, oe .2y50bzsnf and it accelerates at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg ca*(5e vzdi 0wc ztlkq0 1z/g(syn accelerate from rest to 27 m/s in 7.0 s. What is the averagzezz dwqty l(s1 5i* gc00vk(/e 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 i ;jvmmwb x079cs the net force acting on the body?j;w9mxbm 0v 7c

  An antitank weapon fires a 3.00-kg rocket which acquireh 2mreh,9r8v+qr j 5ets a speed of 50.0 m/s after travrq +j ee85tv9rh,m2hreling
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 from kk5,0;dpt0az sadc +s rest+zd dk5,st0c pa;a s0k,

  What is the mass of a g2fr5zt-zt u0 dm fl/:person who weighs 110 lb?

  What is the mass of an object t d7-t6jv-wek9 nfe8e vhat weighs 250 N on the surface of the Earth where the accelerve ee wdv --n7ftj689kation due to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. What is the m. bcfpk7cqxu022toai))*w gk ass of the object on the surface of the Moon where the acceleration due to))aw7cx2. 2o kgb qt*fpkui0c gravity is only 1/6 of that on the Earth?

  Object A weighs 40 N on Earth, and object B wpl 9(,bghls *cc h0eh 8vub()aeighs 40 N on the Moon. The Moon's gravity is one sixth of Earth's.cuhehlgpbhs )(8(9a ,v0 *clb Compare the masses of the objects.

  Sue and Sean are havix4p sw n;)oox53.6vx dmcufd4 ng a tug-of-war by pulling on opposite ends of a 5.0-kg rope. Sue pulls with a 15-N force. What is Sea5odo. vwxxmdp46nfx)4uc s 3 ;n's force if the rope accelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books resh g4th 6 xvwjg4i2v/3dts on a level frictionless surface. A force F acts on the stack, and it ag jd /4vhgith4x2vw63ccelerates 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 scal c 2d*i)iyuv(bhabi,7e in an elevator. What will the scale be reading when the elevator is acceleratibu(*v,i dchyiib 72a )ng downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the y9 +cl.czr i;4wkk ;0rbhz,ci mass of the person is 60.0 kg and the elevator accelerates downward with an acceleration ofirylh.9czz +0 , b4c;;rikcwk $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale rides in an elevator. If wx66q, (o la0,iv hhubthe mass of the person is 60.0 kg and the elevator accelerates upward with an acce0w xlvb,uha6oi q h6(,leration 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 magnitude of pie xpt;v 8u)98.0 N av98u;p e)p xitnd is directed due north. 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 flatds k7vuzol v.mbiirm +2y8) *1bed 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 .+8li1vdos u )mvymk* r7ibz 2is not to slide forward into the cab?

  An object of mass 600i m ::fg5,8nch ,,mlgfjtjkz40 kg rests on the flatbed of a truck. It is held in place by metal ,gm:t ,iffm z5,ljkj8c :hn4gbrackets 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. ltjwm19ks(- u4-1, if M = 0.60 kg and m = 0.40 kg, what is the magnitude of the acceleration of the system? (Ignore friction and the mass-9 j(uktl 1wms of the pulley.)

  In the Atwood machine sho/m fhq*j0ur1o wn in Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the tension in the string? (Ignore friction and the ma 1uh 0*jof/mrqss of the pulley.)

  A student pulls a box of books on ace ytr: l+g- -yguc bkh6k2 z+;7ewl0w smooth horizontal floor with a force of 100 N in a directik7 6rhzl2g:ueby- w0l- +c k;wtgyec+on 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 book:b dc*ozd u,z2q9y, pfs 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 40.0 kg, what is the normal forb9 2p,zud:czdy,qf *oce on the box?

  A traffic light of weight 100 N is supported byuj4(e lrjig6 , two ropes as shown in Fig. 4-2. What juje6 ril (,4gare the tensions in the ropes?

  In Fig. 4-2, if the teg:t wqr*3 m6lc ra 4js.l1v(lgnsions in the ropes are 50 N, what is the mass of the traffi(4srrlgwj qlg3lav:1 t*m6 .cc light?

  Two boxes of masses m and 2m are in contact with each other on a frictionlessn7.0 r qyr osi2(pu8gg; gklc0 surface. (Se0 qun8 y7rg.lgs g;(ro2pk0ic e Fig. 4-3.) What is the acceleration of the more massive box?

  Two boxes of masses m and 2m are sggg49.vdvw 8in contact with each other on a frictionless surface. (See Fgd .8v 9vgws4gig. 4-3.) What is the net force on the more massive box?

  Two boxes of masses m and 2m are connected by a rope. (See Fcusnx)flia0 x)aro08 k1 b7l hdh13tonkq. :/ig. 4-4.) If the forward force on the more massive box is F, what is the tensi.7) ann0loqls :0 hx1/a1k dbux8oi)h tk3crfon in the connecting rope?

  Two boxes of masses m and 2m are 4 0tgxnz *o1qopo.n :kconnected by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the acceleration of tgp n x.onqt*0:o oz41khe less massive box?

Two boxes are connected by a(vw2u1):vgwnru 5n yr cord running over a pulley as shown in Fig. 4-5. Box I of mass:1vg v)5unnwu ry 2wr(
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 bo lmcpgzg33c5y324oru 0 rb;nv x and a desk are 0.40 and 0.30, respectively. What is the net force on the box whe 20p lzr;vmy3c34 3 b5rgcuongn a 15 N horizontal force is applied to the box?

  The coefficients of static and kinetic frictiong,d /zj5gaja5/u (v.fa xa p+ps for plastic on wood are 0.50 andv(g j/aj xa gdzp+5/a,pf5ua. 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 surfacef8a*i rk2r q;h in the +x direction. It slows and comes to a stop with a constant krf28*i a;qhr 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 pulledy h,plgx2(ebkl 59jfg0t fcca) )0vq6 by a 5.0-N force. A 3.0-N friction force retards the motion. What is the acceleration of ,62gbqketlf) (g l09 cyv5cp 0)xjfahthe object?

  A horizontal force of 5.0 N accelerates a 4.0-sc0dv.e mn(l -kg 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) ,3a m)qn/ bq50tjsyzcml(teven an initial speed of 10 m/s. It slides 50 m on the ice before it stops. What is the coefficient of kinetic friction betw) ,5bja/ymt n0(sq)czt le mq3een the puck and the ice?

  During the investigation of q18cv fw.xda -0 q;3q w*qsfqoa 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 bed3w-qq8.qw q1sa0ocq x*;fvf 0.500 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 surface v-7*i7twqz2f m/vdeu between the more massivmw7tdufv -ez/ v 2q7i*e 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 static friction force on the less massive box?

  Two boxes of masses m and 3m are stacked. (See Fig. 4-6.) Thwq6: 7n ccccv-e 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 bc:-cc 7cq6nwvox, what is the coefficient of static friction between the boxes?

  An object is on a frictionleunl-w4 enkf6u1gj.)a(9zfn fss inclined plane. The plane is inclined at an angle o9ej1kwn6f4z.f( fn) ug- na ulf $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that makesb vs9 9,bilg.d(fx;( g1mxrvzhdm5/o 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 wfzghvg 3,2)jf ith an 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 plan etvmx yoflu0au66ecvxb.x-y3* v+:6 e 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 pla(ca9:uq*01jic o3uxbq: grm m;ffo4 yne, at a constant velocity of 6u0 (i uc:rgbmo 3q cj:f4of;9m a1*yxq.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 ssv yv2y1 .a7 udy;i6.,kez pqdlides 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 down a rougl 1bny1+ qjd3zh $37^{\circ}$ 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 weig280i(law) 6o,pekfe8n ajp upa qz2u8d-i5cm hing 500 N along a rough surface. The cable attached to theo0(je,pk6i8 8aaf2 p-cnlpdiquew2 8m u za5) log makes 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 rest onc qf 1 uatx-7dp+ zr/ce,11vxm a rough inclined plane tilted at an angle off x1/1 +1xuvcmt7r qpe-zdca, $33.5^{\circ}$ 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 i 1t x+ueyb 7n+3+ilc6egg 2xhgncline is gradually increased ubc2gyu6ein+ l +1xe37hgt g +xntil 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 plane?