Which of Newton's laws best explains why motorists should buckle *q;x: -gkdgohf2twsc39 8ksf-up?

  When you sit on a chair, the resultant force on you92k 6 ze8z.r;zr vaxce17vbby is

  In the absence of an external force, a moving object0nwnh3kye7q :. de l xdx3l:9l will

  When the rocket engines on the starship NO-PAIN-NO-GAIN ar+f5 *8l:0 jhme4nwzrpba) j tie suddenly turned off, while traveling in empty space,4frn) ih aj mpz+:j*58et0lbw the starship will

  A rocket moves through empty space in a s4l a oqxfo4x./) lblu5+nbon -traight line with constant speed. It is far from the gravitational effect of al/bob5 4.axl4)n+onfl u o-xqny 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, facingi w,tu2e5 l8en ghx87+dk8e g,qpk4ee forward, and you suddenly fall forward. You can imply from this that th8 +e hu,kei 8w8qlpg 2,47ek5xgtend ee bus's

  You are standing in a moving bus, facing for270ozenod/r vward, and you suddenly fall forward as the bus comes to an immediate stop. What force caud/oe r72novz0 sed you to fall forward?

  A constant net force acts on an object. Describe the motion of thdqrz4 qut38zfqji2,3.e rde( e object.

  The acceleration of an object is in1 (3jgcg up yialwjci owz1z6w8 8k9-8versely proportional to

  A net force F accelerates a mass m with an acceleration a. If the same neth1eu /x *we*a6;1x9tpreu0 l 9aqux3k)clyvj force is applied to u;9ejlvrt*ae61 9ckhlquae x* 01x yp3ux)w /mass 2m, then the acceleration will be

  A net force F acts on a ma9ky 8x8ou0fyh7 o* rkrss m and produces an acceleration a. What acceleration rrx0 ou 8k*89ykryo fh7esults if a net force 2F acts on mass 4m?

  If you blow up a balloon, and then release it, the balloonx(,0gqyeamih 5xh +- 4nn5j5uw 0biiw will fly away. This is an i 5hq w, 5mbiy4+j(h0weix0au nxn-5igllustration of

  Two cars collide head-on. At ev-y5khcced2 hvti,0n 8 ery moment during the collision, the magnitude of the 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 ofn kce85d0-ch ,iytvh 2

  If you exert a force F on an object, the force which the u1cb4 11 efjlwobject exerts on you wilj4blc1e1 1 wful

  Action-reaction force nzsvb8 do 9r2u5acx7;s

  Action-reaction forces a.pf n k0if72phre

  A 20-ton truck collides with a 1500-lb car and causes a lot of damage to6 3e34por)o54t-t9bf aqh7cbn*l - hwaft jty the car. Since at34-)9twc* 3 rhfhlqepy - 7otbja64nbft o5 a lot of damage is done on the car

  An object of mass m sits on a n-9q.w;gh ow-nq cp;hflat table. The Earth pulls on this object with force mg, which we will call the action fo9no;wh n.h-p wqgc; q-rce. What is the reaction force?

  A child's toy is suspended from the ceiling by means of a string. The Ei8 sox2 2f8:f35cf24ytji ct yl 5zwcrarth pulls downward on the toy with its weight force of 8.0 N. If this is the "action force," what is the "reaction forc2y tc5ci3 2x z:rf2ffjyc8ws8 t54l ioe"?

  Your bat hits the ball pitched to ;vs/ rkt:i j bz6:mv0lyou with a 1500-N instantaneous force. The ball hits the bat with an instantaneous force, whos/ irk::lj0t6 msbvvz; e magnitude is

State Newton's three lan-;b*)hk ft5ysjm7 p8o :qow aws.

  Mass and weight

  The acceleration due to gravity is lower on th r9seu8h.-tvg3f-krw e Moon than on Earth. Which of the following is true about the mass and .rwvk8-sf9e g-hrtu3weight of an astronaut on the Moon's surface, compared to Earth?

  An example of a force which acts atqi w a3.i-r s(vehgq-* a distance is

  Who has a greater weight te3c j0uorpxug,j(,8t o mass ratio, a person weighing 400 N or a person weighingj 0tp,xgc,er3( ju o8u 600 N?

  A stone is thrown straight up. At the top of idzhbmze;v./zx*b 9m-a(- jo rts path, the net force acting on i-bo.m/x*eavbmh-;dzrz9jz( t is

  A 20-N weight and a 5.0-N weight are dropped simultaneously from the same heiajomuz,8uc jrmmax) x87 9n(5b +/uktght. Ignork8zuumaj 8 )c/o9+tnau(b7mxm j ,x5 re air resistance. Compare their accelerations.

  A brick and a feather fall to the earth at their respective terminal vek 01ui2ucb1c 25 fkszt54ybk rlocities. Which object exr5 cz1skyb1i50ft2c2k4u b ukperiences the greater force of air friction?

  An object of mass m is hanging by a string from tkjk6(is, gmy/q wngn zg1/ :1xhe ceiling of an elevator. The elevator is moving up at constant speed.img1x, w (kgy1nj z: n//ks6qg What is the tension in the string?

  An object of mass m is hanging by a stula aohu6l,b7 ) lly381 cw/garing from the ceiling of an elevator. The elevator is movla ll6ogwba7lu/8c13)h , auying upward, but slowing down. What is the tension in the string?

  The force that keeps you from sliding on a yagjpo mjv :3q. .nu+sw5f+g.n icy sidewalk is

  It's more difficult qrlltc* ulia 3**2ds 6cn91oeto start moving a heavy carton from rest than it is to keep p tcc dli16 uq9**n*re3ola s2lushing it with constant velocity, because

  A horizontal force accelerates a box frba.e nj( tq +4ft agm.a9p/gl;om rest across a horizontal surface (friction is present) at a constant rate. The experiment is repeated, and all conditions remain the same with the. 4nabaq(e .agpg9/tm fjlt; + exception that the horizontal force is doubled. What happens to the box's acceleration?

  A packing crate slides down an inclined ramp at constant velocity. tdd9b l8 9k 2rx*m;yj8yxau d;Thus we can deducemj2kab l9 y9 d8;*uxr;dd8tyx that

  A block of mass M slidesy03gi, aa42vh5 dd2hi:ir vkn89 jyjn down a frictionless plane inclined at an angle q with the horizontal. The normal reaction forjh02a5 3jvna9d r84ni:ikdy g2hvyi, ce exerted by the plane on the block is

  A block of mass M slides down a frictionless plane inclined at an angle q with j7(d0nhh7 qjjthe horizontal. The normal reaction force exerted by the plane o7(nq7dhj jhj0n the block is directed

  A block of mass M slides down a frictionless plf2f0g*zgok a 7h,iz6 aane inclined at an angle q with the horizontal. The gravitational forco*af6 20fiz k7agzhg,e is directed

  Two toy cars (16 kg and 2.0 kg) ar9g(d9dw d sz0qadtp33e released simultaneously on an inclined plane that makes an angle of 30e with the horizontal. Make a statement which 9wd0d s(9a33q pdzgd tbest describes their acceleration after being released.

  An object sits on a frictionless surface. A 16-N force is applgi4e 4u0yu; fzied to the object, and it accelerates az uug0ei4f; 4yt $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accelrdau tcn8-yff*n- )(oerate from rest to 27 m/s in 7.0 s. What is the 8)ft-cyuon nda *r(-faverage forward force on the car?

  Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s in ,dd i /s(.o uuf0azdz)2.0 s. What is the nes d/ouz.du( f)i0zad,t force acting on the body?

  An antitank weapon fires a 3.00-kg rocket which acquires a sp f1lg;1ygs e)teed of 50.0 m/s aftgt; sy1 )fe1lger 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 m q yv;5)rhrp;asyc)e /ass with the same force that you push a 10-kg mass from rest, p;c)qvhr5a;yrsye / )

  What is the mass of a person who weighs 1l8q4hl3+vlop,pd jb t 1xn5s ,10 lb?

  What is the mass of an object that weighs 250 N d 8mtov+e,s/ won the surface of the Earth where the acceleration due to gr wme8svt+o,d/avity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Ea*sf-*3 .c zmjv 1mc)bpm ,3slzuztry -rth. What is the mass of the object on the surface of the Moon where the acceleratplcy -3z1msfmcz-*tb zjvmu ,)r* .3sion due to gravity is only 1/6 of that on the Earth?

  Object A weighs 40 N on ()oqnnqep2 itm odi/0: /ota 7Earth, and object B weighs 40 N on the Moon. The Moon's gravity is one sixth of Earth's. Compare the masses of the objects/qntmoa2eqd/:o7it o i0n p().

  Sue and Sean are having a tug-of-c 989lo frhyco::iqz: qi:j d(war by pulling on opposite ends of a 5.0-kg rope. Sue pulls with a 15-N force. What is Sean's force if the rope accelerates toward Sue a( :rcjqcioy89l do9f::hziq : t $2.0 \; m/s^2$?

  A stack of books rests on a level frictionless surfa65 t j4*bkcqeyce. A force F acts on the stack, and it accecqj4 65yb e*tklerates 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 m/y) m u dbduk:+fm7:uon a scale in an elevator. What will the scale be readingu:umm kbu+d:) ym /7df when the elevator is accelerating 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 kgro 5l05tqkw02 yjafal* rz.2f and the ele52fl tqawol z.2y*a0j krrf05vator 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 the mass ofan0s k *uppo8,: xbhn2 the person is 60.0 kg and the elevn8uobp2sk ph0*,na x:ator accelerates upward with an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal forces act on a 5.0-f8 lcrjrqs63 b 1yepg:1c5*xc-rxuoyama* 32kg mass. One force has a magnitude of 8.0 N and is directbf6 32-ejaarr8l*c35 qyscorm 1y* x:xg cu1p ed 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 rests0kl fw bt-k0c+ 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 tk00k cf -l+bwis 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 restkpn75j( isj7y8/ hwkn s 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 time if the load is not to slide forward i i7phyk njwn/k7s j(58nto the cab?

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, c r*)mg dki+w5gemz 70what is the magnitude of the acceleration of the system? (Ignore friction and w)0 +zm5eig 7kr*gcdmthe mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 yy7 07rdktw2ykg and m = 0.40 kg, what is the tension in the string? (Ignore frictio0 dyr7w 72ykytn and the mass of the pulley.)

  A student pulls a box of books on a smooth horizontal floor with pg lbz6vk -sbp55)kj+ a force of 100 N in a direction b5lpkjg p)v +z-56b skof $37^{\circ}$ 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 with a force oclt6v7:)jef)dn 6- eto e)d sif 100 N in a dijf : cl) e dot766)nt)dev-seirection of 37.0e above the 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 roevd6h90 ;dk,z) men wxpes as shown in Fig. 4-2. Whz d 9e;en6, dwhk0xmv)at are the tensions in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, wha)j74cl f1 zcrbt is the mass of the traffic ligj4) 17 zbrcflcht?

  Two boxes of masses m and 2m are in conta3p/o dz3i,pme ct with each other on a frictionless surface. (See Fig. 4-3.) What is the acceleration i/ d3eop,3zm pof the more massive box?

  Two boxes of masses m and 2m are/jfuxnmdh 8 lxh m x.2(h11ij 0n/9ykr in contact with each other on a frictionless surface. (See Fig. 4-dh/2j xnn/rhljyuf 91mk8x x0 m. ih1(3.) What is the net force on the more massive box?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4-4.) If the p.k:b a2);jhgm49w8) zyn;q egbqwlcforward force on the more massive box ism:ej4ba k;qcz2wglpg)w8bn.yq;9) h F, what is the tension in the connecting rope?

  Two boxes of masses m and 2m are connected by a ropezsxx+cg/7k kz v:-6we . (See Fig. 4-4.) If the forward force on the more massive box ezz7k k w /6v-c+x:xgsis F, what is the acceleration of the less massive box?

Two boxes are connected by a cord running oprt) uo74l ps.ver a pulley as shown in Fig. 4-5. Box.r sopp lu)74t 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 a desijg7 ;vbmhiiz f-627e k are 0.40 and 0.30, respectively. What is the net force on the box when a 15 N horizontal force is applied 267g7bmiive;f ij-zh to the box?

  The coefficients of static and kinetic fricti p4oq38mvv1 nuons for plastic on wood are 0.50 ando1q mnvp43 v8u 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 suq-(0(n bcsacyba+ l-nrface in the +x direction. It slows and comes to a stop with a constant acceleration of- 0cn-bl+ aay nqbc((s -$2.45 \; m/s^2$. 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- +w3(l;nug0w i6xxnhvN force. A 3.0-N friction force retards the motion. What iglw0+x iu;whvxn 6n( 3s the acceleration of the object?

  A horizontal force of 5.0 Ni+/og grqt2 au*2wt)w accelerates a 4.0-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 given an initial sp+xgs4q / ppe0fs,- gqieed of 10 m/s. It slides 50 m on the i4g ,fq+/-pgx ess q0pice before it stops. What is the coefficient of kinetic friction between the puck and the ice?

  During the investigation of a traffic accident, police find skid marks 90.0 ng-u*jx u)*wyx(/mxa m long. They determine the coeffxux* mj)xy an /(u*gw-icient 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 m vseca, .)+-n* u)jdo vqxngz 4and 3m are stacked. (See Fig. 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 massiu, q.c4en)vd-njzs xo+a gv*)ve box, what is the static friction force on the less massive box?

  Two boxes of masses m and 3m are stacked. (See Fig.cpbne1g- u:vs,f/s; 5 w7 e8i)g9y q0jxxmjay 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 static friction betwe0 m- /9xgsep8s7eybx;w1fgqu jy5n a) ,:c vijen the boxes?

  An object is on a frictionlessumm4q2rd4 hx fr v94qe2g:0rk inclined plane. The plane is inclined at an angle2rd4 vxurg09q4e:mr kfq 2 4hm of $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down abg3(4rb 3aq uh 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 an n798yam nryo/shq xh2 b+1vr2gle 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 planefnb s n1 ;cti;.s6 q8*9cdirkg 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 plane, at a constant velocit6: 2h,emjynr uh7k+ gdy of2g7hydr 6m:k, h+june 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 m slides d 72wyto4 liw,mb7fa:m own 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 9:yjbyd9a8,q* bkia:(o9hkyiza. bdown 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. Thn4r o 1x )9gan98fl8urdfrqp3 e cable attached to the log makes p8 o)fldxq a4gu 39 rn198nrfran 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 inclinegk1s u 8cgss5f;1u7wkd plane tilted at an angle51gsk f 71 8skcswuu;g of $33.5^{\circ}$ 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 graduq 5lf2 rx(c1teally increased until the object begins to slide. The angle at which this occurs is q. What is the coefficient of static friction between the objt51rx( e flq2cect and the plane?