Which of Newton's laws best explains why m h9ith/ hfhar+g-q g t(;cmbetd;o3.8otorists should buckle-up?

  When you sit on a chair, ih ;i(c0x3hkl the resultant force on you is

  In the absence of an external fop9av*r i 8yw1gz: tqf*rce, a moving object will

  When the rocket engines on tdt 7ybto ed ,( h:1gkw1)b 64gli-gpsyrybr )6he starship NO-PAIN-NO-GAIN are suddenly turned off, while traveling in empty space, the 4h od7 yyr)tgig r ds1:(bkb)1-6t6,yl gpebwstarship will

  A rocket moves through empty space in a straight line -wp xr kd87i -u:jk:vowith constant speed. It is far from the gravitational effect of any star or planet. Under thespd ior:-uk8x j 7-vk:we conditions, the force that must be applied to the rocket in order to sustain its motion is

  You are standing in a moving bus, fr.gfir)0l7g k0,m c,a.w vw gn :8yhguacing forward, and you suddenly fall forward. You can imply from ta.0nwgw .rli r m k)vgf,7:gyu8 c,g0hhis that the bus's

  You are standing in a moving q*t5 l sx .oaos5;j l8e2 pkrcjlv6;j-bus, facing forward, and you suddenly fall forward as 6r q;; jc astslj2j.x8o5kov l*e-5lpthe bus comes to an immediate stop. What force caused you to fall forward?

  A constant net force acts on an object. Des c.at8f*ul 5hocribe the motion of the object.

  The acceleration of an object is inversely proportionlwf 2jo +6)*repv,nlaal to

  A net force F accelerates a mass m with an acceleration ax)gd.c.co7 ze . If the same net force is applied to mass 2m, then tz do.g cecx7).he acceleration will be

  A net force F acts on a mass m and produces an acceleration a. What acce u5:n7gfpuz8e leration resultpu f:gue5n87z s if a net force 2F acts on mass 4m?

  If you blow up a balloon, and then release it, the balloon wx3qyvlw90a qz72gn:yill fly away. This is an illustration ywqva 0gl7y 9xnq2z:3 of

  Two cars collide head 6afp, y9adhpi87e1uk-on. At every 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. pdpa auk6h 1yei,f87 9This is an example of

  If you exert a force F on an object, the force which th*+bbqd t uue35tp73 ag0mz)f ue object exerts on you wiluz degu37 butpa3q*)ft0+b5 m l

  Action-reaction forcy/9bv*fbh(om90 4+ ny imvq gdes

  Action-reaction forces a70kxd:yz.5 9 pkxbh js-uj (rcre

  A 20-ton truck collides with a 1500-lb car and causes a lot of damage to the cc(qrc 6wt y)8nar. Since a lot of damage c )n8ctyrq (w6is done on the car

  An object of mass m sits on a flat table. The Earth pu1ieyw m92 tqx,;bgz:xlls on this object with force mg, which we will call the action force. What iz2etwb9i gx:xymq,; 1s the reaction force?

  A child's toy is suspended from the .4 s+4q j mgkelh(obg vly;,(xceiling by means of a string. The Earth pulls downward qyvlx 4 ;bg(ol.+he4j,s(k mgon the toy with its weight 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 ccp e5+ps5e: +cdq,wo1500-N instantaneous force. The ball hits the bat with an instantaneous force, whose ep5o ccd +,c:s p+qw5emagnitude is

State Newton's three laws*hc*ilcjgnrcxm- j: u( s c3/7.

  Mass and weight

  The acceleration due to graviig3:xdm s 0h 9iqmnh0(ty is lower on the Moon than on Earth. Which of the dxn sh093 m(0gqmii :hfollowing is true about the mass and weight of an astronaut on the Moon's surface, compared to Earth?

  An example of a force which bq7/ fejp;p 6hacts at a distance is

  Who has a greater weight to mass ratio, a person weighing 400 N or wbh)g-o9;e 0btd ayet l8+ 1wma person weighingt;m t18ew b09w)oa -lde+yhbg 600 N?

  A stone is thrown straight up. At the top of its path, the net forycckvvd ( j v+ mm(dq488arh60ce acting on it is88 acv q(6hm0mvd c v4+ydkjr(

  A 20-N weight and a 5.0-N weight are dropped simultaneously froy5 jox wiqh)w(- cgret-89ny.m the same height. Ignore air resistance. Compare c5r oqew9xy n- yt.iw8g-j()h their accelerations.

  A brick and a feather fall to the earth at their respectiys : 0avvmht4d-m; (hive terminal velocities. vat-ihsy m4;hv: m0d (Which object experiences the greater force of air friction?

  An object of mass m is hanging*dr3yqhndx 7v).igq 8ni-r 9u by a string from the ceiling of an elevator. The elevator is moving up at constant speed. What is the tension in the strin- ydngu ) q893vn.xhqdr7r i*ig?

  An object of mass m is hanging by a string from the ceiling of an9hs2a 7fvh3,sz c(cexl9. qvb elevator. The elevator is moving upward, but slowing down. What xsqcvcez9afvs7bhh.9(, 3 2lis the tension in the string?

  The force that keeps you from sliding on an icy sideyf709jkgf -:maup e*rwalk is

  It's more difficult to start moving a heavy carton frocqk9*8xbc ae+c(/n xd.fq 4vt(wr (g im rest than it is to keep pushing it with constant velocic*+t (w 4c xa(kirxndegc qf9/v(.b 8qty, because

  A horizontal force accelx 0crf0+p2+cgujxy 6 kerates 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 acceleration?cpc 00+ur+j6 ygx2xkf

  A packing crate slid9l 46kuq h4xlles down an inclined ramp at constant velocity. Thus we can deduce 4lx l6ul49qkhthat

  A block of mass M slides down a frictionless plane inclined at an ar g 31nrd- r7tbym9c2(5if xg(7iwyqc ngle q with the x 7wrq9 cgrin1yt-27(iy35(cbmfg rdhorizontal. 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 ,jp+ xoj qxhj*8wn-x :q with the horizontal. The normal reactionhxj*x jjnp8qo ,- +wx: force exerted by the plane on the block is directed

  A block of mass M slides down a frictionless plane inclined at an anglpm(,)mj1cqmna// kg; jtxp)fe q with the horicfmng,;mj/j(p tm)x)ka q1 /pzontal. The gravitational force is directed

  Two toy cars (16 kg and 2.0 kg) are released simultaneously on anr 2e.;au:v*1 rvw. ekv (jgamr inclined plane that makes an angle of 30e with the horizontal. Make a statement which best describes their acceleration after beik ;v ..m(a1vrarver*e: ujg2w ng released.

  An object sits on a fr: quc4cu g oe7hi4o.8o r,6jluirt48c ictionless surface. A 16-N force is applied to the object, and it accelera rrc.4i488l o7uihjct:q,oe u cu6g 4otes at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accelerate ps( oc*b 1w.zb,rlh:l from rest to 27 m/s in 7.0 s. What is the average forward force on the ch rbo: ,*ls wlbcz(.p1ar?

  Starting from rest, a 4.0-kg body reaches a speed op ogje9v5i2 1yf 8.0 m/s in 2.0 s. What is the net force acting on g 1jy59e2ipov the body?

  An antitank weapon fires a 3p-vbidb. -s. ;pqzsg:.00-kg rocket which acquires a speed of 50.0 m/s aftez-b-.s qp ps:dvi bg;.r 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 mwxmc, l7w6v u)w6oh y*re 3ng*ass with the same force that you push a 10-kg mass from resty ol, xeumcg) 367w*rhv*w n6w,

  What is the mass of a per5:alpf 9zl )2di;crv pb,tp;fson who weighs 110 lb?

  What is the mass of an object that weighs 250 N on the surface of the g4mxa*aw, n5 sEarth where the acceleration due tox4wgan5sa*, m gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. What is the mass of the object on tfxs8jy:oo g9 d lbgh/jh1eb r.;+ *uq:he surface of the Moon where the acceleration due to .qbo y h8osgujj;h:+bfd 9rx el:g1*/gravity is only 1/6 of that on the Earth?

  Object A weighs 40 N on Earth, and o9z2mry8-pa 9id - nvaibject B weighs 40 N on the Moon. The Moon's gravity is one sixth of 9aipy9d r 2 vn-mz8-aiEarth's. Compare the masses of the objects.

  Sue and Sean are hav7 fwrx5d 7m0x,nc4yjying a tug-of-war by pulling on opposite ends of a 5.0-kg rope.djw5f y7cm ,x0y74xnr Sue 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 surface. A force F acts on th2ml/i e+xxr1mf 8:kv* idql2p e stack, f * ql/:2im xr2xpl8kev1di+mand 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 onpk(li 5da:x 5kvu;na)eg)/yd a scale in an elevator. What will the scale be reading when the elevator is accelerating downwaru l;(ay) n5dg )dxkai5p/kev:d at $4.00 \; m/s^2$?

  A person on a scale r0c q78on a0x9(xqsbk.jcd (r fwhx, e5ides in an elevator. If the mass of the person is 60.0 kg and the elevator accelerates dowodc, 0xbx(98h7 n(wfrjqe .0kx q 5acsnward with an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale rix9nu0xla ;f. ides in an elevator. If the mass of the person is 60.0 kg and the elevator accelerates upward with an accelerf;xx.9n la0i uation of $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal forces act on t-th5jkjo3-ktm t-x+ a 5.0-kg mass. One force has a magnitude of 8.0 N and is directed due north. The second force toward the east hkox-5- jh-jkt3+t mt tas 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 pxc+)hj0y1 j(a8m;*i clj tkholace by metal brackets that can exert a maximum horizontal force of 9000 N. When the truck is traveling 15hj)htl(8mccxk + j a;*0oijy1 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 flatbed o6tu ikj6l+xe;3y4ovk f 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 minimuml;kk4tuixvje3 +o 6 y6 stopping time if the load is not to slide forward into the cab?

  In the Atwood machine shown in Fig. 4-1, if M = 0.60rd/ v)thl a2u. kg and m = 0.40 kg, what is the magnitude of the acceleration of the system? (Ignore friction and the mass of the pulleyh./ auv2rd l)t.)

  In the Atwood machine shown in Fiwnxgj 1 8+wtpc; gaxj /3hri:z,t1 g.xg. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the tensioatx /+twhr1jwzj n8x :gpx ;g1ci, .3gn in the string? (Ignore friction and the mass of the pulley.)

  A student pulls a box of books on a smooth horizonoaxe7ef) 2ya4(kq3 bb5y rp7 mtal floor with a force of 100 N in a direction )4eryoea k35b7xpym q7bf a2(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 with a force o4wk9h + :mz;y n-w.izw 4tdf x+0rulfpf 100 N in a direction of 37.0e above the horizo++ry liw49zw40w;-pdu zhm .t:f nx kfntal. 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 rsbd f qj5w/vqaa5 i;,2opes as shown in Fig. 4-2. Whs5v5fi2w; a/bd,aqqj at are the tensions in the ropes?

  In Fig. 4-2, if the tensions in the ropes awbjp ntr/sj59f d6:)4vad yy)re 50 N, what is the mass of the traffics9)yn )fr 6/ddt:ywvb4pa5 jj light?

  Two boxes of masses m and1wch3 qx l.01o2m w1oppc nl:yghj5 k8 2m are in contact with each other on a frictionless surface. (See Fc5oh3 c8p1ql p0l jwo2nkxwgy 1 :.mh1ig. 4-3.) What is the acceleration of the more massive box?

  Two boxes of masses m and 2m are in c;lfeag809 xiz ontact with each other on a frictionless surface. (See Fig. 4-3.0fa9zge li8 ;x) What is the net force on the more massive box?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. yw03(ftdni2 j- xvp- j4-4.) If the forward force on thej2-y(ni3pwx0f v d-tj more massive box is F, what is the tension in the connecting rope?

  Two boxes of masses m a fetx/ud*v 0ba67qai;fl 4s 4qnd 2m are connected by a rope. (See Fig. 4-4.) If the forward forcufa6x4 tq 4l7b*qefv/i; ads0e on the more massive box is F, what is the acceleration of the less massive box?

Two boxes are connected byma+k o9n3 8mk+d lifp7r8odm+ieo )9r a cord running over a pulley as shown in Fig. 4-5. Box I of md8o l7+9oko+infr mpm) i9em akdr3+8ass
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 kineti .rphg+vf0cn6 :7zzio c frictions between a 3.0-kg box and a desk are 0.40 and 0.30, respectively. What is the net force on the box when a 15 N horizontal force is applied to the bo+z.v0i z cf67ngro :hpx?

  The coefficients of static and kinetic frictions for plastic on wood are 0.z+/q fa/bw9hwy7u u3 x50 and 0.4z9/u3w7uwy qa+h/ fbx0,
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 directp3 28(r qujrd.yto 2kwdl 6rw9ion. It slows and comes to a stop with a constant acceleration of -tr2ru rkd6 lo. 9(8jy3dwp2qw$2.45 \; m/s^2$. What is the coefficient of kinetic friction between the object and the floor?

  A 10-kg box sitting on a horizontal surface kwtex el;:znv6qzl / m9v) s6s-vo):zis pulled by a 5.0-N force. A 3.0-N friction force reta) eqxv:tolwzzvlv s6;-s )nek9/:6z mrds the motion. What is the acceleration of the object?

  A horizontal force og*(8mx3ce- wu ,pqudzgpwm 5* f 5.0 N 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 spedch 2d )u51uthq*ouetfgq *-jhe: l. odte25 4ed of 10 m/s. It slides 50 m on the ice before it stops. What is th c )lte of21hqt-*e5deu:d*qohgh t45u2ju.de coefficient of kinetic friction between the puck and the ice?

  During the investigation of a traffic accident, police find skid marks 90.*ci*qjisd: k 00 m long. They determine the coefficient of friction betweenj:di c**qsk0i 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 ac f2t;ki 5z7ornd 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 morec 7ri5fk;ot2 z massive box, what is the static friction force on the less massive box?

  Two boxes of masses m and 3m 9 u69pmys)ixo are stacked. (See Fig. 4-6.) The surface between the more mas96uy s9omp x)isive 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 between the boxes?

  An object is on a frictionless inclined plane. o lzye6 (z5: eu06 uwrjxw9bm. The plane is inclined at an anglexb. e zzj0u95rw6 w6oe:ym ul( of $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that makes a7 rrcyz p6bl4pnqc )+e8l p;15k2s gjgn 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/7jc / -y1y(ktipvyxfn 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 angleq7,c ;yy jtpt3 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 ,g07wbgwib qp9 2fd0osuv,.h a constant velocity of 6..7 qg0v2p9,s ibbu,ogww dh0 f0 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 rounu8uy :mu/y,litv6+ kgh $37^{\circ}$ 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 rougco3xrmms8u/,qu24f ;kgsb. h h $37^{\circ}$ 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 cable attachh07zqks;a: e ,scnr2n6cs m f.z7jy5 bed to the log makes an angle of ssnrf shm;c,zbe2n07 yjc6 :k7z.q5a $30.0^{\circ}$ 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 tiltedl uz gw:(91omor1a8kl at an angle of 1uk 8lo 9:(gazrwoml1 $33.5^{\circ}$ 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 graduall c c.x/u0ugmig7m*trn:2e dl. y increased until the object begins to slide. The angle at which this occurs is q. What is the coefficient of static friction icm:td./ le g*rc7gm 0u xun.2between the object and the plane?