Which of Newton's laws best explains why motorists should tqu z*m)oi2v 3y4kb/nbuckle-up?

  When you sit on a chaf+h4mq ( , 1ix4bklb. (bxcrncir, the resultant force on you is

  In the absence of an external forc)adh p0 5lvmn-u4pw b6e, a moving object will

  When the rocket engines on the starship NO-PAIN-NO-GAIN are suddenlyo;f,i ivu25nbzf 7 dx 0g5ji :jdzmw,/ turned off, 5jg2w ixj;0mib iun 5z7z f,,:fdo/ dvwhile traveling in empty space, the starship will

  A rocket moves through empty space in a straight line with constan4 xvz 4.*a( t6in0+g cfbk*t. itgkmght speed. It is far from the gravitational effect of any star or planet. Under thei tg*mxkgi b+6v4azg.h4 f.*n(k 0 ttcse 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 you suddenly fallxc6(x0 l;gedq,my bn) forward. You can nq(g mxd)blx,6y0;ce imply from this that the bus's

  You are standing in a moving bus, facing forward, and you suddeoha .k. :n6hdqnly fall forward as the bus comes to an immediate stop. What force caused you to fall forwad.:.kohn6hq a rd?

  A constant net force acts on an o 95ls9se8xgbz bject. Describe the motion of the object.

  The acceleration of an object is inve. umz,h3hj/r*bi9 pnwp. ;;zmx5 dbrsrsely proportional to

  A net force F accelerates r:b6oodr75jvoxa y yxw9ki+ 0fs3t46 a mass m with an acceleration a. If the same net force is applied to mass 2m, then the accelerationifx0ow y+4a 9o6o kx:7db63 5 tyvrsrj will be

  A net force F acts on a mass m and produces an acceleration a. wnqun;zqhc02 4n7u kbw :1zz/What acceleration results if a net force 2F acts onzkn quuw:/wn0nz 1 hc4;2zbq7 mass 4m?

  If you blow up a balloon, and then release it, the balloon will fly away. T7 hi0;9bcce d t/mi8kvhis is ahc di08e7/m it9k;cv bn illustration of

  Two cars collide head-on. At every moment during the collision, the magnitu1 ymt1o23 v3,nopbf smde of the force the fnpbof3v, sm3mo1 y12 tirst 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 the object exertsds mgcnm-2172sm(8s:ufud j k on you wil7mc(2m s-suk us82fmd 1jg: dnl

  Action-reaction forci38lamfv1: zam1-c uj es

  Action-reaction forces aw (gr 7ddcjy69re

  A 20-ton truck collides with a 1500-lb car and causes a lot of damage to the car u:ra3dtq/ b81r28j4v kzs knn. Since a lot of damage is d 1 3t8zr4v2 kunda/:r8bqnsjk one on the car

  An object of mass m sits on a 0y /j .6cz-pbb7 usfqua *39sp 9erqcvflat table. The Earth pulls on this object with force mg, which we will call the action force. Wf3c0caq9z sj7.p ey6psb*u9 q- ur /bvhat is the reaction force?

  A child's toy is suspe60 d),)gx yejc-ecf/2b*o hmqy*k dg nnded 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 "reaction 0ee d )y) *f-g2bmgcck*h6/q dn,jxoy force"?

  Your bat hits the ball pitched to f8afmm w5v ,b9you with a 1500-N instantaneous force. The ball hits the bat with an instantanembwafv9fm 58, ous force, whose magnitude is

State Newton's three law ,b d 4xb5t7j t(q8oe;4adsnbns.

  Mass and weight

  The acceleration due to gravity is lower on the Moon thz y;u2fm--k;nzo8ul f5m,y uban on Earth. Which of the following is true about the mass and weightz ,ynb;f8y 5fo ;lu2umuz-m-k of an astronaut on the Moon's surface, compared to Earth?

  An example of a force which acts a31f+6r ndl 3lspin4ow k7bv3 yt a distance is

  Who has a greater weightaki0qz 6p+i99ss siz/ to mass ratio, a person weighing 400 N or a person weig qis0 i9z/i69k+a psszhing 600 N?

  A stone is thrown straight up. 5 *k*/vdakjfw At the top of its path, the net force acting on */dvf kwk 5*ajit is

  A 20-N weight and a 5.0-N weight are dropped simultaneousldhw xrwyr/;p )g 6c+1gy from the same height. Ignore air resistance. Compare their acceleratir+ 6pwwrx )ydg1gc/;hons.

  A brick and a feather fall to the earth at their respective :/.2 z;tlkeo:m(zuo lyjz7wl terminal velocities. Which object experiencesyzoolellmj u zz/ (w::k2 .;t7 the greater force of air friction?

  An object of mass m 9))yaq uetaf5 is hanging by a string from the ceiling of an elevator. The elevator is moving up at constant speed. What is th e)a qy5f)t9aue tension in the string?

  An object of mass m is hanging by a string froyzw)00ocjdy,sgk .l ,m the ceiling of an elevator. The elevator is ), ldkzj0sy0goc wy.,moving upward, but slowing down. What is the tension in the string?

  The force that keeps you from sliding on 7 vbr8fs*/oeay*x p3k an icy sidewalk is

  It's more difficult to start moving a heavy carton from re7op)f 6d zmh* 45kxbakst than it is to keep pushin *4hkbmf5p6o7z )dx kag it with constant velocity, because

  A horizontal force accelerates a box from rest across a horizontal sur)m1b x5m h-:k(tthdlrface (friction is present) at a constant rate. The experiment is repeated, and all conditions remain the same with the exception that bh l)kmtt1: dx-rhm(5 the horizontal force is doubled. What happens to the box's acceleration?

  A packing crate slides down an inclined ramp at constant velocity. Thus wv7smp4opcb s.y-3-n me can des7s. cpnv-m4m y-bpo3duce that

  A block of mass M slides down a friction lu :avh5/aeh/less plane inclined at an angle q with the h5va:/ h/ laeuhorizontal. The normal reaction force exerted by the plane on the block is

  A block of mass M slides down a frictio1w)t*tbb a u0,(zi gpbnless plane inclined at an angle q with the horizontal. The norma,*bga0 p b)u (titw1zbl reaction force exerted by the plane on the block is directed

  A block of mass M slides down a frictionless plane i8;vp;n+gnm a inclined at an angle q with tn n +i8a;vgmp;he horizontal. The gravitational force is directed

  Two toy cars (16 kg and 2.0 kg) are released sim pagt hl)6 ..c5j7msgmultaneously on an inclined plane that makes an angle 5pmm g76). g.tchjals of 30e with the horizontal. Make a statement which best describes their acceleration after being released.

  An object sits on a frictionless surface. A 16-N force is applied to tvaddj::7n qbip5 :9zu he object, and it acc udq:vb:jz:7 nd9 pai5elerates at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg cajr8:3o/hl e yln accelerate from rest to 27 m/s in 7.0 s. What is the average forware lylo:8/ jh3rd force on the car?

  Starting from rest, a 4.0-kg body reachu e6 7zoedm04fes a speed of 8.0 m/s in 2.0 s. What is the net force acting on the mdoue7 6ez04 fbody?

  An antitank weapon fires a 3.00-kg rocket which acquires ng- r0/. *j5cpuay 7ibij,p-uzgw*vl0f- lfz a speed of 50.0 m/s after tru -vfnl7.ja0iu jf5z yiplbp,*/- rg0wgzc*- aveling
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 wtrcuw(h9:w rfx o.x5y 4 6p(tjith the same force that you push a 10-kg mass from re(:9ju ptfr wt6c(o xyx.5rh4wst,

  What is the mass of a pe( 5fv(,t njdtlrson who weighs 110 lb?

  What is the mass of an object that weighs 250 N on the loapu *v u5.1:uvr i9isurface of the Earth where thevlop*u:5uavu1i.r 9 i acceleration due to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. What is the mass of the objecgs hndel 4l:f:m),a q/t on the surface of the Moon where a:/lmldh4: n,egq ) sfthe acceleration due to gravity is only 1/6 of that on the Earth?

  Object A weighs 40 N on * 7g(4ezszwheEarth, and object B weighs 40 N on the Moon. The Moon's gravity is one sixth of Earth's. Compare the masses of th7g(4zez hs ew*e objects.

  Sue and Sean are having a tug-of-war by pulling on opposite ends of a ;nn) c4 vx4(visdos+k 5.0-kg rope. Sue pulls with a 15-N force. What is (iv+4xkn;c vn4) sdosSean's force if the rope accelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books rests on a level frictionl x(6ful z h9+w/wjkt7lum :6hjess surface. A force F acts on the stack, and it accelerax9 tjj m6u7k h+u/6lfhzw(:lwtes 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 scale in an 91wvose 3sa6aj92ad 7 h xuolr2me9(uelevator. What will the scale be reading when the elevator is accelerating downward atv 2o1 2ushw9o3amesr967a(9x auldje $4.00 \; m/s^2$?

  A person on a scale rides in an elevatoxpsktbl ;u .z1j3f, wyw6v8 h32p2fxgr. If the mass of the person is 60.0 kg and the elevator accelerates downward with an acceleration wxf,3hz6u.lg 3 8pp ty;j 2fs2w1vxkbof $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale rides in an elevatoyecixr ix i,mra a.415z 4.-tdr. If the mass of the person is 60.0 kg and the elevator aar-. ye.4x, x4izd5ctmra i1i ccelerates 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-kg mass. One force h zilvkczu-v1em+o6)+-djcf 6as a magnitude of 8.0 N and is directed due north. The second force toward the e+- fcv+li )dujze6-okzcvm61 ast has a magnitude of 6.0 N. What is the acceleration of the mass?

  An object of mass 6000 kg rests on the flat f jrlvl51*q8bbed 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 mqjbl*rf185 l v/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 of a tr09x lw ngdi9 2*22v6t bcrltd7d knox*uck. It is held in place by metal brackets that can exeb 20xgw7otrk n69v 2d*d9lnct* i2xld rt 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.yb5qk d4ap)v7 :y jht bfu7e-* 4-1, if M = 0.60 kg and m = 0.40 kg, what is the magnitud4f5:qph*ky ejabt ud 7v)7yb-e of the acceleration of the system? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown inekv ((7.hhi8 mokw7 w8*llogn Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the tension in themv l(k78oln8.o*khgwh 7ew i ( string? (Ignore friction and the mass of the pulley.)

  A student pulls a box of books on a smooth horizontal fl+ )hqo6s-rw- 2faaulgko r4/voor with a force of 100 N in a 2h6f vsak4/oao gu-+qr w-)lrdirection 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 owke0-knman3wy 6 /r-j:dj +bnf 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 for ny-j3k0 wr+: /n amn6j-dekwbce on the box?

  A traffic light of weight 100 q ,svz3 uvy 1z.v+ffk:N is supported by two ropes as shown in Fig. 4-2. What are the tensions in fuvv.+,13q f z :zyskvthe ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, whcxn d s5f,ff43at is the mass of the traffic lighfxsdf,4f5 3cn t?

  Two boxes of masses m and 2m ayuu u h;t 16mnxo:7 i(o8dwvd.re in contact with each other on a frictionless surface. (See Fig. 4-3.) What is the acceleration ofo6tu: xh dy;1um o.uwd( v78in the more massive box?

  Two boxes of masses m and 2m are in contact with eaq kq/cwf f4q/7ch other on a frictionless surface. (See Fig. 4qqc/ f7w/qk4f -3.) What is the net force on the more massive box?

  Two boxes of masses m a(pag l vdem2d2- )zv3wvc+jr(nd 2m are connected by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, whv(vacdd 223pj -rmgv+(z) elw at is the tension in the connecting rope?

  Two boxes of masses m and 2m are connected gv- u v5n0d.lrby a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the acceleration of the less0v5-dv .nl gru massive box?

Two boxes are connected by a cord running over a pul52uu tw d+o(dgley as shown in Fig. 4-5. Box I of masg2dwu o u+(t5ds
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 ws w6swfm -dc:g7 4iia;s,x (d3.0-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 forfdsi wg(i:;s6d74x -cmwaws ,ce is applied to the box?

  The coefficients of static and kinetic frictions for plastic on wo +bw g*/dw+th3h f:uqcod are 0.50 an/u3:th dc+*g bqhwwf+d 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 e0./f8di pyff the +x direction. It slows and comes to a stop0f8 . i/eypfdf with a constant 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. A 3.u+n)1um6rxl926vcz s2 ns 1i e vgz;t;upo7 ih0-N friction force retards the motion. What is the acceleration of the objcv9) uuis6vmzr 7l +n;gx en2o ;u1z 1p6i2tshect?

  A horizontal force of 5.0 N accelerates a 4.0-kg mass, from rest, a5 5 r4buwf4l,22r0*sfwe9h mo o pfuiwt 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 speed of 10 m/s. It slides gi2: m2d**/vh*i 4zaazalkop50 m on the ice before it stops. What is the coefficient of kinetic friction bet2* kad2vz gzmah 4iiao**pl/ :ween the puck and the ice?

  During the investigation of a traffic accident, g gn+;veidp8dph*5vcdi89b /police find skid marks 90.0 m long. They determine the coefficient of fric58hvcddidp/+ * 8eg ;9vp nbgition 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 and 3m are stacked. (See Fig. 4-6.) The sur.e9pg eu dp7p-face 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 static friction force on the less massive udgp p9p7-e e.box?

  Two boxes of masses m and 3m are stacked. ( ,e0y5x9t bcsiSee 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 massive box, what is the coefficient of static friction betx5y i,cb0e9 stween the boxes?

  An object is on a frictionless inclined plane. The plane is inclined5 v :r7(bonsat at an anglevr(b:s n o5a7t of $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a w-7 lmu6t kp9g;* kwm y xq2kli*9zcz4flat 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 of ; xd/rezsp ,-oswfq): $37^{\circ}$ 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 angledi6-v w:e )poilpj-; d 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 cc84fjsi gi0azvc ):7constant velocity of 6.)igaz4vj:cc 7c0sif8 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 s)7svp,q/bfa4ufj; c:ky *m ddown 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 dow rvghtp+;;wx,f*w*n yypf 6 l,n 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. Thet;995qz qpn1ngmdd 0t cable attached to the log makes an angle o99tqdqzd 0p; nm1g5ntf $30.0^{\circ}$ 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 planeh *nmkyoqs*xm 1c+*x5 tilted at an angle n q yxo s*c5mkx**1hm+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 graduallyi7b :gayd-l:* uy2xdn increased until the object begins to slide. The an2lguxb n i7dd::ay*- ygle at which this occurs is q. What is the coefficient of static friction between the object and the plane?