Which of Newton's laws best ez)te2bg3o(m gqlb35 m xplains why motorists should buckle-up?

  When you sit on a chair, the resultant f4lpv*e; htxk6/wqma nbt r+)qoxk2, / orce on you is

  In the absence of an external force, a moving hhb1100eo dpqobject will

  When the rocket engines on the starship NO-PAIN-NOuj +5os z uv1e )taa2w8xt:q8y-GAIN are suddenly turned off, while ws + v85:ouzt a)a82qj1 xyeuttraveling in empty space, the starship will

  A rocket moves through empty space in a strai819l*jb /7,pn2 zfnzijx fdq aght line with constant speed. It is far from the gravitational effect of any star or planet. Underjaqdijb7918zfn* z/pf,2nl x 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, facing forward, and y9i iapqav-,)uj *dg 3hou suddenly fall forward. You can imply fraj)g vuq-id,p h a*9i3om this that the bus's

  You are standing in a moving bus, facing forward, and you suddenly fall forwardio rc1gpv q*3- as the bus comes to an immediate stop. Wha -por1c i3*qvgt force caused you to fall forward?

  A constant net force acts on an object. D5rx4rf/k y7qt escribe the motion of the object.

  The acceleration of an object i *uzm x ll 6rcphf13c.gf3/heok;:- zls inversely proportional to

  A net force F accelerates a mass m with an acceleration a qy/hzgp6eo ,-. If the same net force is applied to mass 2m, then the acc h,-qegpoy6z/eleration will be

  A net force F acts on a mass m and produces lm0cxagl6 v:; an acceleration a. What acceleration results if a net glm;0 alxc:6v force 2F acts on mass 4m?

  If you blow up a balloonit;rx *4 l4fu2h 1igd(fl1zr7 s1bzd d, and then release it, the balloon will fly away. This is an illustdif1ls1 xg z4ib (2 d1tzf4;rlh r7d*uration of

  Two cars collide head-on. At ehsn8skm7g6j ,very moment during the collision, the magnitude of the force the first car exerts on the second is exactly equal tom7shkn g8j s6, the magnitude of the force the second car exerts on the first. This is an example of

  If you exert a force F oxp;xj58yd zdu+fj8 ( ono(.jhn an object, the force which the object exerts on you wi(fh jdxd ;8ojoupj+85 .xz(nyll

  Action-reaction forceo6qx p.k-p/of a9)hats

  Action-reaction forcn*o8) qig c(getvcd9owv 7; 6pes are

  A 20-ton truck collides with a 1500-lb car and causes a lo wyn6bx-wi.o*cy2) memx lo6p91 bs a*t of damage to the car. Since a lot of damage is done ob )6 nw*9paom 1bxl *-wy2e.xmy6cison the car

  An object of mass m sits on a flat table. The Earth pulls on this o.0 cfg;c5etm8 hsg9gx p 9fw3fbject with force mg, which we will call the action force. What is the reactxcg0wg3s9 9f5mt ;8gpf.fhceion force?

  A child's toy is suspended from the ce6a1d4 qyvw8m,w vzwn,iling 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 forw1,ya 6,m vww4zv8 dqnce"?

  Your bat hits the ball pitched to you with a 1500-N instantaneqqsiv.9 1pw1 jb .rnv+ kgf+*sous force. The ball hits the bwq.+vijr.1 n9 v pqg*k+ssb 1fat with an instantaneous force, whose magnitude is

State Newton's three lahk;z ta pmbs-gh(8htw11 wo5: d2x0 faws.

  Mass and weight

  The acceleration due to gravity is ycf1.nmz ybd:r-*.l o lower on the Moon than on Earth. Which of the following is true about the mass and weight of an astronaut on the Mo.yzfymco ndr*-1l. b:on's surface, compared to Earth?

  An example of a force which acts at a distance i z oqs9elx*9)t*tgbl vt( 6 bkij16d9vs

  Who has a greater weight to mass ratio, a person weigh z8qjmu17 ttjsgu,d86ing 400 N or a person weighinjtg,87j1 z 8 smutudq6g 600 N?

  A stone is thrown straight up. At the top of its path, the net forceuc *g)wjd: ud/n5c g;h acting on it )c u5gudg:wdc*njh/;is

  A 20-N weight and a 5.0-N weight are dropped o.e/, ampu, zxa2z*p/cx pp7r9hgru 9 simultaneously from the same height. Ignore air resistance. Compare thg eo*p9 c.uphp rxp9,xuz,ma a/z/r7 2eir accelerations.

  A brick and a feather fall to the earth at their respective termi3v8s 7cv/ somgui( ll0nal velocities. Which object experience/u lgvcmis3ls7 o8(v0 s the greater force of air friction?

  An object of mass m is hanging by a string from the ceiling ofcbqq+cr) mm9xh2j2x -)pum d ,bik 2y2 an elevator. The elevator m29mhrp ujdbqi)+ bx2m ,y)qk2c- x2cis moving up at constant speed. What is the tension in the string?

  An object of mass m is hanging by a string from -ynp6ox 9 ei-cqbga*3 the ceiling of an elevator. The elevator is moving upward, but slowing do*n9q-go 3iyc-pae 6bxwn. What is the tension in the string?

  The force that keeps you from slidio6h) z8hm)z qx7 bo5ntng on an icy sidewalk is

  It's more difficult to start moving a heavy (i miq:q k+sv)carton from rest than it is to keep pushing it with constis+)k:mi(v q qant velocity, because

  A horizontal force acpj70x tj2 la8p7phfl;celerates a box from rest across a horizontal surface (friction is present) at a constant rate. The experiment pp728jl0ljht;7 ax fpis 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 inclined ramp at constant veloy73 zgefb(5v /8aegguc 7d.yj3qto:xcity. Thus we can dedug8/.go3fzg yb(qa:y7t3e5cj udv7e x ce that

  A block of mass M slides down a frictionless plane inclined at an angle q wit5attgl5osq b9 -1k6koh the horizontal. The normal reaction force exerted by the plane on thlgt5k16bk5-9t aq oo se block is

  A block of mass M slides down a frictionless plane inclined at i5l*ss )7 uewy6tq4wk ,o*y tvan angle q with the horizontal. The normal rky*itst)l, uyv5w7s *q wo 64eeaction force exerted by the plane on the block is directed

  A block of mass M slides down a frictionlnr 0-r.cc5cd g 1d4m ia.9bguh.pn(ngess plane inclined at an angle q with the horizontal. The gravitatib p nm.cg-5gndr 1r.a cn9u4ighdc 0(.onal force is directed

  Two toy cars (16 kg and 2.0 kg) are released simultaneously on an inclined pg*z b6t .d/y hky9f;gtgrdp)5lane that makes an angle of 30e with the horizontal. Make a statement which best descri.rf;* gd gyk 65 /tpbdyg9zht)bes their acceleration after being released.

  An object sits on a frict)m7tqr7au el o 2;9afpionless surface. A 16-N force is applied to the objectae t9q7mau2pl;fo7r) , and it accelerates at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg :// 3nf le t+smvyq;zkcan accelerate from rest to 27 m/s in 7.0 s. What is the average forward force /:keyqm vls3t/ n+fz ;on the car?

  Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s in 2xhw;jwl:il4 y2s/7 huav d1(5iqj5ic.0 s. What is the net force ac55v: ix(jhjwy 4i/s dllai1qu;7 wh2cting on the body?

  An antitank weapon fires a 3.00-kg rocket which acquires a speed of 50rc46rsy*sk4/5 os utlbvb 0:k.0 m/s after trau*s0r tc ov56krkbys l 4b/4:sveling
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 you7od,t*z-xc3d hm 9g rx push a 10-kg mass from res z g-m7*3d,dxcxht9rot,

  What is the mass of a person whoygic2* cwoagu( v-u5 ;, x5shx weighs 110 lb?

  What is the mass of an obje (0.*xp c1z3axkky7lr i-uggkct that weighs 250 N on the surface of the Earth where the acil0r c-.(u *y31g7gxxkzk pakceleration due to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60p//:bp epto)e n20)e j+ba.3dvk awsp kg on the Earth. What is the mass of the object on the surface of the Moon where the acceleration due to gravity is ekaa+p/dj npt)vw:/p 2 oee) bb.3s0 ponly 1/6 of that on the Earth?

  Object A weighs 40 N on Earth, and object B weighs 40 N on the Moon. The Mook+f ( plm4koe; 9n*cdin's gravity is one sixth of (id4 n; elp fk+*m9cokEarth's. Compare the masses of the objects.

  Sue and Sean are having a tug-of-war by pueu46nbeeo52r 1d -5id o+btmt lling on opposite ends of a 5.0-kg rope. Sue pulls with a 15-N forc e 16b4erbmdo2t eno-du+ 5ti5e. 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 fribn *afd cr,k,e8) fpj+o55 gdkctionless surface. A force F acts on the stack, a+, 5rb of, 8cg e)5ddjkafkpn*nd 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 on a sco8jw qc tb+4get8yb *7t:wu+yale in an elevator. What will the scale be reading when the elevator is accel 7yuw qcg+8:wtt+ b8ejt y*b4oerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the mass of the person o u :f7a1k5*ovb ik,kris 60.0 kg and the elevator accelerates downward wir ou :vk15kbi,a k7fo*th an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale ridespsyhi:8/0 or0 dzsx5o:9a tyt in an elevator. If the mass of the person is 60.0 kg and the elevator accelerates upward with ao: t 05:yizx0/dsoa h8p9yt srn 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,bgtdyq7 /jc l5k/pm+ as a magnitude of 8.0 N and is directed due north. The second force toward tcjk bm/l tq5/y7dg+,phe east 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 .c;n1acyo6u rs*/ supwz*eo3 o:)zseplace by metal brackets that can exert a maximum horizontal force of 9000 N. When the truck is traveling 15 m/s, what is the minimu)s 6 .cpr1 nuw**yssoau: oo3zceze/;m stopping distance if the load is not to slide forward into the cab?

  An object of mass 6000 kg rests on the flatbed o 19tqfjf85v )fou3t fkf 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 tt tk9f jouffq 15f38v)he load is not to slide forward into the cab?

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg i6vwfa735qt a and m = 0.40 kg, what is the magnitude of the acceleration of the system? (Ignore friction and the ma5wftia7a 3v q6ss of the pulley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, whaxtzoj8bw+ 6 zkv82tz4n) k/ rwt is the tension in the strinz48nk wrvj/z to6)w8k+ xb2tzg? (Ignore friction and the mass of the pulley.)

  A student pulls a box of booksfx3yw bf2n+e*7 es0 lu on a smooth horizontal floor with a force of 100 N in a direle7 xsun2wf3bf0y*+ ection 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 of sud) 3ar,dp /j100 N iadp jurd),s /3n 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 force on the box?

  A traffic light of weight 100 N is sur2zk v5bhl + w2ol2o4uq+6 vxypported by two ropes as shown in Fig. 4-2. W4vh6ou2lvrq2bw y++ k z5oxl2hat are the tensions in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is the mass m+()x zto a-p3k8yztlzmp9k) of the traffic mk93l p mp at)z)zxtz+ ky-o8(light?

  Two boxes of masses m an4y0hyppqy + t7e4- nvxd 2m are in contact with each other on a frictionless surface. (See Fig. 4-3.) What is the accqypp7nvex4 0h+ y yt-4eleration of the more massive box?

  Two boxes of masses m and 2m 14:p 1txn4rm1x ;xulc/r chhaare in contact with each other on a frictionless surface. (See Fig. 4-3.) What is the net force on the more mass h/n r ur41:hxl4xtac c1;mp1xive box?

  Two boxes of masses m and 2m are co9i1go x pvh )vc:e(h6lnnected by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the tension 1vhh) i6c ovxe(:p g9lin the connecting rope?

  Two boxes of masses m and 2m are connected by a dkif)t . 0*owptbn9x 8rope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the acceleration of the .b09 fdknx*t )tpow8i less massive box?

Two boxes are connected by a cord runnidy7 qb *0r28nps+rxp kng over a pulley as shown in Fig. 4-5. Box I of m xp+*bq7sp2n yr0r 8dkass
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 betw po:cq4v/ tf0(jp jk8qeen a 3.0-kg box and a desk are 0.40 andjp8:(qvfoj p t0 cqk/4 0.30, respectively. What is the net force on the box when a 15 N horizontal force is applied to the box?

  The coefficients of static and kinetic frictions for plastic ony+ d n*.)ivbwc wood are 0.50 and 0.40,vbcw* dn+iy ).
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 surt/m: dp -7lodmface in the +x direction. It slows and comes to a stop with a con:m/ l-omt p7ddstant 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 byi5m0o z4h,cz3jib;xv 5 i/wcsnya: pc-7d5qg a 5.0-N force. A 3.0-N fr5:q7y cich5p-a /m,0;4ivs5bjgxiznz3ow c diction force retards the motion. What is the acceleration of the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg mass, from2,9m uh/r blcktj*d j; 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 speed of 10 m/s.g9qp7o t ee0 lmiv8w,: It slides 50 m on the ice before it stops. What is the coefficient of kinetic friction between the puckv7epo9 8gm: i0lte,qw and the ice?

  During the investigation of a traffic g3pgo37cep /s 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 0.500 for the prevailing conditions. Estimate the speed of the car when the brakes were applig c3/pg e3ps7oed.

  Two boxes of masses m and 3m are stacked. (See Fig. 4-sh0 epkis-d9 (mqwh486.) The surface between t9-im ss8h4 edwpk hq0(he 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 box?

  Two boxes of masses m and 3m are stacked. (See Fig. 4-6.) The surfac)a3.sj0 4qm vkkgbw/v e between the moqak 3)k /b4.0jmgvvws re 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 between the boxes?

  An object is on a frictionless inclined plane. The plane is inclined at a*zm /*we xf-p01 yzvynz6lx d.n angle of 0z */zz.* 1xn ewdfx-lymvy6p $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that makes an angle of , e3ou5isx,ll $10^{\circ}$ with the horizontal. If friction is negligible, what is the resultant force on the sled?

  A mass is placed on a smooth in w6nfjfgtk);wq 950rpclined plane with 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 plane vl4 ;juterzzsciit90 2*xr9-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 directlgkw8 0gxd,fk6d ze+z(y down an inclined plane, at a constant velocity of 6gd(z ,0+dgezx6 8fk wk.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 7 xz m*-mwbwi p:29,xnrh5 liedown 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 dowiv0bq bf 8zb/4;w x.naeh(v:ri; x(rb 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 rougho8 p2d-gch,pk+yhyq bqqk 01 7 surface. The cable attached to the log makes an angle8cpkbk q,yy7+- 0 p12hqgo dhq 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 rolmkc+bt 4z vgee, n;q ,*wq+.rugh inclined plane tilted at an angle of +; *+nltkerq4e gz .wc,qmvb, $33.5^{\circ}$ 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 graduall0: ywfy1zo xj+y increased until the object begins to slide. The angle at which this occurs is q. What is the coefficient of static friction between1y0zjw +f:yx o the object and the plane?