Which of Newton's laws best explqc 47dets1b:k ains why motorists should buckle-up?

  When you sit on a chair, the resultan gl.cimsfqe2/5 l.rd;i.vi g/t force on you is

  In the absence of an externaimd :ethyh,gqxn2z4 rl7 k8.8l force, a moving object will

  When the rocket engines on the starship NO-PAIN-NO-GAIa ,nd+(3q6sl/ittaiu 3k fb+t N are suddenly turned off, while trbu ltf/6 ikn3d 3q atta,i+s(+aveling in empty space, the starship will

  A rocket moves through empty space in a straight line with constant s.u q( sp9obvv 2mt8g17hg ha6kpeed. It is far p7gmk2bo(q9h .v 8ust6hg 1vafrom 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 is

  You are standing in a moving bus, facing*p1 fkx0: sxlg*squrn 8lu21jczj)2c forward, and you suddenly fall forward. You can imply from this that tx0)g2k**jru czjsn1p fcqu2:1l8 sx lhe bus's

  You are standing in a moving bus, facing forward, anqo 03f 2u6movsd you suddenly fall forward as the bus comes to o63mfsovq2u0 an immediate stop. What force caused you to fall forward?

  A constant net force acts on o6w2iy4 xy g4zan object. Describe the motion of the object.

  The acceleration of an object is inversely proportion) ak 2i+skdhb,al to

  A net force F accelergw) 4t;+:ypml +(kvye sw;q biates a mass m with an acceleration a. If the same net force is applied to mass 2m, then the accelera bsl m+ v4:gp;(tqy; i)wke+ywtion will be

  A net force F acts on a mass m and produces an ap0r aeb26q ss8jhh6upq5 i,l 14 c0tttcceleration a. What acceleration results if a net force 2F acts on masqsur64 t5pjlit ,6s2pq8he ab0t1c h0s 4m?

  If you blow up a balloon, and then release it, the balloon will fly away. Tln8r )9bm3iushis is an illustrat8brnul) 3 9simion of

  Two cars collide head-on. At every moment during the t sx1 c:ph:nq)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 fc 1qn:shxp:)t irst. This is an example of

  If you exert a force F on an object, the force which 2, /xsqzhw ox z* ,mjqx4sd6.0wx1tyethe object exerts on you wils4,q qy,h/ xs06d. t2zz*m1wjx ox ewxl

  Action-reaction forc0jmc59cd (y8 al(cyules

  Action-reaction forces arip,qillfp3921bzxw g*ih +bf9rgl2( e

  A 20-ton truck collides with a 1500-lb car and causes a lot of damage to the careva +;:ygsd v(* *ejrv. Sincejvvs +*yv*ear:d eg;( a lot of damage is done on the car

  An object of mass m sits on a flat table. The Earth pul0 fu1 (ov,hwvcls on this object with force mg, whicvcvf(0,uo 1h wh we will call the action force. What is the reaction force?

  A child's toy is suspended from the ceilingimhu1c c y6fmx2-i5 w( by means of a string. The Earth pulls downward on the toy with its weight force of 8.0 N. If this is the "actiu16im cf2-hx5m c(ywion force," what is the "reaction force"?

  Your bat hits the ball pitched to you with a 158cgrey9 cc. j/bx1* im00-N instantaneous force. The ball hits the bat with an instantaneous force,jxccy 9r mbc*.g /e8i1 whose magnitude is

State Newton's three law+btxn6lr7) crsj ;vmb1jj)n:s.

  Mass and weight

  The acceleration due to gravity is lower on the Moon than on*jr,j30 wy(ok7x; bswd910h taj cvnh Earth. Which of the following is true about the mass and weight of an astronaut on v0 t3a wojwc ;d7shbhk0n,rjj( 1yx9*the Moon's surface, compared to Earth?

  An example of a force which ath) (uxf6e4nw; p8 yqjcts at a distance is

  Who has a greater weight to mass ratio, a person weig.sjkua,+h) rl1udk ;)exsj*q 6su h-dhing 400 N or a person weighing sr* 1 uluq )ajesj k -.,dk6;)+sxuhdh600 N?

  A stone is thrown straight up. At the j6 -b0; i sxo9t,nd6hwd4ln mhtop of its path, the net force acting on ib9 jmx6tn6ddl;0h 4-w,soh nit is

  A 20-N weight and a 5.0-N weight are dropped simultaneously from the same heigza.erd,2k5d.attsi(m5 og d4ht.rt k.(o2azd g4dedis. t,a5m5 Ignore air resistance. Compare their accelerations.

  A brick and a feather fall to the earth at their respq9x:t:h ,pctw ective terminal velocities. Which object experiences,h9x twc:q:t p the greater force of air friction?

  An object of mass m is hanging by a string from the x ps41buz :j+dceiling of an elevator. The elevator is moving up at constaxj4p+ud: 1b zsnt speed. What is the tension in the string?

  An object of mass m is q;a,kjks h p,q -pc;;uhanging by a string from the ceiling of an elevator. The elevator is moving upward, but slowing down. What is j;;hs,, u- kqckpqa;pthe tension in the string?

  The force that keeps you from sliding on an icy sidewf)s37d gl :lxtalk is

  It's more difficult to start moving a heavy carton from rest than ia9fr) iqdb,p 0t is to keep pushing iqb9ifrp a)d0, t with constant velocity, because

  A horizontal force accelerates: rgmlk; agdh ktl4dk3 *6(sq3 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 excepti k3:;3gqh6 * dmlkkl4 ds(agtron that the horizontal force is doubled. What happens to the box's acceleration?

  A packing crate slides down an inclined ramp at constant velocitay /lfr;bcx,9 3(besxy. Thus we can deduce thae(yx;f b,/xl rc3bsa 9t

  A block of mass M slides down a frictionless e:r19* g + brlcywxqs3t8h1dh plane inclined at an angle q with the horizontal. The normal reaction force exerted by the p 3rx9h8g:*cytblew1q h +1rs dlane on the block is

  A block of mass M slides down a frictionless plane u);e5 f(w amufo*frf1inclined at an angle q with the horizontal.f (5w * 1;oauruff)fem The normal reaction force exerted by the plane on the block is directed

  A block of mass M slides down a frictionless plaw z8* 9i7gxvuxnj ;4 elp:zn9tne inclined at an angle q with the horizontal. The gravitational force is :w48l v xu97npgz t i9zn*xj;edirected

  Two toy cars (16 kg an9 8q5 jy vyesj7o(r:mdd 2.0 kg) are released simultaneously on an inclined plane that makes an angle of 30e with the horizontal. Make a statement which best des 5jvo9(dsy:e m8y jqr7cribes their acceleration after being released.

  An object sits on a frictionless surfacvz;ra; oqrn)(kxc 0jh7pxr76uw; z p/e. A 16-N force is applied to the object, and it acceleracw;k /6a ppqhu7zx(r nj;v) r7;orz0xtes at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accelerate from rest to 27 m/s in 7.0 s. f4ci9xn9*: pjkb 0y tc What is the average forward force oy ipf 9kx:9tc4j0 c*nbn the car?

  Starting from rest, a 4.0-kg7br0tacr2hi q go(5e3d)e/ne body reaches a speed of 8.0 m/s in 2.0 s. What is the net force acting ontee)dgoa cn7i2r( 35r /ehq 0b the body?

  An antitank weapon fires a 3.00-kg rocket which acquires a s i3c7-,rq2) qh0ilhg 7cfpjm ypeed of 50.0 m/s after tyh jql,r27p hc g3i0i) cmf-q7raveling
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 witfqs6ws/oep-g+ue jwk )d; 1w izo76+lh the same force that you push a 10-kg mass from rest,wq/ 16k+) wow efls7i -6udszo;e jg+p

  What is the mass of a person wh1gmb kh7e k(+io weighs 110 lb?

  What is the mass of an object that weighs 250 N on the surface of the Earth -yt5-ll .u it56 7g ad-vjnskfwhere the acceleration due to s j-ldtn-vug.til a f56k y-57gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. What is the mass ol .t7be0fvr+e 6qw/i 2vx(z xdf the object on the surface of the Moon where the acceleraz0x wxeb27/. (6ferqv vd i+tltion due to gravity is only 1/6 of that on the Earth?

  Object A weighs 40 N on Earth, and object B weighs 40 N on the Moon. xb1o ,yzbg0 pt(u1hu5 cb8:xxThe Moon's gravityx 5x(bpctxh1 1z :ub0by, uog8 is one sixth of Earth's. Compare the masses of the objects.

  Sue and Sean are having a tua h/a+ wv .:hbdvxwy.8g-of-war by pulling on opposite ends of a 5.0-kg rope. Sue pulls with a 15-wdwv+h .av/:ayhb8x . 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 surfu vli55s6 vublqa 6w)lk1/h .face. A force F acts on the stack, and it accelew 651lv. s 5uuv)b hqllf/ia6krates 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 elevato h2qy z -/fdvq3f+5xvvr. What will the scale be reading when the e+zfv-3h5d fxqv/2q yv levator is accelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an ele c 4i-h/m yvdbw02ir/zvator. If the mass of the person is 60.0 kg and the elevatorri/b wcyhdi2 40m-z/v 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 of the person is 2pvh:ds 5r:*amv1tw p60.0 kg and the elevator accelerates upward with an accelerationhs:a vm2pt1d5r:p *wv of $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal forces act on a 5.0-kg mass. One forc33xtu4r k+nxb+x cf (kjw: t0ce has a magnitude of 8.0 N and is directed due north. The second force toward the east has a magnitude of 6.0 N. What is the acceleratixnckxckw +b0j(t 3rft+34 :xu on of the mass?

  An object of mass 6000 kg rests on the flatbed of +t 4qh.ehjh3pa 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, whatte. p3j4hqh+ h is the minimum stopping distance if the load is not to slide forward into the cab?

  An object of mass 6000 kg rests oz9qebpx7emc.n0 w; qks) *qs.n 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 . sp.0bnm)9see;kcqqx7qz w*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. 4aw1kawx1e72z j6hs- c8r i g)b-1, if M = 0.60 kg and m = 0.40 kg, what is the magnitude of the acceleration7w8jwar2xae) 16g hskz1ci-b of the system? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg and m = 0.40 t-i7lqx-7 ku.kj z9cbj,;o; dbrw o4gkg, what is the tension in the string? (Ignore friction ano;i7ct lqk.rw,-;g k dxub-j4 o z7b9jd the mass of the pulley.)

  A student pulls a box of books on a smooth horizontanewpxc9 * )ta4l floor with a force of 100 N in a direction of xw9ct) en4*pa $37^{\circ}$ 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 horizontagp9ib 8ndc.l.az.v.z qm9,wjl floor with a force of 100 N in a dqg.zija98nvcmz.,. . 9p lbwdirection 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 ropes as shown y0b ugpz00.jlin Fig. 4-2. What are the tensions in t0pg0zl j. 0ubyhe ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is an/)+*b uqb mathe mass of the traffic lia bu/)a *b+qnmght?

  Two boxes of masses m and 2m are in contact with eqwftk,lu 8cgb h:1y9x1cvl9 bsq776 qach other on a frictionless surface. (See Fig. 4-3.) Whautkwc9 g7 , :81yqb q9l fbl6hcx1vqs7t is the acceleration of the more massive box?

  Two boxes of masses m and 2egk1yr34o : ;8bhatpl b gmn52m are in contact with each other on a frictionless surface. (See Fig. 4-3.) What is the net force on the more massive boxb5gka ;rb photmg382en:y1l4?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4-4.; do7qe+cr0f(cjas tv,wp;* y) If the forward force on the more massive box is F, what is the tension in the connectinpsvo;7r( at q y; e0ccjwd*+,fg rope?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4-4ykd-d kb4 xrbs3 5h6b1.) If the forward force on the more massive box is F, what is the acceleration of the less massive box?d3b4b5ry x6 kkshd1- b

Two boxes are connected by q -4/b 6 dnw;shpi*vrpqs3 zi.a cord running over a pulley as shown in Fig. 4-5. Box I of mass d;rpbq/ . ss-*z3i qnwh46vpi
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 bucofx7d 6;6 t fhj8kntr3 5d-desk are 0.40 and 0.30, respectively. What is the net force on the box when a 15 N horizontal force xutf 6d8n-7f5t b6oc;3hk rdjis applied to the box?

  The coefficients of static and kinetic fguw-syt9 e6d x;fa e/brh.lejn, +/v1rictions for plastic on wood are 0.50 and /f alxydut.nbhw,e 1jv6/r-s; e+ 9 ge0.40,
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 thn7.f t pa(cyfnm8i38ve +x direction. It slows and comes to a stop with a constant acip f87mn y .fta3nv8(cceleration 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 suruwi t))wagj v*2u-chu; 5ne9kface is pulled by a 5.0-N force. A 3.0-N friction force retards the motion. What is the acceleratiohk nw*a;wj)vcgtu u 9u) -ie52n of the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg mass, +cq5;9u9vuzr8mbt+e9 u ea nxfrom 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. It slijw402)v3dm tptkj-k2 v/f wxx gt+9rpdes 50 m on the ice before it stops. What is th2-4wx gfkp2wj0dj 3+ mk9pt /)trxvtv e coefficient of kinetic friction between the puck and the ice?

  During the investigation of a traffic accident, q.gtzdk2 r1q d1btg tyss07m *;4 0gsepolice find skid marks 90.0 m long. They determine b . eyq10q12smt 0d7dzrtgss*gkg; 4tthe 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 applied.

  Two boxes of masses m and 3m are stacked. (See Fig. 4-6.) The surfacwb+ ye;;q)x9l+r f1ybh ssht +e 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 9q1w)xbsfs h;+ +yblhy +re; tslide 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. 4wbfzgegk e1l679xx(te 17 +uh -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 masslux7(k1g9ee +wehz6x7t1 bgfive box, what is the coefficient of static friction between the boxes?

  An object is on a frictionless inclined plane.auv4 xuzc7q5*6ola6 s The plane is inclined at an angle6 * 6uauczvoq x57la4s of $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that makes an s6*ym :ep8di3/cmu v rangle 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 withy)l)4g )t:j cnsq;;orim7 t v7rclhj9 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 tilted at ani bcfo6.zq*gqc z o.+7 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 ind . 0,v /km(ftaqr d;ouaorz05clined plane, at a constant velocity of 6. u,z0;fo0rt dmrdaqo./k v(5 a0 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 x13ubw reyu8*r1:w bc 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 dow7x rs.*tex9bon 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. vu1jtu/:ztf yub) m,fg1 q*h+ The cable attached to th m j g/z*qb ),+:fvyu1tufu1the 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 , 0hlp xv kdcw,+y.ae:rest on a rough inclined plane tilted at an angle of k,v+eywa0 cld,pxh :. $33.5^{\circ}$ 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 inclsjmx+mfd g v2h9:-l h-ined plane. The angle of incline is gradually increased until the object begins to slide. The angle at which this occurs is q. What is the coefficient of static friction bes-l-: dm 2mjh9hgf xv+tween the object and the plane?