Which of Newton's laws best exhdh 0c; + jep6- ;fzzyls5*zhfplains why motorists should buckle-up?

  When you sit on a chairkorrie)j1 b9b) hwta*,z (4c i, the resultant force on you is

  In the absence of an external force, a moving object willhf/so m:yr//e ecx 7r+u(vm*y

  When the rocket engines on the starship NO-PAIN-NO-GAIN are suddenly turnedsuo.z00eq;x n-iv 4rh off, while traveling in empty space, nr-hi;q4szvxo.00e u the starship will

  A rocket moves through empty space in a straight linn.fu 6+d 3ouqhe with constant speed. It is far from the gravitational effect of any star or phquun6f .o+ d3lanet. 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 forward, and you sbb 3x/8+jwdc*e e0v xlxj3 u8juddenly fall forward. You cax*wed0 /cj3+8xlj8xjebvbu 3n imply from this that the bus's

  You are standing in a moving r,hdq( m5sp6 (,jivwi bus, facing forward, and you suddenly fall forward as the bus comes to an immediate r(,wds5m,(6ji p vhiqstop. What force caused you to fall forward?

  A constant net force acts on an object. D -dhn,yv (6pwbhhw6l2escribe the motion of the object.

  The acceleration of an object is inversely proportiona99boet*l( whfl to

  A net force F accelerates a mass m with an ac5dsr)g(idwec: 8m3 tf celeration a. If the same net force is applied to mass 2m, then the acceleration will irds:e dmcf )5wt(83g be

  A net force F acts on a mass biocz -cl0 +s-m and produces an acceleration a. What acceleration0s+-iocbl- zc results if a net force 2F acts on mass 4m?

  If you blow up a balloon, and then release it, the ball-xs.hvybfnn ,bzo-3j.iif s70 s/ j5moon will fly away. This is an illustratf., /v0-nz 5.jo7s-hb3 ijyi xfbsnmsion of

  Two cars collide head-on. At every moment durinlk( +-/fud,y65e h aey t)fiong 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 ex fd/t-iunyha 6) +5(,oey eflkample of

  If you exert a force F on an object, the force which the object exerts m(vxqdu9*:w+n.hd tt on you wi*t( tq:w.9xhvd undm +ll

  Action-reaction forcerowb.w l29i:a ek45jh s

  Action-reaction forces .j sll4qd+ks 3:f0 bzxare

  A 20-ton truck collides with a 1500-lb car and causes a lot of damage to the cq hkz)wuk*r q .046xqgar. Since a lot of damage isxquk k6wq h0r*)4gzq. done on the car

  An object of mass m sits on a fl-lkchd-vdv(*p f7 sz0 at table. The Earth pulls on this object with force mg,dkzd c-s v-v(0h *7fpl which we will call the action force. What is the reaction force?

  A child's toy is suspendeh+u*ahcncr ;p m+6ah, d from the ceiling by means of a string. The Earth pulls downward o urcnh +ch*m;hp6a, a+n 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 1500-N instann;xifi7uvi ec d8p;,p*t p *b4taneous force. The ball hits the bat with piu,;i8 v epnit*xfp *47bd;can instantaneous force, whose magnitude is

State Newton's three lah *zv: w3z-xjmws.

  Mass and weight

  The acceleration due to gravmsw/ *iwz*ox -ity is lower on the Moon than on Earth. Which of the following is true about the mass mwz /w o*xs*i-and weight of an astronaut on the Moon's surface, compared to Earth?

  An example of a force which acts at a dista9(suevea0qif (0qul , nce is

  Who has a greater weight to mass ratio, a person weighing 400 N ordfzb6e+e5 m: j a person weighing d6efe:zm5 j+b 600 N?

  A stone is thrown straight up. Ata0mmw0 hl,z:2 c)uwsj the top of its path, the net force acting on ,lhswajm0z )m: c2uw0it is

  A 20-N weight and a 5.0-N weib -cssjom; l )-l;cb9cght are dropped simultaneously from the same height. Ignore air resistance. Clsj c-mcs)l ;b;9bco-ompare their accelerations.

  A brick and a feather2nnjc* 0-su4 yazz- uq fall to the earth at their respective terminal velocities. Which object experiences the greater forczqu*ac 2j-ns4n y-uz0e of air friction?

  An object of mass m iglh 6q7 )-ibnb0bxk g*s hanging by a string from the ceiling of an elevator. Theqgl0h 67n) xgb *-ibbk elevator is moving up at constant speed. What is the tension in the string?

  An object of mass m is hanging by a st;k 57ylseu6a lring from the ceiling of an elevator. The elevayla k;seu675l tor is moving upward, but slowing down. What is the tension in the string?

  The force that keeps you from sliding on an icy sidewhhm xgaz*b0) bw9/wh6alk is

  It's more difficult to start movit.l ,wythch/; dlc2y.ng a heavy carton from rest than it is to keep pushing it with constant velociw;cltld .yt.h,h2c/y ty, because

  A horizontal force accelerates a box from rest across a horz 5ba-cao i6wstb44u5izontal surface (friction is present) at a constant rate. The experiment is repeated, and all conditions remain the same with the excep4w45uoac6-b tsbia5ztion that the horizontal force is doubled. What happens to the box's acceleration?

  A packing crate slide:d* a n7k+jgbcs down an inclined ramp at constant velocity. Thus we can d*cjbg:na+dk 7 educe that

  A block of mass M slides dhsz q,dw c/duq8 s185bown a frictionless plane inclined at an angle q with the horizontal. The normal reaction force exerted1cqbu qwd sz,hs8d/85 by the plane on the block is

  A block of mass M slides down a frictionless plane inclined at an angle q-ws7.wop; hr)ndkn 0o with the horizontal. The normal reaction force exerted by the plane on the block is dirpn.n;sorok 7ww)h-0 dected

  A block of mass M slides down a frictionless plane inclined at an angle2rv3,d wwr boypb (3t/1ift /l q with the horizontal. The gravio/wv rywd pti3b,b tl (3/21rftational force is directed

  Two toy cars (16 kg and 2.0 kg) are released simuh2x5i j9 cmwn.ltaneously on an inclined plane that makes an angle of 30e with the horizontal. Make a statement which best .2wjhmn9c ix 5describes their acceleration after being released.

  An object sits on a frict,+*c , fb+7nndxrmcfd- p (ckjionless surface. A 16-N force is applied to the object, and*b,+(kcmnf j7 crpc-+n dfx, d it accelerates at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accelerateixmz;3s y 0v 7ca*x8h1ooi0 gt03pgo a zz4o+m from rest to 27 m/s in 7.0 s. What is the average forward forciapsvxmxazo8t z 4+30z*3h70g1m cyo;0gioo e on the car?

  Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s in 2.0 s. What is vlc,md0 2y xb.jf;m2 gvk6hx9r0lah:the n0l02jl6,hbvmay.cdg2k:h9m xv;f r xet force acting on the body?

  An antitank weapon fires a 3.00-kg rocket which gbbro0)-*p d-l zlh3e acquires a speed of 50.0 m/s after travelz)gd b- o3*-p0ll rhbeing
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 forcs*:;nzvf -b j k3a,sfqe that you push a 10-kg mass from rest,;nf :q,3fk a*zss-vbj

  What is the mass of a personv w z1s os.obeg*+u72hk9 8cms who weighs 110 lb?

  What is the mass of an o2pdg k )wr0h: pzs;.pq4cm82wk8p ragbject that weighs 250 N on the surface of the Earth where the acce .gzsqwrkpw0p4; g:kd2pp8)r ac8h2m leration due to gravity is $9.80 \; m/s^2$?

  An object has a mass of 6/ xoyt+nr 0pf)0 kg on the Earth. What is the mass of the object on the surface of the Moon where th+x/r) fn0ypto e acceleration 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. The Moonk3; p gvvxzsdzk*i; :)'s gravity is one sixth of Earth'dzz: s;i3kkx) v*gpv; s. Compare the masses of the objects.

  Sue and Sean are having a tug-of-war by pulling on oppositks ,xl kgi/ylfa3 0w(1e 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(k y0x3siakl/, 1w flg at $2.0 \; m/s^2$?

  A stack of books rests on a level t3pb/iz2m p) lepo ci/0a;6nbfrictionless surface. A force F acts on the stack, and it ac c2p)z btepp0//;l oi6 mnia3bcelerates 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 elevator. What :ijn;yp4,q) jq q,aht will the scale be reading wq:, q )t,ahpyqn i4j;jhen the elevator is accelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the maxg m3ao8g ae9xa0l8c3ss of the person is 60.0 kg and the elevator accelerates downwar3gcag eo a3am8x08 l9xd 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 or*gq9 w rv7j;x/-ocz j m:r*jvf the person is 60.0 kg and the elevator accelerates upward with an accelemjzvr;-o rj*jvq/r9:x*wg c7 ration 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 has 4f; v,mm kqqbxq.u wczyfc((*t1y 73qa magnitude of 8.0 N and is directed due north. The second force toward tht cmqf( czb qw41qfx(ky*,.q u;m7v3ye east has a magnitude of 6.0 N. What is the acceleration of the mass?

  An object of mass 6000 kg resi6k-i q 8sc k *vjbm8eu,ofrqwv; --0lts on the flatbed of a truck. It is held in place ci ,0efkjr-v6k uq 8b8qsi-v*wo;- mlby 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 distance if the load is not to slide forward into the cab?

  An object of mass 6000 kg rests on the flatbed of a trp+wo mj mp33oluw;r, 5zzec ,5.1cbvyuck. 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 ir3p5wy, 5euo1 p.clzczmbj,+o; w3m vs the minimum stopping time if the load is not to slide forward into the cab?

  In the Atwood machine shown in Fig. 4-1, if M = 0.6i * 57ax.per ddu,sfi a+:.veq0 kg and m = 0.40 kg, what is the magnitude of the acceleration of the system? (Ignore friction and the mass oii f5axeeu.7:.v s +*r dpqd,af the pulley.)

  In the Atwood machine shown in Fig. 4-1, if t9-)kmj9( 4txxaa dedM = 0.60 kg and m = 0.40 kg, what is the tension in the string? (Ignore friction and the mas jatxm d4 )(x9-da9kets of the pulley.)

  A student pulls a box of books on a smooth ho-+r e3.4isd-(y w, xk;er2opcyg bklorizontal floor with a force of 100 N iie(er,o-4oyc y -sp gkbx l2.kr3d;w+n a direction 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 l.;tyi5i)htx smooth horizontal floor with a force of 100 N in a direction of 37.0e above the horizontal. If the mass of the box and the books iyti5;xt.h) lis 40.0 kg, what is the normal force on the box?

  A traffic light of weight 100 N is se)kykmqi) lu *;72 ws ze1g6vnp q(d,pupported by two ropes as shown in Fig. 4-2. What are the tensions ;) (iu2m es)vq7gk ,enkl6zyp1q*dwpin the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is the mz/y 7 *uldl5tntdy63ah:lz5gass of the traffic litzgnzd d6h l3l*yu/ l557tay:ght?

  Two boxes of masses m and 2m are in contact with each other on a frictizl 5dyh. sqm,,,d -rcy6dpw 1konless surface. (See Fig. 4-3.) What is the acceleration of the mok,-w 5sl d zqy,6d1.cdm,rhypre massive box?

  Two boxes of masses m ao- rbkm + ;pvt6lq1,ndnd 2m are in contact with each other on a frictionless surface. (See Fig. 4-3.) What is the net force onml,-povd kn +q;61btr the more massive box?

  Two boxes of masses m and 2m are comcdn9 ,-)zvc;r,(q uy/;gx iu c0svdjnnected by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the tension in the connc;)v 9x;/d scvuz,nj-g0idu mqc ,y( recting rope?

  Two boxes of masses m and 2m are connected by ab0 x 2oz2zb,)ah ea0w: xo*goo rope. (See Fig. 4-4.) If the forward force on the :a,z2x)o0 x2aoo zeb0wgoh b*more massive box is F, what is the acceleration of the less massive box?

Two boxes are connected by a cord running over a pulley as shfs dcn; v/-ui0own in Fig. 4-5. Box I oifu c/;0v-dsn f 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 kinetp) +hs39:bolgpf hjc *ic 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 pglch3)f:sp +*9j ohba 15 N horizontal force is applied to the box?

  The coefficients of static and kinetic frictincw:2 / y 0tik-)t.ndd:pn hegons for plastic on wood are 0.50 and h2)cynpn-dw .e :0t /d:ngi tk0.40,
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 the u xf +0lle)w-.jx1d:yfir pf2+x direction. It slows and comes to a stop with a constant acceleration of - jix21 lf fuw)-xrd+0 :yf.lep$2.45 \; m/s^2$. What is the coefficient of kinetic friction between the object and the floor?

  A 10-kg box sitting on a homt;b, 9xdp 9qco5wec l.sjt,4rizontal surface is pulled by a 5.0-N force. A 3.0-N friction force retards the motion. What is the ac9qt, d;cto9b,ps 4cejl.5xmw celeration of the object?

  A horizontal force of 5.0 N fbld6 x )(/-m3esidbxaccelerates 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 i;wb:r 0 i4/2bu ai7e4xj8d:hf c0h)iluii r sgnitial speed of 10 m/s. It slides 50 m on the ice before it stops. What is the coefficient of kinetic friction bet2berh:4;/74i)iu 0:hi s f jlc irx8iagw0b duween the puck and the ice?

  During the investigation of a traffic accident, police 9 2o+1,3g.wkgtze, dsm egmfnfind skid marks 90.0 m long. They 3d,et9g f1.w+gg os en,2zmmk 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 applied.

  Two boxes of masses m and 3m are stacked. (See Fig. 4-6.) Tu*ej r kq,;-ml70ay rd-r d:ckhe 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 thd:c*eludj-7rrm0 ;ry-,qka ke more massive box, what is the static friction force on the less massive box?

  Two boxes of masses m b91d/ua yltyq- v9,ie and 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 boxa td91/iyql yu,-v9b e does not slide on the more massive box, what is the coefficient of static friction between the boxes?

  An object is on a frict, s/xpw1bm(ax ionless inclined plane. The plane is inclined at an angle ofmw/ xbp ax(,s1 $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a f jbqr.08n56ettt0(p mh 3xtajlat 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 inclins +nqe2 zxi3:ted 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 tilt e8kwg( kpj0e;6hytr6ed 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 vprq );v vsncb -vddp-m--74wvf:w3vp elocity of 6.0 m7s3:bvqmnr; pc-ww-4 -vp vv-pf)vdd /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 dyl ky4 f,j7fkc) nj9b6own 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 m8y.n0kuop f +w slides down 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. The2l9qyo ,vx :+l5zomeu cable attached to the logm92lvo,5+lux:q zo y e 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 rest on a rough inclined plane tilted at hr)c z/jx25lc0 3deux an angle ofjz) /c xcd2uhe3 0xrl5 $33.5^{\circ}$ 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 ak+zc veb7 5j. :w+rtxy8niur :ngle of incline is gradually increased until the vyk c5iwb+n:ze.+xtu7:jr 8r object begins to slide. The angle at which this occurs is q. What is the coefficient of static friction between the object and the plane?