Which of Newton's laws best explains why motorists sh + u41-uqbrjduould buckle-up?

  When you sit on a chair, the resultant force on yol eq3ex1(e;s,(g5 /ts.nexp c vtqs6ku is

  In the absence of an external force, a movit hsus9;0i)xf ng object will

  When the rocket engines on the starship NO-PAIN-NO-GAINl (oyfwkeb q2c+ 5r9z( are suddenly turned off, while trav y+2w(rz fqkbec9( 5loeling in empty space, the starship will

  A rocket moves through empty space in a straigp7be r,e 4ez1pht line with constant speed. It is far fro 7 r1pzeb4epe,m 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, facinn.r,pb.r/ m cte7o9zxazy 8u/ g forward, and you suddenly fall forward. Yo /m89rp ty/z,bz a nr7eocx..uu can imply from this that the bus's

  You are standing in a moving bus, facing forward, and you suddenly fall/ 2d65 oxbggqe forward as the bus comes to an immediate stop. qo/e5b2 x6dgg What force caused you to fall forward?

  A constant net force acts on an ou xcin4 d(2:7ag:ma flbject. Describe the motion of the object.

  The acceleration of an object is inversely proportiona ve/61v+gpg(r(rg ga52vw rkj l to

  A net force F accelerates a mass m with an acceleration a. If the same net foc5d scgh4w638yyp4 2d5 mlqdsrce is applied to mwsd hycy6d q4c25m38dgl5 s 4pass 2m, then the acceleration will be

  A net force F acts on a mass m+0t dlqte b2mavu)s26; hkcgfc0(e f* and produces an acceleration a. What acceleration tqset(leu)c;+2hd c a00m bgf 6vf 2*kresults if a net force 2F acts on mass 4m?

  If you blow up a balloon, and then ;2js hw*q l a+10 o wyka:)xkzc2ncf*crelease it, the balloon will fly away. This is an illustration o+ f1qj cc;*:yc2aknw slka hzx2)w *o0f

  Two cars collide head-on. At every moment during the collision, the magnitude ofh r(og; ioyvgl8.4vt ) the force the first car et8)yv( i og.h;4olvgrxerts 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 fo6 z5zh)7j mb f;d7vnbvrce which the object exerts on you wi; nbz)z6b5mf h7vdjv 7ll

  Action-reaction forceo/ ( kf4d a0jvh l1;y8ez iesz)*u7imps

  Action-reaction forces ares( +vp9ho;zd7-unvs no2r9iw

  A 20-ton truck colli-3gae e 2v xr.tbxwe573f l6rxdes with a 1500-lb car and causes a lot of damage to the car. Sincb3f vwa 62eg35etx.rlxx re-7e a lot of damage is done on the car

  An object of mass m sits on a flat moahh apzg 3)1(kae;1table. The Earth pulls on this object with force mg, which we will call the action force. What is thoh p zaeahk;1)(m a31ge reaction force?

  A child's toy is suspended from the.e86h*uow wr e 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 threou*.hew6 w8e "reaction force"?

  Your bat hits the ball pitched to you with a ppvxh*c8i -( iaa:jt- 1500-N instantaneous force. The ball hits the bat with an instantaneous-pi p(-aix jhcavt8 *: force, whose magnitude is

State Newton's three lawa:exd th9m++pwg:us+s.

  Mass and weight

  The acceleration due to gravity is lower on the Moon than on Earth o j 6qjun5+*)bd8wnr hzcupq 9wbn//,. Which of the following is true about the mass and weight of an astronaut on the Moon's surface, compared to Earthb+q hnozjn,duj958* ub/c /p6wqn) wr?

  An example of a force which acts at a diy-bz(/vo jp9ystance is

  Who has a greater weight to mass ratio, a persontvk*d36e tcw . weighing 400 N or a person weighi*w6ck. tt 3dveng 600 N?

  A stone is thrown straight up. At the top of its path, the net force actinmopbq.y/vj 88z(n(8d- sfci zva 2tt(g on it imo(na .t8- vc( p8qjtb /i2dyv (zsfz8s

  A 20-N weight and a 5.0-N weight are dropped simultaneously from the same heaft3f7:3hgg1hg3 : cy i* :oxeu ek.vjight. I7*ef:uxgg f.kc13:: ihj h3y o3a tveggnore air resistance. Compare their accelerations.

  A brick and a feather fall to the earth at their respective term)uu6 )mu-stm sinal velocities. Which object experiences the greater force of air frictu-6 tm)ss) uumion?

  An object of mass m is hanging by a string from the ce6q7pf e8.bi/taa l jj,*9d icxiling of an elevator. The elevator is moving up at constant speedqxf/bic7 89lijp6, . jat ad*e. What is the tension in the string?

  An object of mass m is hanging by a string from the ceiling of an elev:4 obb zxh:1(wey kfc6ator. The elevator is moving upward, but slok4 y(bxz1f6c:hob e w:wing down. What is the tension in the string?

  The force that keeps you from slidin/o pmy89lw8jb g on an icy sidewalk is

  It's more difficult to start mov;i5em/ys+g*s( wc5 fvd c;h3nyv di ;oing a heavy carton from rest than it is to keep pushing it with constant velocity, because; dw5 gy;/vim v+n*;ce 5hocdyi3ss f(

  A horizontal force acceleratesjzxl 5t9p7fz4 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 fof5xl t7jz9z p4rce is doubled. What happens to the box's acceleration?

  A packing crate slides down an inclined ramp at constant velocity. Thus8.fscw4ck4h h we can deduh wcsc .h4k4f8ce that

  A block of mass M slides down a frictionless plane inclined at acp3jq 9c7*ye+m wz+auctq2 :xn angle q with the horizontal.umyjxcw7 :ae+p *3c2 +q zt9qc The normal reaction force exerted by the plane on the block is

  A block of mass M slides down a fry8/ 9 (xaua*tyvq e,a/pacm w d)kf2c-ictionless plane inclined at an angle q with the horizontal. The normal reaction force exerted by the plane on the bloc w-kcd(va /xqup/9aft)8ma* y 2eca,y k is directed

  A block of mass M slides down a frictionless plane inclined at an anglebz+ c -5x.crq*lnk9jz q with the +cb. rlz 5cj*zqn- xk9horizontal. The gravitational force is directed

  Two toy cars (16 kg and 2.0 kg) atn:feg) vsf y6l2ck 2,re released simultaneously on an inclined plane that makes an angle of 30e with the horizontal. Make a statement which best describes their acceleration aft) t2:s, cf gfe6vl2nkyer being released.

  An object sits on a fric 7,;wd vvhdqe3tionless surface. A 16-N force is applied to the object, and it accelerates atqved7w ;,dh 3v $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accelerate mu4hp. dimt2cyxhv)++ws ;y/from rest to 27 m/s in 7.0 s. What is the averi /2 tmm+4dhwyupc+hvx. ys; )age forward force on the car?

  Starting from rest, a 4.0-kg body reaches a speed of 8.0efkb2((k l2vd+yh (f, jho*bl m/s in 2.0 s. What is the net force act2yloe l(db*fk( hfbk +, j(vh2ing on the body?

  An antitank weapon fires a 3 w7 e hdp7vjqf+u.8 b)9aklmhy)5w.t,d-khm p.00-kg rocket which acquires a speed of 50.0 m/s after traveli ktv5em hp7 ) da7wjw)+mqpkhy u98b..-lh,fdng
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 wi/v/ y tgp 3i*hkuyd/)gth the same force that you push a 10-kg mass from reu vt/p*gkh)g /iyy 3d/st,

  What is the mass of aa c:5ot,ze-dz person who weighs 110 lb?

  What is the mass of an object that weighs 250 N on the sura3iv :wzvw9 l-face of the Earth where the acceleration due to gravitlaw-zv9v 3i:w y is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. What is the mass of the objmxq 5hn rin3.3ect on the surface of the Moon where the accnh3mx5 r3qi.n eleration due to gravity is only 1/6 of that on the Earth?

  Object A weighs 40 N on Earth, and objvfy5(wwzp j ,2ect B weighs 40 N on the Moon. The Moon's gravity is one sixth of Earth's. Compare th,j( wv25pwzfye masses of the objects.

  Sue and Sean are having a tug-of-war by pulli-s wg ph .s-fiti8-dc9ng on opposite ends of a 5.0-kg rope. Sue pulls with a 1cw gfp--98-h s.itdsi5-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 the s hrua)k3dnv 5bm/ ue5w:m8w l3tack, and it acce mk58a3h5l v:r)u3/ dmuenbw wlerates 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 will the scalu 9 fbr.y;p3jce beb3.u c9j yprf; reading when the elevator is accelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the mass of the pers2p(pyie:vol 1h qze4u (isc5o-8,c .enjj1vton is 60.0 kg and the elevator accelerates downward with an accelee o24tc -l5(jyqcps1up8e:inhji ev.o,(1z v ration of $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale rides i1+u s- e6n*g:c 5mzq; fkanyzmh*: tez7pzcn+n an elevator. If the mass of the person is 60.0 kg and the elevator accelerates upward wistzz+ca y7u; +mmkg5 qp 6** h :zn-zfce:nn1eth 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 has a magnitud:j e24f pzgy znw-08asphl-)de of 8.0 N and is directed due north. The second force toward the east has a magnitude of 6.0 N. What is s -jh-0a 4y:z2w8epgf ld )pznthe acceleration of the mass?

  An object of mass 6000 kg rests oq4v ysu:23px zn 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 truck is traveling 15 m/s, what is the minimum stopping distance if thspxyu24vq 3:z e load is not to slide forward into the cab?

  An object of mass 6000 kg rests on the flatbl5.njox3 n. rved of a truck. It is held in place by metal brackets that can exervrxn. nj.3o5 lt 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. 4-1, if M = 0.60 fgin w1j0;hd. kg and m = 0.40 kg, what is the magnitude of the acceleration of the system? (Ignore friction and the mass of the pulleyd;ijwgh 1.fn0.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg and m c* z4ui -60v esxn9caf= 0.40 kg, what is the ni4u c esavx*cf9-6z0 tension in the string? (Ignore friction and the mass of the pulley.)

  A student pulls a box of books on a smoothl ifq1)9rqku rl,0 ,yn horizontal floor with a force of 100 N in a direction oyi, ,ln1 r0qkl fru)q9f $37^{\circ}$ 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 10shmej8 r 24t4i0 N in a direction of 37.0e aboveih s4j42rmte8 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 idyii-c t 6n,l4n Fig. 4-2. What are the tensiotil4dn, c6-iyns in the ropes?

  In Fig. 4-2, if the tensions in the ropes : qy usc18lnawwpui6p 9 *:e:rz)gu3 dare 50 N, what is the mass of the traffi*9lu us:p ):irwqu:a dz38cgn py1ew 6c light?

  Two boxes of masses m and s( lsq8p9v.qddxceu1 con34-2m are in contact with each other on a frictionless surfacn .uvcs(l93dxpq8-dse1 qco4e. (See Fig. 4-3.) What is the acceleration of the more massive box?

  Two boxes of masses m and 2m are in contact with each otherlv iow9 i8m9cfsy+mrk/g pxd- 64:-tk on a frictionless surface. (See Fig. 48iif:yl6+ r kw c-ox9/s-ktvm94 dpmg-3.) What is the net force on the more massive box?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4-4.) *gp.dy tx fnt+pyf40 ) If the forward force on the more massive box is F, what is the tension in the connex+ g0)4pfyp*tny tdf.cting rope?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4-4.) Ichf/s td4a /a63xxfh6y a8+ggf the forward force on the more massiv3 da4xx6/ a8ggs t+hf ayhf6c/e box is F, what is the acceleration of the less massive box?

Two boxes are connected by a cord running oz8v4f wa8 a4gover a pulley as shown in Fig. 4-5. Box I of8oz4afv4 8g aw 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 stai9c kz)6) axlh loi5zr4fn9+wtic and kinetic frictions between a 3.0-kg box and a desk are 0.40 and 0.30, respectively. W)f5wzi 46knclo9r+)axzhl i 9hat is the net force on the box when a 15 N horizontal force is applied to the box?

  The coefficients of static and kinetin+ 8 l(o 2 hybtzlja,:qc+wk;mc frictions for plastic on wood are 0.50 and 0.jc(+a 8lh,mo b+2kqyltz n :;w40,
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 direction. It slo c8s1un8k aowp ns14-pws and comes to a stop with a constant acceleration of -op1a8s 1p-wu cns k48n$2.45 \; m/s^2$. What is the coefficient of kinetic friction between the object and the floor?

  A 10-kg box sitting on a horizontal surfac lhjbj:8sr ecqj0n,-+ e is pulled by a 5.0-N force. A 3.0-N fricti0-rcj+sbel:qh ,j jn8 on force retards the motion. What is the acceleration of the object?

  A horizontal force of 5.0 N acdz.bcbwvod l3/bfea398)s2 scelerates 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 speed of 10:jq wbile49u 7 m/s. It slides 50 m on the ice before it stops. What is the coefficubji :q7 we9l4ient of kinetic friction between the puck and the ice?

  During the investigatik,y.nroc- b b0on of a traffic accident, police find skid marks 90.0 m long. Thok0bcn byr-.,ey 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 a,z7q 8p+fxpa 8.:xcfsk c zf)fre 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 slif+ xfk:x)a fc 8fzs.ppz87, qcde 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. mbv w/)r 0a;8h1rinmk(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 mabw kr h/ra ;)vi180mmnssive box does not slide on the more massive box, what is the coefficient of static friction between the boxes?

  An object is on a frictiobb/ *o9lfe:. sv1peypnless inclined plane. The plane is inclined at an angle ob*o9p l/yb p1ee:.fsvf $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that mx:5v5/1m res *esuynoakes 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 /,: +,vlhw+ qf esafdxa smooth inclined 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 inclinj oz -dx23-dqled plane 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 directly down an inclined plane, at a constant velocity da5:,pfv0xuf a ,qqq0;gz3s j of 6.0 m/s a5jqfq fap q,0vs;0g xdu3z:,.
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 dow4m)ok7g u8xxiho5aldlrhe l7 1/ g65wn 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 down a ro15c06xd;7ptfzlr p ,ltb7whi ugh $37^{\circ}$ 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 cabce09-kts7ei b2 5qnl nle attached ttlkq2bn-e5n 70 c9ies o the 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 rest on a rough inclined plane tilted (mf ob,hpi9l tkorqv7.u 7m1ai;z* a/at an angle of 1vaoi9rfi mq u/l.zt,pa*o mbh7k; (7$33.5^{\circ}$ 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 inclinedmtu,)ouyz gyl eqew03b55e)7n r*5u6oxd1yb plane. The angle of incline is gradually increased until the object beg d5q70byuew3zr xe*utlnyo1g5mu,o6)5 )yb eins to slide. The angle at which this occurs is q. What is the coefficient of static friction between the object and the plane?