Which of Newton's laws best explains 7ueyste + ewa wn:+3goim(f59 why motorists should buckle-up?

  When you sit on a chair, the rvsfiax3ac/c4( mz9 v/esultant force on you is

  In the absence of an external c 48xf zwt+jhto3i:8 wforce, a moving object will

  When the rocket engines on the starship NO-PAIN-NO-GAI/ udv /ktkbu.; 9uf*skN are suddenly turned off, while traveling iktbk;uuk.dv *9/ fu /sn empty space, the starship will

  A rocket moves through empty space in a straight line with constant spef: b09m gnn9ep+sdb li8s- *ctbkc0c6ed. It is far from the gravitational effect of any star or planet. Under these conditions, the force that must be applied to the rocke s8gb9bt+0ne-ps9m*kbc d 6 i:f0n clct in order to sustain its motion is

  You are standing in a moving bus, facing forward, and yo xyq7(-fm( 46rbe8mznuwv zto x,xb;,u suddenly fall forward. You can imply from this tr(qzm 6v7 e xwtn-o(8 fuxxb;yz,b, 4mhat the bus's

  You are standing in a moving bus, facing forward, and you suddenly fwz*/,pbum9s5m. ajpz all forward as the bus bsu/*,jzampzpm 5 9w .comes to an immediate stop. What force caused you to fall forward?

  A constant net force acts o3u * o,z0fjurzn an object. Describe the motion of the object.

  The acceleration of an object is inverse,1f n)vm7 )qdutpkl6 bly proportional to

  A net force F accelerates a mass m with 7 oh:.xuyjvydxf46c+an acceleration a. If the same net force is applied to mass 2m, then the acceleratjvcdf4yxyx7u:+h o .6ion will be

  A net force F acts on a mass*dzxhy5+m):e hvt+m d-k db kx0 w-d7a m and produces an acceleration a. What acceleration results if a net fodz0+h*k-wyxd7 bd mh kt5:v)xme +-d arce 2F acts on mass 4m?

  If you blow up a balloon, and then release it, the balloon will fly away. This : pr/ ome skp-li05q,a8yl.qr ilo-/.:le k,rpyp5 0qms 8qr ais an illustration of

  Two cars collide head-on.3xdk8e k tm g4e)zrtb+m1(n9nl 2.tzd At every moment during the collision, the magnitude of the force 2b rd1. nm ke (gtet4+ z3xdlzn9k8)tmthe 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 example of

  If you exert a force F on an object, the force which the object exerts on you dzw me;hu4 .:bd- n1szwilz41 n;h - dbmd:z.wseul

  Action-reaction forceiw:f o.igdi0q/8 s4li s

  Action-reaction force my4e vgd7afy2x0m.-js are

  A 20-ton truck collides with a 1500-lb car and dtrf+ tvo(7czi adwf w45 17b2causes a lot of damage to the car. Since a lot of damage is +d(fwda 4f75v irz7t1co tw2 bdone on the car

  An object of mass m sits on a flat table. klk7 qqm6/ro2mf e6 n( The Earth pulls on this object with force mg, which we will call the actionqf2m/ k emqro6(6nkl7 force. What is the reaction force?

  A child's toy is suspended from the ceiling by means of a string. The Earth1lq , radf:7( z,h5(gso)vlaxg,g ht r pulls downward on the toy with its weighvgoh h ,trgx,da q:)srfl(a,7g15l( zt force of 8.0 N. If this is the "action force," what is the "reaction force"?

  Your bat hits the ball pitched to you wit*h z;xs -8ir 3v3 fve3ch-wpthh a 1500-N instantaneous force. The ball hi-8psh h itrv ;vex*-3h3wcfz 3ts the bat with an instantaneous force, whose magnitude is

State Newton's three lh y5*t/kl4mtox-a8vgm9q zg 5aws.

  Mass and weight

  The acceleration due to gravity is lower on the Moon than on3 u qsyu*kv p2cmx:*/n5vt9n z Earth. Which of the following is true about the mass and weight of an astronaut on the Moon's s ykt *vzxqv9n2um / 3:5*pcsunurface, compared to Earth?

  An example of a force which acts at a distancuuhjw /g *nn(:e is

  Who has a greater weight to ;h . 9lvsgb1kkmass ratio, a person weighing 400 N or a person weig1.;kvh9skg blhing 600 N?

  A stone is thrown straight up. At the top of its path, the net force acting )i1ojw)h :i -xpo skb*on it * bxwi) o)pokisj-1:h is

  A 20-N weight and a 5.0-N weighrlfbru q( qwe+-y*.1lt are dropped simultaneously from the same height. Ignore air resistance. Compare their accelerationsylr+fr*wq .qe1 (l -bu.

  A brick and a feather fall to the earth +n*m ir-udngebb; + ;u)f jzg+at their respective terminal velocities. Which object experiences the greater force of air frictioi*)b+n fjdb++-;;gmzgern uun?

  An object of mass m is hanging by a dp/d94f ( df1 xetdoc(string from the ceiling of an elevator. The elevator is moving up at constant speed. What is the tension in the string9f(t eo4 cdddx(/ 1pfd?

  An object of mass m is hanging by a string from the ceiling of k(w:m4n 33o:mzn zbw1 x2awpjan elevator. The elevawoz1: jww n z(pk24:3n3amx mbtor is moving upward, but slowing down. What is the tension in the string?

  The force that keeps you from sliding on an icy sidewaletq2n a ;87wvmk is

  It's more difficult to start moving a heavy carxrwn. 6g yw0ywno55loi- 8,cxton from rest than it is to keep pushing it 5 gow. 0nx8r5yyi-xlwc wn,o6with constant velocity, because

  A horizontal force accelerates a box frd(wp/9crvgf vpf ./;axder:2om 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 force is doubled. What happens to the box's accfdcapr;d2 ( v xrpg9wfv: //.eeleration?

  A packing crate slides down an gyahu86hoy)g8*csc cgn d -;4 inclined ramp at constant velocity. Thus we can dedusynh d-* )gu oca68g 4gcc8hy;ce that

  A block of mass M slides dv *6xo1; eykhcown a frictionless plane inclined at an angle q with the horizontal. The normal reacce1 yh*6 v;xkotion force exerted by the plane on the block is

  A block of mass M slides down a frictionless plane inf;;+ky-*6x bctp6 uikect. i oclined at an angle q with the horizontal. The normal reaction force exerted by the plane on ;; eti+ 6p -fbuxk.*kotyc ci6the block is directed

  A block of mass M slides down a frictionlessautbr6hm3 n 4q:-c ho; plane inclined at an angle q with the horizontal. The gravitational force is direct h64b -3 quch:ratom;ned

  Two toy cars (16 kg and 2.0 kg) are released simulta *vv:eb/pg6sh neously on an inclined plane that makes an angle of 30e with the horizontal. Make a statement which best describes esp/g :bvv* 6htheir acceleration after being released.

  An object sits on a frictionless surface. A 16-N t ; k* gs/vm01ugent0m8d8tarforce is applied to the object, and it accv*trtgunm0d1sm8;/a g 0ket 8elerates at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can p hqssn31 xw+f.gr(xq3 7ge0d3 .wk vqaccelerate from rest to 27 m/s in 7.0 s. What is the averageg1+37 qwx(fdx qgq .rsn0w v3h3.ek sp forward force on the car?

  Starting from rest, a 4.0-kg body reacheg ta*.3kns736mi jsaes a speed of 8.0 m/s in 2.0 s. What is the net force actin6k .genij 3mt3ass*a 7g on the body?

  An antitank weapon fires a 3.00-kg rocket which acquires a speed of 50.0 o8*nsyxr+egn+ hg.75di6q r um/s after travelxy +rr*8ignh qs7egn6d.ou 5+ing
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 wf5e9:n(wiygvh zp : p/ith the same force that you push a 10-kg mass from reph / giv: 5fn:9ez(ypwst,

  What is the mass of a person whob dx)bpja,ko(y;(w8 t weighs 110 lb?

  What is the mass of an object that weighs 250 N on the su8vkwl x cp3o.ix4/u6o4,iuwlrface of the Earth where the acceleration due to gravkxiv ,x3pio lc w/4w.86luo4 uity is $9.80 \; m/s^2$?

  An object has a mass o8pg kt);lbv6nf :;bkpf 60 kg on the Earth. What is the mass of the object on the surface of the Moon where the acceleration due to gravity is only 1/6 of that kl6pbb;)nk fvp:g8t ;on the Earth?

  Object A weighs 40 N on Earth, and object B weighs 40 N o7fgg-oy 7 fs)bn the Moon. The Moon's gravity is one sixth of Earth's. Comparo 7fy-f gsgb7)e the masses of the objects.

  Sue and Sean are having a tug-of-war by pulling on opposite enugilzyw8s:9: ds of a 5.0-kg rope. Sue pusg:i z8wluy: 9lls with a 15-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 a6wqt(mvqtycs) +r w,p u7ek8(cts on the stack, a c,s(tq w8v(mqrut)7+ kye6wpnd 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 scale in an elevator. What will the scale),icg 8tk;fh b be reading when the elevatorg, ;khb8f)t ci is accelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elcqzql9; (hx52kl (hzcevator. If the mass of the person is 60.0 kg and h( c;2k(zx9 l5qlqzhcthe elevator 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 mass0t*3j3 bowdo o3wq)q83 3t,hcns kkix of the person is 60.0 kg and the elevator accelerates upward with an accele3wc*30n3 k h kt3 , dsob)wqo8xq3ijotration of $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal forces act on a 5.vxh - (9,av oa)fuk aa/xpu)-x0-kg mass. One force 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 accvxak(f- aa9 ,/) x-) xpuhovaueleration of the mass?

  An object of mass 6000 kg rests on the flatbed of a ,fu bc 0bg/s6vwfqn-8h26bm s 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 the -,bwv q /hcbsfsbnf860m ug 26load is not to slide forward into the cab?

  An object of mass 6000 kg rests on the flatbed of a truck. It is held in p ;kxhg s;nz(3tlace by metal brackets that ;h stz3 k;n(gxcan exert 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 =yoh up+ v:(kw, 0.60 kg and m = 0.40 kg, what is the magnitude of the acceleration of the system? o (y +vwh:uk,p(Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1,g0 1oy9e2fit d/ohle 4 if M = 0.60 kg and m = 0.40 kg, what is the tension in the def 1 eoh20yi4glt9 /ostring? (Ignore friction and the mass of the pulley.)

  A student pulls a box i1s+3 *maoql uof books on a smooth horizontal floor with a force of 100 N in a direction qlua+1om* i3sof $37^{\circ}$ 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 bonb: qwjhe( t/ 1ge(r-aho2gx6oks on a smooth horizontal floor with a force of 100 N igjq6nbrx ogh(e twh2-/(1 :ean 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 weif9 gw8:h5o+ hqwf z8swght 100 N is supported by two ropes as shown in Fig. 4-2. What are the z5w:9h8h+ swoqf 8wgftensions in the ropes?

  In Fig. 4-2, if the tensiomf( +zq c;6/1jwj yxmmns in the ropes are 50 N, what is the mass of the traffic 6m mjym(c xz;+w /1jqflight?

  Two boxes of masses m and 2m are in contact with each other on a frictiong2tw xa( u0ha3less surface. (See Fig. 4-3.) What is the acceleration of the mou(ht2 w a03xgare massive box?

  Two boxes of masses m and 2m are in contact with uh(3 /k1bj+qhs1szjfeach other on a frictionless surface. (See Fig. 4-3.) What is the n+ jz1(jh3s/bskfqh u1 et force on the more massive box?

  Two boxes of masses m and 2m are connected by a rftfnwa afa(8ei;gsb )o a :h ;qj-j:-9xp, of:ope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the tension in the connectinfqj -)tasf ;:no-( woiab :f8ae,hx:;ag j 9pfg rope?

  Two boxes of masses m and 2m are connected byf b)6w /i,fket a rope. (See Fig. 4-4.) If the forward force on the more massive bo)ei fk wb6,/ftx is F, what is the acceleration of the less massive box?

Two boxes are connected by a cord running over a p7 pfpdlz7*dqunx* o/p1db.*q ulley as shown in Fig. 4-5. Box Il1nu*db. qd*pp x77 zdopq/f * of 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 kinetic frictions between a 3.0-kgb.a e9rw(bsl2 box and a desk are 0.40 and 0.30, respectively. What is the net force on the box when a 15.wa r9(bes2bl N horizontal force is applied to the box?

  The coefficients of pbb58b 7jces/static and kinetic frictions for plastic on wood are 0.50 and 0.4b78j5bpsbe c /0,
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 + / ru/go5zf ig:ix5:rl5bs4fjx direction. It slows and comes to a stop with a cj55l/f5o :r /4:zgg sbxrii fuonstant 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 icpei ,zh0n5t 0s pulled by a 5.0-N force. A 3.0-N friction forcpc ,he5n0i0zt e retards the motion. What is the acceleration of the object?

  A horizontal force o 5 8icje2(mak2f)cooef 5.0 N accelerates 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 sp kg9i dlh1hvv6cd510qx)ac) deed of 10 m/s. It slides 50 m on the ix561 a k gcd0)idh hldvqvc)19ce before it stops. What is the coefficient of kinetic friction between the puck and the ice?

  During the investigation of a traffic accident, police find skid marks 4 thax mw 9.)to;mz.geq ;aj1e90.0 m long. They determine the co g)aeomwe..4j9tzx1 h ta;q m;efficient 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 surfacem+eak z:i* dj2x)zo ag7u +,nd between the more massive box and the horizontal surface is smooth and the surface between the boxes is rough. If the less massive box :i7uz+2 kdgo+)*zane ja ,xmd 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 surface betwe oc1ry* di/l+p96dvic :iem2aen 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,6v+2icl ip*1rcdy mda/oei9 : what is the coefficient of static friction between the boxes?

  An object is on a frictiom) qgk ev50ik.s ska 0/iiked1bz71l6nless inclined plane. The plane is inclined at an anglekz)576a1dl.vkmkb0 gskei 01ii qe s/ of $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that ma b3bxjunf+d9m( wf9z 1kes 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 -m3,7jdssyrc vyx1k+ 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 inclined plane tilted at an angld3v1yjxm,w:7x b0iw2q:ob:m tromj) zz jc : 3e 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 constan4l8(vu)patrg1wi 2drt velocity of 6. ()4rr2gapvilt w1u8d0 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 :x qw;mj sc.xsxb/(-gh v37sqm slides 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 down a rojpi5:swhh( f/2 kcd/r.dqm4e1 jj2 an7tkfs: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 weighinguqm chym: twg0gc;( 7y8;oc8g 0wxmr8 500 N along a rough surface. The cable attached to tc87rg gthu 8w y;o0wmg(xymc08 qc:m ;he 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 qybghhzv+k9dh7 btl:3k (o;8 rough inclined plane tilted at an angle ofvk8+( qhbhod:glh k 9tz7;b3y $33.5^{\circ}$ 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 in8.0rw d uafogvc-(-ptclined plane. The angle of incline is gradually increased until the object begins to slide.(0 rwof --dc .gap8uvt The angle at which this occurs is q. What is the coefficient of static friction between the object and the plane?