Which of Newton's laws best explains why motorists should buckle-up?c u3:fg9e9 v;d4 0 -gztw0mgsyirmdh9

  When you sit on a chair, the resultant force hb :2-o cu1uqv1z)e kr q0d:vlon you is

  In the absence of an external force, a mov5 ajf w9nk b:mkv4tz*4ing object will

  When the rocket engines on the s,9h ess x1p (obh 1r468vt/ fo mjxzwg:keq)*ttarship NO-PAIN-NO-GAIN are suddenly turned off, while traveling in empty space,6x sze48h, q) : 1*/tm(ftwkx9sog1jpov rbeh the starship will

  A rocket moves through empty spaies8*irar eqn2odjha77 81 2oce in a straight line with constant speed. It is far from the gravitational effect of any star or planet. Under these conditions, the force that must be applied to the rocket in order to sustain itsoae7sraro 7828i1je* nidqh 2 motion is

  You are standing in a moving bus, facing forward, and you suddenly fall t 8adupg ,za2*forward. Yo *uz ,2ga8padtu can imply from this that the bus's

  You are standing in a moving bus, facing f) b0 p6+ws.utzl8r jyvorward, and you suddenly fall forward as the bus c0y86w .zrvbluj)ts p +omes to an immediate stop. What force caused you to fall forward?

  A constant net force acts on an object. Describe the motion of ther+ 9(hyqcu 2sa/lh4im object.

  The acceleration of an object is inversely propfcttzxfzt2c4xo : rr1*ri36 rx6qv )9 ortional to

  A net force F accelerates a mass m with an acceleratior:w gf(ar3dr7 n a. If the same net force is applied to mass 2m, then the acceleratif3wr(argr7 :d on will be

  A net force F acts on a mass m and produces an acceleration a. What acceler nqq+8 r9ihy,iation results if a net force 2F acts on mass 4m?8r 9qhq+,ii ny

  If you blow up a balloon, and then release it, the balloon hj.+w*j7 pw)2 wfttfv will fly away. This is an illustr*j) wvft .fp2 wj+htw7ation of

  Two cars collide head-on. At every moment during ljd 4 *w36jcsxthe collision, the magnitude of the folw4x* j36 scdjrce 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 example of

  If you exert a force54dzgt3h m. sc F on an object, the force which the object exerts on you willt3 s.cm h5dgz4

  Action-reaction forc /*o-kgec fo,da6hm 1zes

  Action-reaction forcesto7p zdt;t:)f aab,y b:f i.:c are

  A 20-ton truck collides with a 1500-lb car and causes a lot of damage to the bf+lod5l gi5;00frim car. Since a lot of damage is don;0l50lrmg b5fdi o+fie on the car

  An object of mass m sits on a flat table. The Earth pulls on i;wv hu. j;9g6iaf 3zwthis object with force mg, which we will ca6gf9a3wih;v. ju; wz ill the action force. What is the reaction force?

  A child's toy is suspended from the ceiling by means o+tj j 8/(xfq3frtv fm+f a string. The Earth pulls downward on the toy with its weight force of 8.0 N. If this is the "action force,"f 3t/f(jx+tvqr+m f j8 what is the "reaction force"?

  Your bat hits the ball pitchesj. fagf8 q(o)khb ,+:fu jto o bk+eh4(ic46bd to you with a 1500-N instantaneous force. The ball hits tkuef:q) c4 h (oo +6bh48jasjogftb.+fik,b ( he bat with an instantaneous force, whose magnitude is

State Newton's three lax 7qgf2iai*o-41cfw i ws.

  Mass and weight

  The acceleration due to gravity is lowe *2/qa3mdvvu1o2mv -aqv - demr on the Moon than on Earth. Which of the following is true about the mass and weight of an astronavdaqv1 2d/oea3 vm-q2um vm-*ut on the Moon's surface, compared to Earth?

  An example of a force which acts at a *5nz :i cb7 ,. hwvyynv;5nfctdistance is

  Who has a greater weigheb e,1v3czo4g t to mass ratio, a person weighing 400 N or a person weigh 1g,4z3b veoceing 600 N?

  A stone is thrown straight up. At the top of its path, the net y ey7ugn+w3ucbm 5kf(r fp8 5;force acting on yupw+fk; c8u37ygnrb5( ef5mit is

  A 20-N weight and a 5.0-N weight are dropc pa xnqj*0z*2*yqt:jped simultaneously from the same height. Iy2pqt*q na 0*c :jjzx*gnore air resistance. Compare their accelerations.

  A brick and a feather fall to the earth at their respe i8oh zkmh ;2jfkx-c69ctive terminal velocities. Which object experiences the greater forckm 9 6 ;fcoj8zhik2h-xe of air friction?

  An object of mass m is hanging by ai(okhh/ f7 ob1g aty +hx4eiow6p43c - string from the ceiling of an elevator. The elevator is moving up at constant speed. What is tofwocph(io k 6h/b3+4e4ah t-ixg7 1yhe tension in the string?

  An object of mass m is hanging by a string from the ceiling of an elevator. Thw(k5edz i30 , nq9dhq 6up3kyde elevator is moving upward, but slowing down. What ,kn kqdpuwd95(qe3yz i d0h36is the tension in the string?

  The force that keeps you from slm6kf:;/hrkm d xnioe/qd,0 l*iding on an icy sidewalk is

  It's more difficult to start moving a heavy carton from rest than it is to ke6:3 y-ifk :clqau6vi)v3gxw, )qoefn ep pushinyl: ) f,v oiqvwfa3u6i)ce :xn 6k-g3qg it with constant velocity, because

  A horizontal force accelerates a bo 2nvqjn52c b: :x77qih:t+flo l;cgqjx 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 force is doubled. What happens to the bognotx:f ;ij5lncql::72 bj+v7 q2ch qx's acceleration?

  A packing crate slides down an i2 dcfmxeb p2mt-a -b9,nclined ramp at constant velocity. Thus we can dede-t2cpx ,mb 92bdm f-auce that

  A block of mass M slides down a frictionless plane inclinedw- dy z0m4rhll/;:cd o at an angle q with the horizontal. The norl:4mz-d rldchw/;oy 0 mal reaction force exerted by the plane on the block is

  A block of mass M slides down a frictionless plane inclinob:tm p5+/ajx;c gr)lp3hb7f ed at an angle q with the horizontal. The norma m7lb g+3)pbpjoh xca;5/t f:rl reaction force exerted by the plane on the block is directed

  A block of mass M slides down a frictionless plane inclined at a(v5*q7t,/tnrtcbzt an angle q with the hor(rztvnct*t7/q 5 t, abizontal. The gravitational force is directed

  Two toy cars (16 kg and 2.fb/ yno0 bo+2susmr9 :0 kg) are released simultaneously on an inclined plane that makes an angle of 30e with the horizontal. Make a statement which bestfoorsu m2n 0sb b+9:/y describes their acceleration after being released.

  An object sits on a frictionless surface. A 16-N force is applied to theo *w3sgmie +tvk/9cof roh); + object, and it accelerates atog/oh+i*k 3;tse9+ oc fvwmr) $2.0 \; m/s^2$. 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. Whaq8-yg xs-gta8 t is th a-t-gy s8qgx8e average forward force on the car?

  Starting from rest, a da55 nmu1mhi4r a +g9l4.0-kg body reaches a speed of 8.0 m/s in 2.0 s. What is the net force i+d5gmlh r49un 5am1aacting on the body?

  An antitank weapon fires a - vahkntfu(yv,7ov+2 ,l* )he)h bmubpjag:)3.00-kg rocket which acquires a speed of 50.0 m/s after traveum v7+ypto)e(,v2hkah) bba:h v)jg- fnul*,ling
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 you push c mk 0l*7( 6g9jawcn41 dy(6hsmlrqcs a 10-kg mass from resssn (m09 7w6k14qlcjc( hrd*cgyl6am t,

  What is the mass of a person who weighs 110 lb?6lhbq qqkojg8 :*25pz

  What is the mass of an object that weighs 250 N on the surface of the Earth wheyhc(ob/n/)dhsp/7,al ar5) ow 8z cz +4ragtz re the acceleration due to gravl(/z7)a)/z 8 ct rh4 nd ar5/+bayz,pg hoowscity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. What is the mass9;t68;stt /5rtym.vmnm t a2 obvv w:n of the object on the surface of the Moon where the acceleration due to grv9snt.tym5 b2vt ar:o8mn t6m /wt;v;avity is only 1/6 of that on the Earth?

  Object A weighs 40 N on Earth, and object B weighs 40 N o 7x2a ek f(d.w7/mbjijn the Moon. The Moon's gravity is one sixth ofde/72 jb( mk.7xfajwi Earth's. Compare the masses of the objects.

  Sue and Sean are havingq 2kgvw +4+wo t0oya2n a tug-of-war by pulling on opposite ends of a 5.0-kg rope. Sue pulls with a 15-N force. What is Sean's force if the rope accele2kw o2n 4y q+v+agw0otrates toward Sue at $2.0 \; m/s^2$?

  A stack of books rests on a level frictionless surface. A foc9f:a(l t fll.15oy nprce F acts on the stack, and it acceleratenp lcaft 9l1(f:5 o.lys 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 ;;7a bed-qptei.n;fa. What will the scale be7d-npa ;. qia e;eb;tf 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 thok3 zpa1)k jjs73i9t7ag*qe xe person is 60.0 kg and the elevator accelerateso1 jpg*39x qs)a3ek7tzkj7 ia 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 ma; zz47)6xbh9 fpfgbnxss of the person is 60.0 kg and the elevator accelerates upward with an acceleratioxp;6)b79 ffzz gn b4xhn of $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal forces act on l4mo-g0 hq0ra a 5.0-kg mass. One force has a magnitude of 8.0 N and is directed due north. The seconag40-mlh rq 0od force toward the east has a magnitude of 6.0 N. What is the acceleration of the mass?

  An object of mass 6000 kg rests on a 4eu,ajwy t;7the flatbed of a truck. It is held in place by metal brackets that can exert a maximum horizontal force of au,y 7t4ej;a w9000 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)ds59ql w+r kr rests on 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 time if the load is not to slide forward into the 5rlq)rk +w9sdcab?

  In the Atwood machine sho7 tewt: 02 ldl yi6z5,is8qzvxwn in Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the magnituds:0z, 75wxqzy2elt6il8 vdti e of the acceleration of the system? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1, if M hk nrebwh,cdf2 *6 ) n;hztj8+= 0.60 kg and m = 0.40 kg, what is the te6whr;c *k)2, hen zndjbhf+ t8nsion in the string? (Ignore friction and the mass of the pulley.)

  A student pulls a box of books on a smooth horizontal floo; yq99. h7t0ndcwmzyxr with a force of 100 N in a dy.mq ht ; n0w9zxyd97cirection 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 forcen*py-*,dkwz xc6pn6h of 100 N in a direction of 37.0e above the horizontal. If the mass of the box and the books is 40.0 kg, what is the ny*wdphnpn z c k66-,x*ormal force on the box?

  A traffic light of weight 100 N is supported by two ropes as shown in Fig. f; . +yq lezd4ol 8s9)d0hgdhx4-2. Wdf9+ hz0o hxy8 eq.d 4ld;sgl)hat are the tensions in the ropes?

  In Fig. 4-2, if the tensions in the ro ie2n)d+ts- iipes are 50 N, what is the mass of the traffic ligh)endi+st-2 ii t?

  Two boxes of masses m a+pb :cj). b 94xv)-bmhzyoxubu 1k -iwnd 2m are in contact with each other on a frictionless surface. (See Fig. 4-3.) What is the acceleration of the mobj 9xkb-v b):1 )upz-m4yu w oxi+h.cbre massive box?

  Two boxes of masses m and 2m are in contact with each other on a frictionle:o6 clgq(v/jcss surface. (See Fig. 4-3.) What is the net force on the more massive lgc j (ov:qc/6box?

  Two boxes of masses m anf;0;omqx4 do /5w -nm.pmwa wmd 2m are connected by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the tension iwfm;a q0m.-w x /;w4m 5pomodnn the connecting rope?

  Two boxes of masses c ju6z1r((m z absn. jqe+-al-m and 2m are connected by a rope. (See Fig. 4-4.) If the forward force on the more massive b.b6 r(-aj ( m+j1alczz eun-qsox is F, what is the acceleration of the less massive box?

Two boxes are connected by a c21tfhz+. e.w:o sld mlord running over a pulley as shown in Fig. 4-5. Bhlsem zf.:2d .w+1l toox I 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 fricny2si0/ e7dx )b 9nhymtions 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 a 15 N horizontal force is appliedd hx mye7s n/b)i9y20n to the box?

  The coefficients of static and kinetic frictf3xd p a92+xecions for plastic on wood are 0.50 and 0.423cdepx+a xf9 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 +x direct0mc +swn3c wl8ion. It slows and comes to a stop with a constant accelerawsw8 mcn03+lction 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 by a 5.0-N force. A5h0mzfrq.;k u 3.0-N frizku q.;fmhr05 ction force retards the motion. What is the acceleration of the object?

  A horizontal force of 5.0 N 3cefw,dypu 2xi m0- 1laccelerates 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 m/s. k10ujj/1 *xrku j+ xpl It slides 50 m on the ice before it stops. ju x+kj 11u /px0rljk*What is the coefficient of kinetic friction between the puck and the ice?

  During the investigation of a traffic ac67zf io; ainv2cident, police find skid marks 90.0 m long. They determine the coefficient of frictionif 6v noi2z;7a 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 surface betxwgrvf wl/h:2 hxy+);ween 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, what is the static friction force on the xfy/2gr : h+whxl;)vw less massive box?

  Two boxes of masses m and 3m are stacked. (See 7+lw3d( 7lhsn4ti0)bxqhu:eb k:d zbFig. 4-6.) The surface between the more massive box and the horizontal surface is smooth and the surface betweeex3q+)l:bhdb 7uw:nt0s d (zbl4 hki7n 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 am99-(e) rz zbwm :lxv izr91x85y.o9hm ruyujn angle of(:emr19zwhxbrz8 m)x vuy y9-9.uo5lr9 izmj $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides downfa63atphh) 7v kb3/x6 ezt e2tg h,;ut a flat 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 inclined lr6l m8;g rqoka6k1j;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 pf j,/sle/5entg;l)b 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 constaral uys, eqp:tn2+7: fnt velocity of 6.0 7q+efnua2 p,stry :: lm/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 vx- xj:hgmb +;s7ug+b/p g0l uslides 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 mmx)nd2ke g9p ed,os7) 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 lo/izvzy:o* c;lt (74 su o3hmjqg weighing 500 N along a rough surface. The cable attached to the log makes an angle;oj vmhct3 7 zzl*:o(s4y qi/u 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 an 9lce8cxfhy0 t.b sp88angle o 8h xsc tplyef988c0b.f $33.5^{\circ}$ 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 e)bia 66if s* ikfsw2*of incline is gradually increased until the object begins to slide. The angle at which this ofb ei6)2* *isiw sfk6accurs is q. What is the coefficient of static friction between the object and the plane?