Which of Newton's laws best explains whyua);u6jg/+zj+ cdq a /+pimnt motorists should buckle-up?

  When you sit on a cha ( k;d v-oty 3p,eeuo2uj1xpp*ir, the resultant force on you is

  In the absence of an external force, a mv (lxkeb 9,l2toving object will

  When the rocket engines on the starship NO-PAIN-NO-GAIN are suddenlymfhq bp .:zbw1(225rg5ubdvz qn4w 9c turned off, while traveling in emzpwf bgqm :.v(qcr 1hz 52b5d294bwunpty space, the starship will

  A rocket moves through empty space in a straight line with constant s22k s+m4zkgyspeed. It is far my42k2 k+zs sgfrom 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 forward, and you sudd1s5l p:gfriz/enly fall forward. You can imply: fr5 sil/p1gz from this that the bus's

  You are standing in a moving bus, facing forward, and you suddenly fall forwarj kob:1pb 5*jhd as the bus comes tohb*b1jj p5k:o an immediate stop. What force caused you to fall forward?

  A constant net force acts on an object. Depz v6 j +1.nnt rryu8rm-al/u: tpcj3gv-u *a,scribe the motion of the object.

  The acceleration of an object is iu:xt7 yo.z*d knversely proportional to

  A net force F accelerates a mass m with an acceleration a. If the same net for7sta:*ad ljo:02xy3y v vx ;vace is applieasyalxv;t*3 2::x v dv70j oayd to mass 2m, then the acceleration will be

  A net force F acts on a mass m any w 0kcj,:aqc8d produces an acceleration a. What acceleration results if a net force 2F aq8,jc0:kw caycts on mass 4m?

  If you blow up a balloon, and then release it, the balloonvy0vltn8(5mpm,mnn 9 will fly away. This is an illusn (nn8m90v,lmp5ytm vtration of

  Two cars collide head-on. At every momentno4*jxhmw+eg6.lg d /caw8:e:5u wc o during 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 th:cj o+edw4oneh gua*6wc w:.l 58g/xme first. This is an example of

  If you exert a force F on an object, the forc bbvvda8zy+x.c()v-vs :pk j 2a0u c8se which the object exerts on you willvcvp8yj.bcz sk v-udv a:xb 2a(+ )s80

  Action-reaction forceak ii1+dku qrfq(xj8a53c 7r 3s

  Action-reaction forcesd /) s*talqxp4 are

  A 20-ton truck collides with a 1500-lb car and causes a lot of damage tohjwc*h) i 540igj/y1asis2n h the car. Since a lot of damage iss04hhg5 i1 jih*/ins2aj y)cw done on the car

  An object of mass m sits on a flat table. The Earth pulli2-ygdov (r9gr5(5 ho ;xmcxy s on this object with force mg, which we will call crx(y9;5 h(rd vy gox-og 5im2the action force. What is the reaction force?

  A child's toy is suspended from the ceiling by means of a string. Theb 65u e7dabn+4(/mze 1yw suiq Earth pulls downward on the 1ys5 ibweb4e6dqnu zm+ (u a7/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 instantaneous force. Th k: 1b(gm5csx.au z9yqe ball hits the bat witkxazsc5bq y .9:1u(mg h an instantaneous force, whose magnitude is

State Newton's three *mk4 :pu ,aizyv;a6k3 sc4 fjulaws.

  Mass and weight

  The acceleration due to gravity is lower on th iad6nq zi76t3akw-vh,: trm1 ,xgi.z e Moon than on Earth. Which of the following is true about the mass and weight of an astronaut on the Moon's surface, compared to Earth7.r1 :iiq x d,-znw,hagka vz 36i6mtt?

  An example of a force which acts at a distance*izk1hi f:i,f(i v (fs*h5hsc is

  Who has a greater wei6yg)alh71tb*t be5 w nght to mass ratio, a person weighing 400 N or a person weighing 6tg16 bbey h7 ln5wt*a)00 N?

  A stone is thrown straight up. At the top of its path, the net+s i,*0tpb uvo force acting on itv 0s+iu *botp, is

  A 20-N weight and a 5.0-N weight are 85w *mghv a -ugb*+m:9yvo ciadropped simultaneously from the same height. Ignore air resistance. Compar:w+yu*cva8gmo vb*5 h9a g-ime their accelerations.

  A brick and a feather fall to the earth at rjbh-rc9k:j0k0 v2lp their respective terminal velocities. Which object experi-2jckk0p bvr9l jh:0 rences the greater force of air friction?

  An object of mass m is han jgm8 :ogp4)+ z:8ux-m hupnliging by a string from the ceiling of an elevator. The elevator is moving up at constant speed. What is the tension in+lg8 x8jm) -mpp:ouu gh 4z:ni the string?

  An object of mass m is hanging by a string from the ceiling of an elevator. +7.w/ mc, ih xvmoatpl8xzpgw4hi+b,3f 2)j fThe elevator is moving upward, but slowing down. What is the tension in the sgi)l7j3vhp tf bxcm2, pa o4+w/,zfx8mw.+h i tring?

  The force that keeps you from sliding .t;dw 5.fbf2lw6 senj on an icy sidewalk is

  It's more difficult to start moving a heavy carton * +x u4ips:vgxwl4puw*6 a p8gfrom rest than it is to keep pushing it with constantpx+4 pguwi : *g4wu*avp6sl8 x velocity, because

  A horizontal force accelerates a box from rest across a horik.u-d/qf i l3izontal 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 happui id./fq-3l kens to the box's acceleration?

  A packing crate slides down an inclined ramp at constant velocity. Thus weh,(b1 q(j olklh-o3hx can d1(hl- , objxkhho3 l(qeduce that

  A block of mass M slides down a frictionless plane inclined at an angle q withmllvd0m zjal y08).;w the horizontal. The normal reaction force e0 )ll 0.d;j 8vmzmwalyxerted by the plane on the block is

  A block of mass M slides down a frictionless plane in.q l:d- .bu.pey)ankeclined at an angle q with the horizontal. The normal reaction force exerted by the plane.nbqykp l u.:aede -). on the block is directed

  A block of mass M slides down a frictionlessc6yx0 4 imlm;y 09joc dqq+lv5 plane inclined at an angle q with the horizontal. The gravitational for 4y cm5+6jqdll0 vmqcyx;0o9ice is directed

  Two toy cars (16 kg and 2.0 kg,x0eiewohv8p 1 y5z9h) are released simultaneously on an inclined plane that makes an angle of 30e with the horizontal. Make a statement whic9zhp815he,0 wixy e ovh best describes their acceleration after being released.

  An object sits on a frictionless rfyy9o+bv;2f surface. A 16-N force is applied to the object, and it accelera bf +;9rfyyov2tes 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/sz:7 wqsc9k t1h in 7.0 s. What is the average forward f:czwqh 91t s7korce on the car?

  Starting from rest, a 4.0-kg body reaches a u:qcws-.9 sfw speed of 8.0 m/s in 2.0 s. What is the net force acting on theucw :qs -fw.s9 body?

  An antitank weapon fires a 3.00-kg r1i-5u9pes 8l j2gidmmei- m /eocket which acquires a speed of 50.0 m/s after travel2 e5se /m mi1-m8gjuel-pii9ding
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 sameme jl013 ogz2q/fbr 4q force that you push a 10-kg mass from rest,q23r /4 1 flebgm0ozqj

  What is the mass of a person who weighs 110 lbi: 4o0j mv-yyr?

  What is the mass of an object that weighs 250 N on zz502/*lle8)jrtbebt5vcng ez z 6)fthe surface of the Earth whererl5blt 8fn) z)*6b0zcgezv/z 2etj5e the acceleration due to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60lohxqlc 40bga.( 7 dg; 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 on dgqba7hlo04;l cg(.x the Earth?

  Object A weighs 40 N on Earth, and object Bl 1hd27n:fiwq/v3 dpl weighs 40 N on the Moon. The Moon's gravity is onl3n:v1 p f7 wh2ld/qide sixth of Earth's. Compare the masses of the objects.

  Sue and Sean are having a tug-of-war by pulling on opposite ends of a 5.0z -m+fy4- nzbz-kg rope. Sue pulls with a 15-N force. What is Sean's forzy-fz zn+4-m bce if the rope accelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books rests or d- wtre2nmz7t(vi*u u9ss*6n a level frictionless surface. A force F acts on the stav* uwsz(6*isrd-ut7m92 ent rck, and 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 theqp1 e5ttd .ysj3oc3e8 scale be readingp3co8s5e1d t tje.3qy 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 personf4+- 8t0abtj*zhngfa is 60.0 kg and the elevator accelerates dojfznb0th8ga4* ft -a+wnward 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 60.0 kylnk 9sh h* n/mjc5u* )j*xkf0g and the elevator amj*y* hsxhjc 9n *f5kln)k/u0ccelerates upward with 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 :u-0a hfcuqf0a magnitude of 8.0 N and is directed due nor f0cq0-hufu: ath. The second 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 the flatbed of a truckd iy e/4p.kyw0b6- +(qvekt7 s7jl gsx. It is held in place by jws7(g xi s6 / 7.key dkb4yl+eq0p-vtmetal 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 truck. It . rdksgb,9,mf s r1bv,m)4gznis 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 tvmd zr)mng4,bg ,b,.9 kss1fr o slide forward into the cab?

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg and m = 0.40 s8g 55s 5upjpus))2asy (qabk6a,ik z kg, what is the magnitude 6 )kai 5q,jpps8uyg(k ba5zssua52)sof the acceleration of the system? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1, y(kt uiuae:,2if M = 0.60 kg and m = 0.40 kg, what is the tension in the string? (Ignore friction and the mass of the pulley.2e ay,u( tik:u)

  A student pulls a box of books on a hv1o7f; 33xtm dz j3hmsmooth horizontal floor with a force of 100 N in a direction xhohj3 1z3fvdmt ; 37mof $37^{\circ}$ 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 for5 * -kifkitr pjz/c-qiz;u4- nzb :ga(ce 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 normal force on t( cjgt-aqip:ii;f- 4k br/ n*-kzzu 5zhe box?

  A traffic light of weight 100 N is supported by two ropes as shown in Fig. 4-2i*4kwa lb0 kj*. What are the tensions in thea*l0ki*kj w4 b ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is the mass 9g(nw; 0bxlbr of the traffic bnb; 0gxlr(9w light?

  Two boxes of masses m and 2m are in contact n9x8:7xzl th gwith each other on a frictionless surface. (See Fig. 4-3.) What is the acceleration of the more mass 7nhzxg8 :x9tlive box?

  Two boxes of masses m and 2m are in contact with each other on a f)o0 ew p kwx )v95j8e:,cn1nofyk1mzj rictionless surface. pnyv90 )oj5 k z1:fo) xwcw 1e,je8nkm(See Fig. 4-3.) What is the net force on the more massive box?

  Two boxes of masses m and 2m are ca;dl,,.vl89wa*2 ofm c4faro xtfeny +6g2f zonnected by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the t e,wa9 f +xyla, m86ao.o*24rf;v zglf2dfctnension in the connecting rope?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4-4.) If ts+ w/g :o:ud/pi-bchih1aiv5 he forward force on the more massive box is Fp h:-:siio w +ug/i5vb/dcha1, what is the acceleration of the less massive box?

Two boxes are connected by a cord running o3+yv3pvr 4 bmn6+ksha ver a pulley as shown in Fig. 4-5. Box I of yh vp+4b +vkansr336mmass
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 jyr:)nartke5 *4xv5 e a desk are 0.40 and 0.30, respectively. What is the net force on the box when atra* eeykvn:5xrj) 54 15 N horizontal force is applied to the box?

  The coefficients of static ana)h je07na0h nd kinetic frictions for plastic on wood are 0.50 and anena ) h70jh00.40,
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 8 :yzpl2c*we czd(zg ;surface in the +x direction. It slows and comes to a stop with a constant acceleratp(zzd2l;we ycgc 8*:zion 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 c6d/o1jp2 5 ief9 yyorforce. A 3.0-N friction force retards the motion. What is the accelerfpj2orc/69yoie 1y d5 ation of the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg mass0h6gad cnnh53u+e: vm, 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 iniz ( a ms /)t3dyermfa95xi(lp*tial speed of 10 m/s. It slides 50 m on the ice before it stops. What is the coefficient of kin9p5s (tdaifrxl3 y() aez/mm*etic friction between the puck and the ice?

  During the investigation of a traffic accider+ogc/ 8kk*yznt, police find skid marks 90.0 m long. They determine the coefficient of friction between the car's tires and the roadway to be 0.500 for the prevailing +*kz 8oc/ykgr conditions. Estimate the speed of the car when the brakes were applied.

  Two boxes of masses m and 3m are stacked. (See Fvx.e.rw(:q/,+7ap rifhj+fvg s qg8u ig. 4-6.) The surface between the more massive box and the horizontal surface is smooth and +vxqa(r upev g7.hwi gj f8./ f:,+sqrthe 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 less massive box?

  Two boxes of masses m and 3m are stacked. (Send ;vy.ym.y3 ee 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 slide on the more massive box, what is the coefficient of stat v3.eyny;m.y dic friction between the boxes?

  An object is on a frictionless inclined plaa6ytj8sp 37 sap (vbb1ne. The plane is inclined at an angletb y6asj(pa 387vs1pb of $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill t6:pb i0n:dy; bea obv+hat 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 plane withjqx s*68i 0 ifd5i+knxvp9 qp3 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 v9x:uflpk1s5do(0/ecvrle 0 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 plbvi5)a-y.tkv./ wou kk ;rkr)wf(+ qrane, at a constant velocity of yrrkafvb).kk+. i-rvuk twoqw5/) (;6.0 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 down agi c1 pv h2a4jqmmz0(17t* gmy 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 d.ryq k-29o xpoown 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 al9k ,t tzdwqr+0- zgi0cong a rough surface. The cable attached to the log mar0zd+i9w qc tz-g0,tk kes 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 a9lwqtr52d o.tqp, tcspfr/71x( ,b uc t an angle 1crrt,s qfo5 q 2x bplwt./t,dcp9u(7of $33.5^{\circ}$ 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 of incline is guyhu hoo/*avn255l+ g radually increased until the object begins to slide. The angle at which this occurs is q. What is the coeffic/+ u 2yahuo*g5hvlo n5ient of static friction between the object and the plane?