Which of Newton's laws best explains why motorists should buckle-upo a8c26()re; o8 f txh) 7qvqh/ux*khhreh8y p?

  When you sit on a chair, the resultant forcego e- r,tbs:+us7bql/ on you is

  In the absence of an extermx0.usji,hjy6)3gs v nal force, a moving object will

  When the rocket engines on the starship NO-PAIN-NO-GAIN are suddenly turpl i0eca/5 pk;ned off, while /ipka; e05 lcptraveling in empty space, the starship will

  A rocket moves through eo jc2f,f-.hb2g-xu mxfan 3 w;mpty space 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 thegf .-b-2f ;coja32hnxu wx,mf rocket in order to sustain its motion is

  You are standing in a movi2suqn jo:f23 ung bus, facing forward, and you suddenly fall forward. You can imply from this that t2 n2uq u:soj3fhe bus's

  You are standing in a moving bu 7cdaaa gq)1a,s, facing forward, and you suddenly fall forward as the bus comes toaacg)1 a7a q,d an immediate stop. What force caused you to fall forward?

  A constant net force acts on an object. Descrio6vj1ub l).+ lfr nso2 own2/fbe the motion of the object.

  The acceleration of an object is inversely proporglm :1j f:;udorfc2t: tional to

  A net force F accelerates a mass m with an acceleration a. If ttzo-.9cpn 6 fkhe same net force is applop.-t6knf z 9cied to mass 2m, then the acceleration will be

  A net force F acts on a28cnp;x mb:xo mass m and produces an acceleration a. What acceleration results if a net force 2F acts on mass 4b2x8nmcx: po ;m?

  If you blow up a balloon, and then release it, the balloon will fly away. Thb c8i1x;vtdv 2is is an illustration o1b x8;vdci2 vtf

  Two cars collide head-on. At every moment during the cob l5 q ef(zg1zc/z2b3yllision, 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 e5l3b 1y cf/ zqbgz(z2an example of

  If you exert a force F on an object, the force which the object exerts on you .h,* u-w8 lyd6 fzqh hst3-iiuwill 63h.*uyhtl udqsz-,i -iw8hf

  Action-reaction force5fqxzxw kt(cq2+ a9+ ss

  Action-reaction forces ar,n b atm3 kz7mrhq* +0iohi4fskj3,e 0e

  A 20-ton truck collides with a 1500-lb car and c1to(z8dvi, gn)gx f;g auses a lot of damage to the car. Since a gg,d1 nz(vig8 ; tx)oflot of damage is done on the car

  An object of mass m sits on a flat table. The Earth pulls on this objec l, (5rtj 59tca.dxxdft with force mg, which we will call the action force. What is the ct 9d(,.fr l5dx5atx jreaction force?

  A child's toy is suspended from the ceiling by sgpskutsz,:0 qe,76f;m0 jmomeans of a string. The Earth pulls downward on the toy with its weightm;sqg7, s6oskp mf:t0u jze0 , 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 ins1i;xt ee7 .qo-cc a4aotantaneous force. The ball hits the bat with an instantaneous force, whose magnitudq o.a- c;ta4o1cxe i7ee is

State Newton's three *m /j0xmka*iq7 pgy. x6n1snwlaws.

  Mass and weight

  The acceleration due to gravity is lower on the Moon than on Ea dhr9+ n u7qlqz5 mccs/rd+:t;rth. Which of the following is true about the mass and weight of an astronaut on the 7;/:tr m+ c5d+qnhqrzu9sdlcMoon's surface, compared to Earth?

  An example of a force which aco8.w2/p i /ikwb1p jr4z9w vzqts at a distance is

  Who has a greater weight to mass ratio, a person weighi+ jd /7z yh8osomxz +(5o0xhxlng 400 N or a person weighinxh l+x7 ojzmood0 58(szh+/x yg 600 N?

  A stone is thrown straight up. At the top o10yw *tk tp78 capgr. -5reesaf its path, the net force acting on it w p-s ketaceg.15pt r*8 a7y0ris

  A 20-N weight and a 5.0-N weight are dropped simultaal74-g augff 3neously from the same height. Ignore air resistance. Compare theagugl f43 f7-air accelerations.

  A brick and a feather fall to the earth at their respective terminal velocitiesuhmu 0(vdd a 2om19b*+uo0-adhe6fc2tz3 lo h. Which objefc m 03u 1ulmoh-20 *e+ouhobav2dzd96 ahd(tct experiences the greater force of air friction?

  An object of mass m is hanging by a string from the ceiling of an elevator. vqoo+bf b* g4mv(c 6c *:y/4mr +xkiezThe elevator is moving up at constant*(b:rok* x+v 6qye vo fgmc/44+cizbm speed. What is the tension in the string?

  An object of mass m is hanging by a string from the g/q1aa)grcy2 s*/ i vpceiling of an elevator. The elevator is moving upward, but slowing down. What is the tension in th2*ycgg/)p rivsaq/1a e string?

  The force that keeps you from sliding on an icy , cth+92h15ee uj vwic50hnq,r -iagh.qj (xvsidewalk is

  It's more difficult tzq/nj 6rc h/bwzga5 8 y5+toe:o start moving a heavy carton from rest than it is to keep pushing it with constant vj5 rgqn a5wh/t/6y+czz8 o:ebelocity, because

  A horizontal force accelerates a c(hc/o( pk5 bnypt;0d box from rest across a horizontal surface (friction is present) at a con b (hcp5p0d(tnyck /;ostant 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 acceleration?

  A packing crate slid3u ,k gqkp-xc 9k17 fo,ilebx qri.s10es down an inclined ramp at constant velocity. Thus we can deduce th0c1qkukfi,r.eb k17spq,x- gxi3ol9 at

  A block of mass M slides down a frictionless plane inclined at an anmod e(k)5ik :agle q with the horizontal. The )o:kiae(k5dm normal reaction force exerted by the plane on the block is

  A block of mass M slides down a frictionless plane inclinedjt+ 0uu+s dk-s at an angle q with the horizontal. The normal reaction force exerted by the pl0ut skdj++u-sane on the block is directed

  A block of mass M slides down a frictionless plane inclined ao1pnqd t4qdi;/p g. l,t an angle q with the horizontal. The grag p.p 4 tln1q;qd/doi,vitational force is directed

  Two toy cars (16 kg and 2.0 hjplj.d2vr )16b*qlbk8cd3cqidq n.-0u+e tkg) are released simultaneously on an inclined plane that makes an angle of 30e with the horizontal. Make a statement which best describes their accelerat+bb c1 j)q*cp2k.-utqen v 3 djl6iql 8r0d.hdion after being released.

  An object sits on a frictionlesshs h b4rnv144rcj 4ea: surface. A 16-N force is applied to the object, and it acceleraa vn4ber:4jhc s441hr tes at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accelerate fr)gqu nih5sm7gjs65+2 8 rir9 av7j ltpom rest to 27 m/s in 7.0 s. What is the average n9q8l +v5)2ugsh jmi7irrs65a jg7tpforward force on the car?

  Starting from rest, a 4.0-kg body rejhnnl-31j p/ctgzip ;w3wv (6aches a speed of 8.0 m/s in 2.0 s. What is the net force a3hn/tp v6zj pwg( 1w lc3j;n-icting on the body?

  An antitank weapon fires a 3.00-kg rocket which yhuld;:t r:1ty-khj-ym 8oh)acquires a speed of 50.0 m/s after yt8 )- ;dkth o:rh1:-mhlyyuj traveling
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 fo k0kr;l6vnz(uj b:d6jrce that you push a 10-kg mass from restjr6dknv ;bz0(6l:ku j,

  What is the mass of a person who;do,/va9 qn60teuj i ++bwa (k)bj flz weighs 110 lb?

  What is the mass of an object that weigieq cpz6-l+ u)g jpn7ce1,fi;hs 250 N on the surface of the Earth where e;e1 6 )c,zjlcqpni u7ifg+p- the acceleration due to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Enileb .*ceho3s0 p;q+ arth. What is the mass of the object on the surface of the Moon where the accelerat3l.hecqsnb0+* ;p eioion 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. f4tx ah3(j :w+3h,nnq+e zouu The Moon's gravity is one sixth of Earzw3hj4 fn( atounxu3h,+e+ : qth's. Compare the masses of the objects.

  Sue and Sean are having a tug-of-war by pullh+ lcdp,eu u7l,/x,yting on opposite ends of a 5.0-kg rope. Sue pulls with a 15-N force. What is Sean's force if th ,xl y/ ,uec7+utlp,dhe rope accelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books rests on a le cvr9ft 4rj,1tvel frictionless surface. A force F acts on the stackr19tt4 cvr ,jf, 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 staxi z13 4n22uatsz4s hvnds on a scale in an elevator. What will the scale be reading when the elevator is accexs 1z42z3h2t4u saivnlerating downward at $4.00 \; m/s^2$?

  A person on a scale ridesw j,tqc;l y*g tc5 1cvf.jy0r. in an elevator. If the mass of the person is 60.0 kg and the elevator wjc1*qgy5yr..c;f, c v0jt lt 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 m)jh lud bznkr): .9j(mass of the person is 60.0 kg and the elevator accelerates upward with an an(k.rl ) mjj)hbu9:dzcceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal forces act on a 5.0-kgz) ,e1nto.n df 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 aof )n .ed,1nztcceleration of the mass?

  An object of mass 6000 kg rests on the flatbed of a truck. It is held in place wwpa+et( xm 5nkq9 p/4by 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 m9 a +pewt5/ nq(pxw4kis not to slide forward into the cab?

  An object of mass 6000 hy ce 4-ifilw5 ijy+)0kg rests on the flatbed of a truck. It is held in place by metal brackets that can exert a maximum horizontai-+e04h clfyyi5j w )il 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. )i+k vd rot*b(f s4gv04-1, if M = 0.60 kg and m = 0.40 kg, what is the magnitude of )do b0 vsf+vgr(t4*ik the acceleration of the system? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg and c 4l/ q blcjt6/5*fr1tsv46ne7mr5 fdixmur, m = 0.40 kg, what is the tension in the stringd ,mfec*ll /vmir1ctn76r u45/s 46xrfb qjt5 ? (Ignore friction and the mass of the pulley.)

  A student pulls a box of bak6,2q,7(otoq8p kxb+ddxl hooks on a smooth horizontal floor with a force of 100 N6o,+ dxb hox7 ka(2q qdkplt,8 in 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 smooth horizontal floor with a force oqf5ethy8ozk3f 6 g/k; f 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 nokg hy/zef; k3qf658tormal force on the box?

  A traffic light of weight 100 N is supported by two ropes as shown in Fig. 4-2. x8u(b zetpvd-rs20o jca 7+r5 What are the tv8( edu-bj +t25 a0cpoxrzrs7ensions in the ropes?

  In Fig. 4-2, if the tensioyb498kv se+ht ns in the ropes are 50 N, what is the mass of the traff 94bh8yesv +tkic light?

  Two boxes of masses m and 2m are in contact with each other on a friction*p/7 hdw;l cp3eokc5bless surface. (See Fig. 4-3.) What is the acceleration of the 7p cwp5kbde/o ;3lc*hmore massive box?

  Two boxes of masses m and 2m are inmd7* fvdz-p(9sd-yqqwfe* mfvj 85 /n contact with each other on a frictionless surface. (See Fig. 4-3d/ sw9 p8-(-z 5dv*md 7eqyqv*fmfjf n.) What is the net force on the more massive box?

  Two boxes of masses m and 2m are connected by a rope. (See 1o ztx. h/ 3t8g:qz6t+jtoeut7t xg*uFig. 4-4.) If the forward force on the more massive box is F,zoz6uq ghgt/x3+t78tujtt* :xeto.1 what is the tension in the connecting rope?

  Two boxes of masses m and 2m are + wkq8slso0+ l (fmwd2a0y8di connected by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the acceleration of the less massive sodl 80i aw20++wsd qf( kyml8box?

Two boxes are connected by a cord running over a pulleyp7ie ykoahc; *y:i97e as shown in Fig. 4-5. Box I of mas ;iey9y p7:7 aohkei*cs
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 am *om.be9t.c1 fj;yif3vhfe- desk are 0.40 and 0.30, respectively. What is the net force on the box when a 15 N horizontal f m1.fmtb;v 9yoi j3*fe cf-h.eorce is applied to the box?

  The coefficients of static and kinetic frictionslv0y5u5i-g y5of wb nae ,x9 bza*7+cf for plastic on wood are 0.50 and 0.40y,5yz*gbub f +cex vl90o -fawi7a 55n,
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 di75 lhk(kykp73njag :crection. It slows and comes to a stop with a constant acceleration of k k hgc3naj7( pl:57yk-$2.45 \; m/s^2$. What is the coefficient of kinetic friction between the object and the floor?

  A 10-kg box sitting on a hor0fh,y3bky aeo; -sh x(ss2vz3 izontal surface is pulled by a 5.0-N force. A 3.0-N friction fosf2 x0yho,-he ya (;3k3vbszsrce retards the motion. What is the acceleration of the object?

  A horizontal force of 5.0 N accelerates z kbc 5 dnbbazz,5)pj6mi/6+r 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 i2nj 1 4l2yxntgiven an initial speed of 10 m/s. It slides 50 m on the ice before it stops. What is t2inx24t 1njly he coefficient of kinetic friction between the puck and the ice?

  During the investigatiua;md.+sr8k qz a79adwvoyc1 )5xl b( on of a traffic accident, 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 vu qaa51 lwm. zx7dk+b;(9c8yroasd) prevailing conditions. Estimate the speed of the car when the brakes were applied.

  Two boxes of masses m a ep*b(a*e+6oi mqa ak,nd 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 p a6keam, q eia*bo*(+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. (See Fig. 4-6.) The suf,f1 htisx.rbc 22:ko,shco, rface between the more massive box antr2oic ,hh1 2cfx o.kb,:ss,fd 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 static friction between the boxes?

  An object is on a frictionless inclined h184 0nizck.z zd nj kxt2l13bplane. The plane is inclined at an angle od3bjkn4 810i lnckz.zx2h t1 zf $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a fleynhw e)vuzl9l-yv0gcj:q 3z; 2l); lat 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 plane w0 3l jgmhypa-2ith 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 angle of gh aw8 m4;x-f8oysjw 9$35^{\circ}$ 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 iq8dsb:qj3)ka: a ky-b nclined plane, at a constant velocity of 6.0 m/s.8q b j kky:dbqas-a3:)
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 a g.7vv ei(k(qt0p c5vb 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 down56x/ q *vi2rfrws3 tap:/;zzyjy l( or 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. Th8ccr:w fs nld +m,3oy6e cable attached to the log ma o3 nsclrm86d cyf+w:,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 lngmh rpp) 2zyjup(7g*-f 57aplane tilted at an angle offa-g mjyz *l )7un p25p(hg7pr $33.5^{\circ}$ 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 grady lzb-v7y:rq1 gm0 s68uiuwn) ually increased until the object begins to slide. The angle at which this occurs1iuyy qnsgmw7: 6 buz-0r8 )vl is q. What is the coefficient of static friction between the object and the plane?