Which of Newton's laws best explains why motorists shouh ))q n;;oy1s4.cv) rwd it4jg .orhpdld buckle-up?

  When you sit on a chair, the resultant forc8u 6k qv/m:t 6 e.7zjw4bdwumde on you is

  In the absence of an external forfw ,(gl/ s xbkxs -g hnyxmmy82:g:6+rce, a moving object will

  When the rocket engines on the starship NO-PAIN-NO-GAIN are suddenly turned 6cxw u 7xkp;o(n0biwxd33; p8svn3ea off, while traveling i;vspnu 3bo6 38;eaxd (wxx30wn7ci k pn empty space, the starship will

  A rocket moves through empty space in a straight line with constant speed. Ijb )z tt-24vrpt is far from the gravitational effect ofv-j b)zrptt42 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 foq, gd.v18gkv(lg r l k2dtuc93rward, and you suddenly fall forward. You can imply from this tc3k u9dq8kg.l g2lv tv1r (d,ghat the bus's

  You are standing in aa;ta+-yry(u e moving bus, facing forward, and you suddenly fall forward as the bus comes to an immedia tay ray;u+(-ete stop. What force caused you to fall forward?

  A constant net force acts on an object. Derhov :0spe,b,scribe the motion of the object.

  The acceleration of an object is inversel .id q,zsl7,+r l-kx wtn3g0yoy proportional to

  A net force F accelerates a mass fxcml hl*a m mfj,d5l21+qb86 x 7vg2pm with an acceleration a. If the same net force is x5jlc m1762,vq xfm*a 8fpgm hllbd2+applied to mass 2m, then the acceleration will be

  A net force F acts on a mass m and produces an accel 0*y-pkhd7eo0ez:kxnum ijqdmao5.q 0+ +ll4 eration a. What acceleration res0xu oz:eqojh7. *ed nk4 +myqi0l0pml k+da 5-ults if a net force 2F acts on mass 4m?

  If you blow up a balloon, and then releasgq2vj1pk.yy9ew2r3e wgp; g 7e it, the balloon will fly away. This is an illustration owy1q3 e9w.y2j;k ggpp7e 2 rvgf

  Two cars collide head-on. At every moment during t v mp6jk1+niw9-pm3yi p01swmhe collision, the magnitude of the force the first car exerts on the second is exactly equal to the magv9 mp n1 sp3i6mp jikw-0ymw1+nitude 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 yy9:(p w k2l gw:8rye0mbx,np jou wil w::9g(rxn yk ,jy0lwpbe82mpl

  Action-reaction forcese pznh w44ko74/62 t/ntzhoxc

  Action-reaction forc)flum+2 a sn/l59a 3/ jxwknsces are

  A 20-ton truck collidessli .(a-0u dzy with a 1500-lb car and causes a lot of damage to the car. Since a lot of dald(usz-iya 0.mage is done on the car

  An object of mass m sits on9z)*bqc jmit 9c*ipaz2z 4wf; a flat table. The Earth pulls on this object with force mg, which we will call the action force. What is the jf )z qctpm;zcai*wbi929z* 4 reaction force?

  A child's toy is susp..pjno u60mv 0jy8tpmended from the 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 "acto00v.py8 up.njj t6mmion force," what is the "reaction force"?

  Your bat hits the ball pitched to you with a 1500-N instantaneous force. The b 00)kx9e:m 7ob bnmckqall hits the batk7m0e k)0:qobmb 9cnx with an instantaneous force, whose magnitude is

State Newton's three lfb 0;a hd,jlhbovy -2so()8bnaws.

  Mass and weight

  The acceleration due to gravity is lower on the Moon than on Earcc2yl g.zpdm (i01j/v th. Which of the following is icpjc21g0y /zmdl(. v true about the mass and weight of an astronaut on the Moon's surface, compared to Earth?

  An example of a force which acts ajso:3/b k:6lj jgvrx/3n y nm-t a distance is

  Who has a greater weight to mass ratio, a person weighing 400 N v sg))ff6/ vqdor a person weighing 600 Nv/fs)v)fg q d6?

  A stone is thrown straight up.dmczc1tm0tc+kpw+ ld8d6 j+ 2.f q1lw At the top of its path, the net force acting on i81qwl dmdkctlj1tdc2+c + f 0mp w6.+zt is

  A 20-N weight and a 5.0-N weight are dropped simultaneously ff* bkqc0m c.g1rom the same height. c0fgcm 1*k.bq Ignore air resistance. Compare their accelerations.

  A brick and a feather fall to the earth at their respective terminal velocitiev z6coe1 qv04dg0c no+s. Wh6o1n400 zvec odqcg+ vich object experiences the greater force of air friction?

  An object of mass m is hanging by a string from the ceiling of an elevator. T x7 apw w8ngb;h8c 3on+l1ttw3he elevator is moving up at constant speed. Wha+; b clnnh g8tta8wo31x3w 7wpt is the tension in the string?

  An object of mass m is hanging by a string from the ceiling ofr stw9 q vc65+b4*tnpi an elevator. The elevatorbwt*t4+9q vsrpi6 n 5c is moving upward, but slowing down. What is the tension in the string?

  The force that keeps you fromg; 9e0 .jajhrgn8hdg 1 sliding on an icy sidewalk is

  It's more difficult to start moving a *yx63sj we3 enheavy carton from rest than it is to keep pushing it with constant velo3 n36x*wyj seecity, because

  A horizontal force accelerates a box from rest across a horizontal surfe;4jutloy 30 sace (friction is present) at a constant rate. The experiment is repeated, and all conditions remaijtol;yes034 u n the same with the exception that the horizontal force is doubled. What happens to the box's acceleration?

  A packing crate slides down an inclined ramp at constant v c9y;s0ry0jhvelocity. Thus we can c;v 90h0s yrjydeduce that

  A block of mass M slides down a frictiu . n.h2e kz.r: ay4p:6cqbrkionless plane inclined at an angle q with the horizontal. The normal reaction force exerted by the plane on ther 2.e6bkr. qh:ia.ypkzuc 4n: block is

  A block of mass M slides down a frictionless pllro hsh e ,nf .4mc2xj:j(sa-g4)f,elane inclined at an angle q with the horizontal. The normal reaction force exerted by the plane on the bjxhhe r.jf,l o-:ssan f cmlg), 424e(lock is directed

  A block of mass M slides down a f apz)mgf:62z.-hktw g c,xzzc--h 7rrrictionless plane inclined at an angle q with the horizontal. k6cz.pgt zrgmwzh-rx- )a2h7z ,-:cf The gravitational force is directed

  Two toy cars (16 kg and 2.0 kg) are h/jdi n*l( lb 4-mj.l.blap yc.;nms-released simultaneously on an inclined plane that makes an angcjlnj.m;b .( y.m llpbia4 /h-ls-n*dle of 30e with the horizontal. Make a statement which best describes their acceleration after being released.

  An object sits on a frictionless surfac-(k l 8hdgzhayzz u+/9e. A 16-N force is applied to the object, and it accelerates at +8zzd a lgzy/(h-u9h k$2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 10avw0a )/acw edalr jh5,. 3.ds00 kg can accelerate from rest to 27 m/s in 7.0 s. What is the average 05.wa cjdv/eh3),sd.a wrala forward force on the car?

  Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s in 25u/s y pn3 4inlno/yp;.0 s. What is the net force acting on /ln 5ny; poisu4pn/y3 the body?

  An antitank weapon fires a 3.00-kg rocket which acquires a chj i9kn))7t:hrn1lb 9 1vll: wocub1 speed of 50.0 m/s aftv otc 7cn 1lhlbr:9)unw)lk: 1i1 j9bher 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 force that you (ycnhwsp:k-qo a:g+)push a 10-kg mass from rests(a q co: h)p-+wg:nky,

  What is the mass of oze isc4 i((.ww.lu b3a person who weighs 110 lb?

  What is the mass of an object thatou::uk ot *q8/qbl:k d weighs 250 N on the surface of the Earth where the accelerak8bq:kdlu /* o:qut:otion due to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. h*2t +duy7zx3yg;kis 8dass 4qh /or-What is the mass of the object on the surface of t- 7gzy 4q 3;* +hauti2yro/hs sd8dkxshe Moon where the acceleration due to gravity is only 1/6 of that on the Earth?

  Object A weighs 40 N on Earth, and ov07t rkyw;w,q u ceo)i7 uh/6abject B weighs 40 N on the Moon. The Moon's gravity is one sixth of Earth's. Compare the masses of the obj/0o6ru ev); ,wkuqac7 itw hy7ects.

  Sue and Sean are having a tug-of-war by pulling on opposite ends of a 5.0-kg mx-uqm1g):n lrope. Sue pulls with a 15-N force. What is Sean's force if the rope a-m)1: xgnluqm ccelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books rests on a level frictionless s1p e7 r.1kwizvot/ .zfn +cni:urface. A force F acts on the stackk. 7vtcrn:.fopezn 1ziwi/ 1 +, 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 the scale ,o;c rflgl(+s be reading when the elevator is accelerating downwlcr os;+f,(glard at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator 8 tpa8g2:b t mstn,mzcb2d+*f. If the mass of the person is 60.0 kg and the ele*tnfs2t t+b : m8ab2pdgm8zc ,vator 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 mass of the person is 60.5nyna(8w gz+u 0 kg and the elevator accele5(ynang wu8 +zrates 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 foys.o xj8 m nn,n0e4i2hrce 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.n4m8 iny.e so0x2 njh, What is the acceleration of the mass?

  An object of mass 6000 kg rests on the f,,ujc tg50n cflatbed of a truck. It is held in place by metal brackets that g,u c5c0nfjt ,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 ,lhlarlz ;5 j(8p9xsctruck. It is held in place by metal brackets that can exert a maxix(h8c; lras 9, zllj5pmum 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 = 0.6 * 6+gb7kyxf- dhc2eau0 kg and m = 0.40 kg, what is the magnitude of the acceleration of th6-x 7eg+ a*k fcy2dbuhe system? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown i+bd(hgfo s 7nb37k xk-n Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the tension in the string? (Ignore friction and the m 7d3b(7hxg+n kkb-fosass of the pulley.)

  A student pulls a box of books on a smo ;a/ k y3 s1y:buc6cm2krwzzzmigv/2 ,oth horizontal floor with a force of 100 N in a dik3/svzaczk1ic u:y2wm y;b2 z/gm6 ,rrection 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 wk*xz)zo l.8 dhith a force of 100 N in a direction of 37.0e above the horizontal. If the * .lkxz hz)8odmass 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 in Fig. oti;(//1 g-mvuzzsx5 h2lu ec 4-2. What are t exti1cv (-l/z m52o/hzs gu;uhe tensions in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 2e )5bjm4 pujws)pdog:44 kj(jw7m lz N, what is the mass of the traffic j7jw(z4bjje ):4 gp4p wmmk ld2)u5os light?

  Two boxes of masses m and 2m are in contact withtcs5kmmtmz7 /m +1 xhx +wf3mmo1i; -q each other on a frictionless surface. (See Fig. 4-3.) What is the accelerationfc7 / xsqio3z5m km1tt1mm mm-+w+x;h of the more massive box?

  Two boxes of masses m and 2m are in 4jtvtjp .km4/l+b0-cjplr 5ccontact with each other on a frictionless surface. (See Fig. 4-3.) What is the net05v/ktpj. 4jb-p crjlm lc+ t4 force on the more massive box?

  Two boxes of masses m and 2m are connected by a rope. (See htu v(94(nsor Fig. 4-4.) If the forward force on the more massive boo (t uvh4nrs9(x is F, what is the tension in the connecting rope?

  Two boxes of masses m and1npc*21 bvfnr-h e-od 2m are connected by a rope. (See Fig. 4-4.) If the forward force on the more o-pef 1 1 bdv2nnr-c*hmassive box is F, what is the acceleration of the less massive box?

Two boxes are connected by a cord running over a pulley as shown in Fig. 4-5.9 h-roq1qvoc j els;js(n9q30 Box I onsj;0 91cserv qj ( qqh9oo-3lf 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 andv6df,pm(ok*fzm e v-* kinetic frictions between a 3.0-kg box and a desk are 0.40 and 0.30, respectively. What is the m*(pfv*fz-e mkdo,6v net force on the box when a 15 N horizontal force is applied to the box?

  The coefficients of static and kinetic frictions for plastic on;fdn 3qa-pt -ks,mhs 5gcdn)4 wood are 0.50 and 0c; n-3 gaqs- m) pdst,hfn4k5d.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 surface +8em(wvt 6* g.4v buqk;kzuqcw5dll9 in the +x direction. It slows and comes to a stop with *cg.4tzklwdk (5u;evuqqbvl+ 8 m96w a constant 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 ufyqh 0h8q6 +dsurface is pulled by a 5.0-N force. A 3.0-N friction for8 dq60f yuhh+qce retards the motion. What is the acceleration of the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg mass, fro2kd- r+ul q1by,*bll(q mosx d 1f; :r;jt:cdzm 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 ..woc 4zczcq 3m/s. It slides 50 m on the ice before it stops. What is the coefficient of kinetic friction between the puck and the ic4.zz wcc3qo. ce?

  During the investigation of a.uvo*wr y rwi(k0vu+- cx.w.z traffic accident, police find skid marks 90.0 m long. They determine the coefficient of frictirv0. *ou.zuw(+ rw-i.kxwc y von 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 stack8q43j f .o,tnwj uzu7fed. (See Fig. 4-6.) The surface between the more massive box and the horizontal surface is smooth and the surface between uu8w on43f jfzt.jq7, 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 stackek/ m2yvhtv*+pdk *kv0 d. (See Fig. 4-6.) The surface between the more massive box and the horizontal surface is smopdv 2kv+tyv 0/ **khmkoth 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 plane8vne x2 tuisn.7+rl- b. The plane is inclined at an angle 7xvnrubse. -n2i l+t8of $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that makes a(j tch2wh 2:nan 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 withepgjjb2 luy 9n6h 85tl;ui )0ka r(l5u 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 i+r-qpv3gi- y inclined 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 cons4y5 y5wsq8zmyax q 6p 2r1+ozutant velocity of 6xy51om s4r+w5zqz2y uq y8ap6.0 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 a rough nx(/w.ju p tsyf3f6k1d5a6+bxdo 3s o$37^{\circ}$ 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 dohhd4m;6x 6,tr 1ffk d5:h odfcwn 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 1on(58i zttlhuc2 .tvweighing 500 N along a rough surface. The cable attached to the log makes an angle h t linc21u.8vz(tt5o 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 fropb7 vz/*qs25iup- fki+)op oiw, yv -nm rest on a rough inclined plane tilted at an angle2n+fz kppi oi-/bo 5)sw,pqi -u*vv 7y of $33.5^{\circ}$ 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. Tv 5.bf5jayi c6he angle of incline is gradually increased until the object begins to slide. The angle at 5ia 5bcjfv.y6which this occurs is q. What is the coefficient of static friction between the object and the plane?