Which of Newton's laws best explains why w+z/o:rk0 d/3grh q: y7owghh motorists should buckle-up?

  When you sit on a chair, the resultant forced2i *)oj lq+ty on you is

  In the absence of an eo.fg8 qsak dy tmdio +h5*/j)p/zn5 p1xternal force, a moving object will

  When the rocket engines on the starship NO-PAIN-NO-GAIz/a2jv; -qqzqx0c 6rhN are suddenly turned off, while travelinzqr2; -6zxq j0hq vc/ag in empty space, the starship will

  A rocket moves through empty space in a straight line with constant speed. It ;t(retjee ks* 6n gl,1is far from the gravitational effect of any star or planet. Under these conditions, the force that must ne grts1;te6 (,kj *lebe applied to the rocket in order to sustain its motion is

  You are standing in a moving bus, facing forward, and you suddenly f (hg 5q.v+evtlrew6k;*gp2z5tyl ( kkall forward. You can implyl gykv+(t;g6kp5*hk2qe( t. 5rl vwze from this that the bus's

  You are standing in a moving bus, facing forward, and you suddenly fall forwarj0*ex4z)f h,xb -gle)4h jqat d as the bus comes to an immediate stop. What force caused you4zxe4,al heqhj bjxg*))0 -tf to fall forward?

  A constant net force acts on an object. Describe the motihm 8y1c :w3qr.kkt;u; pdura(on of the object.

  The acceleration of an object is inversely 79 krp( 6drm.i-0wjpmlvt8o q proportional to

  A net force F accelerates a mass m with an accelerationnesbpy488 w 5h * 6qcpinz65ufp.t0 6 ufl.dub a. If the same net force is applied to mass 2m, thenfc8 u5y6itw *6hlu uzpbf0.4.d5npes qp n86 b the acceleration will be

  A net force F acts on a mass m and produces an acceleration a. What accel wzpkx.g1cm.aebt 9r/n 43sn/. ( sxameration res .b/zkt 4s3nm1pa.s (re.xxwa/ n9g cmults if a net force 2F acts on mass 4m?

  If you blow up a balloon, and theoo/yhd b,ezy a+*2rmd9,duw5l d+ l .vn release it, the balloon will fly away. This i*5e o9mv,ydod wy b+ lh/dad2u+,.lrzs an illustration of

  Two cars collide head-on. At every moment during the collision, the magnitude1q-bf o.a 17iblvo m,c of the force the first car exerts on the secon l11mqb-bofcoi,.a7 vd 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 wiva. q(mt n3nl2llq2vm(.atl3 nn

  Action-reaction forc. t yj/mn.s))fljgx9wes

  Action-reaction force5joco7/ubku pw*ssp : j0,xy;s are

  A 20-ton truck collides with a 1500-lb car and cause0)d xqjfh) p2,e c9fxvs a lot of damage to the car. Since a lot of dx 2 e0qhpjf,f9v) )cxdamage is done on the car

  An object of mass m sits on a flat table. The Earth pulls on th 6y j 4; ag,jxcrpa 3+c)hhgchan87*eris object with force mg, which we will call the action force. What is the reaction fo4x8 yj*3hg;gr p6aecrhn 7a c )+ahc,jrce?

  A child's toy is suspended from the ceiling bfm v, qcj3vc,zs4b/d ;tj:nr0y means of a string. The Earth pulls downward on the toy with its weight fd j,cr j,4tf3;z/vbqcs:m0nv orce 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 f/7 6zzurvqs-f18ywi,sk ws j8 orce. The ball hits the bat with an instantaneous force, whose mass6yji1 u8q wzv/kz7w,8-f s rgnitude is

State Newton's three la-mqc4mfx)f viepv06 3ws.

  Mass and weight

  The acceleration due to gravity is lower on the Moon than on Earth. (guc mrycd*b*0* 5 .bpan d8a/qag+oo Which of the following is true about the mass and weight of an astronaut on the Moon's surface, compared*a bd/uc(8obmnagd5 a0*r*qco.p+y g to Earth?

  An example of a force which acts at a distanxzkgb m-c*/yaxbv :52ce is

  Who has a greater weight to mass rat. m,pk wv, u z9*z8lbt(3q psw:h3lwdmio, a person weighing 400 N or a person weigs3 klww,vbzt(8,3. qwl :u9mz*pdpmhhing 600 N?

  A stone is thrown straight up. At the top of its path, the net force ae i8gwp7z o4h8tp-w;uz3 nnj+)o *mbccting on it e8-*zmtzp 34g b )w7joncuwi;poh+8nis

  A 20-N weight and a 5.0-N weight ak6hpso6pc 5+ tre dropped simultaneously from the same height. Ignore air resistance. Compare their accep6 pco6k5+ sthlerations.

  A brick and a feather fall to the earth at their respective terminal ve;3 .yfcgr/m(r5 .fnfro6 h fubn/paf( locities. Which object experif(/o( gnnffa; pubmr. r yc /6r.hff35ences the greater force of air friction?

  An object of mass m is hanging by a string1o:v*vdc :w lt5cz7( 0olvfm e from the ceiling of an elevator. The elevator is moving up at constant speed. do0mvfo 1:v :tvec wc*l z75l( What is the tension in the string?

  An object of mass m is hanging by a string from the ceiling of an elem2t t6) w;bvlhudi.4 whzoh;gdd 776yvator. The elevator is moving upward, but slowing4t.;62bihlu7d wzm hyd7v;d gw)o h6t down. What is the tension in the string?

  The force that keeps you from sliding on an ic)-:im t,/pfcq,cn dlby sidewalk is

  It's more difficult to start moving a heavy carton from rest tha8s 1l6ihhs6km n it is to keep ph816k slms6ihushing it with constant velocity, because

  A horizontal force accelerates a box from rest acrg 8evf0kgqui)( m.v-voss 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 ho .0fmvke)q-g vg iu(v8rizontal force is doubled. What happens to the box's acceleration?

  A packing crate slides down an inclined ramp at constant velocity. (i hu 1o gx -3tw4uvvwnj5q)q2Thus we can deduce thj1n3-h 4o)iuv (qwg2 qx5wvtu at

  A block of mass M slides down a frictionless:oacn6q- 3yyp,y zs2b plane inclined at an angle q with the horizontal. The normal reaction force ex3 cabpo-:ysy yqz26n ,erted by the plane on the block is

  A block of mass M slides down a f9 4; l6yio k9btc75b(gihey ofrictionless plane inclined at an angle q with the horizontal. The normal reaction force exerted by the plane on thk;hl94 7e9ygt6f 5coob iby(ie block is directed

  A block of mass M slides down a frictionless plane inclined aji0.f,yrmol:i5zmi gw t pdz;+r 673m t an angle q with the horizontal. The gravitational force is tdjir:53y+ow i6,rizm; l .f0mmg 7pz directed

  Two toy cars (16 kg and 2.0 kg) are released simultaneously on w/o5t/tf, lvk an inclined plane that makes an a/ ,k5lwo t/ftvngle of 30e with the horizontal. Make a statement which best describes their acceleration after being released.

  An object sits on a frictionless surface. A 16-N force is applied to bn0fs;d. +z sbguk9(e the object, and it sne bg+0 z9sfk.dbu;(accelerates at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accelerate fropk bayy :n1)omow9u, 8m rest to 27 m/s in 7.0 s. What is the average forward force on the opb okm)y9u18:, ya nwcar?

  Starting from rest, a 4.0-kg bt7 nwvbn5*nm *ody reaches a speed of 8.0 m/s in 2.0 s. What is the net force acting 7vnm* nw*bnt5 on the body?

  An antitank weapon fires a 3.00-kg rocket which/cy 4r:qjdhb+qtqr; + acquires a speed of 50.0 m/s after travelin; tc qb/qd+q4+rjhy:rg
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 a 10-khn,b6)fvqac g8-h4 jf g mass from res8hc jna46fbgvfh q-),t,

  What is the mass of a person who weighs 111yh yywpu22 2y0 lb?

  What is the mass of an object that weighs 250 N on the su7equpm j45 /tyrface of the Earth where the acce4 q7um e/5jpytleration due to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on te*+noxkx)l- hx-a0mj he Earth. What is the mass of the object on the surface of the Moon where the acceleratx-n- kjaex *+ )0homxlion 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. Thp3phg9u pfc42e Moon's gravity is one sixth of E43ppgf pu9hc2arth's. Compare the masses of the objects.

  Sue and Sean are having a tug-of-war by pulling on opposite ends r zsz6vd3c7j+4 c3gsp of a 5.0-kg rope. Sue pulls with a 15-N force. What is Sean's forcecg3p4dzcz7j3s 6+sv r if the rope accelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books rests on a letswf(z wh+s ko(9 u00nvel frictionless surface. A force F acts on the stack, anshzo(tus 0(wf0k n w9+d 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 4dab*bx,0ohc N stands on a scale in an elevator. What will the scale be reading when the elev*0,dh ab4xbc oator is accelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the mass of the person is 60.0 k znlmpd9 jk810g and the elevator accelerates downward with an acj8l d1 p9nmkz0celeration 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 6, shll6yciqnt+):d5g e/dzz/ 0.0 kg and the elevator accelerates upward with an acce+)q,cgl6dnd/lzs: z5 /itye hleration 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 a magnc;wik fv+x,ag, fn+v4z6.ixq l+ t1cgitude of 8.0 N and is directed due north. The second force toward the east has a magnitude of 6vf ik,cn+.g+a cxw 4x iql;1g+v6tz, f.0 N. What is the acceleration of the mass?

  An object of mass 6000 kg rests on the flatbedtn ty ,20/lvn. odja9cdo*.gp 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 distance if the load is not to sl,d ltd 9jn 0a.tv/cnyp2og.* oide forward into the cab?

  An object of mass 6000 kg rests on the flatbed of a j-)b+ eyfzo7 50wi 6(mzfu8sqbd kfb*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 sto8bzfef +wob-ydu07m) sj f*k(qi6z b 5pping time if the load is not to slide forward into the cab?

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, whata, vr.s; ysew) is the magnitude of the acceleration of the system? (Ignore friction and thys.)av ,er;sw e mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg an+ d8ebl.n 3weld m = 0.40 kg, what is the tension in the string? (Ig8e. 3 llednbw+nore friction and the mass of the pulley.)

  A student pulls a box of books on a smooth horizontal floor with a fo9p sir2qef45zzy2(wf rce of 100 N in a dir4 q2p9fw2r5 zys( fzeiection 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 horizo/vs8rekb sf5 ( n/vtx+ntal floor with a force 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 normakn /vx b8ss5vft(r+/el force on the box?

  A traffic light of weight 100 N is supported by two(l ,g/ lq2wpcq ropes as shown in Fig. 4-2. What are the tensions in thpl/ ql,g2cqw( e ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, w8vh-rg5srn4 f*ww su :hat is the mass of the traffic lighsw* 4rwr:usnf5-v hg8 t?

  Two boxes of masses m andc /xdw*en-ri9 a( dol:mhbi hi ax(e6*hge,)) 2m are in contact with each other on a frictionless surface. (See Fig. 4-3.) What is the acceleration of the more ma:9n/cl)(i**, i6agmdedeab(-ew x rihh)hoxssive box?

  Two boxes of masses my csbeuo) , /jhl*6xql)km ;jt):k)br and 2m are in contact with each other on a frictionless surface. m b6)bk))*/u; reyx scl:, tk jjl)ohq(See Fig. 4-3.) What is the net force on the more massive box?

  Two boxes of masses m andg3c 2rbkx8q ahpt33 9h 2m are connected by a rope. (See Fig. 4-4.) If the forward force onthk93bqhrx 3 2g8acp3 the more massive box is F, what is the tension in the connecting rope?

  Two boxes of masses m and 2m are cobh8u znt.9q 8b(mmt7jnnected by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F,t j.qm8t(nmzbu89bh 7 what is the acceleration of the less massive box?

Two boxes are connected by a cord running over a pulley as shrs/t6 zyg92 8/xgijg c6g6u jbown in Fig. 4-5. Box I oty c6g bi 8rg/9gszjxj/u26 6gf 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-kg box -+.jh 2vf0gf2bcxbzv(qo*i cand a desk are 0.40 and 0.30, respectively. What is the net force on the box when a 15 N(xhcg*.v ivf-bz c+o2q jf0b2 horizontal force is applied to the box?

  The coefficients of static and kinetic frictions for pla zkt2da kd)iwf:rv52; )xufi 7stic on wood are 0.50 and 0.iaddk 2 w)ur2k;: 5zit) x7fvf40,
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 surfac+:g t3f.tvadg. /vdwae in the +x direction. It slows and comes to a stop wit3: ad.tvgg f t.wva+d/h 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 surface is pulled by stnw 5xxpe63;zp5r +la 5.0-N force. A 3.0-N fr w lt;x e+5rz6nx35ppsiction force retards the motion. What is the acceleration of the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg mass, from rest,i exwmc3y9nm wx3(r8 5 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 d)znjpl+e0n11*bd o rinitial speed of 10 m/s. It slides 50 m on the ice before it stops. What is the coefficient of kinetic friction between the pup+ e* dlz r1jbnd1)no0ck and the ice?

  During the investigationg2l y;unb anu,g87kw9 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 prevailing conditknw g,82u7lgnua 9y;bions. 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 s evpk (l:evj(4 o6xc*iurface between the more massive box and the holo:xc e6k(vi( 4pv*ejrizontal 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 less massive box?

  Two boxes of masses m and 3m are stacked. (See Fig. 4-6.) The surface bet/l9fszxbm5v/ 7 ol t+kween 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 static frictionlz/ +5 s7bftvok/ lxm9 between the boxes?

  An object is on a frictionless uf) r;v9wg;wu8 v1fpfinclined plane. The plane is inclined at an angle ofv 8g vw9fu1rw;up f;)f $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that makes anvhkx8t/ .ev2o g (y e;1gptu-r 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 9 h3h*3sz 9wkvtqu )bbwith 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 smod5lo1ve7n u h1oth 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 incli-rc ar;j4bxmazuv28 b1yk9+g ned plane, at a constant velocity of 61ura-kbbjr 9xy vaz 2m4c8 ;g+.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 s 9 v+s04.v67znqj j:ro yno75t hlpkn3s0gab clides 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 hjud d84: pgm(.ev os4m 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 log weighing 500 N along a rough surface. The cable atdnl)kc bpwa00(fcs zw.*y1(0 eray*itached to the log makes an ang psizr 0b1 an0w(ya0yd fcw(e.k)l** cle 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 fekkqj 9p 9(vkfha2-; an angle (k9k;9vhf p qafe-k2jof $33.5^{\circ}$ 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. aq )f6d:c6j2w1ix s: sxad7go The angle of incline is gradually increased until the object begins to slide. The angle at which this occujd : s):iq2cxasowfa6 6x 1g7drs is q. What is the coefficient of static friction between the object and the plane?