Which of Newton's laws best explains-**nm a 8eyfu*n qsb3t why motorists should buckle-up?

  When you sit on a chai+ sl* j:(rihvyr, the resultant force on you is

  In the absence of an external force, a moving obj7vw.n r3 imqx 8fref5r)zk rs-;ntk;9ect will

  When the rocket engines on the starship NO-PAIN-NO-GAIN are sudcrf9; ;jrr g py:vdd67denly turned off, while traveling in empty space, the starshirgp 6;9r:c;fj7 dy vrdp will

  A rocket moves through empty sp vhd+ (bm29txrace in a straight line with constant speed. It is far from the gravitational effecmb rxv9dh(+2 tt 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 suddenly fall fxm,/ben2z4s z5 sm6oborward.nsb2m s64z/ox ,bze5m You can imply from this that the bus's

  You are standing in a moving bus, facing forward, and you suddenly fall forwaom 0+nurj44nqrd as the bus comes to an immediate stj+qmor04 n4nu op. What force caused you to fall forward?

  A constant net force acts on an objwwcbv nc )o(t :zsi*:5ect. Describe the motion of the object.

  The acceleration of an object is inverc/hzkir c, p23sely proportional to

  A net force F accelerates a mass m with an acx8 av1 cs9mgo0i8ds )wceleration a. If the same net force is applied to ma89 dsx)owgs1cm8i 0 vass 2m, then the acceleration will be

  A net force F acts on a mass m and produceo.k) bfq50kpe nde6l)s an acceleration a. What acceleration results if a net force 2Flk.qonb5k )0e6e) dpf acts on mass 4m?

  If you blow up a balloon, and then release it, the balloon will fly away. o o5sn a.0oozy5e5 1xaThis is an illustrat0 oeoa x15osy .5o5nzaion of

  Two cars collide head-on. At every moment durinohte r+p*lun; 2.f4ea g the collision, the magnitude of the force the first car exerts on the second u;altn.h4 + reo* fep2is 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 utb0km6d jfr zf s f2,e3r+g.-F on an object, the force which the object exerts on you wil tk.2mbgfs+j0 d-6rff ruz 3e,l

  Action-reaction forces6ptm(qba*/0g ns0o eo

  Action-reaction forces*ec3*fdv . zlgkl. )2gh+kh ht are

  A 20-ton truck collides with a 1500-lb car and causes ajy6lp ,7w mlf+p i ()5fn1uroy lot of damage to the car. Since a lot of damag 6 1fr5()yplonj ylm+w,7fiu pe is done on the car

  An object of mass m sits on a flat table. The Earth pulls on thiccf oe*r:/ztve+yw(k7 xkfm : yz,i/+s object with force mg, which we will call the action force. Whatk:fw :ie f cz//e mt(cy7+xkvo*+ yz,r is the reaction force?

  A child's toy is suspended from the ceiling by means of a string. The Eartha9oq8zk:v, 9 y/ +l(;nh4szxeunn lkw pulls downward wnnk9a 4o( l+;9n,ehu z/:qlsv yz xk8on the 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 fr h (j3u sr9e5 leyjlue0gp.:8orce. The ball hits the bat with an instantaneous force, whose magnij.5(l:e le8uyg 9rju ep3sh0rtude is

State Newton's three lawst rz84;omgny urjpmx3xy 1:,4.

  Mass and weight

  The acceleration due to gravity is lower on the Moon 2 td./n79 n3k dxbp9vlrgmdh3than on Earth. Which of the following is true about the mass and weight of an astron vn9 /3xmd3kdt2pnrghl9d . 7baut on the Moon's surface, compared to Earth?

  An example of a force which acts at a dsy0dubo ,y b7)istance is

  Who has a greater weight to mass ratio, a person wt7/2 b pffx(r7ylaz ca/ 2ar,dh: bg/geighing 400 N or a person weighing 60a fggbhx: b22lfz,atpdry7/ (//c7 ra0 N?

  A stone is thrown straight up. At the topz2twqa2m vc uo1qz923 of its path, the net force acting on itq2 19uz c 2qwmat3z2vo is

  A 20-N weight and a 5.0-N weight are dropped simultaneously from the same heighte elizv+7o3q7u06g cv. Ignore air resistance. Compare their accelerations.v7ev0o 3cu l+ ei6q7zg

  A brick and a feather fall to the earth at their res4 pl )7qv:gv/7fhk7 rdt rpdw0pective terminal velocities. Whid4 rq7pgl p:v/7rtv h) d70kwfch object experiences the greater force of air friction?

  An object of mass m is hanging by a string from the ceiling of an elevatorv(k(2z tpjc jb4si7-e . The elevator is moving up at constant speed.cjsv4k etbp (72(i-zj What is the tension in the string?

  An object of mass m svr 1(r1f:4eq,ul:qe qdet.o is hanging by a string from the ceiling of an elevator. The elevator is moving upward, but slowing down. What is the te4ot q rrd,qe(se v.fq1ue: 1:lnsion in the string?

  The force that keeps you from sliding qm0dfaxg0 cr.e.(fikwd1(m 5 on an icy sidewalk is

  It's more difficult to start moving a heavy carton from rest z*v77 nj :ev8gaf nf*cthan it is to keep pushing it with constant velocity, becauseve**c8f 7n nzafj7 vg:

  A horizontal force accelerates a box from gzd.paqv7m: +rest across a horizontal surface (friction is present) at a constant rate. The experiment is repeatea+m7qz.:v pdgd, 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 slides down an inclined ramp at con(jsfpu1 lr12mf2 r,zp6hxe 8sstant velocity. Thus we can deduce thas2rzx12j(pfu hrep ,s 8l 6f1mt

  A block of mass M slides down a frictionless plane inclined at an anglmsn(1jbup+ 8 ge q with the horizontal. The normal reaction force exerted by the plane on the bloc(gpm1 nb8ju+s k is

  A block of mass M slisx7elr py 7s n xy.c8y36b6v/xdes down a frictionless plane inclined at an angle q with the horizontal.p8 7nx3 /le6vxsx76r.bsycyy The normal reaction force exerted by the plane on the block is directed

  A block of mass M slides 4k i 0f(1rrmtxdown a frictionless plane inclined at an angle q with the horizontal. The gravitational force is di1irm r 0xt4(kfrected

  Two toy cars (16 kg and 2.0 kg) are relea gk5j u1i+d9qgsed simultaneously on an inclined plane that makes an angle of 30e with the horizontal. Make a statement which q5ju+k1d ig9gbest describes their acceleration after being released.

  An object sits on a frictionless surface. A 16-N foru,05 h pa da-.ubhj5p6myy8dhce is applied to the object, and it acceyba8h u.h, ah 0dpu6pyd-55jmlerates 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/s in 7.0 s. b*r:scvcf/d2 What is the average forward force on 2bc*:/dcfsvr the car?

  Starting from rest, a 4.0-kg body reaches a spel76t *r6,rogm4x jbw1k1tsxu/ i4c 8 gyxit 2med of 8.0 m/s in 2.0 s. What is the net force acting on thewt2614 4uicsg/1mlxkrmt, 6xy xr*8ib7og tj body?

  An antitank weapon fires a 3.00-kg rocket which acquires a kp1p ,-m6 i;lpdi.uohspeed of 50.0 m/s after u ld6k oi;h.p-impp1, 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 push a m3n 5*wt s o3vz/r)tnk. 08l*grhlgus 10-kg mass from restgzt*)skgm0 vlu.8/r s*rwt h l 53non3,

  What is the mass of a xbbfua:sqk0b6+ *tirr9 c pjl35 59 umperson who weighs 110 lb?

  What is the mass of an object that weighs 250 N on the surface of the Ealmi0zg.v 8ig -rth where the acceleration mvggli0z i8.-due to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg onm u,vdu.h nf..p8ssy8 the Earth. What is the mass of the object on the surface of the Moon where the acceleration due to gravity is only v u.hf,m..ny 8ud8pss1/6 of that on the Earth?

  Object A weighs 40 N on Earth, and object B weighs 40 N on the Moon. Tp e,)po5ibb z.x2;:n9 r(ltgg qk:oqwhe Moon's gravity is one sixth of Earth's. Compare the masses of the objects 9)opq 5p gtkegz,;:. :qno(bblwr2xi.

  Sue and Sean are having a tug-of-war by pulling on opv4 u4v50nq a+zrqwhf9 posite ends of a 5.0-kg rope. Sue pulls with a 15-N force. What is Sean's force if uhq a+qw nv4v 450zf9rthe rope accelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books rests on a level frictionless surface. A force F acts on th:lzaev 5ml4* d)7 r5x5ma eljne stack, and it accelerate54ma* )lemzd n5 7l jlax5re:vs 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 scalcn( x.oz/ 1c7ablv)x6zkiah 5 e be reading when the elevator is accelerating dow5 7bhx(a6 )c1 /ovzlzcx.ina knward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the mass 0n.lh64 xgr uzof the person is 60.0 kg and the elevator accelerates downward with an accelera .40nrx6uh glztion 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 6j3j+ 8g(/luwi(v wdb k0.0 kg and the e wbjik/3d+wg(( jvul8levator accelerates 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 a magnitude of 8.0 N adkn c(4slx+y8me-b t 5nd is directed due north. The second force toward the east has a magnitude of+bcln k4y e- 58dxms(t 6.0 N. What is the acceleration of the mass?

  An object of mass 6000 kg rests on the flatbed of a truck. It is held in pla5whro pvqsw).y , /wx.ce 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 h srwwv,5 x.)wq/.y opdistance 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 is held in placedxj,a .rosbanb0benf/ 4i48 ( 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 tosnan iofb r e4b,/j4dxa(8b0. slide forward into the cab?

  In the Atwood machine shown in Fig. 4-1, pkom+0uxzl 55if M = 0.60 kg and m = 0.40 kg, what is the magnitude of the acceleration of tmokz50 5 ux+lphe system? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg and m = 0.40 r ( nj,+d ,2 jjo5tgx rdut(po4(ayqt;kg, what is the tenj +ujaj,2p,gnxtt (r5do 4tqd(;( orysion in the string? (Ignore friction and the mass of the pulley.)

  A student pulls a box of books on a smo(fzkc- qx; edj,zcdzc;*q k 16oth horizontal floor with a force of 100 N in a direction ofdezx;( zqzkcc6 k ;c*dqj1f- , $37^{\circ}$ 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 ad0ape,t9k 7qt 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 normal force on thq7t0dpt ak ,9ee box?

  A traffic light of weight 10p875p t0k3v znswsjnu5r c )o,0 N is supported by two ropes as shown in Fig. 4-2. What are tw8p ,vpzo0c un k7tr5)3sj s5nhe tensions in the ropes?

  In Fig. 4-2, if the tensions rw-rc)ut t(u7dbv )s* in the ropes are 50 N, what is the mass of the traffic light ) (b)r* uurs7dwc-ttv?

  Two boxes of masses m and 2m are in contact with each other on a friction svn;12cyl suu+.l .h*;e cvlxless surface. (See2 + 1x*y lnsulve.ccul;vsh; . Fig. 4-3.) What is the acceleration of the more massive box?

  Two boxes of masses m and 2m are in contact withelgqzdk pm3w3 bg /*++ each other on a frictionless surfak/mp*+l3 +gegzqwd3 bce. (See Fig. 4-3.) What is the net force on the more massive box?

  Two boxes of masses m and 2m are connected by a rope,sc :rf0dr-rkzbtoo 3t:j f 1uyf. 8l/. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the tension in thf.-/ :jzt1d8 otr3f:0f,cy ub orrskle connecting rope?

  Two boxes of masses m 70 4rhim m0,g slcb-iiand 2m are connected by a rope. (See Fig. 4-4.) If the forward force on the more ma0rm4imi lig0 b7csh, -ssive 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 h u9j5z a.uyf5z*usq5 in Fig. 4-5. Box I ofq5ah*s5jfz5 9zuu.y u 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-sbtii3 ;cb6-n;jsq a a 3.0-kg box and a desk are 0.40 and 0.30, respectively. What is the net force on the box wheja bq is;-s nb3ct;-6in a 15 N horizontal force is applied to the box?

  The coefficients of static and kinetic frictions scn/6 0ojanno(xz, )nfor plastic on wood are 0.50 and 0.40,0),6 ojs/n oncnxa n(z
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 levechzca(biun *v4 l2-5 gl surface in the +x direction. It slows and comes to a stop zhg25 *l4 au cnic-vb(with 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 sj0 n-h1b ch9gg s4b+o b;mj 70pobgwv)urface is pulled by a 5.0-N force. A 3.0-N friction force retards the motio-0g)7 ;0 omcbsv1b ojgp bhnhb +w49jgn. What is the acceleration of the object?

  A horizontal force of 5.0 N accelerates a 4.0-yfxdgm/1qw7+jooyv 0vvv7 1 g cz q+x81)ls/tkg 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. It slidesouug e348n0+h6g w tag 50 m on the ice before it stops. What is the coefficiet wu+n0gugha3 6g84eont of kinetic friction between the puck and the ice?

  During the investigation of a traffic accident, police find skidvs*30spgj *vi y j*s8quy 9s,b marks 90.0 m long. They determine the coefficient of fyvv qss* 9b,*0jy8g*ups3i sjriction 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.) Thh pqb,n 6gg,) b0vh0jrr0s,k ze surface between the more massive box and the horizontal surface is smooth and the surface between the boxes is rough. If the less maghkzvps06 g0,,j) nb0rq,rb hssive 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 stacked2+ vfxy1;wh ft. (See Fig. 4-6.) The surface between the more massive box and the horizontal surface is smooth and the surfac+fy;tfw2x 1 hve 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 plane. The plane is inclined44dnl. 8 c t cu8,ir2ref6pjop at an anglej8 c opucped4r fn,i26t4rl8. of $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that makes an tn t hok*y(pgq5+r(x; 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 pla+ ;4, uchyuf2y hxlwjv 3;etp6ne 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 inclipl5pc -7o2ay i;r scemp6n7o;ned 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 inclin awza(k6 1yr dvwy:(9mam/rc:ed plane, at a constant velocity of 6mz kdcaam1r(6yvr (yw:a/ w:9.0 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 9y qlm7j( +w+u/iisworough $37^{\circ}$ 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 dowsmzlu1bk2h- 4r65 oi, fg y)m0b)olrun 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.ogg z b.7(gsl6en 0pnl6n, 9y6js: rbc The cable attached to the log makes an angle of n:0jgbzy6 rs9,s6.pelc nobn7( 6glg$30.0^{\circ}$ 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 relq 4o i.l.mfpv,eased from rest on a rough inclined plane tilted at an angle o 4pvif.q, ol.mf $33.5^{\circ}$ 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 incliui,;vk0r/rq +f 0hsyine is gradually increased until the object begins to slide. The angle at which this occurs is q. What is the coefficient of staticr,k h/iiy 0+u q;frvs0 friction between the object and the plane?