Which of Newton's laws best explains w zi;oz:5bu3r*fkp 7vqhy motorists should buckle-up?

  When you sit on a chhgq(83y uwtbr 9g+nm. air, the resultant force on you is

  In the absence of an externmd 8bvm- */wblal force, a moving object will

  When the rocket engines on the starship NO-Poz,ryf;jr 7yw7 4.bxuAIN-NO-GAIN are suddenly turned off, while traveling in empty space, the starship wir7 .f;xby rouw4yj,z 7ll

  A rocket moves through empty space in a straight line with constant spez,q fku95i7kh7 fik4r ed. It is far from the gravitational effect of any star or planet. Under these conditions, the force that must be applied to the rocket in order to sustf7zikf,7krk4u i5hq9ain its motion is

  You are standing in a moving bus, facing forward, and you suddenly fall forward.ce vwug)w*a l1ht)2 7r You can imply from this th*w g2e1c)lva7) wurhtat the bus's

  You are standing in a movinwid/aqzcsta mv 8 b8cn-1 8k.5g bus, facing forward, and you suddenly fall forward as the bus comes to an nvq8/a wbtc a 5.-8m8izk1s cdimmediate stop. What force caused you to fall forward?

  A constant net force acts on an object. Describe the motion ofdq b ulms) +cb;4ham94 the object.

  The acceleration of al pj/t8ghhz;;n object is inversely proportional to

  A net force F accelerates a mass m with an acceleration a. If the same net fojqy1 6bm qesnaf* x/( xls9d24rce is applied to mass 2m, then the acceleration wiyjf1q/ *n64 s9(axm2x eldbqs ll be

  A net force F acts on rl1s(64 3rgtoo8tejua mass m and produces an acceleration a. What acceleration o14us teo( 3jrr6l8tgresults if a net force 2F acts on mass 4m?

  If you blow up a balloon, and then release it, the bkq p/fct/ +0 jr8xxj,jalloon will fly away. This is an illustjj/0j,k/+xtq xr pcf8ration of

  Two cars collide head-on. At every moment l0e ts m.efx/*during the collision, the magnitude of the force the first car exerts on the second is exactly equal to the magnitude of the force th*/xf em.t 0lese 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 yri+s (zdc7ul /ou wi(+sizru/dc7l ll

  Action-reaction forces87i a, jrqxz99j qpg5d

  Action-reaction forc)g; m5)fcbq kees are

  A 20-ton truck collides with a 1500-lb car and causes a lot of damage toasjfdog) zt58 9l rfo-r.34sw the car. Sin r3os)tdwoz8 .fsj-lf49ag5rce a lot of damage is done on the car

  An object of mass m sits on a flat table. The Earth pulls2g b vpda i*1b/uyq h4;z;csg: on this object with force mg, which h:v*by ;z 1id4sa cug ;pbqg2/we will call the action force. What is the reaction force?

  A child's toy is suspended from the ceiling by mear 3q uimsm;1,voph6y4 ns of a string. The Earth pulls downward on the toy with its weight force of 8.0 N. If this is the "action force," what is the ,sumhi om1y3r6 q4pv; "reaction force"?

  Your bat hits the ball pitched to you with a 4d ls2k.kq48c qtln .m1500-N instantaneous force. The ball hits the bat withmn l.q4 8 dkqkl2t.4sc an instantaneous force, whose magnitude is

State Newton's three lawsenqh 1 ..e5+ho1sj2wftpq. m+ b ehq9o.

  Mass and weight

  The acceleration due to gravc 5+q2nzvi ng4ity is lower on the Moon than on Earth. Which of the following is true about t vq nz2n+g4i5che mass and weight of an astronaut on the Moon's surface, compared to Earth?

  An example of a force which acts at a distance .j- 6x-quip:vy6/fqqqeot2 x is

  Who has a greater weight to mass ratio, a person weighing 400 N or n)ha -hf3f he0a person weighing 600 Nh-03 he)fhanf ?

  A stone is thrown straight up. At the top of its path, the ji)l h(p g95jf.xdd4knet force acting on itpj.hlj (dkg5i 9)4 fxd is

  A 20-N weight and a 5ou :0u/z( s:vo)znwk h.0-N weight are dropped simultaneously from the same height. Ignore air resistance. Compark:0:v(n sz)h/woouu ze their accelerations.

  A brick and a feather fall to the earth at their respective te 1w isqymd2c3 227tixqbyq+c1rminal velocities. Which object experiences theqiy2 +2ixqsyb 1mtc2 7cwd1 3q greater force of air friction?

  An object of mass m is hanging by a string from the ceiling of an elevator. The1o665vjushb /qvxw r;,2rydq elj;s,5 rr16 /ubvh2wvqoqxdy 6evator is moving up at constant speed. What is the tension in the string?

  An object of mass m is hanging by a string from eeyr-4qlq46z the ceiling of an elevator. The elevator is moving upward, but slowil44q6z -yr qeeng down. What is the tension in the string?

  The force that keeps you from sliding on an zpok5 e9o mn3*icy sidewalk is

  It's more difficult to start moving a heavy cartonhlezm *k) +)qz from rest than it is to keep pushing it with constant*l q)zk+ hmze) velocity, because

  A horizontal force accelerates a box from rest across a hori2*q pdkuy)mv p l7k4a2zontal surface (friction is present) at a constant rate.km 4y*dal7 kq2p up)v2 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 slides down an inclined ramp a41vwr ;vj / tx2zcie2rt constant velocity. Thus we can deducrvvetz421;/i xc2jrw e that

  A block of mass M slides down a frictionless plane inclined az . ik)s9syx15g zsmd2t an angle q with the horizontal. The normal reaction forcs .zsk 9mszdy)ix25g1 e exerted by the plane on the block is

  A block of mass M slides down a frictionless plane inclined at an anglaanmdp7nni (n) ad ;)br/70 rce q with the horizontal. The normal reaction force exerted by the p(n a d7n0narcda);pibm n7)r/lane on the block is directed

  A block of mass M slides down a frictionless plane inclined at an angle rgn:vf)8ql)9bu ft: jq with the horizontal. The gravitational force isfnbf) :q )9jl:vu8tgr directed

  Two toy cars (16 kg and 2.0 kg) are released simultaneously on an inc4g.lao/y uv+clined plane that makes an angle of 30e with the horizontal. Make a statement which best describes tu.vly /4coa+ gheir acceleration after being released.

  An object sits on a frictionless5*sajv2hi h5eiv iw1avq e33 0 surface. A 16-N force is applied to the object, and it accehv ea 0 h 3wia2vq*j553ivei1slerates 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 277 9:nit9pg q:jcn( sml1udfzq .lp3*g m/s in 7.0 s. What is the average forward fzimqntp9l7 913gugs( l: qp.*c:j fdnorce on the car?

  Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s in 2.0 s. W 7s8ur:jpc-f5hym a- v04dauphat is the net force acting ojamp 0aus54 r:p7fdu -8 -chvyn the body?

  An antitank weapon fires ur(n lhm 1g,.ea 3.00-kg rocket which acquires a speed of 50.0 m/s after ne m.1ghl(u,rtraveling
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 forc6mq.ngm/ffth 3sr* e: e that you push a 10-kg mass from resfh3mq .ng*/fr estm:6t,

  What is the mass of a persotr2m oeri /oyh7td oz). be6/:n who weighs 110 lb?

  What is the mass of an object that weighs 250 N on the surface of the Earth ww,tz* u* myk-y4t*eo +eaqd:d5vtw 5ahereza *o qw*5-dmeu t kvt ,4:ywte+y*da5 the acceleration due to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. What is the ko j5lu.ox1 0)qcu,k 1k2rcdkmass of the object on the surface of the Moon where the acceleration due to 2u5 r 1co uokk0kxkjc,d)l1. qgravity is only 1/6 of that on the Earth?

  Object A weighs 40 N on Earth, and object B weighs 40 N l/ci(g 8 kjhbh gj7(;*xuh/vhon the Moon. The Moon's gravity is one sixth of Earth's. Compare the masses of theh hu;b x*h/ (8jhg(7gkv icjl/ objects.

  Sue and Sean are having8sidl*,(ef- vj izpc; a tug-of-war by pulling on opposite ends of a 5.0-kg rope. Sue pulls with a 15-N force. What is Seanzi(ep ; d*i, -lvfcs8j's force if the rope accelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books rests on a level frictionless suy ysem:;h- sjw.a52rwrface. A force F acts on the stack, and itw:-wjm seyar.h2sy; 5 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 wvr +egbc (fo56ill the scale be reading when the elevator is accelerobf6 +rcvg( e5ating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the mass of the person y/r0jpb((dyh b x(/kuuzv;h6-7 * xo o+gpp fdis 60.0 kg and the elevator accelerates do/ - br(/obx*k hx(0p+ gpvof7y ;h (j6zddpuuywnward with an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale rides in an elgfbh akq6m,r3h1f l+8evator. If the mass of the person is 60.0 kg and the elevator accelerates mf1f+,36qg rh8b khlaupward with an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal forces act on a 5.0-kh fb)4e72 0 :srbi2vdedg6pbkg 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 acceleration ofrkb07h4egs2 f)pbb6d:vid 2e the mass?

  An object of mass 6000 kkkix*t ti6 pewf*is76p2 eb) fk g-,b9g rests on the flatbed 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 slide fo6*g7*stiw -kbtk,6iefp2f xek9i bp )rward into the cab?

  An object of mass 6000 kg r.i;4mlxu mek:,b3p rh rdx: .wests on the flatbed 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 time if the load is not to slide forward into the .m,u:krex:rp4im3wd.l bh ;xcab?

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what3p9adv 39yia-g i+bnb is the magnitude of the acceleration of the system? (I39n9 g+davp3 -baiyb ignore friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.6hilr10ibp um90 )a,vn 0 kg and m = 0.40 kg, what is t 0a in1 ,r)0mipvluh9bhe tension in the string? (Ignore friction and the mass of the pulley.)

  A student pulls a box of books on a smooth hori 9:jxzh,q/hp bzontal floor with a force of 100 N in a dire/jzb ,9:hhxpq ction 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 of 1q bxsub1(zg.c/w*gc2 7 ;my tf00 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(f y2sgc;1/t .b zcwb7umgq x* normal force on the box?

  A traffic light of weight 100 N is supported by two ropes asqz8mr3 axp j93 shown in Fig. 4-2. What are the tea89p 3 jqxr3mznsions in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N,ga 3 -r b7c t/(7rw6);ka ggfg o2s4ktqvsc(im what is the mass of the traffic lira;gs)c6g7gafvk7 -( gko i2wq3ctbmr st4 (/ght?

  Two boxes of masses m and 2m are in contact with each other on a fi9r8x( b yg/8b/q u9(vqqkgrmrictionless surface. (See Fig. 4-3.) What 9kb8mqgx/y u(8 /9qvirgb qr (is the acceleration of the more massive box?

  Two boxes of masses m and 2m are in cont:dx yue* 4aqb+act with each other on a frictionless surface. ye:b4 xqda*u+ (See Fig. 4-3.) What is the net force on the more massive box?

  Two boxes of masses m and 2m are connected b;wl6-wv8sbgv cksiv4ikq*w9y 0*x(l vlo k/5y a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the tensio5y0* ll obvwl8gckksk;*v4i 6xwsq v/-vw9(in in the connecting rope?

  Two boxes of masses m anf4t 5q; : 10tdmfpknhmd 2m are connected by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the a4fqtk0 pm;d nh:f51tmcceleration of the less massive box?

Two boxes are connected by a cord running overpr+frc8tvk,h iw95 y.hpq. h9 a pulley as shown in Fig. 4-5. Box I qh8,w y pkrchri9ht +59pv..fof 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 betwtr8 (/5rqvnzr 2ui9 jkeen a 3.0-kg box and a desk are 0.40 and 0.30, respectively. What is the net force on the box when a 15 N hoi98t(2n k5zvujr qr/ rrizontal force is applied to the box?

  The coefficients of static and kinetic frictions for plastic on wood are +0ye lat)0ah r0.50 and0a)h0y r+late 0.40,
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 in thex 3loktswm0+ ikq210 i-fsf0o +x direction. It slows and comes to a stop with a constant acceleratx oi q0w -o0k+l0s tfismk2f13ion 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 s9latw-*a0:*t7ei-av ezy hf z4 z6jbqurface is pulled by a 5.0-N force. A 3.0-N friction force retards the motion. What is the acceleraqh 0:ij4 zaewty-v6let a* z9zf7-ab* tion of the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg mass, from rest,jxe, .e0jl,+.e;yz:qw pxm fmro* *ry at a rate of $0.50 \; m/s^2$ in the positive direction. What friction force acts on the mass?

  During a hockey game, 28ky : z7bo0ctqa2b(kjxtdf:a puck is given an initial speed of 10 m/s. It slides 50 m on the ice before it sto27ft 0odtxzj 2c(a qkb:kb8: yps. What is the coefficient of kinetic friction between the puck and the ice?

  During the investigation of a traffic accident, police find s 4k-*wqagxseh .l q43u4ef tdqt jeni,:3;m- qkid 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 conditions. Estimate the speed of the car when the br4sqgu q qj-4tm;x-eqi ta34h,*ke 3:.fndwle akes were applied.

  Two boxes of masses m and 3m are stac ;kc gllxkv pk,90w5fq6do;i+ ked. (See 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 static frictiokg5,wlq 0;+9kvxi olp dc;f k6n force on the less massive box?

  Two boxes of masses m and 3m are (diso 8 9 t5b ssqq4o8)xrtm4*hjek)b stacked. (See 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 static fex k*5qbom4t i(hs8)d s s t8q9)rjbo4riction between the boxes?

  An object is on a frictionf93zi8jt v wh6less inclined plane. The plane is inclined at an angle of v83z6 wijt9fh$30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that mako hwx2yswg.b.2 6x 9c7o-bscves 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 wit+)(ukzii mlq 5n 0y-ie2 jfn8gh 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 annfc8cq jz t ozp9-xb( 1l71r*n 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 4on2 +m7whx 0q.i.nwcjw(bk x constant velocity of 6.0qwx0xo +.2ikmn 7n 4jw wh(.cb 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 roughe g6 hd (1:e*wgyclmt8 $37^{\circ}$ 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 down a q/u islzij52 (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:xau)d ahf;yo .g uk-; along a rough surface. The cable attached to the l )ad.; axk-:u; fhugoyog makes 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 azl,c gp , 5ey.z.m-jmi rough inclined plane tilted at an angle of.,i-c.my, zeljpmz g5 $33.5^{\circ}$ 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 incl.zx(jr+ 1yv nfine is gradually increased until the object begins to slide. The angle at which this occurs is q. What is the coefficientx1.(+ yfj zrnv of static friction between the object and the plane?