Which of Newton's laws best explains why motorists should buckle-up?n4spwxafy4 ph 40,rni x5t1 avex/g7nk .+f6 d

  When you sit on a chair, the resultant force on m9e v:kmea)tc/mgw6- you is

  In the absence of an external fh (jbi/).cis6 jwj eo(q ,w;uvdy7 u6force, a moving object will

  When the rocket engines on the starship NO-PAIN-NOi(+fhy / x mv2+-rhqmr-GAIN are suddenly turned off, w2ifm-+ vh/xq r(mh y+rhile traveling in empty space, the starship will

  A rocket moves through empty space in ajh5w54s)x lz y straight line with constant speed. It is far from the gravitationy) sh wj4xl5z5al effect 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 sudd-0/hhjti+ gx uenly fall forward. You can imply from this t0i/+hjuht-g x hat the bus's

  You are standing in a moving bus, facing forward, and you suddenly fall fohb/ j0c oqj x1y06 z9.)osgau fq8hgy vd2f7i(rward as the bus comes to an immedi0ocf0igvo /jd8b.hq shj zg2y1) fa 769xq(yuate stop. What force caused you to fall forward?

  A constant net force acts on an d5c7 -ucojx6wmlf+:2-sdzo z2wrd1yobject. Describe the motion of the object.

  The acceleration of an object ioqu0;+xcfv(4yje(fhdy vm7. xva4c:s inversely proportional to

  A net force F accelerajrwqhd*iu59 .tes a mass m with an acceleration a. If the same net force is applied to mass 2m, then the acceleration willr5w idh.9 qju* be

  A net force F acts on a ma+ ),qq;zrwjx5nc if+xss m and produces an acceleration a. What acceleration results if a net force 2F a,+ni jw5+ )rzxxq cf;qcts on mass 4m?

  If you blow up a balloon, and then release it, the balzffs:t02 azwe. 5fwz6 ay6p5rloon will fly away. This is a:zw2yf5zp66fwzft r0 . seaa5n illustration of

  Two cars collide head-on. At every moment during the collision, the magnitude of 3 qzlb64i1y ;dik:o8lro4r gr the force the first car exerts on the second is exactly equal to the ma kz4 634bl 8lr :yrdioiq;1ogrgnitude 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 f/31r *; gufmhd lhl(p)o2ipee+pig) sorce which the object exerts on you wi (;g *2l lippf))sr1+umogh pi/ehe3dll

  Action-reaction forcdc ;8d7.tsrkss)wr 4fes

  Action-reaction forc:mfbrpgs;e5p -4nc( yes are

  A 20-ton truck collides with a 150uj(1:fed gehsi)5 qk 00-lb car and causes a lot of damage to the car. hef5djk )1u(:0igseq Since a lot of damage is done on the car

  An object of mass m sits on a flat tabl 9hyjii/u5d 5ee. The Earth pulls on this object with force mg, which we will cal uhjy ie59id/5l the action force. What is the reaction force?

  A child's toy is suspended from the ceiling by means of a string. Thj:c*zt(wa2p.fe1me (pogr r/+ rsf+oe Earth pulls :pe gc(1rw+( f eozmr+ /toj *a.prsf2downward on 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 pitchgq/ w*be r*9hfed to you with a 1500-N instantaneous force. The ball hits the bat with an instantaneoureb*/g f*wh9 qs force, whose magnitude is

State Newton's three laws.yqdyp mui.67c9/.joi r;gwi2bo r8c 7

  Mass and weight

  The acceleration due to gravity is l*ya(i k)o v csi nsdou:u507x+ower on the Moon than on Earth. Which of the follow5+a)s y o(sciix *vkuu dn07o:ing is true about the mass and weight of an astronaut on the Moon's surface, compared to Earth?

  An example of a force q0n(z0l 3 f6 kqstj)tk1pp:lawhich acts at a distance is

  Who has a greater weighnkt6 mmyy7jv 7 ;t7gcq;u/h ;qt to mass ratio, a person weighing 400 N or a person weighing 600 N?kqqy/c ;j;7hg7n7y mt;mv t6u

  A stone is thrown straight up. zxk.0- l4e ocu At the top of its path, the net force acting on ik-l4e0c x zo.ut is

  A 20-N weight and a 5.0-N weight are dropped simultaneously blyb3wh q( gm16*td q8from the same height. Ignore air resistance. Compare their accelera 8bhtg1(*6 yqd 3qmwlbtions.

  A brick and a feather fall to the earm whmz+66hin o 4q-s9nth at their respective terminal velocities. Which object experiences tzn 6io 9hws6 m-mn+h4qhe greater force of air friction?

  An object of mass m is hanging by a string .g14wu7/ek ekgi/ j6 08l)gztdbn nyb from the ceiling of an elevator. The l8kgky/14geej u wd /)n.6z bit70 nbgelevator is moving up at constant speed. What is the tension in the string?

  An object of mass m is hanging by a string from the ceiling of an elevavj(g u ds.7dm fgwy)+1tor. The elevator is moving upwa1fm d(gu gsvw.jd7y +)rd, but slowing down. What is the tension in the string?

  The force that keeps you from s.r mce6a/q 6+i ddqei kb+38 cmt.w,ealiding on an icy sidewalk is

  It's more difficult to s l kso4py4pmia;2x gc;s 4h79otart moving a heavy carton from rest than it is to keep pushing it with constant ; ;ismph 4a279os4k4pl yxcgovelocity, because

  A horizontal force accelerates a box from ret;si8cot2k0xo;es 7 kmu0 *cqst across a horizontal surface (friction is present) at a constansct 7 *texo; uioq c2k00k;ms8t 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 slider:ayt r9. mm3ps down an inclined ramp at constant velocity. Thus we can deducep a3y.mr:9 rmt that

  A block of mass M slides down,gt gfqic5l p1 b6.xj8 a frictionless plane inclined at an angle q with the horizontal. The normal reaction force exerted by,. g tg8j c6bipxf5ql1 the plane on the block is

  A block of mass M slides down a frictionless plane inclined )r 7bxsz: k6l9ke-vzmat an angle q with the horizontal. The normal reaction force :r k9)kex6v s7z-bzlm exerted by the plane on the block is directed

  A block of mass M slides down a frictionpi5li-gjh5 wg4(ojw0 7o 7qceless plane inclined at an angle q with the horizontal. The gravitational fo-5iwjg 7 7e lqg(i5o4jo 0hwpcrce is directed

  Two toy cars (16 kg and 2.0 kg)zi u(7 nhl8.f22xaoe s are released simultaneously on an inclined plane that makes an angle of 30e with the horizontal. Make a statement which best describz uh fos2i2.le8(xa 7nes their acceleration after being released.

  An object sits on a fricti*pm qxxyrrz/90(,ac3j 9lykwonless surface. A 16-N force is applied to the object, and it accelerates at*xx(9/ py0rqmackw yjl 9z, 3r $2.0 \; m/s^2$. 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.4 nkl 74yk1b )bcv0ev/kue5er What is the averaukyv0b ceee71)/b4rlv kn45 kge forward force on the car?

  Starting from rest, a 4.0-kg body rvbc0.kgi q / pjiaa43s8 )7bkxeaches a speed of 8.0 m/s in 2.0 s. What is the net force acting on the bodyiqkvc/.i xp3ak7) 4jsa g0 8bb?

  An antitank weapon fires a 3.00-kg rocket which acquireni1x 6c-mra9 zbbu(j(n*zb ( s 2nr3wes a speed of 50.0 m/s aft 2x (s*be6 i(ub1 jn(nar93nbzcwm-zrer 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 fodzi mow3mzz, /i:,qk0hz 9j1vrce that you push a 10-kg mass from restm3,9,zkiz0 hzzqom1/di w : jv,

  What is the mass of a person wlkuu*h rlj t8v*h( li-lj5*:rho weighs 110 lb?

  What is the mass of an object that weighs 250 N on the surfac++ pt jbp)d /:9ndmnoqe of the Earth where the acceleration due to gr: oj nq m++pdt)p/bnd9avity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on thec vt/j,ncz:apwy/ 75 q Earth. What is the mass of the object on the surface of5w yj, pztcv//qanc:7 the Moon where the acceleration 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. Th-o5qsj a2avj4 e Moon's gravity is one sixth of Earth's. Compare the masses ofa4 v-os 5ajq2j the objects.

  Sue and Sean are having a tug-of-war by pulling on opposite ends of a 5.0-kg /z5a 8ij5/ s70btbg v7varlemdf:.q rrope. Sulm7/ .:7z 8t5rda /g5bjvviq0f aerbs e pulls with a 15-N force. What is Sean's force if the rope accelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books rests on a level.5hh *9ygpl u b-/fxtz frictionless surface. A force F acts on the sxtz f gb*.huhp-/5ly9tack, 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 scalti7k4j.j3e1.-z 0 lzc2vsfrbss z c1 xe in an elevator. What will the scale be reading when the elevator isicszs.. vxj bc11 rs7t-2z0ze4k3ljf accelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the mass of the person is 6g6rygii7 n 0biq-m8c(y9/ c ys-8odyv0.0 kg and tii g q7i8y (8vdccs9yyn/6rb --ymg0ohe elevator 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.w 1wxls7w31ix izmt2 .0 kg and the elevator accelerates upward with an acceler2iz3mw 1sx7 li1.xwwt ation of $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal forces act on a 5.0-kg 5* r*twnaxd*5 1 vtyv h7h+bypmass. One force has a magnitude of 8.0 N and is directed due north. The second force toward the east has a mag avy7*p5ywh r *xtvd15 nh*t+bnitude of 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 place ef-a x7y 18ujesvdy6/yvi (qe7+x0zuby metal b j+uys qa7fe (ey-evxu 178xdv0 6iz/yrackets 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 forward into the cab?

  An object of mass 6000 kg rests on the f;vq.f6; z akhylatbed of a truck. It is held in place by metal brackets that can exert a maximum horizontal force of 9000 N. When the truck zyfa.;v 6qh;k 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 /k3)u /v:+v wm 7ssj uerej+ypin Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the magnitude of the acceleration of the +/ y7um 3u:)k/vv wj+esepsjrsystem? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4sf7r7 al9pmd5bp d,zaqj2 stm, w(w5,-1, if M = 0.60 kg and m = 0.40 kg, what is the tension in5zbat7r wm9al qpsd,dj(s,7 ,mwf52p the string? (Ignore friction and the mass of the pulley.)

  A student pulls a box of books on a smooth horizontal floor wj, ea5fkx a zoty328z:ith a force of 100 N in a direo e53fa28yazz txk:j,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 bookkykyc0ag9 r1x r*kk36 s on a smooth horizontal floor with a force of 100 N in a direction of 37.0e abov6rky*a1k c3xk9 yk rg0e the horizontal. If the mass 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 b71npz8:n j i lbk6mbw95- )no f/wlbpdy two ropes as shown in Fig. 4-2. What are thew15d jlbz kb: ppnn)on8wf6/l9 b7-im tensions in the ropes?

  In Fig. 4-2, if the tensionsaq +.p(+leeu gmir53aartl( vl1h/.e in the ropes are 50 N, what is the mass of the traffilt m3i l 5r(/1.agvh uea+le(pa e+rq.c light?

  Two boxes of masses m and 2m are in contact with each other on a frictioau9yqh(i8 .hc 7vd 3onnless surface. (See Fig. 4-3.) What is the acceleration of the morincv(9ayhd .7u3q8h oe massive box?

  Two boxes of masses m and 2m /;nnlxshr7;lzai (5w ,b+o tvbp6bh)are in contact with each other on a frictionless surface. (See Fig. 4-3.) What is the net force on the more massive bb; +7a/wz;bn5 hl( txspnh i,o 6vbl)rox?

  Two boxes of masses m and 2m are connectedobrl1(8f r)vb by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the tension in the connectin)8(lr o 1fbbvrg rope?

  Two boxes of masses m and 2m are connected by a rop hgc7t+scmii4 k v-gg81fm(o.e. (See Fig. 4-4.) If the forward force on the more massive box is F, whagmc-(is vmc1o8th7f+k 4ggi .t is the acceleration of the less massive box?

Two boxes are connected by a cord r/-j(,bxeopbasn++d e ;-4y2wb t rzcaunning over a pulley as shown in Fig. 4-5. B b+b j /zdaw-rae+bt-(ns,op4e2cyx;ox I of 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 and a qoqf2+ 82*br1 j dkso*.:s3 q oieo4khnhceb 3desk are 0.40 and 0.30, respectively. What is the net force on the box when a 15 N horizontal force i sh2*kcb 1o2 334reobnje *d8iqoqkh:o+q.s fs applied to the box?

  The coefficients of static and kinetic frictions for plastic on iaje+53hkcrnr - .x8rwood are 0.50 and 0.40,j5rai-3cre xrh .n8k+
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 direction.;-hd9 cfi bhm2h 2mn .zjfw:/n It slows and comes to a stop with a constant acc.jh/nnb-z:fm 2i mf hch;2wd9eleration 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 a 5.0-N force. A 6xwya 0 lw(-uf*mvre; 3.0-N friction force retards the motion. What is the acceleration of the objectul6ewv rxmy*-0 a ;(fw?

  A horizontal force of 5.0 N accelerates a en:/k, h v;nfg4.0-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 given an initial speed of 1z:4 /wpirbyd *jto2e10 m/s. It slides 50 m on the ice before it stops. What is the coefficient of kinetic friction bett1bjoiw 42 r:z*e /dypween the puck and the ice?

  During the investigation of 58kinnbrk b)3rko 5kko*6c3zlt( a a9a 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 conditions. Estimate (lrn8*3oc zk6k 3r5okk5aabb9 i nkt )the speed of the car when the brakes were applied.

  Two boxes of masses m and 3m are stla 2xh.x/r xvx a65tl5acked. (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 friction force xal .6tlvhx 5/5 rx2axon the less massive box?

  Two boxes of masses m and yp6xx2+zr a ,.x2ma oi t9-wtx3m 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 is rough. If the less massive box does not slide on the more massive box, what is the coefficient of sy .ip22 -xo xz9r+atax6txwm ,tatic friction between the boxes?

  An object is on a frictionless inclined pla* , zn+shs3(t(fupsr 8zygcz2z4 gjd5ne. The plane is inclined at an angle ofugs,h4zz358zd(tc2( s jnsy* z+r gp f $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill k*fu wg:k6 2mclo;7pr 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 with an ani3r3 d ,utbsm)b*vb3 igle 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 incline9qoxm;kr.u,g5z clp 4yi2d-yd 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 constant velocity t(im ge3,pp7i74tb+yaee,hoe(qw t : ofq ae ,bi ge(wt7eoe7mh+yi3t,p4( :pt 6.0 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 n1q /8ud u7atk$37^{\circ}$ inclined plane where the coefficient of kinetic friction is 0.20. What is the acceleration of the object?

  An object with a mass m sl;d s3bp/a(xwb6tjurh+ iw.p + ides 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. bb/x8wua9vbx8jk d x4 *l0r. -v 7xgyp upf50l The cable attached to the log makes *x u0fvyxj 5gpxb7w/ -8vbllu8kp.a r9xdb04an 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 incy+e 9:yo1 :knwknb.tws/xl:gx9 t2 nz/:tjit lined plane tilted at an anglewx tz1 nnybk+ 2:9 /ie:g./9 njlkowtt:st:yx 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. The angleb-tq p84;prc h of incline is gradually increased until the object begins to slide. The angle at which this occurs is q. What is the coefficient of static friction between the object an8-phc b4;rptq d the plane?