Which of Newton's laws be)cvo;m 2w cn3fst explains why motorists should buckle-up?

  When you sit on a chair, the resultant force jy-uy0p4kt9j on you is

  In the absence of an externa(zl- ;aq iuds1 )lkg1el force, a moving object will

  When the rocket engines on the starship NO-PAIN-NO-GAb llopje7s33mf),c ; pIN are suddenly turned off, while traveling in empty space, the starship wil)psbl,7 cj;pofem 3 3ll

  A rocket moves through empty space in a stra f .,vthtscnc;*2 yd c)ao7lv9ight line with constant speed. It is far from the gravitational effect of any star or planet. Under these conditions, the force that must be appli2ltf;)d, .anvtv9 *yo c7 hscced to the rocket in order to sustain its motion is

  You are standing in a mov88sr rocm8 -pping bus, facing forward, and you suddenly fall forward. You can imply fro88-p rmr c8posm this that the bus's

  You are standing in a moving bus, facing forward, and you suddenly 9zzd1)h:fj sshq72ey fall forward as th:h9z fsj eq72s1) zydhe bus comes to an immediate stop. What force caused you to fall forward?

  A constant net force acts on an object. Describe the motion onk73(1vfm txpbc qql ch .8.8wf the object.

  The acceleration of an object isj a.).w qgi.pi inversely proportional to

  A net force F accelerates a mass m with an acceleration a. If the same ner68tay7o4 lknbpxn,a.c5xb*u y l4p(1n f tg5 t force is applied to massp5lupnkn415 tf by y7 .a xxla(6*g4bconr8,t 2m, then the acceleration will be

  A net force F acts on a mass m and produces an acceleratitn0yx-v gl 3h7on a. What acceleration results 3tnvxyh7-0lg if a net force 2F acts on mass 4m?

  If you blow up a balloon, and then releaqv8om k fz+ o.aep6lf+)j 8wosh6e 871wntz,b se it, the balloon will fly away. This is an illu8sf7e6onb kzf+w)q mhe , pjl zw+881to ao6v.stration of

  Two cars collide head-on. At every moment during the collision, the magnitu86 3yyfa(iv hn zzqucjrhvi7k92;1n; de of the force the first car exerts on the second is exactly equal toyk z(fycvar;6zjiu i92 q3h 81n n7h;v 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 iw ,)ec:djg0dik bkx.7,t()z 3tld e7spo9lxwhich the object exerts on you wildll ,dkxcij )z0e.)w,3ge 7 7o(9d: bst xtikpl

  Action-reaction forcesz ho t8 i 4dlv( d3jld:-vfoezolj:*,7

  Action-reaction force.bih3i237 6soiai afg s are

  A 20-ton truck collinl29rs:9lv. o5 1w thuinzv 6wdes with a 1500-lb car and causes a lot of damage to the car. Si rtv19:i wovnhl6nz. 9usw 5l2nce a lot of damage is done on the car

  An object of mass m sits on a flat table.l. n1aktqzj2w75n8 xar r a vss7lb:c0 k9:l:g The Earth pulls on this object with force mg, which we will call the action force. What is the:g7cq5 8 kvl0 t9:z.an2xr71wa:jnlba srkl s reaction force?

  A child's toy is suspended from the ceiling by mean2,na/v*up aw ldu)5rq s of a string. The Earth pulls downward on the toy with its 5 q 2au ndl*,vrpwa)/uweight 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 su.eb7:(vfv-, q nsgrinstantaneous force. The ball hits the br gq-nsebsu 7vv (:f.,at with an instantaneous force, whose magnitude is

State Newton's three lawog(yb)d 4r srvc5e)3nj*w/z ks.

  Mass and weight

  The acceleration due to gravity is lower on the Moon than on Ear5wmppw:kxe -.th. Which of the folle-wpw5: kx.mpowing is true about the mass and weight of an astronaut on the Moon's surface, compared to Earth?

  An example of a force which esg rw 7jh.*9c(ap -cma5ag.xacts at a distance is

  Who has a greater weight to mass ratio, a person weighing 400 N or cnkuj3pf 7xr;e(*ta oy2v. 2oe,a6m+fhq w/ oa person weighing +ar2(6ouop7ntwhfeec*fqakyo v2,x3 ;jm/.600 N?

  A stone is thrown straight up. At the top of its path, tn:sg 4pi .o zqlg4l.:cftm9p 3he net force acting on i m4 .po4lg:3nglzp9ist:qf. ct is

  A 20-N weight and a 5.0-N weight are dropped sia o s-s7v .: x3d8dnhwdi;m)pqmultaneously from the same height. Ignor)73 q8nxs pmh a.dvi-wsd;od :e air resistance. Compare their accelerations.

  A brick and a feather fall 3dz 7anro*ad)cykd 21o q 05jato the earth at their respective terminal velocities. Which object experiences the greater force of air frictio3)1z dadqonkr aocd270a5j y* n?

  An object of mass m is hcn; apkq8w77 hanging by a string from the ceiling of an elevator. The elevator is moving up at constant speed. Wha ap7hkw7n;qc8 t is the tension in the string?

  An object of mass m is hanging by a string fow9og0vz+s i2 rom the ceiling of an elevator. The elevator is moving upward, but slowing down. Whai 92ov +gzwos0t is the tension in the string?

  The force that keeps you frvo vpo+svut iq5ol9:22+o(jhom sliding on an icy sidewalk is

  It's more difficult to start moving a heavy cdlu8 oekeg3,;n n:8 gp)wjd0p-phr+zarton from rest than it is to keep pushing it with constant ve;j -0 8ukgdpd gpwon)rz+p8:,eh ln 3elocity, because

  A horizontal force accelerates a box fru/t6 a dechih8or p,v/c 9r.g9om rest across a horizontal surface (friction is present) at a constant rate. The experiment is repeated, and all conditions remain the same with the except/ uc pe9hvco6g9r h,a it.rd/8ion that the horizontal force is doubled. What happens to the box's acceleration?

  A packing crate slides down an incli+ b,h v46mvh otj.6plxned ramp at constant velocity. Thus we can deduce x vot+vp46bj ,6m hhl.that

  A block of mass M slides down a fricqvhoetc1 ea 0h+8 zw7*tionless plane inclined at an angle q with the horizontal. The normal reaction force exerted by the plane on the 1qh 70vhazece tw*+ o8block is

  A block of mass M slides down a frictionless plane incliny69nj 7h.edlw2y.y-5ahkp jk4qa) v t ed at an angle q with the hqj-pv)k6tea94j.w 7.y5 kh nhal y2ydorizontal. The normal reaction force exerted by the plane on the block is directed

  A block of mass M slides down a frictionless plaw 5ealuehr +r8g)v :3xne inclined at an angle q with the horizontarh:uw rexe 5lv)+8g3al. The gravitational force is directed

  Two toy cars (16 kg and 2.0 kg) are released simultaneously on an incl4yh:b dwh i ghzh.q-62ined plane that makes an angle of 3hzhwh24 6i-byd :h q.g0e with the horizontal. Make a statement which best describes their acceleration after being released.

  An object sits on a frw +mv d*/rw4pbo.x.i m ddz,, y2chf.kictionless surface. A 16-N force is applied to the object, rh vmpi yb+/cx.k,.fwdd,.2z4m*wo d and it accelerates 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. cgb l4s+bks+87og rm v g**1kl0pbu7t What is thu g brcsk70b4p s*g+lv b g*t8koml7+1e average forward force on the car?

  Starting from rest, a 4.0-kg body rea f0t1w4e (kb xzgosv1h;/er;yches a speed of 8.0 m/s in 2.0 s. What is the net force acting on thezx(w41ovg;;s0 kefe1y htr/b body?

  An antitank weapon fires a 3.00-kg rocket which acquires a sp. ptl. - t6ie c-zgts6dia4vaeyd 3p/+f4p fa5eed of 50.0 m/s after travelitlsa 5 p e yiadze.4 ippd 6tvt.4+6f/agcf-3-ng
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-kg mass from re+c 95 yrp8 jqpkgbfw.n 0v*m0sst* gfky08jp mwv9 qn.+5cbr0ps,

  What is the mass of a person who weighs 110o8*qgptxot 4 y2bujr( xm01g* lb?

  What is the mass of an object pctqevk0qh ,)v-v2e3zrw:.jthat weighs 250 N on the surface of the Earth where the acceleration due tz,evjq.wh 2v r 3ect0kqp- v:)o gravity is $9.80 \; m/s^2$?

  An object has a mass ofadq qsns(9v-br0 l 53m 60 kg on the Earth. What is the mass of the object on the surface of the Moon where the acceleration due to gravity is only 1/6 of that on the Earth?qs9 ra35 mdsbl(nq0-v

  Object A weighs 40 N on Earth, and object B weigh j 98x3w1 /r*7g+ekgyf eaywyvs 40 N on the Moon. The Moon's gravity is one sixth of Earth's. Compare1vy8gejyg 9x3w/7eywf+a* kr the masses of the objects.

  Sue and Sean are having a tug-of-war by pulling on opposite5z(d,mitkd l rtn+:lc vk o3:c+ tr1(v ends of a 5.0-kg rope. Sue pulls with a 15-N force. What is Sek,nm (1itt :tc3++lr clv (dvzd r:o5kan's force if the rope accelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books rests on a level frictionless surface. A force F acts o.gpf u76dp4qn0z kz/bn the stack, and it4gn f0dbpqz.p 7z6k/u 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 scal4sw;7/lsm0fdjzbt zz z,-ir (e be reading when the elevator is accelerating d4z/t0;(-z bzw7z,m ifj slrd sownward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the mass of the person is z. ,*lmn 5sgi2nmiz3 znf4b7p 60.0 kg and the elevator accelerates down 2nniz5.,g7mbipzlmfsz * n 43ward with an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale rides in ag0-w1a ice*o zcug x8vg,11tzn elevator. If the mass of the person is 60.0 kg zzie1vato*-cug 80 ggw,1cx1 and the elevator accelerates upward with an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal forces act on awd mjty1 at : xsl9ie/.e:.h(p 5.0-kg 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 acceleratdie .e:at(sjmx. 1hylp/:9wtion of the mass?

  An object of mass 60bl 0y2k4j q( c5niqk6tf*ul efdb7a3 300 kg rests on the flatbed of a truck. It is held in place by metal brackets that can exert a maximum 2n30 eat f6lbi(kl dy7 k45 jcb3quf*qhorizontal 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 truck. It is held in e,0z) l5rw-xf7 2 b 2cmzf9onpzn.ugvplace 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 the5x ,e 9.rwo-f02vfz cln7 2nbpzguz)m 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 kgh a2rwal(dkjm+9 qwj06 zv((x , what is the magnitude of thw20dlr9h(awqz j 6 vkj (ma+(xe acceleration of the system? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1, i5 t/c7 hlitt+ c)j6ehaf M = 0.60 kg and m = 0.40 kg, what is the tension in the string? (Ignore fr /+hh7ce6 tatj5ci) tliction and the mass of the pulley.)

  A student pulls a box of books on a smooth horizontal floor with a force of 10hvkv0(1mf ) jlw d(u;c0 N in a did0(vv uh;(1mfjwk) c lrection 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 horizontr bwq/3wh.i .5wcp* fwal floor with a force of 100 N in a direction of 37.0e above the horizontal. If the mass of the box andh35wwc.w.p*rbw q/fi 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. 4-jr ,jt; g/x(pr2. What are the tensiotr p/;jrxg( j,ns in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is the mass of thejjram6kc slw 238bv9q;x- du 7 traffic li2 l b8d m;7jwxqjsa 6uc9-kv3rght?

  Two boxes of masses m and 2m are in contacf mab.m5n( khfk)fc r2)p)u)q t with each other on a frictionless surface. (See Fig. 4-3.) What is tkmn) f(f u) a5hbpr q2f)c).mkhe acceleration of the more massive box?

  Two boxes of masses m and 2m are in contact w (uodrztj 73o1ith each other on a frictionless surface. (See Fig. 4-3.) What ijtz7u1o3d(o r s the net force on the more massive box?

  Two boxes of masses m an/3jr qo7 xubh8d 2m are connected by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the tensiono xjuqb7 /38hr in the connecting rope?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4-4.) If toy m/;0: nd,ziw7w n9hr xktda5an09 mhe forward force on the more massive box is F, what is the aoa w,0nn9 0; tz/7i mrman9w:5 ydhkdxcceleration of the less massive box?

Two boxes are connecteq6 czv0 yb1cm:wc8xcde k b1+:d by a cord running over a pulley as shown in Fig. 4-5. Box :mb1 e0wk1cdczcv:+ bqxc 86y 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 af mfrcr(*bx55p k5q6a desk are 0.40 and 0.30, respectively. Wxr55 b(mr*p 6fkc5aqfhat is the net force on the box when a 15 N horizontal force is applied to the box?

  The coefficients of static and kinetic fj+9 *olvk /wned9(umzrictions for plastic on wood are 0.50 and 0.4e dwukoj*mv (+zn99/ l0,
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. It sl 7evo*yx)1ecojf) g 6xows and comes to a stop with a constant acc x6gf1c)oeoj*7eyv x )eleration 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 5yhjq* 6:z7yee9mg:iyc 3s9knjvk n 36 .0-N force. A 3.0-N friction force retards th6 k n7jscky* iv3ynzye69j 9m:e:g q3he motion. What is the acceleration of the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg mass, from res snanf;+1uo4lrsr1rd. 9.n f bt, 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. n66bko1- nq2gjmvi -pIt slides 50 m on the ice before it stops. What is the coe n j2io16-p-6 bnqmvgkfficient of kinetic friction between the puck and the ice?

  During the investigation of a traffic accident, police find skon3 pz/ gj2fq qcu76cg6hy: .jid marks 90.0 m long. They determine the cogjo:6z/u cyqp67 j q2fgnc3h .efficient 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 brakes were applied.

  Two boxes of masses m and 3m are stacked. (See Fig. 4-6.) The surfa v xk0(.xe-azvce 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 on the less maaev .kv(zx-x0ssive box?

  Two boxes of masses m and 3m are stacked. (See Fig.sots-xt9/i jkvc*7f 2 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 tiovt7kf-j 2*s s/9ctxhe more massive box, what is the coefficient of static friction between the boxes?

  An object is on a frictionless inclined plane. qppl/s trp+r.ik08 l)e4yh,pThe plane is inclined at an angle .ie8tk0 )ls4pq+,/pyrprplh of $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that makes an angle jxebnn659 0p mof $10^{\circ}$ 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 angle o z;eyza9m c*r ys1 e8:iz)2yhsf $37^{\circ}$ 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 smoot5kdc;p)iw9/ fnzhpk5bj(vp8+ x b4 glh 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 6jg t9ntfxz. kq54s8e inclined plane, at a constant velocity of 6.0 m6s8kqntg4ztxj5 .9ef /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 s6ue.h) mq3 pyma;. lunlides 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 m slideem, 3q0 vm(oqus 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. Th6 i/r0657 gmacnunocvz6s did *ba)j6 6bit q8e cable attached to the log mak qnrvi667ot b6dn8z65i6jiu/dmcaab* g 0s)c es 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 rele9s-q/p)g:thena kzf1ased from rest on a rough inclined plane tilted at an angle e hts-g1kapq9z / )f:nof $33.5^{\circ}$ 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 s;51ogk.i dxeg61 ms hplane. The angle 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 .;16hkodg xm ses15 gifriction between the object and the plane?