Which of Newton's laws best explains w70 +u 7nssobf9(fjvmzhy motorists should buckle-up?

  When you sit on a chair, the ns:tabk 0v:xy6z2 p7w resultant force on you is

  In the absence of an qac 6yo*z sav.e4ps 9r*dp-5 )ez)wovexternal force, a moving object will

  When the rocket engines on the starship NO-PAIN-NO-p cq,-x8lyl)cco d2d :0 nnr0mGAIN are suddenly turned off, while traveling in empty s0,npc dn m-)qoc 0l:clyx8d 2rpace, the starship will

  A rocket moves through empty space in a straight line w:jpl mi ru)j89,u6r ahith constant speed. It is far from t6uil,a pr8h )mujr9j :he gravitational 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 movin4q:hphd pl0a6g bus, facing forward, and you suddenly fall forward.pd hhla60q p4: You can imply from this that the bus's

  You are standing in a moving bus, fac/aisaybz *7xu6:t-bt m)vk;ying forward, and you suddenly fall forward as the bus comes to an immediate stop. What force caused you to fall m6yzbk:u-v 7 st)y/aixtb *a ;forward?

  A constant net force acts on an object. Describe d( h-y 939zy n1aancnkthe motion of the object.

  The acceleration of antq/60d s( 5ig uwl2ysr object is inversely proportional to

  A net force F accelerates a mass m with an acceleration a. If the smq ja0ayjn;or-o jm5jr2 / 26aame net force is applied to mass 2m, then the ar-j6m a ajj ;oy250/an rqo2jmcceleration will be

  A net force F acts on a mass m and produces an acceleration a. What acceubstyzgzly6lh 4(c*8n6:q ng1 :h4 l eleration results if a net force 2F acts on mass uzh4(geq 6*: nt1ybsnl:gz8c yhl 46l4m?

  If you blow up a balloon, b(hmc5jf (13n)ywyw y2gy r-sand then release it, the balloon will fly away. This is an illustration ofn (2rw3gh y 1yyy cmj)-bsf(5w

  Two cars collide head-on. At every moment during the collitr23z4 ,5h6t n kphawksion, the magnitude of the force the first car exerts on the second is exactly equal to the magnitude of the h6,nrk3tp24h5ka tzw 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 ex802ajck1mbuk 2ach o 7erts on you wi20koc8 c12ama7khubj ll

  Action-reaction forcc 74hrsj 7kf2qes

  Action-reaction forc7jvru* p 2fdc-es are

  A 20-ton truck collides with a 1500-lb car ma*ibp0cf 7cxr;g / u1and causes a lot of damage to the car. Since a lot of damage is done on the capub*;crac1f g70x /imr

  An object of mass m sits on a flat table. The Earth pulls on2axip -al d2j4 this object with force mg, which we will call txpjial 42a 2-dhe action force. What is the reaction force?

  A child's toy is suspended from the ceiling by means of a string. Thbbltl-m:ld5; af;b :r e Earth pulls downwardlf rt;b lbmd:;:a5-bl 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 pitched to y7- jw i+4d4is mvvqo,iou with a 1500-N instantaneous force. The ball hits the bat with ani sd i-47vo4+ wjv,miq instantaneous force, whose magnitude is

State Newton's three laws)-agzt2jyujws al-* 1 ykbh22.

  Mass and weight

  The acceleration due to gravity is lower on the Moon than on Earth. k v4.6vf ds(koWhich of the following is true about the mass and weight of an astronaut on the Moon's surface, compared f(o.6k4dsv vk to Earth?

  An example of a force which acts at a distan)5ovwv1l pzisll 6f7cae b8)*ce is

  Who has a greater weight to mass ratio, a person weighing 400 N or a 08skbkhc3)sv person weighinh 3k bs8c0ks)vg 600 N?

  A stone is thrown straight up. At thepw:/:9g p6,vt cni7xbegrc6e top of its path, the net force acting on itt6gn69ebci xr, p7p:/:gc evw is

  A 20-N weight and a 5.0-N weight are dropped simultaneously from the same he hu: dts6de68eight. Ignore air reedts :6e8u6dhsistance. Compare their accelerations.

  A brick and a feather fall to the earth at tc9dkg7 0. (, sbwozwycheir respective terminal velocities. Which object experiences the greater force of air frc.b9g7c (d,k 0wwsoyz iction?

  An object of mass m is hanging by a string from the ceilin2 on)xg4rmnw* z)ty+*h b xok /(7gtgpbne7 q/g of an elevator. The elevator is moving up at constant speed. What is the tension in h (*7 g)o+tgnobnbge*7/tnzqy/wx2 ) 4 kmprxthe string?

  An object of mass m is hanging by a stri*87md ca)rye w k,,gdwng from the ceiling of an elevator. The elevator is moving upward, but slowing down. y,g 7edmawdk,cr) *w8 What is the tension in the string?

  The force that keeps you from sliding on an ; 4;8jrazq78n bf kp+skcyw 1uicy sidewalk is

  It's more difficult to start moving a heavy carton from rest than qzr ca:*: x+iza2z8 agit is to keep pushing it with consta82ixzzazaqa: r *:+ gcnt velocity, because

  A horizontal force accelerates a box from rest :p *d2 r nbefsn+pjgw +6i+r6xacross a horizontal surface (friction is present) at a constant rate. The experr+p2*6gn +dfipjx b6:esn w+riment 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 at consta8d5ed,zd v:fy:zxbj04sruf2 nt velocity. Thus we can de:x 5evrb4d:jy ,80dz sd u2zffduce that

  A block of mass M slides pa9e7*uz1so0yip q/r down a frictionless plane inclined at an angle q with the horizontal. The normal reaction fo y*paor/9qi ze01s7purce exerted by the plane on the block is

  A block of mass M slides downdw9,t0p95mvm do (vv9hyka )j a frictionless plane inclined at an angle q with the horizontal. The normal reaction force exerted by the plane on the block 5tav(v9j,mykodh )dp0 99 mvw is directed

  A block of mass M slides down a frictionless pzy s2btxd0l dv.z-qv7. vd u62lane inclined at an angle q with the horizontal. The gravitatix2t72yubd0.v ldvd svq 6 -zz.onal force is directed

  Two toy cars (16 kg and 2.0 kg) are released simultaneously on an inclined plane:d8 fmaz2ad dej 8lp31 that makes an angle of 30e witmae1 a38:ddd8j2 f lzph the horizontal. Make a statement which best describes their acceleration after being released.

  An object sits on a frictionless surfaczuh 0-1z excaagk,z:5nr lp t5/ 8tvv2e. A 16-N force is applied to the object, and it acue z/a-8a0gz ,hkxnv 5r5 tt1c:vz2plcelerates at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accelerax;j8v 44ryre rw h-2u/.ar uolte from rest to 27 m/s in 7.0 s. What is the average forward forcer4r./a -yol4;hwj8e vrx2u ur on the car?

  Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s in 2.0 sfg. r6cr 0rm2;xxsl0s o-iw:k. What is the net force actingl.mwxigs-0sc :fxr;0r ro26 k on the body?

  An antitank weapon fires a 35btka5b;yh w 3.00-kg rocket which acquires a speed of 50.0 m/s after travelin;b535bk yhaw tg
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 fro: .j8f2z0soh ( cigpjqm rest,i z.s (c2g0:jpjhof8q

  What is the mass of a pve xsq z.v mfw7m2u1)ztj.0 v,erson who weighs 110 lb?

  What is the mass of an object that weighs 250 N on the surface of the Earth wsns9q cbs2y*+ow qg+ 2here the acceleration due to grw s9oqq2+g*by s sc2n+avity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the E - bui.kh 5rcxog,c3nsi 7rf)7arth. What is the mass of the object on the surface of the Moon where the acceleration due to gravity is only 1/6 ohgs)7fri5 rui3kc,n.7-x cbof that on the Earth?

  Object A weighs 40 N on Earth, and object B weigho-h rm90nyit9 s 40 N on the Moon. The Moon's gravity is one sixth of Earth's. Compare the masses of the objects.tir9hny9m0 o-

  Sue and Sean are having a tug-of-war by pulling on opposite ends;mj(fhd+e1l *o q v3ku of a 5.0-kg rope. Sue pulls with a 15-N force. What is Sean's force if the rope accelerates toward Sqe d hmu+j 1o;v*k3f(lue at $2.0 \; m/s^2$?

  A stack of books rests on a level frictionless surface. A force F ak etc 9fmpkf(m 0m,47j -6rkkkcts on the stack, andt0,9-4k e mcfkkrj6mkm(7 pkf 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.y wshow 1n6v/5n v0du stands on a scale in an elevator. What will the scale be ren.ow5v/6dv nw1usyh 0ading when the elevator is accelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the mass of the-:exm380 *pxief0/p1e2mn lgx keh dj person is 60.0 kg and the elevator accelerates downward with an am0pl d8exmg1x x p 2/jn0ik* e:3eehf-cceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale rides in an ele1(i nissy07g5-xn v wwvator. If the mass of the person is 60.0 kg and the elevator accelerates upward wixv5gni0w sw-y1 7i(nsth 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 p-mzwfvut3 1c05qg4zmz.wj ov/py**a magnitude of 8.0 N and is directed due north. The second force toward the east has a magnitude oq3/uz -0mpog5mtc *f yw1v *4.pv wzjzf 6.0 N. What is the acceleration of the mass?

  An object of mass 6000 kg rests on t;axiilirn6wr;v qk4t (d*z 8: he flatbed of a truck. It is held in place by metal brackets that can exert a maximum horizont4lv ;inrak8iq6i* ;rz dw(xt:al 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 ph *hxi worv+7t1y 1g5kg 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 oi17*hhyg v+xp wr51t, what is the minimum stopping 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 l2 yz.8yu1h zg;t4 ybhz+la4i.40 kg, what is the magnitude of the acceleration of the system? (Ignore +y8 ;1 zuz42tizl4yl yg.hhabfriction and the mass of the pulley.)

  In the Atwood machine sho ;) zmx ab/04r,o rqo7cj(yogtwn in Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the tension in qoj;mta c o/o0rg zy4(r,)b7x the string? (Ignore friction and the mass of the pulley.)

  A student pulls a box of books o:cyyth dl40g5 n a smooth horizontal floor with a force of 100 N in a direction ofcty4:yd gh 5l0 $37^{\circ}$ 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 x 5azq ua-d.b:smooth horizontal floor with a force of 100 N in a direction of 37.0e above the horizontal. If the mass of the b.5au d:-ab zxqox and the books is 40.0 kg, what is the normal force on the box?

  A traffic light of weight 1z+b pj2-9gegy vzn oh6 c 2j,.neg40tr00 N is supported by two ropes as shown in Fig. 4-2. What aret2,nj+4gr62ny.coz b-p9vgzg 0e j he the tensions in the ropes?

  In Fig. 4-2, if the tensions in the ropesv 5vl xnhtoy+01j(llad 5-sf ; are 50 N, what is the mass of the traffic liy ln(d5h5voa;j-f+1v 0 xsl tlght?

  Two boxes of masses m and 2m are in contact wi88mckr;sp:mbqaz;a-dbo : q) k ,p4nwth each other on a frictionless surface. (See Fig. 4-3.) What is the acceleration of t r ;do-)zq4:kqw;k8pna8b ,acbp: mmshe more massive box?

  Two boxes of masses m and 2m are in contact with each other on a fricticirofol ;l+7rpl0 -3o2e* qgv onless surface. (See Fig. 4-3.) What is the neti7pro-f0 2 clvl er q*+go3ol; force on the more massive box?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4-4.) If ao64mvq9txm o,6q 3u+:sqk lfthe forward foxvkl6:6qt aq4fu9mo,3qm o +s rce on the more massive box is F, what is the tension in the connecting rope?

  Two boxes of masses m and 2m are connected by ad l3 ohc)t:/3qhrv jg2 rope. (See Fig. 4-4.) If the forward force on the more 3lrd2 vq:thcoh3j)/ g massive box is F, what is the acceleration of the less massive box?

Two boxes are connected by a cord r;musyxnokc a78 tq656- hp j*tunning over a pulley as shown in Fig. 4-5. Bo6u7np 8yxjc6-; 5katqso m* thx 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 )j1sf it6lo8h zj4xv ws3u4u-desk are 0.40 and 0.30, respectively. Wha )zj 4sjuvx u38otsfi14wl h-6t is the net force on the box when a 15 N horizontal force is applied to the box?

  The coefficients of static and kinet8n i3qh2.x xggeg7v ,mic frictions for plastic on wood are 0.50 and 0.mi28,7 qx3g vxh.ng ge40,
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 slows8)r raxk 0.+,gw /sx,ykbrumv and comes to a stop with a constant acceleratrr.k /srguaw,,mxb80 )kxv +yion 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.dkozp6u cf6cw o+e zf41: ,yadk+ 9if+0-N force. A 3.0-N friction force retards the motion. Whdkf9d p+:46ykwao 6cf1cz+z ,u i o+feat is the acceleration of the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg mass, from rest, at a rate drmo2x29l d.iof $0.50 \; m/s^2$ in the positive direction. What friction force acts on the mass?

  During a hockey game, a puck is given an initial speedl68)wmcgw 5kvf9 2dr5u-ttva of 10 m/s. It slides 50 m on the ice beforelm26t5-rdwf5uw9 tv v)8k gc a it stops. What is the coefficient of kinetic friction between the puck and the ice?

  During the investigationyp(tge 6+7nzt gvla8; 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 prevap7 y8z(g 6ttvge+al;niling conditions. Estimate the speed of the car when the brakes were applied.

  Two boxes of masses m and 3m are stacked. (See Fig. 4- );q 8bxvgk0shx7.7h r f92 whpo/7mcjk)ceit6.) 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, w.hq2xjbh9rec ckos)8px7mfhw)7 0i /k 7tvg ;hat 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 betw.d,hso24ixg9jk ; g1r op 8ccdeen g2. oc,;18cj4xr9hg kid dspothe 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 friction between the boxes?

  An object is on a frictionless inclined plane. Thov pksb.m,24( p.krr)me hfcd:m. sb6 e plane is inclined at an angle ofksbr.pd2f h,:e()bo6. pm4kc .rvm m s $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that makes m6z *3c7jsotzbri(0q 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 .q3yd xe/ rttd qe5c(3b0w0 fra smooth inclined plane 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 inclined plane t:r aq 6;qrt,0g t:phrpilted 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, :fd;j:zs: 7x+k1qxfvvfl*g k at a constant velocity of 6.0kzv:;+:vsfgd *qxkx l7jff1: 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 sa0oii+36:d r xbl otu4lides 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 slides dm )t93 5k: 6j0egzzn 8-swavvsk sc1ccown 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 atn +o45iajg bpis ;(ss.o(e5hytached to ti boha4os;g jy+ens.55s(i(p he log 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 frog;gfio* +cjkumcv 5 11m rest on a rough inclined plane tilted at an angle 15ugic1+k om*g; fcjv 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 any qkqbiyl3 ,3 6d/3bsigle of incline is gradually increased until the object begins to sl 63q,3yikd3y/si bb lqide. The angle at which this occurs is q. What is the coefficient of static friction between the object and the plane?