Which of Newton's laws best explains why,syf p,(pj bu.je6fg: msg mc2)3e6ybart/y ( motorists should buckle-up?

  When you sit on a chair, the resultant force on youblj dinjseu*(v113. p is

  In the absence of an exte,nhv *p3dpnv l .v9s.o xa3b9lrnal force, a moving object will

  When the rocket enginengwkvy79/q p6d, q:yyh2 jc9 ks on the starship NO-PAIN-NO-GAIN are suddenly turned off, while traveling in empty spa 9gd6/7:h,yj9y2pncqkq kv wy ce, the starship will

  A rocket moves through empty space in a straight line with cocmv t y86ck;k2* ul)cvnstant speed. It is far from the gravitational effect of any star or planet. Under these conditions, the force that must be applied to the roc)*ltk;c8 mvc kv62 uycket in order to sustain its motion is

  You are standing in a moving bus, facing forward2rq :7a-t hrk*behd4x , and you suddenly fall forward. Y:h2r-h b 7r atxeqk*d4ou can imply from this that the bus's

  You are standing in a moving bus, fa/m/fv4e4 nj gycing forward, and you suddenly fall forward as the bus comes to an immediate stop. What force ca y//4jg4v fnmeused you to fall forward?

  A constant net force acts on an object. Describe the m*axea-+wk:1/ps g vgkotion of the object.

  The acceleration of an objcj*bs /e9+vbu mone20wn 2 :xeect is inversely proportional to

  A net force F accelerates a mass xenhey/ pdu(49mjzi s(i82 3rm with an acceleration a. If the same net force is applied to mass 2m, theenm prid2z4u9jex sy8 (/ih3 (n the acceleration will be

  A net force F acts on a mass m and produces an acceleration a. Wh8xd/w y t:xy) 4onm7pqat acceleration results if a net force 2F ac4yq7x8 n)ypdtx w o/m:ts on mass 4m?

  If you blow up a balloon, and then release it, the balloon will fly awaxhpe.z7iq3p ; /gip)wy. This is an illust)h x;iewqi /p pp73gz.ration of

  Two cars collide head-on. At every mome1phjql 4pnw.8u94*w y:8o gke:w6ufauj z 6l tnt during the collision, the magnitude of the force the first car exerts on the second is exactly equal to the magnitude of the force the second car exerts on jnlfua4 :8t 6j8p lze6 9ugpw o1w:uq.wh*yk4 the first. This is an example of

  If you exert a force F on an object, the force which the object exerts onf1+n.: ,4h uu zkleuhr you wil r.fulz+ueh4k:n u 1h,l

  Action-reaction forcejrwek i9: u3 rt06x*qjs

  Action-reaction forces ar7c43fm/6q: ubfv g xvae

  A 20-ton truck collides with a 1500-lb car and causes a lq( a.9-77nna9-qgqh uv shcmmj0uopk7/cx8 wot of damage to the car. Since a lot hnc7-a7x. qomgmau(qpj/ khw n0s9v8q- u97 cof damage is done on the car

  An object of mass m sits on a flat table. The Earth pulls o4p co/ngi9up)l 4hjc7 n this object with force mg, which we will call the action force. 4n)7lc94icu/po gjph What is the reaction force?

  A child's toy is suspended from the ceiling by rw men-0l;o)w means of a string. The Earth pulls downward on the toy with its weight fo-wn0);lmwe ro rce 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 force. The yh,9jn31yxz0; ,qivrenb k s*ua h0e2ball hits the bat with an instantaneous force, whose magnij v ry1suqixenk,y,z00hn;*a 29 he 3btude is

State Newton's three lawu;ifgh2p (.ks/qv70e l/rvj as.

  Mass and weight

  The acceleration due to gravity is lower on the Moon than on Earth. i sjmurzx+d- 9bk2d h:te*p( e.)xx7g Which of the folh xs ixpz(ek7b-xr *d2m+.9duj)e :gtlowing is true about the mass and weight of an astronaut on the Moon's surface, compared to Earth?

  An example of a forc+qvf79 v efp,rbuap++e which acts at a distance is

  Who has a greater weight to mass ratio, a person weighing 400 N or a perw( uwf,2 gyzh)son weighing guz wy f)wh,2(600 N?

  A stone is thrown straigkq tj+:.6c edwht up. At the top of its path, the net force acting on it iq6 :dtcke.wj+s

  A 20-N weight and a 5.0-N weight are dropped simultan0 :eoah,hqjku1 ,kg(beously from the same height. Ignore air resistance. Compare their accelerations e:g(ko,h10auj kqh, b.

  A brick and a feather fall to the earth at tss3 cg.b f8pf3heir respective terminal velocities. Which object experiences the greater forpsbscf gf3.83 ce of air friction?

  An object of mass m is hanginq9e1il(k w93hamy x l/g by a string from the ceiling of an elevator. The elevator is moving up at constantxm3w klh9e ayql(i9 /1 speed. What is the tension in the string?

  An object of mass m is hanging by a string from the ceilbejxu/x: ;2p 5hm 4fr9h ui:o2t9emsying of an elevator. The elevatu 24/pjbi xs 99:;e2ehxu 5mhmtof:yror is moving upward, but slowing down. What is the tension in the string?

  The force that keeps you from sliding on an icy ssfhpvt:6f 0psg*f fes+. ,ej 6-u) cqtidewalk is

  It's more difficult to start moving a heavy carto8np zw)kl6zesb :1q k(n from rest than it is to keep pu p:b zs61kkze(l) qn8wshing it with constant velocity, because

  A horizontal force accelerateskvgpsjpl n:5 x ( p2stsm;)h(kiw b0/5 a box from rest across a horizontal surface (friction is pi 5v/;k spb:thksj0g( w(2m5p)xl spnresent) at a constant 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 slides down an in.-gswn6e+j h*l8kqgpclined ramp at constant velocity. Thus we can ded.p* qgkneljhw8 -g s6+uce that

  A block of mass M slides down a frictionless plane inclined at an angle q with 7cq cn/d6jz/j , wuy *3ixv.j, dliu,gthe horizontal. The normal reaction force exerted by thx3 /, .yvqji ucn/l6ugw7 dc,jj*zi, de plane on the block is

  A block of mass M slides down a frictionless plane:k4ldqg n4 puocg sxv/77 64vqco.t*d inclined at an angle q with the horizontal. The normal reaction fosc4dxo4c6q/v74 do7lp: tk.g q vgn* urce exerted by the plane on the block is directed

  A block of mass M slides docy,+j l +gq b8pfpn78w)wn9 jlwn a frictionless plane inclined at an angle q with the horizontal. Th7jn+lc)pb88yw 9gpf+jq lnw,e gravitational force is directed

  Two toy cars (16 kg and 2.0;p ii59ni .6v72vlga*pvnra5 ob sv:j kg) are released simultaneously on an inclined plane that makes an angle of 30e with the horizontal. Make a statement which best describes *: in7.vbg p l5j2i isrp;n9av65voavtheir acceleration after being released.

  An object sits on a frictionless surface. A 16-N force is applie1mtju tg5x3 bm:d**uy/ji)jsd to the object, antjjmudb/t)* yu3 xs ij*g5 m1:d 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 k3czq.r 222k9l 5jwxhaulh+s in 7.0 s. What is the average forward force x5 r9zka2luw+hhk l2q.3 cs2jon the car?

  Starting from rest, a 4.0-kg body reachv*mo1(f jf qsz2))uz tes a speed of 8.0 m/s in 2.0 s. What is the net foqj 2f*vozu) s(f1zm)t rce acting on the body?

  An antitank weapon fires a 3.00-kg rocket whi3l h n(7(jugvs ale6ji/jy4- gg j57nvch acquires a speed of 50.0 m/s after tr ge u a/6(73vsh jj(4-nyljj7ggilnv5aveling
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 5/1xkn -wi ll0rvetm 7force that you push a 10-kg mass from rest rkxel- vtw0175mnli/,

  What is the mass of a person who weighs 11w* 81sspf x)vi:q)e0ueez mz g 7tn5/a0 lb?

  What is the mass of an object that weighs 250 N on the surface of the Earth6a-w(1w:fkq b ;z--fila*uw znfw2zi where tfa*z w2wqfw-:un- ibz(1z 6f lk;i-awhe acceleration due to gravity is $9.80 \; m/s^2$?

  An object has a mass of 6o 5nv3qc )mv/rad)r q*0 kg on the Earth. What is the mass of the object on the surfaa )r 3nov/drq)m*qc5v ce of 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 356v4 io+vwsu)erpq,d :la k jthe Moon. The Moon's gravq +,5p6)iovk34 a dsljvu :rewity is one sixth of Earth's. Compare the masses of the objects.

  Sue and Sean are having a tug-of-35s.om ,-gbg p(mj ivd4-fqpgwar by pulling on opposite ends of a 5.0-kg rope. Suep4d.j - f g i5-pqv3sg,ombmg( 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.a rqf4uw)iv6m 9i8gm on a level frictionless surface. A force F acts on the s .)6airv4qm ufi98mwg tack, 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 scale in an elevatct m9a ndefn*i f (1i3::2kvosor. What will the scale be reading when the elevator is m2to ifkn9v 1:s:3f(ncde a *iaccelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevatoh(w,sur ;tfx/ r. If the mass of the person is 60.0 kg and the eleva/ w r;(xtuh,fstor 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 60.0, e71 u msm8 azulq3y,+y1cpq/ozs6lm kg and tzu3+,1l qamceomzm, 1spl8 6u7q yys/he elevator 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 for1srb x,hw qoh9msv( 17mxw c9/ce has a magnitude of 8.0 N and is directed due north. The hvx,c7xh 19smb/o9wwrs q(m 1 second force toward the east has a magnitude 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 inx rscss)-c9/v place by metal brackets that can exert a maximumsv9/r )-cx ssc 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 flatbed of a truck. It is hh-gvr +ukx3 *,yp:sateld in place by metal brackets that can exert a maximum horizontal force of 9000 N. When the truck x*p -:vkh r+atsgy ,u3is 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 in Fig. 4-1, if M = .))q fd.f (pna+t iakl0.60 kg and m = 0.40 kg, what is the magnitude of the acceleration of the system? (Ignore friction and the maqa. d.f kn(lfp))ia+tss of the pulley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg and m = 0hc+k m * 1u70rv9zzjwq.40 kg, what is the tension in the string? (Ignore fri7v1rz 0kc m9jh+uwq* zction and the mass of the pulley.)

  A student pulls a box of books on a smooth horizontal floor with a force qdn 5k+g.vkn4 of 100 N in a dirg k5dnn4+k qv.ection 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 6rk qn l*ojh3y7+al+oforce of 100 N in hr6yk3 olaq7++j onl *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 the box?

  A traffic light of weight 100 N is supported by two ropes as72t9 he kiwnzr a-i8j. shown in Fig. 4-2. What are the tensions in the rwieir ka 2jzn.t- 9h87opes?

  In Fig. 4-2, if the t2exq1nwf rb pv)h30tzm-z9k;ch/r 6aensions in the ropes are 50 N, what is the mass of the traffic liget-vnrf bcx;ap3)wh 0/9r zqm 2 16zhkht?

  Two boxes of masses m and 2m are in contact with each othelo utmny 1;/1u7/- bx4bm pgovr on a frictionless surtoygb4;xu -1vom/b 1lnmu7 /p face. (See Fig. 4-3.) What is the acceleration of the more massive box?

  Two boxes of masses m and 2baj3:m x1q 2s8mi f06o:cl fwcxw73jvmq(o:z m are in contact with each other on a frictionless surface. (Sea 7i1m:lxf8v z::3sc6w(ox qo jw0cb23qfmjm e 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.c tr7uxxi1y v7vvo 9 h96t0e1h (See Fig. 4-4.) If the forward force on the more massive box is F, what is the tension in the contvyhrvuch9 t70i vxo 6e1 79x1necting rope?

  Two boxes of masses m 1 k (t*dqxzy /.uqaw,vand 2m are connected by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, what isk(. quwy , 1z/aqvdx*t the acceleration of the less massive box?

Two boxes are connected by a cord running over a pulley as showxdx(hnpb.:zpbj4 z.x9 xq b2. n in Fig. 4-5. Box I ohz.pd(zxqbx. 2 b.n 4bx9x:pjf 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 vydz2l+eyc pe+ z8*h: between a 3.0-kg box and a desk are 0.40 and 0.30, respectively. What is the net force on y+c8 hv2ez:yp zl +d*ethe box when a 15 N horizontal force is applied to the box?

  The coefficients of s*vey52fptgyfpe :t/; tatic and kinetic frictions for plastic on wood are 0.50 and 0.4vf:;ye/ tf p2yp5*teg 0,
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 direcvthv5+u- vziuy u gw80m*5zq4tion. It slows and comes to a stop with a conz vw*55hvu 4 m+uzuvitygq08 -stant 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 surface is pulled byrk ) d+n7 -f /h5zuy6*fxjuusu a 5.0-N force. A 3.0-N friction force retards the motion. udhy- /sx 56kr f+f)uun7uj*zWhat is the acceleration of the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg masqbwn75r 7 bom(s, 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 initig , 3wv6fgnum.al speed of 10 m/s. It slides 50 m on the ice before it sto,.v6nguw mgf3ps. What is the coefficient of kinetic friction between the puck and the ice?

  During the investigation of a traffic accident, police find skid marks 9 7u -a 2akh()r8njtt +.oaegjk0.0 m long. They determine the coefficient of friction between the car's tires and the roadway to be 0.500 for the prevaila)-jntua j+krgko 27te(a8 .hing conditions. Estimate the speed of the car when the brakes were applied.

  Two boxes of masses m and 3m are stacked. (See Fig. 4-o,o96rq3 ol+(hkf :migjskw36.) 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 ffoho63l( oq93 ,iw:sjrkm +kgorce on the less massive box?

  Two boxes of masses m and 3m are stackz io z7,c1zbv.ed. (See Fig. 4-6.) The surface between the more oc .v7zi,z 1bzmassive 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. m m0eevck ,fragr2nx7t1gjo*zi93 5ykmv*) . The plane is inclined at an angl*kvmm7x5nrt3zeo 2i ac0.mr k1y9 ,gej)gvf*e of $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that mj 7c.vpf+ime 1gy3 ufy,ws1;kakes 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 inclzsqgs/o ,-ljr b*qr 0io,(yp7ined 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 tilted az9 iw)qz-hd7kt 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 /v8 *hxfd v cydw5z;p93h o0uhan inclined plane, at a constant velocity of hc; w3uyhv5h xd*pf dzov98/06.0 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 sl ckqy yx,kx7*f4adx21ides 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 down a g8ba yez up48a 8q-r;rrough $37^{\circ}$ 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 ay2wz z03p3i 9kdqgr8along a rough surface. The cable attached toi9qa8 gkyd 3zr 0w32zp the 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 frot ul78l2nadl,:jxin : m rest on a rough inclined plane tilted at an angle l,a2xldutj:l n:87in 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. Th i ao)cxpo ()a(93k v)feh4o+wo*6cw-qipyqke angle of incline is gradually increased until the ob(3*oqoipef4(+qc- wp ko )cyvw a6xoi k)a)h9ject begins to slide. The angle at which this occurs is q. What is the coefficient of static friction between the object and the plane?