Which of Newton's laws best explains why motorist0q e(e7q g 0hm*q2p+pczl2wefs should buckle-up?

  When you sit on a chair, the gcwr(02b t q+vresultant force on you is

  In the absence of an external force, a movis.0n dtbu14dm9zfq 6v ng object will

  When the rocket engines on the starship NO-PAIN-NO-GAIN are suddenly turne8xxlcw f)rfic2nq 4 :;tfs1 y6d off, while traveling 2ffc;4)r xsnixlf1 t 6:qw8ycin empty space, the starship will

  A rocket moves through empty space in a straight line with 0jvl *o yw1az/on6+ru constant speed. It is far y1o6nj+ ru/*w z0lova from the 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 moving bus, facing forward, and youi4fi7 r9yeyx5p7 5j,bjz m kp2 suddenly fall forward. You can imply from this that the bus5p7fi7pyb ,r5ikzx94myj 2je 's

  You are standing in a moving bus, facing forward, and you suddenly fall forward )uxrrzb 9 t.wx9sry :1as the bus comes to an immediate stop. What force)xzt19.yw rrsur x9:b caused you to fall forward?

  A constant net force 9kg8w g4acac+ acts on an object. Describe the motion of the object.

  The acceleration of an obngs0llq7: g9cc l(av/ ject is inversely proportional to

  A net force F accelerates a mass m with an acceleration a. If the pgh it9( djcs/mcw(lg+6aa k mrm3x 8+go34z4same net force is applied tokh/ 4i go3c ad(lm8j96xmp s3atm++c4(gzrgw mass 2m, then the acceleration will be

  A net force F acts on a mass m and produces an acceleration a. What acm/o2otm+pm ik 2*cqfz 5q-8lsceleration m km+t85oq/coq *lps fi2mz-2results if a net force 2F acts on mass 4m?

  If you blow up a balloon, and then release it, the balloon will fly k .2nyhg fx98xaway. This is an illustrat.9 xfg28hn kxyion of

  Two cars collide head-on. At eg 0nsj9xz34 xbvery moment 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 the first. Th j4gzsb3nx x90is is an example of

  If you exert a force F on an ob7(xpcpkl ,e n wf-pw,8aob48t ject, the force which the object exerts on you willp(, c flptba7o, ex4pknw88-w

  Action-reaction forcez3h+:0oj;g p:o lrqyg a i:x1bz )2trw2xlu-r s

  Action-reaction forces /ax 3l10jdkudx 4vl 3yare

  A 20-ton truck collides with a 1500-lb car and causes a lot of dag1j;.z vv74ayar mei5mage to the car. S; 4gjvar 1 e.amzviy75ince a lot of damage is done on the car

  An object of mass m sits on a flat table. The Earth pulls on tda 3fv, xt2d.mmc-iuo7ki* )5c8e obchis object with force mg, wcm,o 5c2 83* vdao fi.)7ckb-txdiumehich we will call the action force. What is the reaction force?

  A child's toy is suspended l;,e+da)an0tc * 5 gjc,szscsfrom the ceiling by means of a string. The Earth pul+0el* zccntaa s 5gss,),c;jdls downward 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 you with a 1500-N instantaq- cfp d5evkip c.;b3k:), cqyneous force. The ball hits the bat with an instantaneous for.kci:;p3 f) -eybkc5pqv, qcd ce, whose magnitude is

State Newton's threeq (ycaow 3u:isi/x;h34np -xj laws.

  Mass and weight

  The acceleration due to gravity is lower on the Moon than on Eart1 jv ++(,jq(twbgltg o,l3gerh. Which of the following is true about the mass and weight of an astronaut on the Moon's surface, r qolw1eg lbgjt , (+3,jgv(t+compared to Earth?

  An example of a force which acts19rc8mu9zzvft. whz * a 44-4ex q0d2 hngomwg at a distance is

  Who has a greater weight to mass ratio, a person g4yd .n an5f0oweighing 400 N or a person weighingyag4dfn50 .no 600 N?

  A stone is thrown straight up. At tm v*u muwd v,uf06p8,a5mm,y fhe top of its path, the net force acting on it mvupdu8m*f v, 5mu,m0,f y6wais

  A 20-N weight and a 5.0-N weight are dropped simultaneously from t, vv *3p q;c(ady sxos8qw;teyzl.; g7he same height. Ignore air resistancdypeow;,;3 x;yc gz*( . 7 vt8sqalqsve. Compare their accelerations.

  A brick and a feather fall to the earth at their respective terminatos2cjm ;t.fu ;q)1 jil velocities. Which object experiences the greater force of air fr )t2j1m;qf; .jiscut oiction?

  An object of mass m is hanging by a string from the ceiling l)tvmy4u2t hum 1lq 94of an elevator. The elevator is moving up at constant speed. What is the tension in mht 1q9uym42t)l v4ulthe string?

  An object of mass m is hanging by a string fi tiz9,a(f hn/rom the ceiling of an elevator. The elevator is moving upward, but slowing downi, n (9fh/izat. What is the tension in the string?

  The force that keeps you from sliding on an q gqsa ;))b15c spltu4icy sidewalk is

  It's more difficult to start moving a heavy carton from rest than it is to k8zv mv1h5 o6mui03rvdeep pushing 168u rm3i5v vm dozv0hit with constant velocity, because

  A horizontal force accelerates a -iiks .;l 1a lx4(hmp 0nqpno t(wb1,zbox from rest across a horizontal surface (friction is present) at a constant rate. The experiment is repeated, and all conditions rnnq is h(1ix.0, bptw -za;k1m(4plolemain the same with the exception that the horizontal force is doubled. What happens to the box's acceleration?

  A packing crate slides down azgy ;0jsj cz*h+fe64un inclined ramp at constant velocity. Thus we can +z4h6 efs; j*gzucy j0deduce that

  A block of mass M slides down tqttawsm u3x l8.) 3rd48u ,cfa frictionless plane inclined at an angle q with the horizontal. The normal reaction force exerted by the plane on 8ltd w)ctum.su3 , 3rfxq8ta4the block is

  A block of mass M slides down a frictionless plane inclined at anr 8ndq6 a-2j4c kbsv+s angle q with the horizontal. The normal reaction force exerted by the plane on the block is dire- +bqv rsc4kds26ja8 ncted

  A block of mass M slides down a frictiopp-c-mx66 zs-gfc t2bnless plane inclined at an angle q with the t- mb6s-f2p6-xc cgz phorizontal. The gravitational force is directed

  Two toy cars (16 kg and 2.0 kg) are released simultaneously on, +kx:x+fn7gd; ufuia an inclined plane that makes an angle of 30e with the horizontal. Make a statement which best describes their a7n;ufi+kxg +dfuax : ,cceleration after being released.

  An object sits on a fricxbxqpjl.a 286tionless surface. A 16-N force is applied to the object, and it accelerates alq2 px.6b8axjt $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accelerate from rest to 2m 83bw7hbjr2upv6iyoxo8 .p 2 7 m/s in 7.0 s. What is the average forward forcuwo6ib7.hbp y82po3r2 8mxjv e on the car?

  Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s icaq1 c3v:)ium n 2.0 s. What is the net force a1 3uqm ccai:v)cting on the body?

  An antitank weapon fires a 3.00-kg rocket whic g4+xdt.q mhr+h acquires a speed of 50.0 m/s after t.dx+qt+ hrg m4raveling
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 y85n-. vv uxyl2mt u,wgou push a 10-kg mass from resln2 t5 v.xyugvuw-m,8 t,

  What is the mass of a person who ;3ck k9o(wakah 3gv3nweighs 110 lb?

  What is the mass of an object that weighs 250 N on the surface of the Eawda+ qatr 7 w*vg*3el*rth where the acceleration due t3ta*g+wv *edaql w 7*ro gravity is $9.80 \; m/s^2$?

  An object has a mass of 1 b mld+v r(1cm;f,gw(,gvt zk60 kg on the Earth. What is the mass of the object on the surface ofkv, dr (v;g+ ,btm1mw z(c1lfg 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 wysvzklg1-(d 9 eighs 40 N on the Moon. The Moon's gravity is one sixth of Earth's. Compare the mak ls9z gv(d1y-sses of the objects.

  Sue and Sean are having a tug-of-war by pulling on oprq2qybd9). b nposite ends of a 5.0-kg rope. Sue pqrby. dqn9 b2)ulls 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 frictionless surface. amg6 exz( io8;A force F acts on the sz6eix o;g8am(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 -od:f 1yxsh ;yon a scale in an elevator. What will the scale be reading when the elevator is accelerating downw1o :xdfyy-;sh ard at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the mass of the person is 60.0 -x4nmw op8fk-ljk 4he so9g ;;kg and the elevator accelerates downward wlneg- ;894w jo4fksmhp ox;k -ith 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 per5wqo 8h r /: f9pdu:l:u8( mgntw7dcawson is 60.0 kg and the elevator accelerates upwao8gua mtd ::wq(7 8lw:/rdc np hf9u5wrd with an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal force -cgtz(p+gm5m6 cbkge8.tmw8 s act on a 5.0-kg mass. One force has a magnitude of 8.0 N and is directed due nmc-bck(g w p.mg+zt tm6g8e85orth. The 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 oqsyg /ks q3w r*9 z5quyv9bg75n 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 forward wv q g *5bqyrqs3ykzg/59 9su7into the cab?

  An object of mass 6000 kg rests on the flatbed of a truck. Ip67lfzo+fefv4 r;t)u t 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 ltuo 6lfzv rf7 4;ep+)foad is not to slide forward into the cab?

  In the Atwood machine show8*us7f 7kolp nn in Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the magnitude of the accek o7pf*7uls8 nleration of the system? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0/jw8unpm k 6x p,bq0:u(.l osv.60 kg and m = 0.40 kg, what is8uqljp,u.wv6(/0s: xbmnpko the tension in the string? (Ignore friction and the mass of the pulley.)

  A student pulls a box of i :ca7ghf/tr/books on a smooth horizontal floor with a force of 100 N in a d f/i7tc a:/hrgirection 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 booksxa 7xco;mehu: w6 rk95 on a smooth horizontal floor with a force of 100 N in a 6 maw;xhc5o9kur:e7 xdirection 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 q5: 9q,iljk krr,kxh u/d4gp( is supported by two ropes as shown in Fig. 4-2. What are the ,plk4ikdq xhu5gr :q ,9(jkr /tensions in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what 89fi3e x 4lfqsmrm78g is the mass of the traffic lightf7mfr 8 s3e4qi8xg m9l?

  Two boxes of masses m av5kcrh,h dv95y5q l zxk**d82sbud m6nd 2m are in contact with each other on a frictionless surface. (See Fig. 4-3.) csvz59rd k yv8**,b hhq k5l2dm65dxu What is the acceleration of the more massive box?

  Two boxes of masses m and 2m are in contact with each other nd*v4 p4x6d fcon a frictionless surface. (See Fig. 4-3.) What is the net force on t*v4npf64 x cddhe more massive box?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4-4. h5/q 8;9/rusp5ary2jan tkej ) If the forward force on the mor/nyse5r9 hpu ;r52t8k /jaajq e massive box is F, what is the tension in the connecting rope?

  Two boxes of masses m and 2m are conneo* p d5uw4hgtb6e-tvb 0*a t2qcted by a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, what is the acceleration of thea bwopdthqv-eb*20*ug t64 t5 less massive box?

Two boxes are connected by a cord running ovr,ensl:oe;3 m8ps oc*y1)bv x er a pulley as shown in Fig. 4-5. Box I of mas3,)pnx8m;b v:so* cs1lroyees
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 yu7p89 npf2bpq2b 7m2, ypw:anpzb*sdesk are 0.40 and 0.30, respectively. What is the net force a 2zqp2*:b8fusmy9ppy w b72npn,7p bon the box when a 15 N horizontal force is applied to the box?

  The coefficients of static and kinetic frictions for plastic onsj j+e *te2f*w wood are 0.50 and 0.4 + j*eft*jw2es0,
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 directi j1s5rqx/hw zuxd379 jon. It slows and comes to a sto1h qzd97j3x r 5jwxsu/p with a constant 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 ufqk a) m28 +hxbi+sw2surface is pulled by a 5.0-N force. A 3.0-N friction force retards the motion. Whatiu w+8ma)2fx bk+2hsq is the acceleration of the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg mass, from rest, at a rav5s0 tj2w; fg7 (qrsnkte 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 7+s xcx t,00 t6dd: r8m vs1suioihh(san initial speed of 10 m/s. It slides 50 m on the ice before it stops. What is the coefficient of0 dv17(8i dc :tiuhm rsx hsoxss,0+t6 kinetic friction between the puck and the ice?

  During the investigation of a traffic accident, police find skid marks 90.0 m1iw 2 5zjfen4g long. They determine the coefficient of friction between the car's tires and the roadway to be 0.500 for the n1z2fw 45eg ijprevailing conditions. Estimate the speed of the car when the brakes were applied.

  Two boxes of masses m and 3m are 4s i:x ;aoo0bw a:x ni98eqt)lstacked. (See Fig. 4-6.) The surface between the more massive box and the horizontal surface is smooth and the suro4xas :8li 9iat: ;)n0qoxwbeface 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 massive box?

  Two boxes of masses m and 3m aiqoi k0sr. o/05ul5b tre 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 of0 s o/qbokii55l0urt. static friction between the boxes?

  An object is on a frictionle3iug(3ier,xwco l: *fss inclined plane. The plane is inclined at an angle o*3go,u:cxeiw3lr ( fif $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that ma9:hciq:ct)mrsnsz9 p6 6wx a ,kes 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 inclxgso 0e r6e6c-cnc5 bef 7a g1w)vr2;qined 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 smootzk02lh w:g c 1zu2iyz01gx9sgh 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 inclined plane, at a constant velocithf 8 tov/s*a4riqc s9(y of 6.o*8s c 4(9rvfi/ qahts0 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 slidexs eev8)g; j8cs 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 rough 489ewpcy 4wyu$37^{\circ}$ 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 al(kt8q7wj+nvi ong a rough surface. The cable attached to the log mtv(w kji+8 n7qakes 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 relea3q(r7oqtm ux rdg-.w jw)/g 5nyz +e5used from rest on a rough inclined plane tilted at an angle)ju rgt(q./5yer5z +d-7g3 on uwx mqw 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 o(h kqua/lqj1f pde7l.*v.pv 0 n an inclined plane. The angle of incline is gradually increased un*fhq( vljdeavpu 7l p.k0.1 q/til the object begins to slide. The angle at which this occurs is q. What is the coefficient of static friction between the object and the plane?