Which of Newton's laws best explains why motorists should buckle-up?jqs8f:3 g piv(0j/5q rimc7 ut

  When you sit on a chair, z f.3u6fnxi om i 0qt3cc9e7i+the resultant force on you is

  In the absence of an external force, a moz5ni.g+u;rooi qqrn, 7t g a:,pr4vao0 y(;tiving object will

  When the rocket engines on the starship NO-PAIN-NO-GAIN a ewf.yx;7li *3bxf g-7u ,k,w 3utokmore suddenly turned off, while traveling in empty space, the uf ;m bgelt -yow.3 o,ikxu7kw,fx7*3starship will

  A rocket moves through empty sp gf 4xeyz(y6(+i)mhg f 0dwyq6ace in a straight line with constant speed. It is far 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 6i )hy+0d(q z(y ggwffmxey46 its motion is

  You are standing in a moving bus, facipkorm1/k /inqcpz*39ov -/k ong forward, and you suddenly fall forward. You can imply from this that the bus'q //c- nzi/kpk9mo3* koo1prvs

  You are standing in a moving bus, facing forward, and you suddenly fall forwargedyx:k0;m.nm ( fqk8d as the bus comes to an immediate stop. What force caused you to fall forward?.m0ne kgd(:xk yf8;mq

  A constant net force acts on an object. Describe the motion of thehm): v)nx,q q(,jnxqw object.

  The acceleration of an object is id w+ x:f(pk khr/g;r9onversely proportional to

  A net force F accelerates a mass m witaawge+,pgqg84 ;ly )yh an acceleration a. If the same net force)ag8a,gly+w p4;qg e y is applied to mass 2m, then the acceleration will be

  A net force F acts on a mass m and.yr hnq,o7fzbuoe5 52 produces an acceleration a. What acceleration results if a net force 2F actsyr5zo., he7b52fqn uo on mass 4m?

  If you blow up a balloon, and thwl j; tuyomj68 3/7ajsf1ckr :en release it, the balloon will fly away. This is an io68kja/w rf 3j 7y;j 1tcmlus:llustration of

  Two cars collide head-on. At every moment during the collisi r ; vopfgsmm)a0hfg)+nt; : 9uwg8(dton, 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.0gf+:tm 9da8 (t pu) ) sg;vfowmn;hgr This is an example of

  If you exert a force F on an object, the h.fpt+7z i/znforce which the object exerts on you wilft7phznz i./+ l

  Action-reaction force u7-ma+ :dp. qjn7zteys

  Action-reaction force;+r5 pp hrk(4s lwshpqe7 t4(ts are

  A 20-ton truck collides with a 1500-lb carxfu( s 8rje(6h hl/e)h and causes a lot of damage to the car. Since a lot of damage is done on the cahhsue e)/8l6 (xfh (jrr

  An object of mass m sits on a flat taxg*fza9es rv: mkz6:6ble. The Earth pulls on this object with force mg, which we will call the acg9v: *zs6fz6 xkr am:etion force. What is the reaction force?

  A child's toy is suspended from t vyyfu+ e;m-lfs,9 6hzhe ceiling by means of a string. The Earth pulls downward on the toy with its weight force of 8.0 N. If this is the "acti- ly +,fzyvmsfh;69u eon force," what is the "reaction force"?

  Your bat hits the ball pitched ;fy lmyim9ghn1v h x2727 zu,dto you with a 1500-N instantaneous force. The ball hits the bat with nydh 1u yl; vzf97m mgxi27,h2an instantaneous force, whose magnitude is

State Newton's three lckr.zjn eh. /3r7jjx- aws.

  Mass and weight

  The acceleration due to gravity is lo6 ;rb)pe eil(zwer on the Moon than on Earth. Which of the following is true about the mass and weight of an astronaut on the Moon's surface, compared to Eartb;zei( l6p)reh?

  An example of a force which acts at a disepy)* pwui(bvi6cfp k(9o2m ols; p-4tance is

  Who has a greater weight to mass ratio, a person weighing 400 2h vz4.+edeenw-l du+5 s7cvv N or a person weighing 600 ev7+ ush-w.vv +dd5ne24l eczN?

  A stone is thrown straight up. At the top of its path, the net force actis/8 0k4 sfacxhng on it 4fsh8s ca0k/xis

  A 20-N weight and a 5.0-N weight are dro+w,yloardn v7+2 ; uwypped simultaneously from the same height. Ignore air resistance.+ ry a+w; 7nud,ol2wyv Compare their accelerations.

  A brick and a feather fall to the earth at wme1s )b(y p:,r 1k idli pi-l3+qag4ytheir respective terminal velocities. Which object experiences the greater force of ai()w qsi+ g p1maklpy-1,rb:3 idli4yer friction?

  An object of mass m is hanging by a6r,)wriz we; d string from the ceiling of an elevator. The elevator is moving up at constant e) iwrw, z;rd6speed. What is the tension in the string?

  An object of mass m is hanging by a string from the ceiling of stvl(w-.j l zkc8iq fj0xz3;9an elevator. The elevator is moving upward, but slowing down. What is the tensiojf9qvls(lz8.i ;0wx- 3ctjkz n in the string?

  The force that keeps you from sliding on an 37b,qhr ame3 licy sidewalk is

  It's more difficult to start moving a heavy carton from rest than it is to keepqm1e u823) g+n5 .tehp lmw6klg d1xvv pushing it eqhtelp+6m1v3ugglx 15 v 2w)8km nd. with constant velocity, because

  A horizontal force accelerates a box from rest across a horizontal surfwpd+z xyz yy4, ago6;3ace (friction is present) 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 accelz +xdwy, 3yz agop46;yeration?

  A packing crate slides down an inclined ramp at constant velocity. Thus we can w-tj y 4)io s0m5k9(n effo.lyl)jws.yy( eki4 950f o m-notfdeduce that

  A block of mass M slides down a frictionless plane q,8((ut ;hjuzphj /ejjett 92inclined at an angle q with the horizontal. The normal reaction force exerted by the planehz;,(h 2 ejpqjtututj (8j9e / on the block is

  A block of mass M slides down a frictionless plane inclined at an angle q with v q0;p,+iv(32 zh cmeg2bqmufthe horizontal. The normal reaction force exerted by the plane on the0;vgmf(, mbhqpe2v u32 cq+iz block is directed

  A block of mass M slides down aya)3h)6dx oc b frictionless plane inclined at an angle q with the horizontal. The gravitational forc6do3h)) ya bxce is directed

  Two toy cars (16 kg and 2.0 kg) are released simultaneously on an inclined )8kbfy xpdxp.z5 lh (.sg5ki /plane that makes an angle of 30e with the horizontal. Make a statement which best gh x(b) pdys/8i p.5 xfzkk5.ldescribes their acceleration after being released.

  An object sits on a frictiotqc+ azvm0).c nless surface. A 16-N force is applied to the object, and itca.)0ct+z mqv 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. Whatd;bcy.) ea0 or4v(n eo in0o ryc)b .4(aed;veos the average forward force on the car?

  Starting from rest, a 4.0-kg body reaches a speed of 8hslj2(ixk1 lj2,ly(matb( g).0 m/s in 2.0 s. What is the net force ac tikslbgj xh2j((ym(a1 ll ),2ting on the body?

  An antitank weapon fires a 3.00-kg rocket which7ui)oc:as1 ap-ak8 oqz;s bzsi24p.v acquires a speed of 50.0 m/s after t1c zs:8qk p4i ub7aasvp a.o-s)z i;2oraveling
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 1 lta:0p7gogdmx3 *hz40-kg mass from rest,zg tm0g3ox7lp4d:*ha

  What is the mass of a person who weighstvbt(m r0*c:n 110 lb?

  What is the mass of an object that weighs 250 N on the surface of thevksmx 7j,+9mj -pdqh3 Earth where the acceleration due to gravity iskj73v9-p+ mx jsq,mdh $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the E6w yv)hm4mb ;oi1ncovzgm+8w7 d) ;(jzpe0buarth. 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 on4cm7m)vo i(0mp18+ye ;ow zbw; nh)udzgjbv6 the Earth?

  Object A weighs 40 N on Earth, and object B weighs 40foez3eqqv6 9t7c5x; y N on the Moon. The Moon's gravity is one sixth of Earth's. Compare the masses of the ot xvf;ycqe7 zo e5369qbjects.

  Sue and Sean are having a tug-of-war by pulling on opposite enpcu4( ,oko*ji ds of a 5.0-kg rope. Sue pulls wioj*,(kip cu4 oth 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 n a jka;9u/o,hu o:l7ga level frictionless surface. A force F acts on the stack, and it accelerat79ho ua :/gol jn;au,kes 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 elevato(1aqoxcn tzalg1p7 2 +2jicf( r. What will the scale be reading when thet la(2ci7 q jn(zpx1 1agco+f2 elevator is accelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an ele2x8hg:kf/,ce)i-kwq(j nfi d0mq ra +vator. If the mass of the person is 60.0 kg and the elevator accelerates nxweqm2)j+kiigf-f,(r : h q /80ackd 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 kg 8ub *tl3wqj 1hand the elevator accelerates upward with an accbwtu h83qj*l1eleration of $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal forces act o/ 7v tri+ rhkkng0;vurqo -.f7n a 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 mhg kv0q+ 7-;/v t.o7 ukfrrirnagnitude of 6.0 N. What is the acceleration of the mass?

  An object of mass 6000 kg rests on the flatbed of a tru82mo1hiixo5s.6w0/qqm s an x ck. 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 nw6 io/as. 581xqmxn h2sq0 oimot to slide forward into the cab?

  An object of mass 6000 kg rests on the flatbed of a truck. e i7/c :kf0udh It is held in place by metal brackets that can exert a maximum horizontal force of 900ei/7kdh: f0 cu0 N. When the truck 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 iav9gza+-):fo) hbwg0pzx ;fb n Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the magn+gfx:h z;v-o9pfzwg)b)aab 0 itude of the acceleration of the system? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-;; f(o iigwsad t/r9w+.sa5 nj49ryb l1, if M = 0.60 kg and m = 0.40 kg, what is the tensioa r5 l.94s ind(;+oyrwg9;t is fwab/jn in the string? (Ignore friction and the mass of the pulley.)

  A student pulls a box of books on a smooth : g1xivynf3m- horizontal floor with a force of 100 N in a directionfgynvm 3:1xi - 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 horizohucm0e (xc 8 8x2pxofq)s-ay-ntal floor with a force of 100 N in a direction o 82e x)8sc-mh0a yf( cpxu-xoqf 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 suc/wvgnj z5(6sd qz34epported by two ropes as shown in Fig. 4-2. What jez /3(s6 qzvwc4n 5gdare the tensions in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is the mass of the ti qkyl3:vip-k9 1n)qpm:dfh *raffic lig :hdqmpp l:*qyin k1vk9if -3)ht?

  Two boxes of masses m and 2m are in contact with each dm dec9h)5 )bhother on a frictionless sur c5ed)hh9)bmdface. (See Fig. 4-3.) What is the acceleration of the more massive box?

  Two boxes of masses m and 2m are in contact with efw+ tihec:g(w9f r oh52v k-t5ach other on a frictionless surface. (See wh5:fko(t-hfiertv+ 5c9w g2 Fig. 4-3.) What is the net force on the more massive box?

  Two boxes of masses m and 2m are connected by oaf* m2cs(i t8j72rqd a rope. (See Fig. 4-4.) If the forward force on the more massive box is F, w 8mrscjdf*a2t27 oqi(hat is the tension in the connecting rope?

  Two boxes of masses m and 2m are connected by a rope. (See Figp5dvp/un5) ih. 4-4.) If the forward force on the more massive box is F, what is the acciph5/ pnv5u) deleration of the less massive box?

Two boxes are connected by a cord running over a odsqg3pz 4.c a3q h1;hs.d)tzs*7ijxpulley as shown in Fig. 4-5. Box I o*sph;c4o a q17xzhstqsd .)z gjd. 33if 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 and0fd :zpmjujl 3pm x3(3 kinetic frictions between a 3.0-kg box and a desk are 0.40 and 0.30, respectively. What is the net force on the box when a 15 N horizontal force is appli:lp 03(3mzj uj3fm pxded to the box?

  The coefficients of static and kinetic fric *28a ox+dvz4j e1dirwtions for plastic on wood are 0.50 andow+r jizx8 *12aevd4d 0.40,
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 lek4m:0- j :s rcub/ouxfvel surface in the +x direction. It slows and comes to a stop wito/f:b 04uck ru:xj- msh 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 surface is pulled b45m4b6 idqiyejg; w4c y a 5.0-N force. A 3.0-N friction force retards the motion. What is the acceleration of the objg;w4c4yib m 4q6i dje5ect?

  A horizontal force of 5.0 N accelerates a 4.0-kg mmm l-)y1oho6h 3bqq z3ass, 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 hrx 8*cr5rg 8k bh3 w4zs5ch5kspeed of 10 m/s. It slides 50 m on the ice before it stops. What is the coefficient of kinetic friction between the puck and the 488ckr g5hxc5 rzb3wh5 skrh* ice?

  During the investigation of a traffic accident, police find skid marks4 :hkgoy;cow2 +9l,f) y mfqop 90.0 m long. They determine tyc,fm+)w9 ; yog4qpfl ok2o:hhe coefficient 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 sujx3; fp r.v)cn wbk8z1fbu8/o rface between the more massive box and the horizop1/o8vk )xun cb8 .rzf3fjbw; ntal 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 massive box?

  Two boxes of masses m and 3m are stacked. (See Fig. 4-6f4om .2s7 banl.) 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 moab .7 nmos2lf4re massive box, what is the coefficient of static friction between the boxes?

  An object is on a frictionless inclined plane. The 5tn t21w2hjoc8 -23jdxcl f tcplane is inclined at an angledft2h2 2-lwjcjxt 1538ct nco of $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that makuq,- b2iyzwq8 es 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 anglyafd)-8ru fi-:qa d *d+aqud5j qk0q )o ac+r/e 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 athr jq sbg49wuou.2 r)f9b;)yw 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 *2wnycmw(ixz mc4k; )an inclined plane, at a constant velocity of 6.0 m/mcy*;z(wi c 4 m)xwn2ks.
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 6vcof+wdt:fk hx9zho-9 l2p 3 $37^{\circ}$ 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 roug z*7qfgbsm0vr,j:l c*z r* b;dh $37^{\circ}$ 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 attachettngdv q+- *9ed to the log makes an angle ofd*vq9en+ -g tt $30.0^{\circ}$ 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 ; 9yd.(2;lty)ok vo xlzmzd-.fseic1 , 9unsurough inclined plane tilted at an angle o.m1xlsy tvi9e 9c(z;;lo u)d,zdo-fu n . ys2kf $33.5^{\circ}$ 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 anj hoqa+/ws:ay 0z6je3 inclined plane. The angle of incline is gradually increased until theq0 h6 oa3jajwzs +/ey: 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?