Which of Newton's laws best explains why motorists should buckles6g f hu2mlh/-ye.x s;-up?

  When you sit on a chair, the resultant 2 7eazqp62 rsvforce on you is

  In the absence of an external force, a moving object wgvvvlr vo9i *7b t:nqxi4+: l8ill

  When the rocket engines on the ), .ekuda +s+*ecezqh starship NO-PAIN-NO-GAIN are suddenly turned off, while traveling in empty space, the .s+)qk*+heeez,ua c dstarship will

  A rocket moves through empty space in a s *lp r ,:kvx;*vh kqloafb)y+:traight line with constant speed. It is far from the gravitational effect of any star or planet. Under these conditions, the force that m+x, :lqk ) ;ylo*:rpvakfbv*hust be applied to the rocket in order to sustain its motion is

  You are standing in a moving bus, facing forward, and you sxz5dbm*8 08*zamw vdguddenly fall forward. You can imply from this that 5azbz*8wdd*80 xvmg m the bus's

  You are standing in a moving bus, facing forward, and you suddenly ty- (vunqc*g: fall forward as the bus comes to an immediate gvt: n -*yu(qcstop. What force caused you to fall forward?

  A constant net force acts on an object. Describe the motion of the obje x3ks7-c wl.da sw57joct.

  The acceleration of an object is invet0h :s;pjiz)v4/ emfyk1 v*mwrsely proportional to

  A net force F accelerates 7i ppscxreyp(c- pq5 x.88cl+j6xq;v a mass m with an acceleration a. If the same net force is - jqc867r(;i5+xlppx p8ps ey.qxc vcapplied to mass 2m, then the acceleration will be

  A net force F acts on a mass m and produces an accelerasz0awbjru k8 4y ua 9(8s0dqfmpr (;s1tion a. What acceleration results if a net forceuwr;pmf a ys dbkz(ru9q 848010(s asj 2F acts on mass 4m?

  If you blow up a balloon, and then release it, the baku8f) en;:h-y4lkrjf+h la p6 lloon will fly away. This is an il )l+4fl6h:arf8; -k puyejkh nlustration of

  Two cars collide head-on. At every moment dtuxaa.cf(.. j uring the collision, the magnitude of the force the first car exerts on the second is exactly equal to the magnitude of f jct .(xaua..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 which the object exerts on kn-xz* x-j8axr tx80b you wi8txr-8xjxx zkb n-0a*ll

  Action-reaction forch ziq1k;w(** e7qua ukes

  Action-reaction forc cu )2bsvq5 g..00am ijuv9mvwes are

  A 20-ton truck collides with ars6yfp z,8n p/ 1500-lb car and causes a lot of damage to the car. Si8s r6ypn /z,pfnce a lot of damage is done on the car

  An object of mass m sits on a flat table. /je+g wjpc l/)kysg(6The Earth pulls on this object with force mg, which we will call the action force. What is the reyj+/c j/sgkp el(w6g)action force?

  A child's toy is suspended from the ceiling by means ofm0q(qgvyo5k e *c q+r9 a string. The Earth pulls downward on the toy with its weight force of 8.0 N. If this is the "action force,"9o(q5vq+qr0my *e k gc what is the "reaction force"?

  Your bat hits the ball pitched to you with a 1500-N instantanky7z(i/0itxqg 1-ybw vr;s-peous force. The ball hits the bat with an instantany/-;x pvbz0wq kt is1iyg 7-(reous force, whose magnitude is

State Newton's three lawpgay e71b)jy) anq66f ibge7;s.

  Mass and weight

  The acceleration due to gravity is lower on the Moon than on Earth. Whichj w+ xv+ vdssi4j*;7u+emqf;1(uw6 w dhc5jma of the following is true about the mass and weight of an astronaut on the Moon's surface, com;4 i++ *jsv6x ued fw;dvmmj( +uc71waqjsh5wpared to Earth?

  An example of a force which acts at a m/4ic6 rq5i4s* yu 02nw vtoms: bfhj3distance is

  Who has a greater weight to mass v(y y dkt-(ng8ratio, a person weighing 400 N or a person weighing 600 Nkydt8 -vny( (g?

  A stone is thrown straight up. At the top of its path, the net forc5;w7i.jyi3 k ijv a1goe acting on ijjw1vo;ag i7 k5iy.3i t is

  A 20-N weight and a 5.0lvu8ig 8wg7 0v ,k61sq s77ou7xdoldb-N weight are dropped simultaneously from the same height. Ignore air resistance. Compare their acc8o 8bg7 vs1k dq67ulivu707xl sowg,delerations.

  A brick and a feather fall to the earth at their respective termivnrv)t 2aozj e,0iaw k))/kf/nal velocities. Which object experiences the greatk2a n/0r) ioz)f,/atjv)vwe ker force of air friction?

  An object of mass m is hanging by a string from the 6(wbp)9*8hj cfdad;6o jgi yt ceiling of an elevator. The elevator)p6i of8hcbja6( gy 9;*tjdd w is moving up at constant speed. What is the tension in the string?

  An object of mass m is hanging by a str99frw: mcxt 1sing from the ceiling of an elevator. The elevator is moving upward, but slowing down. What is the tension in the strs:w9 x9cmf 1tring?

  The force that keeps you from sliding on a kj8zx y2,g +12w f/tebntqyl/sai8ry:u 3 yi2n icy sidewalk is

  It's more difficult to star68 jk1 zbdmj3mlxh4 bo chh0(4t moving a heavy carton from rest than it is to keep pushing it with constant vzh6ob0m8d lbkj 4j( h1mx c43helocity, because

  A horizontal force accelerates a boxoj9 /aa bq kbob.e070z from rest across a horizontal surface (friction is present) at a co.e70o kjb9 ozq0b/ba anstant 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 inclined ramp at consob rz4 qpp07-ttant velocity. Thus we can deduczp4 7br0qto-p e that

  A block of mass M slides down a frictionles d/q*ph/)/q8m4cb f-tu*dsq+tph k bi s plane inclined at an angle q with the horizontal. -)/bhsqk4+8f/qptq iudmbcd* p*th / The normal reaction force exerted by the plane on the block is

  A block of mass M slides down a frictionless plane inclined at an angle q with t,pfog.t/h:o gg3* cv yhe h,gc*3gg .vfotp: o/ yhorizontal. The normal reaction force exerted by the plane on the block is directed

  A block of mass M slidesl*-h/xk1so c q r*koe7me7*lk down a frictionless plane inclined at an angle q with the horizontal. The gravitational forc*lsrkoec*k1 o7 e/k* qxl m-7he is directed

  Two toy cars (16 kg and 2u4iorenxabx.9 :.-zg8j; s9bg xvj.n.0 kg) are released simultaneously on an inclined plane that makes an angle of 30e with the horizontal. 8n 9j 9v:.z ai4bxbxr je.g; gunso.x-Make a statement which best describes their acceleration after being released.

  An object sits on a frictionless surface. A 16-N force i7u.eab)3ve o ws applied to the object, and it accelerates atuw)eo3v7. a eb $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accelerate from rest to 27 m/s in 7.pez :u, x-*.glh+ dpms0 s. What is the average dhm*euz:g+p,- .slp x forward force on the car?

  Starting from rest, a 4.0-kg body re k-xk8 e5 v)2wenbm/qzaches a speed of 8.0 m/s in 2.0 s. What is thewn8 / evkzqmk-52xb) e net force acting on the body?

  An antitank weapon fires a 3.00-kg rocket which acquires a speed o0gt4ni 4*lqo-bzt r; ni 5/jypf 50.0 m/s after trave5ri4i*nl0qo/bt;yt jpz4- ngling
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 pusm +m a)qcl6c+rh a 10-kg mass from rest,ma m)+6+crqc l

  What is the mass of a person wic/ :u.hy ivo1//k (ogd9osgl ho weighs 110 lb?

  What is the mass of an object that weighs 250 N on the a-q. dhqtja9w0 6xi.zsurface of the Earth where the acceleration due to gra.d- xh0tqwa .q9j6iazvity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. What is the mass of the :h oha3d, fynyhl8;z,object on the surface of the Moon where the acceler:,n; h8 hozydlay3 fh,ation due to gravity is only 1/6 of that on the Earth?

  Object A weighs 40 N on Earth, and object B weirg/ 7hu(oz+n cghs 40 N on the Moon. The Moon's gravity is one sixth of Earth's. Compare the masses ou+z/n cog(r h7f the objects.

  Sue and Sean are having a tug-of-war by pulling on opposi0smtohy3a.k (+u uj x0te ends of a 5.0-kg rope. Sue pulls with a 15-N force. What im0(j s0u. +y xhao3tkus Sean's force if the rope accelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books restsw*5yh+7jl nvl on a level frictionless surface. A force F acts on the stack, and *lwlvnj h+y 75it 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 ilu6wy rx9i(k 72/uh/,i p;eu(tw haqwn an elevator. What will the scale be reading when the e7xiu2uwt(9;,w w k/ a/iyhr(6epqu lhlevator is accelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an elevator. If the mass of the person is 60.0 kzg+-6 6y2gucoddralzd- x3/ +wv4bzkg and the elevator accelerates downward with 4o6bg-rz2zadxu gy 3/k+vld z+-6dc wan acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale ridrj+ )bgmyyo(d r mf/ y.:r02ides in an elevator. If the mass of the person is 60.0 kg and the elevator acceleratesm 0rjmobd+gr /:.2(iry dfyy) 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 force has a magnitude of 8.0 N qp z4o(0l,0ckwbtm0z and is directed due north. The second force toward tpc0 b00w,(mozt4klqz he east has a magnitude of 6.0 N. What is the acceleration of the mass?

  An object of mass 6000 kg rests on 6wcf+e,klk *scxmu ,2 the flatbed of a truck. It is held in place by metal brackets that can exert a maximum hou,smkc wekl2x, c+f6*rizontal 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 he p -w5cff4 ymfjd341stld in place by mettf4djmwcfs41py 5 -3 fal 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 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 kg, whatmbg 5y5v0d bic.lq(2 :tk6uno is the magnitude of the acceleration of the system? (Ignore friction and the mass of the pul d o(kb b 5c5:uqmtgn2y.0v6liley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what isb7 fiy 7k*k9rl4jdho1 the tension in the string? (Igkl*ok j1 f hyb774dri9nore friction and the mass of the pulley.)

  A student pulls a box of books on a smooth horizontal floor with a force of 6sizb+t, *h6 7 pakdkn100 N in a direct+tak7 , h*is b6znpd6kion 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 z v. brlnb0),qbad dk8*nge. gf81 af-smooth horizontal floor with a force of 100 N in a direction of 37.0ea1rzg *eg)-fkbqf8d8a,db. . 0vn n lb 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 as shown in b,)r ae74mpzl Fig. 4-2. Wh el,74rzp)abmat are the tensions in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is the mass of the trafwm 78k.5khhdyfic lkh75yw .mdh k8ight?

  Two boxes of masses m and 2m are in contact with each other on au3l9 (gvmy +6 h)aziic oyz74i frictionless surface. (See Fig. 4-3.) What is the acceleration of the more massive box?mic3o7yz) y(g6au9i vz4+ hil

  Two boxes of masses m and 2m are in contact with each othhaa4)-ah+nzet z( p+g er on a frictionless surface. (See Fig. 4-3.) What is the net force on the more mazg-(n+hp h )4ta eaza+ssive box?

  Two boxes of masses m and 2m are connected by a rope. (Sej 61.b*;t a od.ibjldbf*an) oe Fig. 4-4.) If the forward force on the mor joat 1nbfod **)a6bj.;b il.de massive box is F, what is the tension in the connecting rope?

  Two boxes of masses m and 2m artytyo7p6jicb l t -1/*e connected by a rope. (See Fig. 4-4.) If the forward force on the more massl7op t/i6*t 1jy- tbycive box is F, what is the acceleration of the less massive box?

Two boxes are connected by a cord running over a p+md i+ 8 atuq/mihzm82(0i1re2csxxoulley as shown in Fig. 4-5. Box I of zhmu+(2 ammsei0d xo i8+x8ritq12 /cmass
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 betwee+ 2 sug*pfz6/1 p8eq8tlhwalln a 3.0-kg box and a desk are 0.40 and 0.30, respectively. What is the net force on the box when au z +*lg lh88qes1a6p lp2/ftw 15 N horizontal force is applied to the box?

  The coefficients of static and kinek /4t sasgl,-ub9pr::+ q kzettic frictions for plastic on wood are 0.50 and :e4+z-ru qabs9kt lt gps/,:k0.40,
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 level surface i 61k/ht 4, auj3tncd)sr(ydui n the +x direction. It slows and comes to a stop with u (ta/jci3r4sdt,nu)6hky 1d 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 horizouz5i yte+rzxhi0)/k 383p 4dt)ndm ylntal surface is pulled by a 5.0-N force. A 3.0-N friction force retards the motion. Wh ) 4/thny uzl3pmt8 5krii3zdxey d+)0at is the acceleration of the object?

  A horizontal force of 5.0 N e,6nj34pr e:d6:v xq,jdevnf accelerates a 4.0-kg mass, 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 speed of 10 m/s. It sli4k/h(j4 b3r q z0uto3qq 2lq 53o6batz,hzreldes 50 m on the ice before l6q 43 z(0t3orz3h buak rq2hqez5q to,jbl4/it stops. What is the coefficient of kinetic friction between the puck and the ice?

  During the investigation o mi e:5vb7i*idf 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 pi i d*vb:7im5erevailing 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.) au.o g;i/n uhg4m5nc7l(ww 7xThe surface between the more massive box and the horizontal surface is smooth and the suownwhg7u 7/cn;xa4m ul.ig5 (rface 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 52ybiqzl s,g9lxb3kpolz w*: (/c w9jare 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 sll(* y2gwxz o pz5k/bc3,:bqwlsi9 9jlide on the more massive box, what is the coefficient of static friction between the boxes?

  An object is on a frictionless inclined planf/p6kr k uth)1j5zb9 ye. The plane is inclined at an angle off rbjp) yu6z9/15hkk t $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill t y8evw ,si8,hv*xq u v8zfvp:1hat makes 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 pl s -:fzs;r5ixoane 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 tia9e:a mni1d0 alted 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 izw u.gtgj-qg:xwvdky+ ; s-+lls/+*rnclined plane, at a constant velocity of g zwx-.+g j /ss;+*qy:rvwdt llu -kg+6.0 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 s9x9 a 68mmqe cbsoy;,i*m;d qxlides 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 dowgt(x*1iaf8c *pp z-c7 3av aajn 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 cableyk:. 2cbm87z r3d vzeq attacheq .r m8ez2v3y7zcbk d:d to 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 from wxu7gmp 8/phr:- m x7irest on a rough inclined plane tilted at an angle r7 mim87gxh pxu/wp-: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 )w g662mhtg1y faayl6an inclined plane. The angle of incline is gradually increased until the object begins to slide. The angle at which this occurs is q. What is the coefficiena6glyw62aymfg) h6 t 1t of static friction between the object and the plane?