Which of Newton's laws best explains whyvkfu 77db3:ht motorists should buckle-up?

  When you sit on a chair,9 dw +sryt:sm1p w/uj, the resultant force on you is

  In the absence of an externe4 zj(x7(jy cxal force, a moving object will

  When the rocket engines on thpl e/o86 hw*pvnuhb(4 ;( fgmre starship NO-PAIN-NO-GAIN are suddenly turned off, while traveling in empty space, h;bp8w( 6*vl(fhor4men/gup the starship will

  A rocket moves through empty space in a straight line 6 0pb,y7yl woiwith constant speed. It is far fromoiy6,y bl70wp 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 yoju3orhg5x p.) u suddenly fall forward. You can imply from this that jrx. h)uog p35the bus's

  You are standing in a moving bus, facing forward, and you suddenly fall foxad2 yfzc w6 f8) ey9k5z/j1trax0 jz3rward as the bus comes to an immediate stop. What force caused w x y/2xez 1fdf5)ck3y6jtarz9j8z0 ayou to fall forward?

  A constant net force acts on an object. Descr2 qtcyy 4*c/m0mjm,tkibe the motion of the object.

  The acceleration of an ob sbc3iiev4q 1 vi))n7hject is inversely proportional to

  A net force F accelerates a mass m with an acceleration a. If the same*sgufq* q(,a m net force is applied to mass 2m, then theg*(a* qm ,fuqs acceleration will be

  A net force F acts on a mass m and produces an acceleration a. Whatm (h.e 8x-ogup acceleration re8h u(g pmeo.-xsults if a net force 2F acts on mass 4m?

  If you blow up a balloon, and thenf6: lup2b)(n; a fqfp-t.cl2djo fk)s release it, the balloon will fly away. This is an illustration o6-oblupk2aps.): dfq ltffjncf2 (;) f

  Two cars collide head-on. At every moment during the collisy el:xtvg4q :/ion, 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:xeg:tv4 /lq y. This is an example of

  If you exert a force F on an object, the force which the object1ikl3xn +swc su3z 91w exerts on you wiluz 3nw kx93slsw1ic+1l

  Action-reaction forces ,aufra84xfdu .avf+ jscc42,

  Action-reaction forces k88 zoo-b 3uvqgtrc/6 are

  A 20-ton truck collides with a 1500-ycl2 q/4ffwnu ep8l rk h61u66lb car and causes a lot of damage to the car. Si4 fulhq 1cpf 6kr6unlyew/6 82nce a lot of damage is done on the car

  An object of mass m sits on a flat table. The Earth pulls on this object wit wi(2 uf.::dsbl9*zt culnzq*h force mg,lbistulqd:c:u.nz9 (w*f2z * which we will call the action force. What is the reaction force?

  A child's toy is suspended from a55 dzav euzy ihx4--4the ceiling by means of a string. The Earth pulls dozi-y-u5 d45ze ha4xv awnward 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 bal*8iblrp 1;ffhc:zyun; j 9g/ol pitched to you with a 1500-N instantaneous force. The ball hitbphyz l 8;cof/*r9jng:u; i1 fs the bat with an instantaneous force, whose magnitude is

State Newton's three j k qo:wd8r*irxyy7,u4 c5p .ulaws.

  Mass and weight

  The acceleration due to gravity is lower on the Moon than on Eamfkd0 goh(y0.i1l;s xzv/(r r 4 mt;oxrth. Which of the following is trues ;4l(.m(z yhgxtoif ;o k0 1/rmvxr0d about the mass and weight of an astronaut on the Moon's surface, compared to Earth?

  An example of a forc b94j vi0ux hw2 hle7tqap/3j2e which acts at a distance is

  Who has a greater weight to mass ratio, a person weighing 400 N or a peruph62r )y(v pjson weighing 60rp h (pu6v)yj20 N?

  A stone is thrown straight up. At the top of its path, the net force actf 9 :qwqo3vdfr) 3cz-wing on it is3cww3 vr)-od 9f:qfqz

  A 20-N weight and a 5.0-N weight are dropped simultaneouslyo nitw/ldb 4ba4yyfw+xhn)y8,( k;;g from the same height. Ignore air resistal ) oiwt4n 4 k8gybbyda+xf;y,(/w;nhnce. Compare their accelerations.

  A brick and a feather fall to the earth at their ref v5 dn89 ejt/nmi0:8de rd2xhspective terminal velocities. Which object experiences the greater force of an98m5t :e j 8f dr/eddxvihn20ir friction?

  An object of mass m is hanging by a string from the ceibpht ybf-q9 j8y1g)k3ling of an elevator. The elevator is moving up at constant speed. What is the tension in the str-8pkj ytg9fq)h31bby ing?

  An object of mass m is hanging by a string r3e*b9omn 6rj+k z-itfrom the ceiling of an elevator. The elevator is moving upward, but slowing doz+*6errkntm- 3 boij 9wn. What is the tension in the string?

  The force that keeps yydlk/h+bit)+ -gm l-pou from sliding on an icy sidewalk is

  It's more difficult to start moving a heavy carton fro1vj2 eua:zg5 tdv.fm; m rest than it is to keep pugf5v a:j; ut1 vmedz2.shing it with constant velocity, because

  A horizontal force accelerafecz q04 2kb)e/qsq+ ptes a box from rest across a horizontal surface (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 acceleratipzqesq/fbq2 e +) 40ckon?

  A packing crate slides dpyk(up,p,qnwk gh5r2 - +rss8 own an inclined ramp at constant velocity. Thus we can deduce t(pq8sppw2y-ks, ,n+ ru5 ghrk hat

  A block of mass M slides down a frictionless plane inclined cii* -)qnmyc.ri 2w, nat an angle q with the horizontal. The normal rcmiy,n-i.2 *r) qniwceaction force exerted by the plane on the block is

  A block of mass M slides down a frictionless pla:*n wprtoljg1i: pr8tgr ; nd,4 ,6umgne inclined at an angle q with the horizontal. The normal reaction force exerted by the plane on the block is direcn lp:* ,g gpw dun14t:jmr;ro 8ti6gr,ted

  A block of mass M slides down a frictionless plane inciff) j2 vlmx/)9s. fnhlined at an angle q with the horizontalv fn .li/92 )hsfm)xfj. The gravitational force is directed

  Two toy cars (16 kg and 2.0 kg) are rpa4k-mw up:7 -kvt /g he6zq9yeleased simultaneously on an inclined plane that makes an angle of 30e p wm7eqh-tpu4k 6yv9/k -a gz:with the horizontal. Make a statement which best describes their acceleration after being released.

  An object sits on a frictionless surfacexrcu4ftz ekzp olz(8r ;623n:. A 16-N force is applied to the object, and it acceler;zft:p2r3kco n z(6u e8lrzx 4ates 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. W /upu+mkd., ,qylvu;9lhxr *ehat isl m*xvluqh e,k+/u; py,du 9.r the average forward force on the car?

  Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s (v hztvi.ap,- u(i9nq in 2.0 s. What is the net force inhz9qt. a(iuv(, pv-acting on the body?

  An antitank weapon fires a 3.00-kg rocket which acquirs:qo29 3qpwupes a speed of 50.0 m/s after travelinw9p:suq o2q p3g
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 fozd t0c(-vx pur+)pu,rom re- uro)czuxp,dp(0v +tst,

  What is the mass of a person who weighs 115b+ o122qji ,pspk as z;h;g6 svttbq-0 lb?

  What is the mass of an object that weighs 250 N on the surface d 1z5ac6sms28 b entr*of the Earth where the acceleration dusmt8nc56s*rdeb12 a ze to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. What is the mas 1 9q*kmfccp/ofs: t1fsz4b:rs of the object on the surface of the Moon where the acceleration due to gravity is only 1qt4s/mfs z9rp:c*f 1:c bkfo1/6 of that on the Earth?

  Object A weighs 40 N ongoh ;p0 t6bs+ pgm2qm:hql,h. Earth, and object B weighs 40 N on the Moon. The Moon's gravity is one sixth of Earth's. Compare the masses of the o qhop m g2g+; lhmq.0h:,stb6pbjects.

  Sue and Sean are having a tug-of-war by pulling o ool q;,biz r25n -,achn3gt5wn opposite ends of a 5.0-kg rope.;3lt 5b , owzrg-nca2 q5ho,in Sue 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 on a level frictionless surface. A force F y o5 *n3 iogvle)ztr. f3t wr)5,uhnz,acts on the stack, and it5or*n,fh)rg i oe3utl ny,3)5zt.wzv 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 elevator. What will the scale-ra:y x) yei27,z vvsi be reading when the elevator is acceleratingyi -is v: zav2)xy,7re downward at $4.00 \; m/s^2$?

  A person on a scale riw(h-sbjp2- l9b w(, ,b oyznsgdes in an elevator. If the mass of the person is 60.0 kg and the elevator accelerates downward with an accjyblh,- b( ns2(wz g9p, -wbsoeleration of $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale rides in an elevator. If the mass9ia k4e4vh2kuhw0 ;4fg q:kui of the person is 60.0 kg and the elevator accelerates upward with an acceleration 2aq:0f huhieui 4gkwk ;k 4v49of $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal forces act on a 5.0-kg mass. One force has t7stocs1 tu:4a magnitude of 8.0 N and is directed due north. The second force toward the east has a magnitud:ot4tss1ut c 7e 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 in p k- (l(vkmwa+ulace by metal br+al vk(w-umk(ackets 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 into the cab?

  An object of mass 6000 kg x)/w4 esjnp0 xxy b9l0rests 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, what is nw p/x 9xxe040 yjsl)bthe 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.+uec-n7n cp lye-y 5+t40 kg, what is the magnitude of the accele n ccyet+ly+un75e--pration of the system? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0-.1av6-z undwzlau 1 d.60 kg and m = 0.40 kg, what is the tension in tunaw-6z 1z d-1.av udlhe string? (Ignore friction and the mass of the pulley.)

  A student pulls a box of books on a smooth horizontal flowwk);u(tt4z b.cg wm*or with a force of 100 N in a direction owc .twtmwb *4z (gk;u)f $37^{\circ}$ 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 horizontl;+f h yayr,1gj;fgu2al floor with a force of 100 N in a direction of 3 u f,2;hyj+;ar gfgly17.0e 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 as shown in Fig. 4 1ko:;igc1ql xz o.j:h-2. What are c.g1o ;xk1hi qljoz::the tensions in the ropes?

  In Fig. 4-2, if the tensions in tuv (soy:qs85;wokx fy3t :/xshe ropes are 50 N, what is the mass of the traffit sxoy5sqwy x/3v u: ;:kf8s(oc light?

  Two boxes of masses m and 2m are iw4 1dvltj2gr-o6rnm ,n contact with each other on a frictionless surface. (See Fig. 4-3.) What is the n o, dgj4t-w1l2rr6mv acceleration of the more massive box?

  Two boxes of masses m and 2m are in contact with each oth5t0 z:v-e h (ks;m*aoizfef f9er on a frictionless surface. (See Fig. 4-3.) What is the net force on the more massive o(*5ffzezs 0fae - :;imvk th9box?

  Two boxes of masses m and 2m areydg n 4u,.xl; ypd;*jm1+ apwt connected by a rope. (See Fig. 4-4.) If the forward force on the1yyp;,m;4dwla ptujdx n +.*g more massive box is F, what is the tension in the connecting rope?

  Two boxes of masses m and 2m are connected by a rope. (See Fig. 4uw92yfax)pf m a6 b7hg -9x0nm:n6o6 gclh mx)-4.) If the forward force on the more massive box is F, what is the acceleration of the les6m6byca9)6n7mafnpgfhx xl g2 w xo-m:h90)us massive box?

Two boxes are connected by a cord running over a pulley as shown ogzf3r-s89 3xg zw7a-da uy*sin Fig. 4-5. Box I g swyg3o z u3sard f8a-7z-x*9of 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 wrn .x6;iska3 frictions between a 3.0-kg box and a desk k s6;i wan.3rxare 0.40 and 0.30, respectively. What is the net force on the box when a 15 N horizontal force is applied to the box?

  The coefficients of static and kinetic frictions for plasta 3 gegabu1(tfx;p,v0ic on wood are 0.50 and 0.4a(gfpb a,;30 vxgt1u e0,
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 levetzg ouvg98vq)9a)eu8l surface in the +x direction. It slows and comes to a stop with a constant acceleration of -v 8)gtuu9)8vzog9qea $2.45 \; m/s^2$. What is the coefficient of kinetic friction between the object and the floor?

  A 10-kg box sitting on a horizontal kn, g+v sjkvh68k7c3 -qocz5osurface is pulled by a 5.0-N force. A 3.0-N friction force retards the moti skc o-qvog6,5v7 z3kjhc +nk8on. What is the acceleration of the object?

  A horizontal force of 5.1 x -2:dm1-j y5hh3aojdrl1 re0mjsmo0 N 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 slides 50 34zp6zhb2 qhm m on the ice before it stops. What is the coefficient of kinetic friction between thezzbm hp26qh43 puck and the ice?

  During the investigation o7kma0tl/dpu ooe-30h f 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 prevailing conditions. Esp/ e-3u7tamo0h 0 koldtimate the speed of the car when the brakes were applied.

  Two boxes of masses m anmra(n4 v8veobrf//k 4gd od87) , vjcbd 3m are stacked. (See Fig. 4-6.) The surface between the more massive box and the hor/)od k7oe4vd,4 bcrv(vj8nba8f/ mgrizontal 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,tri6-y iv74igh: g gny f:nnftl5.g9. 4-6.) The surface between the more massive box and the horizontal surface is smooth and the surfacenrin t65:f-i 4,tyg9gv7f:ngh gi l y. 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 frictionlejsi4:hwrj13 ,za7,p+hu j obfss inclined plane. The plane is inclined at an angle of bfo1,3 s,ahi:hjpu jzw7+ 4jr $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hil byzvi.5ynup uc4q,0xw6 3n 9nl that 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 plane with an anglj vhm3j8r i lk2u(v7k+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 tibsr+anzbuc )e 9m2jc )b;8tbj9 (vw+olted 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 slidest-t+ u:t 4:yxypsj l;a directly down an inclined plane, at a constant velocity of 6.j+aspyt -;t:u4:yxl t0 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 slides down a rougje.o h.;z : ,bh35tz6duvum;:dodeiuh $37^{\circ}$ inclined plane where the coefficient of kinetic friction is 0.20. What is the acceleration of the object?

  An object with a mass m slidet/zx63 . 0 1bpdvl w l)x)bzlr;clxo2qs down 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 weighinl*hyhl l(y2t 8g 500 N along a rough surface. The cable attached to the log makes an angle of *hy8l2 tly (lh$30.0^{\circ}$ 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 rough inclined pla nlf74h xbg-q7ne tilted at an angle- 7hfxqg4lb7n 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.g.ul o0il qn3/ The angle of incline is gradually increased until 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 p03. qgio lnlu/lane?