Which of Newton's laws 25h1 n7jv)+elg khdzp best explains why motorists should buckle-up?

  When you sit on a chair, the resultant force on yorx w bgz.z9su-97nog 6a;/mw xhi1lt4u is

  In the absence of an external force, a movird4qx i,oo6)njv; q83w *ql6eqapb3 l ng object will

  When the rocket engines83eiy;h6u whs on the starship NO-PAIN-NO-GAIN are suddenly turned off, while traveling in empty space, the starship wiu;i s yehwh683ll

  A rocket moves through empty space in a straight line with constajm+oy7 c) jlv *+yerk3;5:,9htysmp pu meiu,nt speed. It is far from the gravitational effect of any star o,lp* jpmm7y ceiju +e)9+ us;tvh3:yrmo yk,5r 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 you su /brufo+0 m-nq 3mu2olddenly fall forward. Yrn/b q-o0 +ufuo 32lmmou can imply from this that the bus's

  You are standing in a moving bus, facing forwa ihf2r0,ru ph1rd, and you suddenly fall forward as the bus comes to an immediate stop. Whai,rh r1p20 ufht force caused you to fall forward?

  A constant net force acts on an object. Describe the motion ofp4j+3jlne)e+ d/ fgj tp* vq(g the object.

  The acceleration of an object is inversely f;61bk5y jo5u6hqo k yproportional to

  A net force F accelerates a mass m with an acceleration a. If the e+zc21 *yzftnlpn1*n same net force is applied to mass 2* t*pc1 yl 2+1znzfennm, then the acceleration will be

  A net force F acts on a mass m and produ, dg 3rupi3j;s jxt-q0ces an acceleration a. What acceleration results if a net force 2F ac3it3sqp;gd -,jj xu0rts on mass 4m?

  If you blow up a balloon, and then release it, the balloon will fo)fygo,8:i t gly away. This is an illustration yg: g)f oi8,toof

  Two cars collide head-on. At every i.6ipbj*kx4-z kf w;umoment during the collision, the magnitude of the force the first car exerts on the second is exaw uf4 p-bz.*ki6; kjxictly equal to the magnitude of 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 ob ae iiim2)je g8o.; ieqp5+v1yject exerts on you wi8 5)ee. 2v;a 1oii+gjpiiqmyell

  Action-reaction forcfsrzxka cq 54p4p.y47es

  Action-reaction forces arejttsl2w(n pgcv**7 6z

  A 20-ton truck collides with a 1500-lb car and causes a lot of damage ts7cm1*)0 xr,wd bkqow o the car. Since a lot of damage is done on tcwo,ksb wq7r)mx 0 1d*he car

  An object of mass m sits onz. xsfwc7-uerto *b0 +.f2bei a flat table. The Earth pulls on this object with force mg, whicht.ixz bfe2sb7f .+*-w0uecro we will call the action force. What is the reaction force?

  A child's toy is suspended from the ceiling by means of a string. The Eartldea/ tw.ni 4-s/7mtb h pulls downward on the toy with its we7 m4 wae /lntb/s.id-tight 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 inst p* sd w-o)2fq86h3el j.tagmnantaneous force. The ball henj2 hl s3d*w8p a.qo6mg)t-f its the bat with an instantaneous force, whose magnitude is

State Newton's three lkgl/ t cqum1gdl f**33aws.

  Mass and weight

  The acceleration due to gravity is lower,h f+lof.ht-uknwx6 . on the Moon than on Earth. Which of the following is true about the mass and weight of an astronaut on the +nw kl htxo -h.f,6fu.Moon's surface, compared to Earth?

  An example of a force which acts at a distance2 fm* cep zl5od7et dae-w4lvnz08+k6 is

  Who has a greater weight to mass ratio, a person weighvo27 1 mqgi64tn mf;1q amu/rqing 400 N or a person weighingu4m t/1v ai;o qq1mqmr276nf g 600 N?

  A stone is thrown straight up. At t3v8q-kn0eqr s 9mj 7jghe top of its path, the net force acting on it7nr 8kj3 0gq9eq- jmvs is

  A 20-N weight and a 5.0-N weight are dropped simultaneouslydg0emg/ 8n2;skfp/m h 7giqo0 from the same height. Ignore02sk0n gq/mgd7;fe gip/oh8 m air resistance. Compare their accelerations.

  A brick and a feather fall to the earth at their respective terminal velocities7 yawa ).1di ubuzt;t9. Which object experiences the1awua u; 7it)d yzt.9b greater force of air friction?

  An object of mass m is hanging by a string from the ceiling of an elevator. 6**3 r *f /h8jymrqysav dn7bc The elevator is moving up at consrh/f d3b 7a8*mqnsv*yyr6 j* ctant speed. What is the tension in the string?

  An object of mass m is hanging by a stringg1bvl)b s + g4uxn1 0dynlih:) from the ceiling of an elevator. The elevator is moving upward, but slowing down. What is the tension in the stribungi)nyhl:l114xb 0v +)gd sng?

  The force that keeps you from sliding on an icy oi v 1rx52yhdui)5nrw 6i )h)ysidewalk is

  It's more difficult to start moving a heavy carton from rest than it is to keepb/zvb/xlxv1k i; u2-lt w a8q) pushing it with constant velocity,2v l;/bqvwxxl1at /)ui k-zb8 because

  A horizontal force accelerates a box from rest across a horio:b 0sio7ch4m)gk4*e2h jny zzontal surface (friction is present) at a constant rate. The experiment is repeated, and all conditions remain the same wicj)h k:4z7hgi eynm4osb0 2o* th the exception that the horizontal force is doubled. What happens to the box's acceleration?

  A packing crate slides down an inclined ramp at constant vw3mnb ctr5pn70,xzdpwu3z0rp o , ,q0elocity. Thus we can deduce thatnw50 zpb,,nt dpzcq ox3,mr7wp300ru

  A block of mass M slides down a frictionless plane inclm g5i9 yh-9-e:aluemo ined at an angle q with the horizontal. The normal reaction force exerted by the plane on the bloheygoem -:- ml9a 9u5ick is

  A block of mass M slides down a frictionless plane inclined at an an,wvki0o 47spr gle q with the horizontal. The normal reaction force exerted by the plane on the block is directed7ir0okw4,ps v

  A block of mass M sl 8w 7cyi4gv;pzvf/v1i g 4r7obides down a frictionless plane inclined at an angle q with the horizontal. The gravitatb7z pgf 4/; oyii1vg7crv wv48ional force is directed

  Two toy cars (16 kg and 2.0 kg) are5ed rjxrud8 z(+c7bl(d ch5+me 1q8xl released simultaneously on an inclined plane that makes mrlqd58( (du+b8xerj 1cc lh+ex 7d z5an angle of 30e with the horizontal. Make a statement which best describes their acceleration after being released.

  An object sits on a frictionless surflu3d0a4wav( a ace. A 16-N force is applied to the object, alwa0 u3a4d(vand 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 in 7.0 s. What mw mdy7 itqpg6k;d756is the average forward force on the cad7p5i7kqdgy;6 tw6mm r?

  Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s in 2.0 s. vwthdz;3 ;zpvi c a5pdj)3ye. 6.qm b2gi00er What is the net force acting on thepva m3.yc;gz26qb0 eerd;03htw) z i 5v .pdij body?

  An antitank weapon fires a 3.00-kg ro xa,t8.no4qalit6 nb *cket which acquires a speed of 50.0 m/s after travelingn,tnl. abo*6a8 t 4iqx
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 from rediz-ky 70rn24;indi f st 0ddi4i- n;yz ni2f7rk,

  What is the mass of a person who weigh 3 zubt5rrc2:vf9 1yhrs 110 lb?

  What is the mass of an object that weighs 250 N on ;upifk hi)-jh y8p9p/the surface of the Earth wherh;pp yp8-iih/9fu k j)e the acceleration due to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. /dvoswodds at --e1-k + )mz*iWhat is the mass of the object on t1oka +w ie--d*s vdd)/ s-zomthe surface of the Moon where the acceleration due to gravity is only 1/6 of that on the Earth?

  Object A weighs 40 N zv,wis4t8dz0sk c w( iy x*i34on Earth, and object B weighs 40 N on the Moon. The Moon's gravity is one sixth of Ea8iwzwk4 4yi,i 0(zxc sst3*dvrth's. Compare the masses of the objects.

  Sue and Sean are having a tug-vyftxp5 t . mqrn2,:n6 xa;f. q*gqbs/;ctsm9of-war by pulling on opposite ends of a 5.0-kg rope. Sue pulls with a 15-N force. What is Sean's force if /xsmfq*y af 5crp6t;t ,mn:bgv..;9t q sq2 nxthe rope accelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books rests on a level frictionless surface. A force F acts on t(. 5j1lcf afmohe stack, and it acceleratej.om5 l1afc(fs 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 2yc.rsow5je5 r. What will the scale beo .2yrs5w jec5 reading when the elevator 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 60.0x0/1gc rm/c0dey3hz kal w8(y. g0e ft kg and thc (8hrc.gw0 keyzl31mxy/e g/0tfa0de elevator 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. Ifmuo hsp(iz46z:u7:z x the mass of the person is 60.0 kg and the ou4zpui m s6 zh:(7:xzelevator accelerates upward with an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  Two horizontal forcess 3k xwj8y,*v- a4m5gaw rjc0d act on 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 magnitude of 6.0 N. What is the ac8c0gms*j3yxjrak a -vw w54d, celeration of the mass?

  An object of mass 600vux2u*;b fuu00 kg rests 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 the minimum su ubv2f;u u*x0topping 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 her5fk ahriup8q0i 8s10ld in place by metal brackets that can exert a maximum horizontal force of 9000 N. When the truck is travelinf0au0i ps8rh i51kq r8g 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, what ism1lbo ulr,7 w5hnh( *s the magnitude of the acceleration of the system? (Ignore friction and the mar (5 7bu1lh,ho* wlmnsss of the pulley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.c* rw92wi .z2pt j;lye3p f7op60 kg and m = 0.40 kg, what is the tension in the string? (Ignore friction and ty*p tof ejczp;ir29lp732 w w.he mass of the pulley.)

  A student pulls a box of books on a smooth horizontal .4a5t nfukyf(5t6 l3d7nn:iojt;c qu floor with a force of 100 N inc.7oj 6tl y; (i:5nad34ufut5nknft q a direction 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 wix*enb) 3 2x,1dee (airo7 z5/rspjlkxth a force of 100 N in a direction of 37.0e above the horizontal. If the mass of the box and the boorn7el1b 3se25ijp/dzx ,*k)oea(x rx ks is 40.0 kg, what is the normal force on the box?

  A traffic light of weight 100 N is supported by two ropes v3r6px f w:r2kh ht))el*a+inf ys3c9as shown in Fig. 4-2. What are the tensions inelf a*wsi9nf33 yr:6vx)h)r +kchp 2 t the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is the 6:upq.s bgq2ymass of the traffic u b6:pq.s y2gqlight?

  Two boxes of masses m and 2m are in cnpfd* s :ogq y/5;:iyrontact with each other on a frictionless surface. (See Fig. 4-3.) What is the acceleration of the sy:f d5 i:*po/ngy;qr more massive box?

  Two boxes of masses m and 2m are in contact with each other lmx2,q-kr j8c on a frictionless surface. (See Fig. 4-3.) What is the net for2 ,q ckx8jrl-mce on the more massive box?

  Two boxes of masses m u)bcoeo. u *3ndcu,s/fy9ff ab;03 mkand 2m are connected by a rope. (See Fig. 4-4.) If the foy ;)oa3sfnok9du*ec u03m .bubffc,/rward force on the more massive box is F, what is the tension in the connecting rope?

  Two boxes of masses m and 2m are connected by x:p+pmtsau jrxkw,46 - *k,tia rope. (See Fig. 4-4.) If the foxm,:pttr x k u+-jwk,a46p* sirward force on the more massive box is F, what is the acceleration of the less massive box?

Two boxes are connected by a cord running ove;; s.s4j 5rrapsgs.xuh-eo y7 r a pulley as shown in Fig. 4-5. Box I .us;. 4ar7x-g5ep rsoyshs; jof 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 betweenjzt1 w s2.ge*t a 3.0-kg box and a desk are 0.40 and 0.30, respectively. What is the nwtje. 1g *tz2set force on the box when a 15 N horizontal force is applied to the box?

  The coefficients of static a:z lr k2gmn/r*c3 t7*wt0kkue nd kinetic frictions for plastic on wood are 0.50 and 0.4zugr*k:c0el/k 2t*m7t3r kwn0,
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 direction. It slows and com2ve a jsp96hm9es to a stop with a constant accel9m6j2 vps9aeh eration 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 surfy*e3mz*rra( k.rem*o ace is pulled by a 5.0-N force. A 3.0-N friozay 3m*r*re m(.re k*ction force retards the motion. What is the acceleration of the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg mass, from ( r7v0x7znctmrest, 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 su*.oy+7 urti-nva5 jcpeed of 10 m/s. It slides 50 m on the ice before it stops. What is the coefficient of kinetic friction between the pjayt*7 uun.c-v5ro+iuck and the ice?

  During the investigation of a traffic accident, police find skid marks 90.0 m l 5m6pr-yzj8v hbs dd a383pzp,ong. They determp6j a5m3 pds8hdz bypvr z38-,ine the 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.)x-z7/sbtcyx ahe.9 8 u The surface between the more massive box and the horizontal surface is smooth /czxsx8b .h-7t y9ueaand 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. 4-6.)9v 01srd 5r2tnkhh )mazz.de:fkn q+) The surface between the more massive box and the horizontal surface is smoot)n192:r5 h+.kf)sqnke t z zr0ma hddvh 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. The plane is inclined at an zegf* ; y)+l nnk 2ax314fwzglangll z34z)n; kxwlfn12 ef+gayg *e of $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a f, a, oiy lj)7hhrl+;mklat hill 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 witf 9c ub2c+ux,7s n sb8oph7ll0h 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 incliwo8s5h6kuh aj hvmz h+ *r x tt;v70.g7h5ab:sned 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 inllq*vt- -3p,gbqdzlm 0gr f +.clined plane, at a constant velocity of.l-3,lm-t*brfqdp vz+ g qlg0 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 slides down a rod)mkq5k;,o ibv,v/ejugh $37^{\circ}$ 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 ro+ +pb+ dj-tzqfugh $37^{\circ}$ 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 roughk,gk6xh:b u xice13 p1vb/ )uq surface. The cable attached b i:1 x)k13e,hku6g/uvqcxpb 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 rest on a rough inclinednl0ttwtep+ /mze.h8+ 7bmng + plane tilted at an angle of en/bhw 8 + znt+t.emml 7p+0tg$33.5^{\circ}$ 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. The angle of incline is g*tpkxu 0lw 8/bradually increased until the object begins to slide. The angle at which this occurs pbxklt *w8/0uis q. What is the coefficient of static friction between the object and the plane?