Which of Newton's laws bestoitev a3r zbs9: 7d:y9 explains why motorists should buckle-up?

  When you sit on a chair, the resultant f5b ud,er9 0pvqorce on you is

  In the absence of an external force, a moving s) fa(d.)sre3p g-g tyobject will

  When the rocket engines on the starship NO-PAIN-NO-GAIN are suddenly tt k22 :z.9f0c-oqsi0ujsfcb y urned off, while traveling in empty space, the scqu2 c -s0sofjy k 0.zt2:9ibftarship will

  A rocket moves through empty space in a straight line ff la2bp-g (-iwith constant speed. It is far from the gravitational effeffa l(-igb2- pct 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 movivsx58esc:-mmzxcaw / 81 hf5sng bus, facing forward, and you suddenly fall forward. You can imply wma8zxs1mhc55vecxs- 8f : /s from this that the bus's

  You are standing in a moving bus,wa sy7ji;(w;9ws.xxc facing forward, and you suddenly fall forward as the bus comes to an immediate stxa(wsx7wywi .;9 cj ;sop. What force caused you to fall forward?

  A constant net force acts on an objeiva6 /ubaesw iy r1v4d p;am3+nt/1k9ct. Describe the motion of the object.

  The acceleration of an object is iorp n;-x m7*bynversely proportional to

  A net force F accelerates a mass m with an acceleration a. If the same net fo e /m9dasu*a8qrce is applied to mass 2m89dquaa /m*se, then the acceleration will be

  A net force F acts on a mass m and o+p ojxyosdi*r w1b:t+* ,w:bproduces an acceleration a. What acceleration results if a net 1oytdob s j:*ow*p:ib+,+x r wforce 2F acts on mass 4m?

  If you blow up a balsoss-f r+i//d (dmp3-rhtdc -loon, and then release it, the balloon will fly away. This isd r- tp//m(rsds foc-dh+-3is an illustration of

  Two cars collide heaz 8cd((tuxlyfy+8o x8eb a7g+ d-on. At every moment during the collision, the magnitude of the force the first car exerts on the second is exactly equal to the magnitu (+gx+e(ol8b y cxy7z f8d8taude 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 object6s wwbn+ eeouc: a6r65 exerts on you will6ane6eb 6+:wrw5co s u

  Action-reaction forces(pg7k1gvv/xhhgp .5a

  Action-reaction force )6gz lzgreqbw1)qg :mk v*:e9s are

  A 20-ton truck collides with a 1500-lb car and causes a lot of damagt;vyns roy x4gw-9b7j w)l e/7e to the car. l/w9j7 yw e - yvo74tsbg;nxr) Since a lot of damage is done on the car

  An object of mass m sits on a flat tablecvb(n.6)j g bw. The Earth pulls on this object with force mg, which we will ca).cw(6gnv b jbll the action force. What is the reaction force?

  A child's toy is suspended from the ceiling by means of a stnv(3 llcma834 zz9gf lring. The Earth pulls downward on the toy with its weight force of 8.0 N. If this is the "action force," what is the "reactiovfl(3 834zalgmzl c 9nn force"?

  Your bat hits the ball pitched to you with a 1500- yhv3rkx097zoniskhf*cn )op7;+n e*N instantaneous force. The ball hits the bat with**h) vyofnkzkr;x7nien+s 0 c39oph 7 an instantaneous force, whose magnitude is

State Newton's three la( g e)kd tzg6lozr;d*5ws.

  Mass and weight

  The acceleration due to gravity is lower on the Moongyb2 9.cc d *zfhh pf--a5hz0p than on Earth. Which of the following is true about the mass and weight of an astronaut onpdh*0p--ba9y.cfhh z52g fcz the Moon's surface, compared to Earth?

  An example of a force which acts at a distance +ebwt d ;6k8xeis

  Who has a greater weight to mass l3l le)6 v0 li (fchx9e,zrfn0ratio, a person weighing 400 N or a person weigxlefv,0le 3lchf06 iznr)9 (lhing 600 N?

  A stone is thrown straight up. At the top of its p:c yvo7fh6v)k f;ia m;ath, the net force acting on fc:v;k my6v7 fa;ih)oit is

  A 20-N weight and a 5.0-N 0zsqt-5n*(c p g 8iu;q auzz)9c(gui )+vajt yweight are dropped simultaneously from the same height. Ignorz-(iyqcu)uaz tzsnj5 ;qg)+u8gi( vac 0* 9t pe air resistance. Compare their accelerations.

  A brick and a feather fall to the earth at th(og yst a)5nc6x85p steir respective terminal velocities. Which object xgtc s5 )5nos68ypt( aexperiences the greater force of air friction?

  An object of mass m is hanging by a string from z0kz9n9pdm)l the ceiling of an elevator. The elevator is moving up at c)k z90 nlzpmd9onstant speed. What is the tension in the string?

  An object of mass m is hanging by a string from theadh+e0p0bh/1k) e t i5ymc*mq ceiling of an elevator. The elevator is moving upward, but slowing down. Whatc0*ad)h i m+h0q1pe/5m etbky is the tension in the string?

  The force that keeps you from sliding on8jbil6lq umw e9nr-y r+p e8u+le(). e an icy sidewalk is

  It's more difficult to start moving a heavy carton from rest than it is to +q-i l 7dcgsd+t;4+ ocys xk5 f9x/moukeep pushing it with constant velocity, beca s +x-7xs4 +9dt+5/;yli duqofm ckgcouse

  A horizontal force accelerates a box from rest across a horizontal sy.uukz f +3p- 5-xotfaurface (friction is present) at a constant rate. The experiment is repeated, and all conditions remain the same with the exception that the hor-x3+yukf5 oa-p utf. zizontal force is doubled. What happens to the box's acceleration?

  A packing crate slides down an inc( trh :)g:uqpslined ramp at constant velocity. Thus we can d s) :gup(h:tqreduce that

  A block of mass M slides down a frictionless plane inclined at an angle q dxo /m7/7skow/ pn dk q8qz* b),i4uvrwith the horizontal. The normal reaction force exerted by/m rkdnb) 7x q7z,p/* su/k vwido4oq8 the plane on the block is

  A block of mass M slides down a frictionless plane inclf/:n5kr r7 pqyu 1c*ztined at an angle q with the horizontal. The normal reaction fonqrc 7kuptz:yr1*/ 5frce exerted by the plane on the block is directed

  A block of mass M slides down a frictionless plane inclined at an af+bosd*hv f*3 ngle q with the horizontal. The gravitational ff+ *ho vs3fb*dorce is directed

  Two toy cars (16 kg and 2.0 kg) arxq3eq9ky v r*1e released simultaneously on an inclined plane that makes an angle of 30e with the horyv*qk 9qe 13rxizontal. Make a statement which best describes their acceleration after being released.

  An object sits on a fri:xaid7sk*/xs w* wuj5ctionless surface. A 16-N force is applied to the object, and it accelera5 x/ x:jui*wds* 7kwastes at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accem2 grx(w(qg0 dlerate from rest to 27 m/s in 7.0 s. What i gwxmr0(g2dq (s the average forward force on the car?

  Starting from rest, a 4.0-kg body reaches a speed of 8.0 m/s in 2.0 s. What isqwakp- 840k5-wc0e2q*rajo qd z3 uen the net k0 no-ew4wqqa2c0 -5ua8 3pkj* erqdz force acting on the body?

  An antitank weapon fires a 3.00-kg rocket which ac8 ;a2f yldok0oquires a speed of 50.0 m/s after trav ka2of;8o0dly eling
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 y;fi qt51gtw :you push a 10-kg mass from restq1w g;tf :y5it,

  What is the mass of a person who weconv6zh o0tg7:gf d./ighs 110 lb?

  What is the mass of an object that weighs 250 N on the surface of the -iy)put6a k:/0zamo rEarth where the ak/a60 r)pziat-yu :m occeleration due to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on the Earth. Whalpz 64a8mr6s 5:a rrx vh*r0iit is the mass of the object on the surface of the Moon where45ph 60ralz i6isr: 8avrrmx* the acceleration due to gravity is only 1/6 of that on the Earth?

  Object A weighs 40 N on Earth, and object B weighs 40 N on the Moon.joc;6b.h adub)3 tuz , The Moon's gravit)bo.ha;3u 6bcz,jd ut y is one sixth of Earth's. Compare the masses of the objects.

  Sue and Sean are having a tug-of-war by pulling on opposite ends ob9 g8 u-nr.dgvqj-fab9 dr a+7 ldkq79f a 5.0-kg rope. Sue pulls with a gfg l9nr9rab+ ua-d jbd 7-.7dvq8qk915-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 frictionlesh qq5b3j anw/b,t u0t+s surface. A force F acts on the stack, and it accelerates anq,w+j/b t a0btq5uh3t $3.0 \; m/s^2$. 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:.cml euw 21d9wz7qnk in an elevator. What will the scale be re1 ce2 zm7lwnqd:w9 u.kading 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 60.0 kg6irlqbttw8o0 nr t i0p,0:l; j and the elevator accelerates downward wit0o6ri,q w jtt :il0r;tl0 bpn8h 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 masg(zs6,ncdk)ycp1e3 g, tb .uis of the person is 60.0 kg andycgs)u3,p gb d enk(i,z1ct.6 the elevator accelerates 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 8.0km 3f8cxtv(dq 7y fc:4 N afc8fxqy :t 4m7d3( cvknd is directed due north. 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 on the flatbed of a truck. It is rcd s04tj i8pi9d)i+wheld in place byi+ s8c4) 09dj idpwitr 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 into the cab?

  An object of mass 6000 kg1ta; nvbd-x n+ 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 stoppxat+v 1n-bn; ding time if the load is not to slide forward into the cab?

  In the Atwood machinp2(5f zhhdq z7js6 aj(e shown in Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the magnitude of the accefpqjj2s5 zhh ( d6(a7zleration of the system? (Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 km-hez f3z ly9dzs ue/b,3 3ak8g and m = 0.40 kg, what is the tensi8 z93z /,kd 3yezhsl-e 3ubafmon in the string? (Ignore friction and the mass of the pulley.)

  A student pulls a box of books on ayg 0v/w6rwq g3 smooth horizontal floor with a force of 100 N in a direction ogv/3wwqyg r0 6f $37^{\circ}$ 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 book-t;iaxi: bvy6s on a smooth horizontal floor with a force of 100 N in a direction of 37.0e above the horizontal. If the mass of the box and the books is 40by;ii6x avt :-.0 kg, what is the normal force on the box?

  A traffic light of weight 100 qzg1ot10n-hsN is supported by two ropes as shown in Fig. 4-2. What are the tensi t z1n-1ghs0qoons in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what t/(qb 06rhcpa is the mass of the trafficbtqc6a(hr0 /p light?

  Two boxes of masses m a/yy- je7+shownd 2m are in contact with each other on a frictionless surface. (See Fig. 4-3.) What is the acceleration of the +yo-7hwe /jy smore massive box?

  Two boxes of masses m and 2m are in contact with eac/i8/ 7vgujwc z//h ksfh other on a frictionless surface. (See Fig. 4-3.) What is the net force on the more massive / /fgi 7wck/hs8/v zujbox?

  Two boxes of masses m and 2m are connectedl ydj z)b02f. zr4cvxn j4,(xs by a rope. (See Fig. 4-4.) If the forward force on the more massinj.4z,z(x ry 4fxvc0)s 2l jbdve 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. 4-4.) Ifi4t yq ug)jn:( the forward force on the mn y q4:g(iju)tore massive box is F, what is the acceleration of the less massive box?

Two boxes are connected by a cord runnndf as;,a8jkd n vt1et.v+.7uing over a pulley as shown in Fig. 4-5. Box I 7k;js . vdt,1nev +dfa.ta8nuof 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 between a 3.0-kg box a7si. uwns+cr :nd a desk are 0.40 and 0.30, respectively. rsic7ns.w:u +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 plastic on wood are 0x9u r6g c wfy4c(6r2ai;v) whu.50 any6r c uf w94;vg2irw)u6a(hc xd 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 level surface rbl+a lo+6h4 iin the +x direction. It slows and comes to a stop withiblr+l+6a oh 4 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 by a 5. u kqc.-nvmf-u 3kjp0*0-N force. A 3.0-N friction force retards the motion. What is the accelu. p3*nkcmfv -j0- qukeration of the object?

  A horizontal force of 5.0 N accelerates a 4.0-kg mass, from rest, aybey/xu8e0y oerw29a 0ro /3 6dqj:x h+aer4ut 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 speed5)c8j 0zssem5- k1( f nihfy pz1th5dm of 10 m/s. It slides 50 m on the ice before it stops. What is the coeffic5eim n f-8sfj czhzskh50d) 5t1pmy1(ient of kinetic friction between the puck and the ice?

  During the investigation of a traz:xow zzsd 8o 1q495rwn5z:tuffic 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. :ozzs4t 1zxu8ow5 5wqdr 9z: n Estimate the speed of the car when the brakes were applied.

  Two boxes of masses m and 3m are stackedjffbg9dx5 /ubji( )a7 . (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 static friction force on the less massive box?5b(jix9af )j/ufb 7gd

  Two boxes of masses m and 3m are stacked.6r eo1lu; el)hgzj/ l; (See Fig. 4-6.) The surface between the more massive box and thh z1l;;e) go/e ulj6lre 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 of static friction between the boxes?

  An object is on a frictionless inclined plane. The plane is inclined at an* daks 7):mlvk angle ofkklvas*) m d:7 $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hivw7t.0ppi nldw* z*m :ll 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 withtt/, /-i jnce,x (walt 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 inc pr ukkpavf96wqr7 os )bc);2*lined 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 velocity 7(udszayim 3:q wxkqr2-2 *fg of 6.0 mzi2 dx23-(*q:ryf7w g saqkm u/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 rough g(d3vq0ud z7bjv:6vey5uyk * $37^{\circ}$ 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 dowsm -,g7 aj2smrn 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 weighisrdgxv q xn6hte/)c8 ymy zc4sh2h+o 6r- 059hng 500 N along a rough surface. The cable attached to the log makes anv hc6hsn exh64cdhtm/+xr0)92ryg 5 z-s8 qoy 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 raqp x)ad6 */eo* dnts(est on a rough inclined plane tilted at an angle t6 dndaoa)sqx /*pe*( 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 planc1grp8 -m,n2q9jr2qzkgcm c :3l ;gsfe. The angle of incline is gradually increased until the object begins tomcmzc kl ;spgc12gf,g :2-qrqj3 9n8r slide. The angle at which this occurs is q. What is the coefficient of static friction between the object and the plane?