Which of Newton's laws best explains why motorists should buckle-luaf4l.f13u p+nm b)ozh1,z qup?

  When you sit on a chair, the resultant force on youw(xtg0 c8vtem9 5fiy9 is

  In the absence of an external force, a moving obsbqm( 8 ; 4;w1 umcsew/geabi fx2 od4gl-sk/*ject will

  When the rocket engines on thew,24cp:s- 6jrl pvdar starship NO-PAIN-NO-GAIN are suddenly turned off, while p-6vr wj,:rls cpa2d 4traveling in empty space, the starship will

  A rocket moves through empty space in a straight line with ahv5l ou 3-v .1h:cfzzavqk0 0constant speed. It is far from the gravitational effect of any star or planet. Under these conditions, the force that mus3 h:0-uoahl.0f az k1zv c5qvvt be applied to the rocket in order to sustain its motion is

  You are standing in a movina.adxq 678ygfotv;m1.) wzz wg bus, facing forward, and you suddenly fall forward. taw 6)a8v zqmf7xgw ozd. y1.; You can imply from this that the bus's

  You are standing in a moving bus, facing forward, amu:bye us8 ;;ind you suddenly fall forward as the bus comes to an immediate stop. What force caused youb ue:;ysiu;8m to fall forward?

  A constant net force acts onnf,scbe6cpg i* u*83o an object. Describe the motion of the object.

  The acceleration of an obxx4to.;u y0pdse( n /isy;v( zject is inversely proportional to

  A net force F accelerates a mass m with an accelerat;1q-nbfn xk7e,fxo6v : 2f nbuion a. If the same net force is applied to mass 2m, xvn ,7x1nbqf; k b-n:f 2o6fuethen the acceleration will be

  A net force F acts on a mass m and produces an acazty ixdp+g 6u958e-t i 0mew5celeration a. What acceleration results if a net for u-0 z6imp5ydeg9ae8w ixt5t +ce 2F acts on mass 4m?

  If you blow up a balloon, and then release it, the balloon will fly 2h1 5pq5l.rb d kv1(giwy/qaa away. This qqa1y2 l/ag1w.hk 5 (rp5vb idis an illustration of

  Two cars collide head-on. At every m2:it/5ve os ad.ddr5m oment during the collision, 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. This is an exampd edi .mra52 5/sod:tvle of

  If you exert a force F on an object, the lai ws/7y6per +/h fw:force which the object exerts on you wilwirh7 +/:e y6wafls/pl

  Action-reaction forcev:y kgi71rv:vn r.d c +ss0h0vs

  Action-reaction forces ar9oqbs376n ydm63)d 4afo tb fle

  A 20-ton truck collides with a 1500-lb car and causes a lot of damage to the ca(qjl0f 4u7ytm (ynp :w8psq9jr. Since a m(jp 4q st(nw9yfyp:uj7l q80lot of damage is done on the car

  An object of mass m sitsu cv:w 0)ido 4)wxz5ox on a flat table. The Earth pulls on this object with force mg, which we will call the actioxd):uiw0 5zvow 4ox)cn force. What is the reaction force?

  A child's toy is suspended from the pmhix: yn 6r*7ceiling by means of a string. The Earth pulls downward on the toy with its weight force of 8.0 N. If this is the "action force," what is the "rm*x7pi 6n :yrheaction force"?

  Your bat hits the ball pitched to you with a 1500-N instantaneous force. Ti-egt9p q:r8la)g - bf2 uejqlaab44. he ball hits the batg p:-j9q24freu8b4q a aat -lb)gl.ei with an instantaneous force, whose magnitude is

State Newton's three laws, a: to9h5zpljp:xm8t.

  Mass and weight

  The acceleration due to gravity is lowertyy +g5*b )dgs 6yhc9qxvzi633zr qw; on the Moon than on Earth. Which of the following is true about the mass and weight of an astronsh6y;y*3 z3 cy gbqg i6)+vr9d xztwq5aut on the Moon's surface, compared to Earth?

  An example of a forcee+o h*(ecn/v; esr98 -bov cgm which acts at a distance is

  Who has a greater weig:n8 0o* yg h4tkd3dnmqht to mass ratio, a person weighing 400 N or a person weighing 600 q4*0 :dhdn3ogmkny8tN?

  A stone is thrown straight up. At the top of its path, the net force acti4 )f3vsz,syy yng on if)s 3s4y,yyzv t is

  A 20-N weight and a 5a g17vqe3)cvkd+ht;g5y5 xf57ske k d.0-N weight are dropped simultaneously from the same height. Iggxeqe h+71 c5 v;sdgvfk 35)dtakyk5 7nore air resistance. Compare their accelerations.

  A brick and a feather fall to the eaesx5t3u+ts3 k/fq -r(4 s epparth at their respective terminal velocities. Which object experit(4r3u53xq+/sf-p ks epatseences the greater force of air friction?

  An object of mass m is hanging by a string from the ceiling of an elevator.u1h()k 7ufgey h 9l: kfmn53zu The elevator is moving up at constant speed. What is the tension inhuk h1 z7)(ful y:gufke35 9nm the string?

  An object of mass m is hanging by a-qr i(fs/q yn4 string from the ceiling of an elevator. The elevator is moving upward, but slowifq- s nq4r/y(ing down. What is the tension in the string?

  The force that keeps you frz1l x9m5j 8(o qymke8aom sliding on an icy sidewalk is

  It's more difficult to start moving a heavy carton fro.vgljqr rx/8t9/(ln m m rest than it is to keep pushing it with v /tlj98(xr r.qm gln/constant velocity, because

  A horizontal force accelerates a box from rest ackqthrz2o7 ti+t.4(l+,lb h hzross a horizontal surface (friction is present) at a constant rate. The experiment is repeated, and all conditions remain the .7izr+(thhlo zhbtkq tl,4+ 2 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 atf3)vi qsve) h 25gxwh) constant velocity. Thus we can deduc))5sh3xihv vq e) 2fgwe that

  A block of mass M slides down a frictionless plane inclined at an 3 gxo.vn:8 xwiangle q with the horizontaovix3n x 8wg:.l. The normal reaction force exerted by the plane on the block is

  A block of mass M slides down a frictionless pf jy2j:ykte.f;y6 c5;s.hpgxlane inclined at an angle q with the horizontal. The normal reaction force exerted by the plane on the block if cek.6;5 fhp2.gyyjst:y j;xs directed

  A block of mass M slides down a fricti vkuq js xm(f-s4y*lhth)pl;n)0n/b :onless plane inclined at an angle q with the horizontal. The gravitati )hyv:n s/ju-q pmh*b nl ;0tlf)skx(4onal force is directed

  Two toy cars (16 kg and 2.0 kg) are released simultaneously on an inclined pls,de34x ;/ vlxacu4zb ane that makes an angle of 30e with the horizontal. us44xxbav cle3 d;/,zMake a statement which best describes their acceleration after being released.

  An object sits on a frictionless surface. A 16-N 863dep 2/swjb i-g ce-gm+jf hforce is applied to the object, and it 3mh dg2--j6p sgwfej/ b e+c8iaccelerates at $2.0 \; m/s^2$. What is the mass of the object?

  A sports car of mass 1000 kg can accelerate from rest txp oh:, x+fy za8bswowa799m*o 27 m/s in 7.0 s. What is the averafxx :ah 9pzba o*w+m7ws9yo8 ,ge forward force on the car?

  Starting from rest, a8 po+jo;x45,b n zarib(rkma 5 4.0-kg body reaches a speed of 8.0 m/s in 2.0 s. What is the nbi z+n5 a85o r(;4xk mbrp,ojaet force acting on the body?

  An antitank weapon fires a 3.00-kg rocket which acquires a hyj:8h k5ri 6uspeed of 50.0 m/s after5hr:k8uj6 hiy traveling
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 tha/okop1bk3+ qj t you push a 10-kg mass from reskko1q b+o/jp3t,

  What is the mass of a pe/;5l hlu- tiwdbr8jx*rson who weighs 110 lb?

  What is the mass of an object that weighs 250 N on tho*fvdzf6 m yz+htly /2tl c-i41e )p7fe surface of the Earth where the acce v fl +fh *ptt o)46f1lcziy2-d7/emyzleration due to gravity is $9.80 \; m/s^2$?

  An object has a mass of 60 kg on thjx8g,rtambp5f g4e(: e Earth. 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 trbp:x(m 8 4e,5 jgafgon the Earth?

  Object A weighs 40 N on Earth, and object B weighs 40 N on the Moon. The Moon:ymxtqxb5my 2p+0vqlm 3,- *cd szxp3 's gravity is one sixth of Earth's. Comparel :qmd-+bp3p *cms2q53,x vyytm z0xx the masses of the objects.

  Sue and Sean are having a tug/lj7vvc tsai1)jl e1n(eee3i gcq56 5-of-war by pulling on opposite ends of a 5.0-kg rope. Sue pulls with a 15-N force. What is Sean' ec 7lt(qvea/e15jnlse)g1 i36jvi5 cs force if the rope accelerates toward Sue at $2.0 \; m/s^2$?

  A stack of books restsue p1pw5e6 f;6)lhlgac 5bil1 on a level frictionless surface. A force F acts on the stack, uh611lcwgb5) p 6p;fle5il ae and it 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 anlne0sk+ q5 e*b elevator. What will the scale be reading when the elevator is q5ebekn +0ls* accelerating downward at $4.00 \; m/s^2$?

  A person on a scale rides in an kdfj;( t gb,f-elevator. If the mass of the person is 60.0 kg and the elevator accelerat,(dfjgb- ;ktf es downward with an acceleration of $4.90 \; m/s^2$, what is the reading on the scale?

  A person on a scale ridvf f*4h;vo*z cpc.w ,ees in an elevator. If the mass of the person is 60.0 kg and the elevator accelerates upcc; pf *zh4w,vovef.*ward 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 Nyua*,wj8 k,cpl p( ao/ and is directed due north. The second force toward the east has a magnitude of 6.0 N. What is the acceleratc,yw(a8jlo u pk*a/,pion of the mass?

  An object of mass 6000 kg rests on the flatbed of a truck. It im;hvd+a,n lmf a xv2 h)4n3rc*s 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 not to sli dhnhl3)*n 2a+;mc rf vxv,4amde forward into the cab?

  An object of mass 6000 kg rests on the gfa-5kjs-tpp.l3 ksmg a,/z ; flatbed of a truck. It is held in place by metal brackets that gk; kp--l aasz5s/ f3mpt.g,jcan 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 0gd rbuq,*)mbc,kth1g *y84 atryb6gFig. 4-1, if M = 0.60 kg and m = 0.40 kg, what is the magnitude of the acceleration of the system? (4*)6dugc,8hb r, ryka*mg b1b yq0ttg Ignore friction and the mass of the pulley.)

  In the Atwood machine shown in Fig. 4-1, if M = 0.60 kg and m = 0.40 kg, whaw7 iyhfap 9 e.ef7mq97t is theq wp9 7yeafi7mfh9e7 . tension in the string? (Ignore friction and the mass of the pulley.)

  A student pulls a box of books on a + hw4is;s6 n:2. f,jvy kywxgo:bnogg/;bb2c smooth horizontal floor with a force of 100 N .jx2 g k+;n:g6fob4s i/2bbg;wy , os :wcynhvin 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 hori7hm nax clf0c/l+m z1go/e cp:.fz0 0gzontal 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 40.0 kg, what is af07c1/c hle0zol/n:g+cfpmgz .m0xthe normal force on the box?

  A traffic light of weibbvavxak -+ u/0p* 6xry.bal 9ght 100 N is supported by two ropes as shown in Fig. 4-2. What are thp6bx9av0* l./ yab+-va bxukre tensions in the ropes?

  In Fig. 4-2, if the tensions in the ropes are 50 N, what is the .upv tig8u -.dmass of the traffic l8..vpgut - uidight?

  Two boxes of masses m and 2m are ink8xrc pb9 uav:k q,5 4zobm(4e contact with each other on a frictionless surface. (See Fig. 4-3.) What bk4, azem4o8:5kpqb (c r xvu9is the acceleration of the more massive box?

  Two boxes of masses m and 2m are in contact with each other on a frictionless kt6jr 2q2 au6ibzj1ks(yh26hsurface. (See Figji kuk2h2(bahq66 6r zysj2t1 . 4-3.) What is the net force on the more massive box?

  Two boxes of masses m and 2m are connected by a rope. (See,,nea yzqm9jx3 32qog pp/iv7 Fig. 4-4.) If the forward force on the more massive box is F, what i qxy9o32pz m,7 p/egjiq,van 3s the tension in the connecting rope?

  Two boxes of masses m and 2m are connected by a rope.rwerzxwe mz 7*h4t m55;qsgz, :mpe2- (See Fig. 4-4.) If the forward force on the more massive box is F, what *x4hg;w:7mm52eq p sz ,rm5t zrewze-is the acceleration of the less massive box?

Two boxes are connected by a cord running over a pulley as shown in Fig. 4-5. B/6 xvo93qfzqpst v9j6; h d0hqox I of m9 x/qjpov;hv0qq z 39fdh6 6tsass
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 and j wpc*(ha08 ;6b78ut cylhatda desk are 0.40 and 0.30, respectively. What is the net force on the box when a 15 N horizont ttl6*cb yujacp;0(ah7w8hd 8 al force is applied to the box?

  The coefficients of static and kinetic frictions for plastic on vrnch,y 66f q)wood are 0.50 anq,6yv6h fcrn)d 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 in the +x direction. It slows and cj :lf)cu+lax 4hgj(kng c:-7zomes to a stop with a constant accelerationk:xa l4zf7g)l-g( jh:+ cujn c 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 horizontalm;pfh j; 8:piv surface is pulled by a 5.0-N force. A 3.0-N friction force retards the motion. What is the acceleration of the obje:pjhfp im;8v;ct?

  A horizontal force of 5.0 N accelerates a 4.0-kg mas.5 gm-x7jrnnmk o96n ks, 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 tg o9o-ki-sq (:n7x sgwaw n4810 m/s. It slides 50 m on the ice before it stops. What is the c n:o iowg-7snw q9s8tg -x(a4koefficient of kinetic friction between the puck and the ice?

  During the investigation of a traffic accidenq/ gn9h/xlr 1wt, police find skid marks 90.0 m long. They determine the coefficient of friction between the car's tires and the roadway / hxr 1nwl/g9qto be 0.500 for the prevailing conditions. Estimate the speed of the car when the brakes were applied.

  Two boxes of masses m,j/e4* spsfm2 e d*xrjy/nh9t and 3m are 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 slide on the more massive box, what is the static frij,dt*m*s j9f//xhysrpe4n e 2ction force on the less massive box?

  Two boxes of masses m and 3m are stacked. (See lddxd-xu,q (*w ap1b u +xhj15Fig. 4-6.) The surface between the mor5dwl,1-h dpqdx*xxu ub+j 1(ae 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 coefficient of static friction between the boxes?

  An object is on a frictionless inclir1 msmhpq/bo0:mt-b , ned plane. The plane is inclined at an anglembo,0tb -pm1h:s/q rm of $30^{\circ}$ with the horizontal. What is the object's acceleration?

  A 10-kg mass slides down a flat hill that makeypgh-dax e mdr(.o8;0s 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 ang 4p2wi sgpson d1w2;a(le 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 at an angle of(i3jmoj 2,k*-r ki rbvv4up (z $35^{\circ}$ 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 dowc 3gknqvjxq+kqw :y: 5cs+.r/n an inclined plane, at a constant velocity of 6.qsq++k yjvnkqcrwcx g35::. / 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 rougheh:uqw0h j)7x $37^{\circ}$ 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 roughykinxntvo.t7e ay**97wb - r( $37^{\circ}$ 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 surfacq1dpz ii6zcuwl8+8tacx pg.8hn v6 (/e. The cable attached to the log makes an angle ohczz86w6( x1c p t8+ ni8.gviu/dqaplf $30.0^{\circ}$ 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 ig1 36ruoeqx,n0rmtee o,u m b*8ia4) snclined plane tilted at an angle u,me,aor m 1uo3 e 8 r*4g6sn)tixebq0of $33.5^{\circ}$ 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. q3j 2(jnor hoi3+v1 zk The angle of incline is gradually increased until the object begins to slide. The angle at which this occurs is q. j3qivh(orjz1 no+k 23 What is the coefficient of static friction between the object and the plane?